This document summarizes a study that isolated three strains of Lactobacillus (L. plantarum, L. acidophilus, L. casei) from human intestinal samples. It evaluated the antibacterial activity of these strains against five strains of Staphylococcus aureus, including three methicillin-resistant S. aureus strains. L. casei showed the highest inhibitory activity. The study aimed to explore the potential of isolated intestinal Lactobacillus strains to control methicillin-resistant S. aureus infections.
This document summarizes a study that evaluated the antimicrobial activity of crude culture filtrate and methanol extract of the mushroom Stereum ostrea against bacteria. Key findings:
- Crude culture filtrate of S. ostrea showed the highest inhibitory activity against both gram-positive and gram-negative bacteria based on zone of inhibition tests, with the strongest effect against Bacillus subtilis. Methanol extract also inhibited bacterial growth but to a lesser degree.
- The minimum inhibitory concentration of both crude extract and methanol extract was 20μl for B. subtilis and 30μl for other tested bacteria.
- Results indicate S. ostrea contains metabolites with potential broad-spectrum antimicrobial properties that
A trends of salmonella and antibiotic resistanceAlexander Decker
This document discusses trends in Salmonella and antibiotic resistance. It provides background on Salmonella, including its classification and the historical perspectives of its discovery. It then discusses definitions of antimicrobials and antibiotics, and the mechanisms by which Salmonella develops resistance to various classes of antibiotics, including aminoglycosides, beta-lactams, chloramphenicol, quinolones, tetracyclines, sulfonamides and trimethoprim. Resistance occurs through modification or destruction of antibiotics, efflux pumps, modification of antibiotic targets, and decreased membrane permeability.
1) The study evaluated the antimicrobial activity of crude culture filtrate and methanol extract of the mushroom Stereum ostrea against both Gram-positive and Gram-negative bacteria.
2) Crude culture filtrate showed higher inhibitory activity compared to methanol extract, as evidenced by larger inhibition zones. The crude filtrate was most effective against Bacillus subtilis and least effective against Klebsiella pneumoniae.
3) The minimal inhibitory concentration of both crude and methanol extracts was 20 μl for Bacillus subtilis and 30 μl for the other bacteria tested, indicating Stereum ostrea was most potent against Bacillus subtilis.
The inhibitory activity of L. crispatus against uropathogenes in vitroIJMCERJournal
ABSTRACT: Bacterial interference refers to the use of bacteria of virulence to compete with and protect against
colonization and infection by disease causing organisms. In this study, L. crispatus strain was used to detect its
antibacterial activity towered five species (one Gram-positive and four Gram-negative ) of the most common bacteria
causing urinary tract infection. L. crispatus completely inhibited growth of Staphylococcus aureus , while it had no
inhibitory effect on three of the other species.
Key Words: inhibitory activity, L. crispatus, uropathogens
This document provides information about probiotics. It begins by defining probiotics as live microorganisms that must survive passage through the stomach and intestines. It discusses that probiotics are living organisms that can be influenced by ingredients, manufacturing processes, storage conditions and other factors. The document outlines some of the challenges for probiotics to function properly in the body, including surviving stomach acid and colonizing the intestines. It lists several emerging health benefits of probiotics and recommends their use for maintenance and prevention. The document seeks to dispel myths about probiotics and provides examples of clinical and fundamental research supporting specific probiotic strains. It emphasizes the importance of choosing a probiotic product with high bacteria counts, quality strains, and proven results from
Antagonism of lactic acid bacteria against pathogenic agents not related to g...IJERA Editor
Oar researchhas provedthat lactic acid bacteria possess the wide spectrum of antagonistic activity. They inhibit the
growth of not only agents of intestinal infections but also agents ofdiseases not related to gastrointestinal tract.
A novel biological rote of α l-fucose in mutans group streptococciAlexander Decker
This document summarizes a study on the inhibitory effects of α-L-fucose on the growth of mutans group streptococci bacteria, which are common causes of dental caries and periodontal disease. Samples were collected from 50 patients, and 20 isolates of mutans streptococci were identified, including 10 Streptococcus mutans, 8 Streptococcus salivaris, and 2 Streptococcus oralis. The study found that α-L-fucose inhibited the growth of these bacteria, with the minimum inhibitory concentration being 80mM. The mechanism of inhibition is proposed to involve the fucose metabolism pathway in these bacteria. The findings suggest that α-L-fucose may be useful as an anti-
This document summarizes a study that evaluated the antimicrobial activity of crude culture filtrate and methanol extract of the mushroom Stereum ostrea against bacteria. Key findings:
- Crude culture filtrate of S. ostrea showed the highest inhibitory activity against both gram-positive and gram-negative bacteria based on zone of inhibition tests, with the strongest effect against Bacillus subtilis. Methanol extract also inhibited bacterial growth but to a lesser degree.
- The minimum inhibitory concentration of both crude extract and methanol extract was 20μl for B. subtilis and 30μl for other tested bacteria.
- Results indicate S. ostrea contains metabolites with potential broad-spectrum antimicrobial properties that
A trends of salmonella and antibiotic resistanceAlexander Decker
This document discusses trends in Salmonella and antibiotic resistance. It provides background on Salmonella, including its classification and the historical perspectives of its discovery. It then discusses definitions of antimicrobials and antibiotics, and the mechanisms by which Salmonella develops resistance to various classes of antibiotics, including aminoglycosides, beta-lactams, chloramphenicol, quinolones, tetracyclines, sulfonamides and trimethoprim. Resistance occurs through modification or destruction of antibiotics, efflux pumps, modification of antibiotic targets, and decreased membrane permeability.
1) The study evaluated the antimicrobial activity of crude culture filtrate and methanol extract of the mushroom Stereum ostrea against both Gram-positive and Gram-negative bacteria.
2) Crude culture filtrate showed higher inhibitory activity compared to methanol extract, as evidenced by larger inhibition zones. The crude filtrate was most effective against Bacillus subtilis and least effective against Klebsiella pneumoniae.
3) The minimal inhibitory concentration of both crude and methanol extracts was 20 μl for Bacillus subtilis and 30 μl for the other bacteria tested, indicating Stereum ostrea was most potent against Bacillus subtilis.
The inhibitory activity of L. crispatus against uropathogenes in vitroIJMCERJournal
ABSTRACT: Bacterial interference refers to the use of bacteria of virulence to compete with and protect against
colonization and infection by disease causing organisms. In this study, L. crispatus strain was used to detect its
antibacterial activity towered five species (one Gram-positive and four Gram-negative ) of the most common bacteria
causing urinary tract infection. L. crispatus completely inhibited growth of Staphylococcus aureus , while it had no
inhibitory effect on three of the other species.
Key Words: inhibitory activity, L. crispatus, uropathogens
This document provides information about probiotics. It begins by defining probiotics as live microorganisms that must survive passage through the stomach and intestines. It discusses that probiotics are living organisms that can be influenced by ingredients, manufacturing processes, storage conditions and other factors. The document outlines some of the challenges for probiotics to function properly in the body, including surviving stomach acid and colonizing the intestines. It lists several emerging health benefits of probiotics and recommends their use for maintenance and prevention. The document seeks to dispel myths about probiotics and provides examples of clinical and fundamental research supporting specific probiotic strains. It emphasizes the importance of choosing a probiotic product with high bacteria counts, quality strains, and proven results from
Antagonism of lactic acid bacteria against pathogenic agents not related to g...IJERA Editor
Oar researchhas provedthat lactic acid bacteria possess the wide spectrum of antagonistic activity. They inhibit the
growth of not only agents of intestinal infections but also agents ofdiseases not related to gastrointestinal tract.
A novel biological rote of α l-fucose in mutans group streptococciAlexander Decker
This document summarizes a study on the inhibitory effects of α-L-fucose on the growth of mutans group streptococci bacteria, which are common causes of dental caries and periodontal disease. Samples were collected from 50 patients, and 20 isolates of mutans streptococci were identified, including 10 Streptococcus mutans, 8 Streptococcus salivaris, and 2 Streptococcus oralis. The study found that α-L-fucose inhibited the growth of these bacteria, with the minimum inhibitory concentration being 80mM. The mechanism of inhibition is proposed to involve the fucose metabolism pathway in these bacteria. The findings suggest that α-L-fucose may be useful as an anti-
Identification and characterization of actinomycetes forAlexander Decker
This document describes a study that identified and characterized two actinomycete bacterial strains with
antagonistic activity against Streptomyces scabies, the pathogen that causes potato scab disease. The two strains
were isolated from soil samples. Molecular characterization using 16S rDNA gene sequencing identified the first
strain as Streptomyces avermitilis and the second strain as Actinomyces odontolyticus. Both strains showed high
levels of antibiosis against S. scabies in in vitro and in vivo assays, effectively controlling potato scab disease
symptoms on potato varieties Cara and Diamond.
