Benjamin Taylor1, 2, David Williams1 & Jon Nosworthy3.
1Cardiff University School of Dentistry
2Knowledge Transfer Partnership Associate
3Advanced Medical Solutions plc
This document presents research finding that filamentous bacteriophage produced by Pseudomonas aeruginosa biofilms organize the biofilm matrix into a liquid crystalline structure. This liquid crystalline structure increases the biofilm's tolerance to aminoglycoside antibiotics by binding and sequestering the antibiotics within the matrix. Specifically, mixtures of Pf4 phage and host/bacterial polymers were found to spontaneously assemble into liquid crystals. P. aeruginosa biofilms producing high levels of Pf4 phage also exhibited a liquid crystalline biofilm matrix structure. This liquid crystalline structure enhanced the biofilm's resistance to killing by tobramycin and increased the binding of fluorescent-labeled tobramycin within the matrix.
The document describes several methods for enumerating and identifying microorganisms in foods:
1) Total plate count, coliform test, and tests for mesophilic bacteria, staphylococci, and pathogenic bacteria like Salmonella and Shigella are discussed.
2) Culture-based techniques like streak plating, spread plating, and pour plating on agar plates are used to determine microbial numbers.
3) The coliform test involves presumptive, confirmation, and completed stages to identify coliform bacteria. Testing for specific microorganisms like Salmonella involves enrichment and plating followed by screening and confirmation tests.
The study evaluated the antimicrobial effects of the salivary proteins lactoferrin and lysozyme on Streptococcus mutans and Lactobacillus casei using broth macrodilution and agar diffusion methods. Lysozyme showed bactericidal and bacteriostatic effects on both microorganisms, with minimum inhibitory concentrations of 58.7 mg/mL for S. mutans and 43.1 mg/mL for L. casei. Lactoferrin did not have any inhibitory effects on either microorganism, even at a concentration of 200 mg/mL. There was also no observed synergistic antimicrobial effect when the proteins were tested together.
This document discusses various methods for enumerating and testing for microorganisms in food. It describes total plate counts, coliform tests, and tests for mesophilic bacteria, staphylococci, Salmonella, Shigella, and other pathogenic bacteria. Specific procedures are outlined, including enrichment, plating, screening, and confirmation steps. A variety of media are used, such as violet red bile agar, Baird-Parker agar, triple sugar iron agar, and lysine iron agar. Colonies are examined for characteristics like color, zone formation, and biochemical reactions to identify microorganisms.
Detection techniques for microorganisms in food of animalMANJEET RATHOUR
The detection and enumeration of microorganisms in food are an essential
part of any quality control or food safety plan. Traditional methods of detecting foodborne pathogenic bacteria are often time-consuming because of the need for growth
in culture media, followed by isolation, biochemical and/or serological identifi cation,
and in some cases, subspecifi c characterization. Advances in technology have made
detection and identifi cation faster, more sensitive, more specifi c, and more convenient than traditional assays. These new methods include for the most part antibodyand DNA-based tests, and modifi cations of conventional tests made to speed up
analysis and reduce handling.
Enumeration is counting of microorganisms present in a sample.
This is done to know the intense of presence of the spoilers in the spoiled food.
To detect which type of organism is responsible for the spoilage.
Mostly this is done two important methods.
Viable count
Total count
VIABLE COUNT:
A viable cell count allows one to identify the number of actively growing or dividing cells in a sample.
The plate count method or spread plate method relies on bacteria growing a colony on a nutrient medium.
Number of colonies can be counted.
Plate count agar is used for general count
MacConkey agar is used for Gram negative organisms.
TOTAL COUNT:
The initial analysis is done by mixing serial dilution of sample in liquid nutrient agar which is then poured into bottles.
The bottles are then sealed and laid on their sides to produce a slopping agar surface.
The colonies are then counted by eye.The total number of colonies are said as Total Viable Count. The initial analysis is done by mixing serial dilution of sample in liquid nutrient agar which is then poured into bottles.
The bottles are then sealed and laid on their sides to produce a slopping agar surface.
The colonies are then counted by eye.The total number of colonies are said as Total Viable Count.
Pour plate method:
The same procedure is done for this till serial dilution.
The serially diluted sample is then mixed with the molten nutrient agar.
Then poured onto the sterile petridish.
Incubated under appropriate temperature amd the colonies where counted.
ConclusionThe enumeration of these spoiled food samples are important to encounter the type of microbe is causing the spoilage.
And hence this is used to prevent the same type of spoilage.
This can be avoided by making the environmental changes which inhibits the organism which is responsible for the spoilage.
MPN AND INDIRECT METHODS OF MEASUREMENT OF MICROBIAL GROWTH microbiology Notes
This document discusses methods for measuring microbial growth, including the most probable number (MPN) method and indirect turbidity measurements. The MPN method involves inoculating water samples into multiple tubes containing growth media and observing results to statistically estimate microbial concentrations. It involves presumptive, confirmed, and completed tests to identify coliforms and E. coli. Turbidity measurements use a spectrophotometer to measure light passage through cultures, where increased microbial growth causes higher turbidity and lower light transmission. Both methods provide ways to quantify microbes in samples without direct microscopic counting.
Monica c. del moral and felix valles phages manuscript official draftfelixjvalles
This document describes the isolation and characterization of a mycobacteriophage (Musamodel) from soil samples collected in Puerto Rico. After screening six soil samples without success, a phage was isolated from the seventh sample collected near a plantain plant. The phage was purified through three rounds of plating and was found to infect Mycobacterium smegmatis. Initial characterization suggests the phage has a lytic life cycle based on clear plaque formation. Future work will further characterize the phage through empirical testing, sequencing, and bioinformatics analysis.
This document presents research finding that filamentous bacteriophage produced by Pseudomonas aeruginosa biofilms organize the biofilm matrix into a liquid crystalline structure. This liquid crystalline structure increases the biofilm's tolerance to aminoglycoside antibiotics by binding and sequestering the antibiotics within the matrix. Specifically, mixtures of Pf4 phage and host/bacterial polymers were found to spontaneously assemble into liquid crystals. P. aeruginosa biofilms producing high levels of Pf4 phage also exhibited a liquid crystalline biofilm matrix structure. This liquid crystalline structure enhanced the biofilm's resistance to killing by tobramycin and increased the binding of fluorescent-labeled tobramycin within the matrix.
The document describes several methods for enumerating and identifying microorganisms in foods:
1) Total plate count, coliform test, and tests for mesophilic bacteria, staphylococci, and pathogenic bacteria like Salmonella and Shigella are discussed.
2) Culture-based techniques like streak plating, spread plating, and pour plating on agar plates are used to determine microbial numbers.
3) The coliform test involves presumptive, confirmation, and completed stages to identify coliform bacteria. Testing for specific microorganisms like Salmonella involves enrichment and plating followed by screening and confirmation tests