Modes of action and resistance mechanisms of commonly used antibioticsaMuhanna Al-shaibani
This document summarizes the origins and evolution of antibiotic resistance. It discusses how antibiotic resistance has developed since antibiotics were first discovered and used clinically. The key points made are:
1) Antibiotic resistance has developed and spread rapidly since antibiotics were introduced due to natural selection pressures from antibiotic use.
2) There are many genetic mechanisms that enable bacteria to develop resistance, such as mutations, gene transfer between bacteria, and mobile genetic elements like integrons.
3) Antibiotic resistance genes exist naturally in environmental bacteria and are shared between environmental and clinical settings, contributing to the emergence and spread of resistance.
This document describes a study that characterized bacteria contaminating vegetables from food stalls in Solo, Indonesia using biochemical and molecular tests. Six pairs of cooked and uncooked vegetable samples were collected from three food stalls and tested. Biochemical tests identified glucose, lactose, mannitol and other sugar fermentation. Molecular characterization involved 16S rRNA gene amplification and sequencing. The dominant bacteria identified were 24 isolates of Klebsiella species, 3 isolates of Pseudomonas aeroginosa, 2 isolates of Aeromonas caviae and 6 isolates of Enterobacter asburiae. Only one sample was uncontaminated. Most isolated bacteria were pathogenic, indicating a need for improved food handling hygiene in food stalls to prevent food
wheat article samar final reprint 2014 okSamar Adel
This study investigated biochemical, histological, and molecular changes in susceptible and resistant wheat cultivars inoculated with the stripe rust fungus Puccinia striiformis f. sp. tritici. Disease severity, symptoms, and electrolyte leakage were lower in resistant cultivars, while chlorophyll concentrations were higher. Resistant cultivars over-accumulated the Yr18 resistant gene and had higher reactive oxygen species and lower antioxidant enzyme activities. Susceptible cultivars were colonized extensively by the fungus with many hyphae and haustoria, while resistant cultivars restricted fungal growth and development.
Metagenomic Analysis of Antibiotic Resistance Genes in Dairy Cow Feces follow...Partha Ray
This study examined the effects of administering the antibiotic ceftiofur to dairy cows on the prevalence of antibiotic resistance genes (ARGs) in their fecal microbiome using metagenomic analysis. The researchers found that β-lactam ARGs, which provide resistance to cephalosporins like ceftiofur, were more abundant in the feces of cows treated with ceftiofur compared to untreated cows. However, the total number of ARGs was not significantly different between the groups likely due to the dominance of unaffected tetracycline ARGs. Functional analysis showed ceftiofur treatment enriched genes associated with horizontal transfer of ARGs and caused taxonomic shifts in the fecal microbiome. The
Fernando Vaquero-El impacto de las ciencias ómicas en la medicina, la nutrici...Fundación Ramón Areces
El 29 de marzo de 2016 celebramos un Simposio Internacional sobre el 'Impacto de las ciencias ómicas en la medicina, nutrición y biotecnología'. Organizado por la Fundación Ramón Areces en colaboración con la Real Academia Nacional de Medicina y BioEuroLatina, abordó cómo un mejor conocimiento del genoma humano está permitiendo notables avances hacia una medicina de precisión.
E. coli is susceptible to ampicillin (zone 25 mm), intermediate sensitive to tetracycline (zone 14 mm), and resistant to streptomycin (zone 8 mm). S. aureus is moderately susceptible to ampicillin (zone 18 mm) and susceptible to tetracycline (zone 22 mm).
The document discusses solutions to reduce antibiotic resistance, including administering prebiotics to livestock to reduce antibiotics in animal feed, using the protein HAMLET and Manuka honey as natural antibiotics, and implementing these solutions could help curb the growing problem of antibiotic resistance over the long term. However, producing and approving HAMLET supplements may be an expensive process, and the effects of these solutions will need to be monitored to understand their full ramifications. Overall, reducing unnecessary antibiotic use is key to slowing the development and spread of resistance.
This document summarizes a study that investigated the ability of Lactobacillus paracasei BEJ01 (LP) to prevent immunotoxic effects of chronic zearalenone (ZEN) exposure in mice. Mice were given ZEN alone, LP alone, or ZEN and LP together daily for 15 days. Compared to controls, ZEN decreased body weight gain and immune parameters, while addition of LP to ZEN strongly reduced these adverse effects of ZEN. Mice that received ZEN and LP showed no significant differences from controls in parameters measured. The study suggests that LP has potential to protect against immunotoxicity from chronic ZEN exposure.
Alan Lesniewicz Memorial Lecture at UIC - July 2015Cassandra Quave
This is the keynote lecture given at the University of Illinois at Chicago Garden Walk event in the department of Pharmacognosy. The objectives of the talk were:
·Discuss the role of medical ethnobotany in drug discovery efforts
·Explore state-of-the-art research techniques that examine the activity of botanical natural products with next generation antibiotic discovery efforts focused on “alternative targets”, such as bacterial communication systems
·Provide examples of current research underway by her group both in the field (especially through fieldwork in the Mediterranean) and the lab (natural product research on multidrug resistant bacteria).
This study investigated antibiotic resistance in urinary tract E. coli isolates from hospitalized patients in India. Urine samples were collected from 73 patients with urinary tract infections and E. coli was isolated from 35 samples (48%). The E. coli isolates showed high resistance to novobiocin, vancomycin, and co-trimaxazole. 80% of isolates were biofilm producers, with over 50% producing strong biofilms. 51% of isolates were beta-lactamase producers. The results indicate that biofilm-producing E. coli strains with beta-lactamase activity exhibited the highest antibiotic resistance.
This document discusses the importance of bacterial culture methods compared to genomic analysis in food microbiology. It makes three key points:
1) Cultural methods are necessary for the detection and enumeration of bacteria in foods, as current genomic methods cannot achieve the high sensitivity required to detect potential pathogens at low levels. Cultural enrichment is required to amplify bacteria to detectable concentrations.
2) Only cultural methods can determine bacterial viability. Genomic analysis cannot distinguish between viable and non-viable cells as it only detects the presence of biomolecules.
3) While genomic analysis excels at bacterial identification and subtyping, it is less reliable for predicting phenotypic characteristics. Cultural methods are still needed to validate phenotype predictions from genomic data.
In Vitro Combine Interactions of Antimicrobial Agents with Plant Extract agai...Premier Publishers
The in vitro interaction between n-hexane extract (nhexEXT) of root of Adiantum capillus-veneris and certain known antimicrobial drugs i.e. Oxacillin, Ceftazimide, Cefriaxone, Ofloxacin, Meropenem, Erythromycin, Cefuroxime, Cefoxitin, Cefotaxime and Ampicillin was evaluated. The study was carried out against ten bacterial strains (Staphylococcus aureus, S.epidermidis, Salmonella typhi, Klebsiella pneumoniae, Shigella dysentriae, Proteus vulgaris, Pseudomonas aeruginosa, Providencia species, Citrobacter freundii and Escherichia coli isolated from urine, pus and blood samples. Both disc diffusion and well diffusion methods were used to determine antimicrobial activity of plant extract in combination with antibiotics. Antimicrobial sensitivity indicated that Meropenem was the most effective antibiotic with zone of inhibition (ZI) of 25-33 mm among all tested antibiotics followed by Ofloxacin (10-26.5 mm), Ceftriaxone (8-20 mm), while Oxacillin showed no activity against almost all bacterial strains. The study showed that most bacterial strains were resistant to most of the antibiotics used, ranging from 20-60%. The methanolic extract (nhexEXT) of A. capillus-veneris used alone was active against most of the bacterial isolates with maximum activity against E. coli with 16 mm ZI. The study also indicated that there was an increased activity in case of combination of nhexEXT with antibiotics. The combined effects of plant extract with antibiotics were synergistic against most of the bacterial strains. The nhexEXT showed maximum synergistic effect with Ceftazimide with ZI of 42 mm followed by Meropenem (40 mm) and Ceftriaxone (28 mm) against multidrug-resistant (MDR) bacterial strains. The data suggests that plant extract could be used as alternative to antibiotics. These results give scientific backing that combination between plant extract and antibiotics would be useful in fighting the emerging drug-resistant bacterial pathogens.
Mycotoxins are recognized as toxic compounds of great concern in the context of human health and economy. Mycotoxins are toxic chemical products formed as secondary metabolites by some fungi that readily colonise crops in the field or after harvest. The toxicity syndrome resulting from the intake of such contaminated material by animal and manis termed Mycotoxicosis.These compounds pose a potential threat to human and animal health through ingestion of food products prepared from these commodities.Mycotoxicoses affect various systems of the body according to the target organs of the mycotoxin. This review revealed the major mycotoxins of fungal origin and their mycotoxicoses. The study also reviewed the history of mycotoxin, methods of mycotoxin detection, analysis and the health implications of consuming mycotoxin-contaminated foods/products. In most developing countries, majority are ignorant of the inherent dangers of consuming mouldy produce or food contaminated with fungi and moulds with possible contamination by mycotoxigenic fungi. In view of this, there is need for general and public education to sensitise the people on the health hazards posed by mycotoxins. Proper washing and cooking practices of food commodities, good agricultural practices, fast and effective analyses and detection, good produce handling and storage are some of the control/regulatory measures that should be encouraged, as to assist in mitigating the side effects of mycotoxins in food and health particularly in the tropical and sub-tropical countries and in African where there is enabling environment that promotes fungal growth.
Biochemical Characteristics of Staphylococcus aureusdeeptimishra10
The specific biochemicals showed some changes against S. aureus after biofiel d treatment. In this study, overall 37.93% biochemical reactions were altered in tested twenty nine biochemicals with respect to control after biofield treatment.
Biological balance role of oxidative status for some bacterial speciesAlexander Decker
This study evaluated the oxidative stress of three bacterial species by analyzing culture broths. E. coli, Staphylococcus aureus, and Klebsiella pneumoniae were chosen. The results showed that Klebsiella pneumoniae had higher levels of reduced glutathione and glutathione-S-transferase activity compared to the others, indicating a stronger defense system against free radicals. Peroxynitrate levels and lipid peroxidation, as measured by malondialdehyde, generally increased in the order of Klebsiella pneumoniae > Staphylococcus aureus > E. coli, suggesting more pathogenic bacteria produce more oxidative species. This supports the hypothesis that bacteria modulate antioxidant defenses in response to oxidative stress levels to protect against
Atlanta Botanical Garden Science Cafe: Medicines from Nature - 2014Cassandra Quave
This document provides an overview of Dr. Cassandra Quave's work in ethnobotany and ethnopharmacology. It discusses her early adventures studying medicinal plants used by indigenous groups in the Amazon rainforest and Southern Italy. It then describes her ethnobotanical research methods which include interviews, plant collection and extraction. Several case studies are presented on plants from Southern Italy and Albania that were found to have anti-biofilm and antimicrobial properties. The document emphasizes the multidisciplinary nature of ethnobotany and the importance of collaboration in furthering the field's contributions to drug discovery and local health.
This document discusses different types of bioreactors used in bioprocesses. It describes submerged bioreactors like stirred tank reactors (STR), continuous stirred tank reactors (CSTR), and their components like impellers. It also discusses solid-state fermentation bioreactors like horizontal drums, tray-type, and packed bed bioreactors. Recent applications of bioreactors for mammalian and plant cell culture and algae production in photobioreactors are also covered. The chapter provides an overview of bioreactor design properties for producing biomolecules and considers factors affecting scale-up of bioprocesses.
Antimicrobial resistance as an emerging food-borne infectious diseaseJean Jacques Bernatas
This document summarizes the rise of antimicrobial resistance as a growing public health issue linked to overuse of antibiotics in agriculture. It discusses how non-therapeutic use of antibiotics as growth promoters in farm animals has led to widespread resistance in bacteria. Studies show resistant bacteria can spread between animals on a farm and from animals to nearby humans and environment even without antibiotic use. The overuse of antibiotics in medicine and agriculture has accelerated resistance by placing intense selective pressure on bacteria. Widespread antibiotic resistance now compromises treatment of bacterial infections in humans. Solutions proposed include restricting non-therapeutic antibiotic use in animals and more prudent antibiotic prescribing and use by medical professionals and consumers.
Specific prophylaxis & therapy of infectious diseases. Immune sera & Immunogl...Eneutron
Antitoxins are antibodies that neutralize toxins and can be used to prevent toxins from causing disease symptoms. Passive immunity can be provided through the administration of antitoxins, immunoglobulins like gamma globulin, and immune sera which provide immediate and temporary protection against various pathogens and toxins. Monoclonal antibodies produced through hybridoma technology allow the isolation of homogeneous antibodies against single antigenic determinants and have various applications in research, diagnosis, and potential treatment.
1) MelMedtronics Holdings develops cutting-edge technologies to revolutionize healthcare, mHealth, and telemedicine, including the first iPad audiometer meeting international standards.
2) The company has developed the first tele-audiology system allowing remote hearing evaluations on mobile devices to improve access and reduce costs in healthcare.
3) The Tele-iAudiometer solution simplifies deployment for remote hearing tests and includes air/bone conduction tests, speech tests, tinnitus evaluation and screening, meeting standards. It requires no additional hardware and allows reimbursable remote procedures.
Xuejuan Wang is a hardworking and dedicated individual seeking a new position. She has excellent written and oral communication skills in both English and Mandarin. She also has strong computer skills and experience in nutrition management, sales, tutoring, and volunteering. Wang holds certifications in food protection and handling and has a bachelor's degree from California State University, Los Angeles.
Identification and characterization of actinomycetes forAlexander Decker
This document describes a study that identified and characterized two actinomycete bacterial strains with
antagonistic activity against Streptomyces scabies, the pathogen that causes potato scab disease. The two strains
were isolated from soil samples. Molecular characterization using 16S rDNA gene sequencing identified the first
strain as Streptomyces avermitilis and the second strain as Actinomyces odontolyticus. Both strains showed high
levels of antibiosis against S. scabies in in vitro and in vivo assays, effectively controlling potato scab disease
symptoms on potato varieties Cara and Diamond.
Modes of action and resistance mechanisms of commonly used antibioticsaMuhanna Al-shaibani
This document summarizes the origins and evolution of antibiotic resistance. It discusses how antibiotic resistance has developed since antibiotics were first discovered and used clinically. The key points made are:
1) Antibiotic resistance has developed and spread rapidly since antibiotics were introduced due to natural selection pressures from antibiotic use.
2) There are many genetic mechanisms that enable bacteria to develop resistance, such as mutations, gene transfer between bacteria, and mobile genetic elements like integrons.
3) Antibiotic resistance genes exist naturally in environmental bacteria and are shared between environmental and clinical settings, contributing to the emergence and spread of resistance.
This document describes a study that characterized bacteria contaminating vegetables from food stalls in Solo, Indonesia using biochemical and molecular tests. Six pairs of cooked and uncooked vegetable samples were collected from three food stalls and tested. Biochemical tests identified glucose, lactose, mannitol and other sugar fermentation. Molecular characterization involved 16S rRNA gene amplification and sequencing. The dominant bacteria identified were 24 isolates of Klebsiella species, 3 isolates of Pseudomonas aeroginosa, 2 isolates of Aeromonas caviae and 6 isolates of Enterobacter asburiae. Only one sample was uncontaminated. Most isolated bacteria were pathogenic, indicating a need for improved food handling hygiene in food stalls to prevent food
wheat article samar final reprint 2014 okSamar Adel
This study investigated biochemical, histological, and molecular changes in susceptible and resistant wheat cultivars inoculated with the stripe rust fungus Puccinia striiformis f. sp. tritici. Disease severity, symptoms, and electrolyte leakage were lower in resistant cultivars, while chlorophyll concentrations were higher. Resistant cultivars over-accumulated the Yr18 resistant gene and had higher reactive oxygen species and lower antioxidant enzyme activities. Susceptible cultivars were colonized extensively by the fungus with many hyphae and haustoria, while resistant cultivars restricted fungal growth and development.
Metagenomic Analysis of Antibiotic Resistance Genes in Dairy Cow Feces follow...Partha Ray
This study examined the effects of administering the antibiotic ceftiofur to dairy cows on the prevalence of antibiotic resistance genes (ARGs) in their fecal microbiome using metagenomic analysis. The researchers found that β-lactam ARGs, which provide resistance to cephalosporins like ceftiofur, were more abundant in the feces of cows treated with ceftiofur compared to untreated cows. However, the total number of ARGs was not significantly different between the groups likely due to the dominance of unaffected tetracycline ARGs. Functional analysis showed ceftiofur treatment enriched genes associated with horizontal transfer of ARGs and caused taxonomic shifts in the fecal microbiome. The
Fernando Vaquero-El impacto de las ciencias ómicas en la medicina, la nutrici...Fundación Ramón Areces
El 29 de marzo de 2016 celebramos un Simposio Internacional sobre el 'Impacto de las ciencias ómicas en la medicina, nutrición y biotecnología'. Organizado por la Fundación Ramón Areces en colaboración con la Real Academia Nacional de Medicina y BioEuroLatina, abordó cómo un mejor conocimiento del genoma humano está permitiendo notables avances hacia una medicina de precisión.
E. coli is susceptible to ampicillin (zone 25 mm), intermediate sensitive to tetracycline (zone 14 mm), and resistant to streptomycin (zone 8 mm). S. aureus is moderately susceptible to ampicillin (zone 18 mm) and susceptible to tetracycline (zone 22 mm).
The document discusses solutions to reduce antibiotic resistance, including administering prebiotics to livestock to reduce antibiotics in animal feed, using the protein HAMLET and Manuka honey as natural antibiotics, and implementing these solutions could help curb the growing problem of antibiotic resistance over the long term. However, producing and approving HAMLET supplements may be an expensive process, and the effects of these solutions will need to be monitored to understand their full ramifications. Overall, reducing unnecessary antibiotic use is key to slowing the development and spread of resistance.
This document summarizes a study that investigated the ability of Lactobacillus paracasei BEJ01 (LP) to prevent immunotoxic effects of chronic zearalenone (ZEN) exposure in mice. Mice were given ZEN alone, LP alone, or ZEN and LP together daily for 15 days. Compared to controls, ZEN decreased body weight gain and immune parameters, while addition of LP to ZEN strongly reduced these adverse effects of ZEN. Mice that received ZEN and LP showed no significant differences from controls in parameters measured. The study suggests that LP has potential to protect against immunotoxicity from chronic ZEN exposure.
Alan Lesniewicz Memorial Lecture at UIC - July 2015Cassandra Quave
This is the keynote lecture given at the University of Illinois at Chicago Garden Walk event in the department of Pharmacognosy. The objectives of the talk were:
·Discuss the role of medical ethnobotany in drug discovery efforts
·Explore state-of-the-art research techniques that examine the activity of botanical natural products with next generation antibiotic discovery efforts focused on “alternative targets”, such as bacterial communication systems
·Provide examples of current research underway by her group both in the field (especially through fieldwork in the Mediterranean) and the lab (natural product research on multidrug resistant bacteria).
This study investigated antibiotic resistance in urinary tract E. coli isolates from hospitalized patients in India. Urine samples were collected from 73 patients with urinary tract infections and E. coli was isolated from 35 samples (48%). The E. coli isolates showed high resistance to novobiocin, vancomycin, and co-trimaxazole. 80% of isolates were biofilm producers, with over 50% producing strong biofilms. 51% of isolates were beta-lactamase producers. The results indicate that biofilm-producing E. coli strains with beta-lactamase activity exhibited the highest antibiotic resistance.
This document discusses the importance of bacterial culture methods compared to genomic analysis in food microbiology. It makes three key points:
1) Cultural methods are necessary for the detection and enumeration of bacteria in foods, as current genomic methods cannot achieve the high sensitivity required to detect potential pathogens at low levels. Cultural enrichment is required to amplify bacteria to detectable concentrations.
2) Only cultural methods can determine bacterial viability. Genomic analysis cannot distinguish between viable and non-viable cells as it only detects the presence of biomolecules.
3) While genomic analysis excels at bacterial identification and subtyping, it is less reliable for predicting phenotypic characteristics. Cultural methods are still needed to validate phenotype predictions from genomic data.
In Vitro Combine Interactions of Antimicrobial Agents with Plant Extract agai...Premier Publishers
The in vitro interaction between n-hexane extract (nhexEXT) of root of Adiantum capillus-veneris and certain known antimicrobial drugs i.e. Oxacillin, Ceftazimide, Cefriaxone, Ofloxacin, Meropenem, Erythromycin, Cefuroxime, Cefoxitin, Cefotaxime and Ampicillin was evaluated. The study was carried out against ten bacterial strains (Staphylococcus aureus, S.epidermidis, Salmonella typhi, Klebsiella pneumoniae, Shigella dysentriae, Proteus vulgaris, Pseudomonas aeruginosa, Providencia species, Citrobacter freundii and Escherichia coli isolated from urine, pus and blood samples. Both disc diffusion and well diffusion methods were used to determine antimicrobial activity of plant extract in combination with antibiotics. Antimicrobial sensitivity indicated that Meropenem was the most effective antibiotic with zone of inhibition (ZI) of 25-33 mm among all tested antibiotics followed by Ofloxacin (10-26.5 mm), Ceftriaxone (8-20 mm), while Oxacillin showed no activity against almost all bacterial strains. The study showed that most bacterial strains were resistant to most of the antibiotics used, ranging from 20-60%. The methanolic extract (nhexEXT) of A. capillus-veneris used alone was active against most of the bacterial isolates with maximum activity against E. coli with 16 mm ZI. The study also indicated that there was an increased activity in case of combination of nhexEXT with antibiotics. The combined effects of plant extract with antibiotics were synergistic against most of the bacterial strains. The nhexEXT showed maximum synergistic effect with Ceftazimide with ZI of 42 mm followed by Meropenem (40 mm) and Ceftriaxone (28 mm) against multidrug-resistant (MDR) bacterial strains. The data suggests that plant extract could be used as alternative to antibiotics. These results give scientific backing that combination between plant extract and antibiotics would be useful in fighting the emerging drug-resistant bacterial pathogens.
Mycotoxins are recognized as toxic compounds of great concern in the context of human health and economy. Mycotoxins are toxic chemical products formed as secondary metabolites by some fungi that readily colonise crops in the field or after harvest. The toxicity syndrome resulting from the intake of such contaminated material by animal and manis termed Mycotoxicosis.These compounds pose a potential threat to human and animal health through ingestion of food products prepared from these commodities.Mycotoxicoses affect various systems of the body according to the target organs of the mycotoxin. This review revealed the major mycotoxins of fungal origin and their mycotoxicoses. The study also reviewed the history of mycotoxin, methods of mycotoxin detection, analysis and the health implications of consuming mycotoxin-contaminated foods/products. In most developing countries, majority are ignorant of the inherent dangers of consuming mouldy produce or food contaminated with fungi and moulds with possible contamination by mycotoxigenic fungi. In view of this, there is need for general and public education to sensitise the people on the health hazards posed by mycotoxins. Proper washing and cooking practices of food commodities, good agricultural practices, fast and effective analyses and detection, good produce handling and storage are some of the control/regulatory measures that should be encouraged, as to assist in mitigating the side effects of mycotoxins in food and health particularly in the tropical and sub-tropical countries and in African where there is enabling environment that promotes fungal growth.
Biochemical Characteristics of Staphylococcus aureusdeeptimishra10
The specific biochemicals showed some changes against S. aureus after biofiel d treatment. In this study, overall 37.93% biochemical reactions were altered in tested twenty nine biochemicals with respect to control after biofield treatment.
Biological balance role of oxidative status for some bacterial speciesAlexander Decker
This study evaluated the oxidative stress of three bacterial species by analyzing culture broths. E. coli, Staphylococcus aureus, and Klebsiella pneumoniae were chosen. The results showed that Klebsiella pneumoniae had higher levels of reduced glutathione and glutathione-S-transferase activity compared to the others, indicating a stronger defense system against free radicals. Peroxynitrate levels and lipid peroxidation, as measured by malondialdehyde, generally increased in the order of Klebsiella pneumoniae > Staphylococcus aureus > E. coli, suggesting more pathogenic bacteria produce more oxidative species. This supports the hypothesis that bacteria modulate antioxidant defenses in response to oxidative stress levels to protect against
Atlanta Botanical Garden Science Cafe: Medicines from Nature - 2014Cassandra Quave
This document provides an overview of Dr. Cassandra Quave's work in ethnobotany and ethnopharmacology. It discusses her early adventures studying medicinal plants used by indigenous groups in the Amazon rainforest and Southern Italy. It then describes her ethnobotanical research methods which include interviews, plant collection and extraction. Several case studies are presented on plants from Southern Italy and Albania that were found to have anti-biofilm and antimicrobial properties. The document emphasizes the multidisciplinary nature of ethnobotany and the importance of collaboration in furthering the field's contributions to drug discovery and local health.
This document discusses different types of bioreactors used in bioprocesses. It describes submerged bioreactors like stirred tank reactors (STR), continuous stirred tank reactors (CSTR), and their components like impellers. It also discusses solid-state fermentation bioreactors like horizontal drums, tray-type, and packed bed bioreactors. Recent applications of bioreactors for mammalian and plant cell culture and algae production in photobioreactors are also covered. The chapter provides an overview of bioreactor design properties for producing biomolecules and considers factors affecting scale-up of bioprocesses.
Antimicrobial resistance as an emerging food-borne infectious diseaseJean Jacques Bernatas
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Specific prophylaxis & therapy of infectious diseases. Immune sera & Immunogl...Eneutron
Antitoxins are antibodies that neutralize toxins and can be used to prevent toxins from causing disease symptoms. Passive immunity can be provided through the administration of antitoxins, immunoglobulins like gamma globulin, and immune sera which provide immediate and temporary protection against various pathogens and toxins. Monoclonal antibodies produced through hybridoma technology allow the isolation of homogeneous antibodies against single antigenic determinants and have various applications in research, diagnosis, and potential treatment.
1) MelMedtronics Holdings develops cutting-edge technologies to revolutionize healthcare, mHealth, and telemedicine, including the first iPad audiometer meeting international standards.
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Xuejuan Wang is a hardworking and dedicated individual seeking a new position. She has excellent written and oral communication skills in both English and Mandarin. She also has strong computer skills and experience in nutrition management, sales, tutoring, and volunteering. Wang holds certifications in food protection and handling and has a bachelor's degree from California State University, Los Angeles.
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This letter from Heidi L. Woodman recommends her niece, Dominique Powers, for a scholarship. It summarizes Dominique's accomplishments, including running successful businesses, holding leadership positions, and maintaining a high GPA. It notes Dominique's interest in the medical field from a young age and her goal of becoming an obstetrical nurse. The letter argues that Dominique is an excellent candidate for the scholarship due to her determination and efforts to achieve her goals.
Este documento describe diferentes teorías y enfoques sobre los estilos de aprendizaje, incluyendo las definiciones de Dunn, Hunt y Keefe. Explica los cuatro estilos de aprendizaje principales del modelo VARK: visual, auditivo, lector/escritor y kinestésico. Para cada estilo, describe las características y cómo los estudiantes pueden aprovechar mejor sus fortalezas. También menciona que la mayoría de las personas tienen una combinación de estilos.
O documento discute a relação entre psicologia e educação ao longo da história, desde a Grécia Antiga até a modernidade. Também aborda como a psicologia foi inserida no âmbito educacional e quais são as principais áreas de atuação dos psicólogos, como em escolas, creches e clínicas especializadas. Por fim, apresenta conceitos importantes como psicologia educacional e psicologia escolar.
El documento presenta información sobre diferentes teorías de la motivación. Brevemente describe las teorías de Maslow sobre las necesidades humanas, la teoría de los dos factores de Herzberg, la teoría de la expectativa de Vroom y la teoría Y de McGregor sobre la naturaleza humana en el trabajo. También incluye ventajas y limitaciones de algunas de estas teorías.
Este documento presenta la estructura típica de un artículo científico, incluyendo la introducción, método, resultados, discusión y conclusiones. Explica cada sección, resaltando que la introducción describe el problema y objetivos del estudio, el método detalla el diseño y variables, los resultados muestran los datos sin interpretación, y la discusión contextualiza los hallazgos y establece limitaciones. El documento provee una guía para realizar una lectura crítica de artículos científicos.
Un virus informático es un malware que altera el funcionamiento de una computadora sin el permiso del usuario, reemplazando archivos ejecutables con código dañino. Los virus pueden destruir datos o causar molestias, y se propagan a través de software. Una bomba lógica es código oculto que ejecuta una acción maliciosa cuando se cumplen ciertas condiciones, mientras que un gusano se replica automáticamente de computadora en computadora. El phishing usa correos falsos para robar información personal mediante enga
Probiotics are live microorganisms that are similar to beneficial microorganisms found in the human gut. They are derived from Greek and mean "for life". Probiotics are available to consumers mainly in dietary supplements and foods and can have health benefits such as reducing cholesterol levels and preventing diarrhea. However, there is a risk of probiotic bacteria developing antibiotic resistance as they can act as conduits for spreading antibiotic resistance genes between animals and humans. This document examines the antibiotic resistance and susceptibilities of Lactobacillus bacteria, an important probiotic, and the potential effects of antibiotic resistance in probiotics.
Antimicrobial activity of Lactobacillus spp. especially (L. planetarium and L. acidophilus) against S. aureus were tested using agar-plug, agar well diffusion methods to select the best isolate that could inhibit the growth of multidrug resistance isolates. Further identification for the presence of bacteriocin was done using ELISA kit. Results showed that Lactobacillus spp isolates were bacteriocin producers with different degrees and that L. planetarium (L7) was the most efficient in bacteriocin production. Therefore, L. planetarium (L7) was selected for purification using 70% saturated ammonium sulfate and gel chromatography. The effect of purified bacteriocin was tested on 16 bacterial isolates using micro-titer plate method and well diffusion method. The results showed the ability of the bacteriocin to inhibit bacteria only at concentrations 1866U/ml (50%), 3732U/ml (100%) with a diameter of inhibition zones ranges between (11-23 mm) respectively. The anti-biofilm activity of purified bacteriocin at concentration 100% was investigated and the results showed that biofilm formation was reduced by 100% in the presence of bacteriocin.
The Role of Antibiotics and Antibiotic Resistance in Natureijtsrd
Investigations of antibiotic resistance from an environmental prospective shed new light on a problem that was traditionally confined to a subset of clinically relevant antibiotic resistant bacterial pathogens. It is clear that the environmental microbiota, even in apparently antibiotic free environments, possess an enormous number and diversity of antibiotic resistance genes, some of which are very similar to the genes circulating in pathogenic microbiota. It is difficult to explain the role of antibiotics and antibiotic resistance in natural environments from an anthropocentric point of view, which is focused on clinical aspects such as the efficiency of antibiotics in clearing infections and pathogens that are resistant to antibiotic treatment. A broader overview of the role of antibiotics and antibiotic resistance in nature from the evolutionary and ecological prospective suggests that antibiotics have evolved as another way of intra and inter domain communication in various ecosystems. This signalling by non clinical concentrations of antibiotics in the environment results in adaptive phenotypic and genotypic responses of microbiota and other members of the community. Understanding the complex picture of evolution and ecology of antibiotics and antibiotic resistance may help to understand the processes leading to the emergence and dissemination of antibiotic resistance and also help to control it, at least in relation to the newer antibiotics now entering clinical practice. Mr. Arpit Rajaram Suralkar | Pratibha Lande "The Role of Antibiotics and Antibiotic Resistance in Nature" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-6 | Issue-6 , October 2022, URL: https://www.ijtsrd.com/papers/ijtsrd51998.pdf Paper URL: https://www.ijtsrd.com/pharmacy/pharmacology-/51998/the-role-of-antibiotics-and-antibiotic-resistance-in-nature/mr-arpit-rajaram-suralkar
This document discusses the taxonomy, roles, and significance of microorganisms in food. It begins by defining taxonomy and how microorganisms are classified. It then discusses how microorganisms are essential to breaking down foods into inorganic compounds. The primary sources of microorganisms in foods are identified as soil, water, plants, food utensils, humans/animals, and animal feeds. The roles of microorganisms in the dairy, cereal, meat, and color production industries are described. Finally, it discusses how microorganisms can be used to remove mycotoxins from contaminated foods.
This study aimed to isolate and characterize lactic acid bacteria from dairy products in Egypt with probiotic potential. Fifty-four isolates were obtained from samples including human milk, yogurt and raw milk. Eight isolates from different dairy products were found to be tolerant to low pH and bile salt and had antagonistic effects against pathogenic bacteria. Biochemical and physiological testing identified the isolates as belonging to Lactobacillus casei, L. acidophilus, and L. lactis. The isolates were also found to produce enzymes and have no hemolytic activity, indicating their potential as safe and effective probiotics.
Protein was extracted from muscles of Channa striatus and attempts were
made to evaluate in vitro antibacterial activity against clinical bacterial isolates. The
higher concentration of protein (100μg/ml) extracts exhibited a pronounced activity
against Pseudomonas aeruginosa (21 mm), Proteus vulgaris (19 mm), Citrobacter sp
(19 mm), Klebsiella pneumoniae (18 mm), Micrococcus sp (17 mm), Bacillus subtilis (16
mm), Staphylococcus aureus (15 mm), E. coli (14 mm) and Serratia marcescens (5
mm). The minimum inhibitory concentration and minimum bactericidal concentration
were found to be 20-40 μg/ml and 80-100 μg/ml respectively for the extracts of
Channa striatus protein against test organisms. This study confirms that C. striatus fish
protein extracts possess antibacterial activity against a wide range of microbes and
justified that it could be used in the traditional medicine as a remedy for the
treatment of bacterial diseases.
Microbiome: The genes and genomes of the microbiota, as well as the products of the microbiota and the host environment” [the collective genomes of the micro-organisms in a particular environment. Although the composition of the gut microbiota varies between individuals, the community in each individual is relatively stable over time.
Dental plaque as a biofilm and a microbial communityneooo21
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2) Studies using defined microbial communities found that allowing pH to drop after sugar pulses selected for acid-tolerant, cariogenic species over time. Maintaining neutral pH did not cause such shifts. Low pH, rather than sugar alone, drives changes in microbial population linked to dental caries.
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Safety and toxicity evaluation of probiotics foodsSukhveerSingh31
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Human Microbiome Microbiota Faecal transplant.pdfVivekPatil679088
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Identification of probiotic bacteria in commercially available food products ...Thilina Abhayarathne
This document discusses lactobacillus bacteria, their sources, and analysis of their antibiotic resistance. It summarizes that:
Lactobacillus bacteria are commonly found in the digestive and reproductive systems and are used in fermented foods like yogurt. Sources of lactobacillus include foods like yogurt as well as plants. Studies have found that certain lactobacillus strains can help reduce cholesterol levels and prevent diarrhea.
Analysis of 29 lactobacillus strains found high levels of resistance to various antibiotics. Indiscriminate antibiotic use has led to increased antibiotic resistance in both harmful and beneficial bacteria. Most commercial foods are now supplemented with probiotic bacteria.
ISOLATION AND IDENTIFICATION OF LACTIC ACID BACTERIA FROM PLANTS AND OTHER ...American Research Thoughts
This document describes a study that isolated lactic acid bacteria (LAB) from various plant and vegetable matrices. 22 LAB strains were isolated belonging to Lactobacillus, Lactococcus, and Enterococcus genera. The predominant species were Lactobacillus brevis (57%) and Lactobacillus delbrueckii subsp. bulgaricus (14%). The strains were tested for their ability to produce bacteriocin-like substances (BLS) with antimicrobial activity. A conjugation experiment was then successfully performed between Enterococcus faecium and Lactobacillus acidophilus to demonstrate horizontal gene transfer of BLS production.
This study evaluated the antibacterial effects of copper on microorganisms isolated from bovine mastitis. Milk samples were collected from dairy farms in central and southern Chile between March and September 2013. A total of 327 microorganisms were isolated and identified, with the most common being Escherichia coli, Staphylococcus aureus, Staphylococcus uberis, and coagulase-negative Staphylococci. Antibiotic susceptibility testing found 34% of isolates were resistant to at least one antibiotic. Minimum inhibitory concentration (MIC) assays found that 250 ppm copper inhibited the growth of 65% of isolates. The remaining isolates were inhibited by concentrations between 375-1000 ppm copper. Copper
Aggregatibacter actinomycetemcomitans is a gram-negative bacterium that is considered a primary pathogen in aggressive periodontitis. It produces several virulence factors that allow it to evade the host immune response and cause tissue destruction, such as a leukotoxin that lyses leukocytes, a cytolethal distending toxin that induces cell cycle arrest, and lipopolysaccharide that stimulates inflammation. The bacterium attaches to surfaces using fimbriae and establishes itself in the oral cavity through interactions with other microorganisms and host factors before going on to cause periodontal disease.
The document discusses the human gut microbiota and its therapeutic applications. It provides details on the composition and functions of the gut microbiota, factors that influence it, methods for assessing its functions, and associated diseases. It also discusses probiotics, prebiotics, postbiotics, fecal microbiota transplantation, and the development of microbiome-based therapeutics to modulate the gut microbiota for therapeutic purposes.
Stavropoulou et al-2021-frontiers_in_medicineCarolynCampos4
This document reviews the relationship between the gut and kidney, known as the gut-kidney axis. It discusses how recent technological advances have improved understanding of the gut microbiome and its role in health and disease. The gut microbiome helps absorb nutrients, synthesize vitamins and enzymes, and produces short-chain fatty acids that support epithelial integrity and immunomodulation. Disruptions to the gut microbiome balance (known as dysbiosis) have been linked to various diseases. The review also briefly discusses the urinary microbiome and its role in urinary tract health. It suggests the gut microbiome can influence other body systems like the kidneys, and that disruptions to microbial communities may undermine their interactions with human cells and
3. skin and soft tissue to life-threatening pneumonia and
toxinoses such as toxic shock syndrome (Nawaz et al.,
2008).
Lactic acid bacteria (LAB) are commonly defined as
gram-positive, non-sporulating, catalase negative, aero
tolerant, acid tolerant, nutritionally fastidious, strictly
fermentative organisms that produce lactic acid as end
product of carbohydrate metabolism (Hartnett et al.,
2002). LAB are famous as friendly bacteria for human
health. Most of the Lactobacillus species are normal and
non-pathogenic microorganisms in human and animal
intestine and are a vital part of the intestinal microbial
ecosystem. Lactic acid bacteria have a number of
properties which render them highly suitable for probiotic
therapeutics which are of pharmaceutical interest. They
play a significant physiological role in the maintenance of
the ecological balance because their lactic acid
production is responsible for low pH level in the tracts. In
addition, they also produce other inhibitory substances
such as hydrogen peroxide, bacteriocins and some
organic acids. Other mechanisms proposed for their
microbial antagonism are competition for nutrition,
adhesion inhibition of pathogens to surfaces and
stimulation of the immune system (Voravuthikunchai et
al., 2006).
Lactobacilli, despite of their origin, have potential to
inhibit the growth of pathogens, including problematic
antibiotic resistant isolates due to their production of
several antimicrobial compounds (Petrova et al., 2009).
Verdenelli et al. (2009) reported that two Lactobacillus
strains had an inhibitory effect on potentially pathogenic
microorganisms such as Escherichia coli,
Staphylococcus aureus, Candida albicans and Candida
perfringens. Lactic acid bacteria (LAB) work via different
mechanisms to exert an antimicrobial effect, but the cell
envelope is generally the target. Studies have revealed
that Lactobacillus reuteri isolated from healthy vaginal
ecosystem (Voravuthikunchai et al., 2006) and
Lactobacillus fermentum (Nawaz et al., 2008) have
significantly inhibited methicillin resistant S. aureus. It has
also been demonstrated that L. rhamnosus has the
capacity to displace and kill S. aureus adhering to human
intestine mucus by 39 to 44% (Vesterlund et al., 2006).
Methicillin resistant bacterial infections provide a tough
challenge in the selection of antibiotics. Traditional use of
antibiotics is worsening the problem. Although antibiotics
are available for the treatment of MRSA infections,
because of their numerous adverse effects and
development of resistant strains, there is an urgent need
to search for alternatives to synthetic antibiotics for
treating MRSA infections. Studies were carried out to
search for alternatives to synthetic antibiotics against
MRSA. LAB demonstrates many properties which make
them highly suitable for probiotic therapeutics of
pharmaceutical interest. LAB has become an attractive
option of modern medical practice. Recently attention has
been paid to their health promoting properties. Of
particular importance are their probiotic properties and
Maxton et al. 1803
specially the ability to compete with pathogens.
The present study was carried out to isolate Lactobacilli
and to observe its efficacy against MRSA, in controlling
MRSA infections as well as providing a new strategy to
treat re-emerging infections.
MATERIALS AND METHODS
Test pathogen
Five isolates of S. aureus were collected from Microbial Culture
Collection Bank (MCCB) of the Department of Microbiology and
Fermentation Technology. The S. aureus strains were MCCB0045,
MCCB0046, MCCB0065, MCCB0066 and MCCB0067.
Isolation of lactic acid bacteria
100 human faecal samples were collected and 10³ dilutions of
faecal samples were prepared in sterile normal saline, then swab
inoculated on de Mann Rogosa Sharpe (MRS) agar plates. The
plates were incubated anaerobically using anaerobic jar, at 37°C for
48 h to obtain colonies (De Man et al., 1960).
Identification of Lactobacillus species
The bacterial colonies on incubated plates were identified on the
basis of cultural, morphological and biochemical characteristics as
described in the Bergey’s Manual of Determinative Bacteriology
(Holt et al., 1984).
Cultural characteristics
The isolates were identified on the basis of different colony
characteristics like diameter, consistency, colour, texture, elevation,
margin, etc.
Morphological characteristics
The organism was subjected to Gram’s staining and observed
under 100 x objective for observing the morphological
characteristics such as the shape and arrangement (clusters or
chains) of cells, and gram-reaction (gram-positive or gram-
negative).
Biochemical characteristics
The following biochemical tests were performed for the identification
of lactic acid bacteria.
Indole test
The test tubes containing tryptophan broth were inoculated with the
test organism and incubated aerobically at 37°C for 24 h. After
incubation, 0.5 ml Kovac’s reagent was added gently. Red colour
formed in the alcohol layer indicated positive reaction.
Methyl red test
Five drops of 0.04% solution of methyl red were added to the
4. 1804 Afr. J. Microbiol. Res.
culture in glucose phosphate broth which had been incubated at
30°C for five days. Red colour indicated positive test while yellow
colour indicated negative test.
Citrate utilization test
Simmons Citrate medium was prepared, inoculated from a saline
suspension of organism to be tested and incubated for 24 h at
37°C. Growth in the medium with a change in colour from green to
blue indicated a positive result.
Carbohydrate fermentation test
10 ml of carbohydrate fermentation broth was transferred in culture
tubes along with the inverted Durham’s tube and autoclaved at
121°C for 15 to 20 min. The carbohydrate was prepared at 1%
concentration in distilled water and autoclaved at 10 lbs/inch².
Separately, one loopful of organism from the culture plate was
transferred in the tubes containing 10 ml carbohydrate fermentation
broth and 1 ml of each sugar solution. A control was taken; tube
that is not inoculated (without microorganism the tubes were
incubated at 37°C for 24 to 48 h). After incubation, the tubes were
examined for acid production and gas production. Change in media
colour from purple to yellow indicated the production of acid, which
was a positive test. No colour change indicated negative test.
Accumulation of gas bubbles in Durham’s tube indicated the gas
production and gave a positive test.
Catalase test
A loopful of culture was transferred from tube to a clean glass slide.
Thereafter, a drop of hydrogen peroxide was added and mixed well.
Evolution of bubbles indicated a positive test, whereas no evolution
of bubbles indicated a negative test.
Nitrate reduction
Equal amount of α naphthol and sulphanilic acid were added to 24
to 48 h culture in nitrate reduction broth. The test tubes were
examined for the appearance of red colour and gas bubbles. The
occurrence of red colour and gas bubbles were presumptive for
denitrification and indicated a positive test.
Hugh and Liefson’s test
2.3 ml of 10% solution of glucose was added to Hugh and Liefson’s
oxidation and fermentation medium tubes and inoculated in
duplicate and incubated aerobically at 37°C from 24 to 48 h.
Paraffin was spread over the media in one of the test tube after
inoculation and then incubated to check for anaerobic bacteria.
Positive tubes showed change in colour of the media green to
yellow.
Motility test
The tube containing motility agar medium was stab inoculated.
Positive test is indicated by the growth around the stab line that
radiated outwards in all directions while no growth around stab line
indicated negative test.
Hydrogen sulphide test
Tubes containing sulphide indole motility agar were stab inoculated
and kept for incubation at 37°C for 24 h. Blackening of the culture
medium indicated a positive test.
Antibiotic susceptibility pattern of S. aureus against selected
antibiotics
The test organism was tested for its sensitivity towards the given
antibiotics using the Disk Diffusion Method (Bauer et al., 1966).
Overnight, broth cultures were spread on the surface of Nutrient
Agar Media plates with the help of sterile swabs. The antibiotic
discs were placed on the agar surface and plates were incubated
aerobically at 37°C for 24 h. Zone of inhibition was measured in
‘mm’ and the result interpreted on the basis of CLSI standards
(Wayne, 2003).Antibiotic discs (Hi Media) which were used in the
present study were Methicillin (M, 5 µg), Erythromycin (E, 15 µg), ,
Ciprofloxacin (Cf, 5 µg), Tetracycline (T, 30 µg), Kanamycin (K, 30
µg), Gentamicin (G,10 µg) Rifampicin (R, 30 µg), Linezolid (L, 30
µg), Vancomycin (Va, 30 µg) and Tobramycin (Tb,10 µg).
Screening of LAB isolates for anti-MRSA activity
The antibacterial activity was assayed against isolates of S. aureus
using Agar Well Diffusion method (Schillinger and Lucke, 1989).
The five strains of S. aureus were incubated in Nutrient Broth at
37°C for 24 h. The broth culture was swab inoculated on Nutrient
Agar. For the detection of antibacterial activity, the Lactobacilli
strains were cultured in MRS broth, incubated anaerobically at 37°C
for 36 h. The broth culture of Lactobacilli was subjected to
centrifugation at 5000 g for 15 min. The supernatant was discarded
and the pellet was washed twice with sterile normal saline. The
washed pellet was then inoculated in Skim Milk Broth and
incubated aerobically at 37°C for 36 h. The inoculated Skim Milk
Broth was subjected to centrifugation at 5000 g for 15 min and 20 µl
of the supernatant was filled on each 5 mm well on Nutrient Agar
plates. Wells filled with sterile Nutrient Broth were included as
control. Inhibition zones were measured after incubating the plates
aerobically at 37°C for 24 h (Hassan et al., 2011). Inhibition was
scored positive if the width of the clear zone around the well was
observed.
Statistical analysis
The data was analyzed using Chi-square test, Z-test and two way
classification of ANOVA.
RESULTS AND DISCUSSION
Isolation and identification of lactobacilli from human
faecal samples
In the present investigation of the hundred human faecal
samples collected from healthy adults, 23% were positive
for Lactobacilli. On the basis of the biochemical
characteristics of the 23 Lactobacilli isolates, it was
observed that the three different Lactobacilli species
isolated were L. plantarum, L. acidophilus and L. casei.
Out of the 23 isolates, ten isolates were L. plantarum,
eight were L. acidophilus and five were L. casei (Tables 1
and 2). On analyzing statistically, the data was non-
significant at 0.05% probability. Study conducted by
Dhewa and Goyal (2009) described incidence of LAB
5. Maxton et al. 1805
Table 1. Incidence and distribution of lactobacilli species in human faecal samples.
Total number
of sample
Total number of
Lactobacilli isolates (%)
Number of Lactobacillus
plantarum (%)
Number of Lactobacillus
acidophilus (%)
Number of
Lactobacillus casei (%)
100 23 10 (43.47) 8 (34.78) 5 (21.73)
χ²=5.99 (tabulated value), χ²=24.32 (calculated value), N.S=non-significant.
Table 2. Cultural, morphological and biochemical identification of lactobacilli Isolates.
Characteristic
Organism
Lactobacillus
plantarum
Lactobacillus
acidophilus
Lactobacillus
casei
Cultural characteristics
Colour of colony Cream White Off white
Shape of colony Small, spherical Small, spherical Small, spherical
Elevation Convex Convex Convex
Margin Entire edges Entire edges Entire edges
Morphological
characteristics
Gram’s reaction Gram positive Gram positive Gram positive
Arrangement of cells
Long slender rods in
chains
Rods in pairs and
chains
Small rods in chains
Spore formation Non -sporing Non -sporing Non -sporing
Biochemical
characteristics
Indole test Negative Negative Negative
Methyl red test Positive Positive Positive
Citrate test Negative Negative Negative
catalase test Negative Negative Negative
Motility test Negative Negative Negative
Nitrate reduction test Positive Positive Positive
H2S production test Negative Negative Negative
Carbohydrate
fermentation
D-Glucose A
+
G
-
A
+
G
-
A
+
G
-
D- Galactose A
+
G
-
A
+
G
-
A
+
G
-
Sucrose A
+
G
-
A
+
G
-
A
+
G
-
Maltose A
+
G
-
A
+
G
-
A
+
G
-
Esculin A
+
G
-
A
+
G
-
W A
+
G
-
Fructose A
+
G
-
A
+
G
-
A
+
G
-
D-Mannitol A
+
G
-
A
-
G
-
A
+
G
-
Arabinose W A
+
G
-
A
-
G
-
A
+
G
-
A
+
, Acid positive; A
-
, acid negative; G
+
, gas positive; G
-
, gas negative; WA
+
, weakly positive.
from human faecal sample. Human intestinal mucous
isolated from faeces of healthy Egyptian infants of 36
months of age were used as a substratum for the
adhesion of probiotic Lactobacilli strains (Khalil et al.,
2007). Lactobacillus acidophilus was the most frequently
recovered species from infant faecal samples. This
finding indicates that this species survived better in the
gastrointestinal tract than the other strains (Khalil et al.,
2007). Another study showed comparable results in
which Lactobacilli were isolated from 50 faecal samples
of 3 to 30-day old infants. The isolated Lactobacillus
strains were further identified as L. acidophilus,
Lactobacillus brevis, L. casei, L. plantarum, Lactobacillus
fermentum, Lactobacillus reuteri and L. rhamnosus
(Ozgun and Vural, 2011). Lactobacillus paracasei,
Lactobacillus gasseri, Lactobacillus delbrueckii, and
Lactobacillus plantarum were isolated from faeces of
healthy adults on MRS agar (Delgado et al., 2007).
Antibiotic susceptibity pattern of S. aureus
As a result of the antibiotic susceptibility test for the five
strains of S. aureus, MCCB0065 was most resistant
towards the ten antibiotics used, whereas MCCB0045
was most susceptible. Among the ten antibiotics,
Tobramycin (Tb) possessed least inhibitory potential
whereas Erythromycin (E) had maximum inhibitory effect
against the five strains of S. aureus. On the basis of
resistance against Methicillin, three out of five S. aureus
6. 1806 Afr. J. Microbiol. Res.
Table 3. Antibiotic susceptibility profile of Staphylococcus aureus strains.
S. aureus
strain
Antibiotic
E
(15 g)
Cf
(5 g)
T
(30 g)
K
(30 g)
G
(10 g)
R
(30 g)
L
(30 g)
Va
(30 g)
Tb
(10 g)
M
(5 g)
MCCB0045 +++ +++ ++ ++ +++ ++ +++ +++ - -
MCCB0046 ++ ++ - ++ ++ ++ +++ ++ ++ -
MCCB0065 ++ ++ - ++ ++ + ++ ++ - -
MCCB0066 ++ ++ - ++ ++ +++ - ++ ++ ++
MCCB0067 ++ ++ ++ ++ - +++ ++ ++ ++ +
+++, Sensitive; ++, Intermediate; -, Resistant. E, Erythromycin; R, Rifampicin; Cf, Ciprofloxacin; G, Gentamicin; T, Tetracycline; L,
Linezolid; K, Kanamycin; Va, Vancomycin; Tb, Tobramycin; M, Methicillin.
strains (MCCB0045, MCCB0046, and MCCB0065) were
MRSA and the rest two strains (MCCB0066, MCCB0067)
were MSSA. S. aureus strain MCCB0065 was multi-drug
resistant as it was resistant to Tobramycin, Tetracycline
and Methicillin (Table 3).
In a previous study, the antibiotic susceptibility of the
MSSA and MRSA isolates was tested. The study
conducted to test the antibiotic susceptibility pattern of
Staphylococcus aureus strains showed that both MRSA
and MSSA were susceptibility towards Gentamicin,
Ciprofloxacin and Tetracycline (Sivakumari and Shanthi,
2009). This was comparable with the reports of other
workers (Nwankwoet al., 2010; Khadri and Alzohairy,
2010).
Antibacterial activity of Lactobacilli species against
MRSA
It was observed from the result of the antibacterial activity
test of the three isolated strains of lactobacilli that L.
casei showed maximum inhibition against MCCB0045,
MCCB0065, MCCB0067 but showed moderate inhibition
against MCCB0066 and minimum inhibition was seen
against MCCB0046 (Figure 1). In L. plantarum, maximum
inhibition was observed against MCCB0045, MCCB0067
whereas moderate inhibition was seen against
MCCB0046, MCCB0065 and minimum inhibition was
seen against MCCB0066. In L. acidophilus, maximum
inhibition was observed against MCCB0067 whereas
moderate inhibition was scored against MCCB0045,
MCCB0065, MCCB066 and minimum inhibition was
scored against MCCB0046. On the basis of the above
observation, it was observed that L. casei had maximum
inhibitory potential, showing maximum inhibition against
three strains of S. aureus whereas L. acidophilus showed
minimum inhibitory potential, as it showed maximum
inhibition against one strain of S. aureus. On considering
the resistance potential of the five pathogen strains of S.
aureus towards the three isolated lactobacilli strains, it
was observed that MCCB0067 was most resistant
whereas MCCB0046 was most susceptible towards the
three Lactobacilli strains. The range of the width of
inhibition zones remained between 6.5 to 15.5 mm (Table
4).
On considering the three MRSA strains, MCCB0045
was most susceptible towards the three isolated
Lactobacilli strains. MCCB0065 showed moderate
susceptibility whereas MCCB0046 was least susceptible.
On analyzing statistically, the data was significant due to
Lactobacilli spp, at 5% probability and non-significant due
to S. aureus strains at 5% probability. Studies have
shown that L. acidophilus has the capacity to produce
numerous metabolites that kill pathogenic bacteria (Oh et
al., 2000). LAB were screened previously for anti-MRSA
activity and L. fermentum was able to inhibit MRSA
strains (Nawaz et al., 2008). Bactericidal proteins with
antagonistic activities are produced by some strains of L.
acidophilus. Among lactobacilli, strains belonging to
species of the L. acidophilus and L. casei are frequently
used as probiotic agents (Klaenhammer and Kullen,
1999). In a previous study, the isolated Lactobacillus
strains exhibited the highest zone of inhibition (15 mm)
against S. aureus (Arokiyamary and Sivakumar, 2011).
Conclusion
Out of a total of 100 faecal samples of healthy adults
studied, 23% were positive for Lactobacilli. The 23
Lactobacilli strains isolated from 100 human faecal
samples in which 43.47% were L. plantarum, 34.78%
were L. acidophilus and 21.73% were L. casei.
Statistically, the differences were non-significant. S.
aureus strains MCCB0045, MCCB0046, MCCB0065
were MRSA whereas MCCB0066, MCCB0067 were
MSSA and strain MCCB0065 was multi-drug resistant. L.
plantarum, L. acidophilus, and L. casei demonstrated
antimicrobial potential to inhibit S. aureus including
MRSA strains. L. casei showed maximum inhibitory
potential. On analysing statistically the differences were
significant. It is recommended that they may be
considered beneficial, as compared to the regular
antibiotics. Lactic acid bacteria will be ideal in producing
7. Maxton et al. 1807
A B
C D
E
Figure 1. Antibacterial activity of lactobacilli strains against test pathogen Staphylococcus aureus. A, Staphylococcus aureus
MCCB0045; B, S.aureus MCCB0046; C, Staphylococcus aureus MCCB0065; D, S. aureus MCCB0066; E, S. aureus
MCCB0067; La, L. actobacillus acidophilus; Lc, L.actobacillus casei; Lp, Lactobacillus plantarum.
8. 1808 Afr. J. Microbiol. Res.
Table 4. Antibacterial activity of lactobacilli strains against test pathogen Staphylococcus aureus.
S/N Lactobacilli
Zone of inhibition (mm)
MCCB0045 MCCB0046 MCCB0065 MCCB0066 MCCB0067
1
Lactobacillus
plantarum
15.00 10.50 11.00 6.00 15.50
2
Lactobacillus
acidophilus
11.50 7.00 12.00 11.50 14.50
3
Lactobacillus
casei
15.50 6.00 13.00 8.00 14.00
Due to lactobacilli: F (Cal) =5.98; F (Tab) =3.84; C.D at 5%=3.044; Result=S (significant). Due to Staphylococcus aureus: F (Cal)
=0.03; F (Tab) =.4.46; C.D at 5%=3.044.
antimicrobial compounds effective against MRSA. The
Lactobacilli strains isolated in the present study
demonstrated anti-methicillin resistant Staphylococcus
aureus activity. The isolated strains of L. plantarum, L.
acidophilus, and L. casei can also be used as probiotic
(after the positive reports of in vivo experimentations).
This strategy should be applied for the control of re-
emerging MRSA infections.
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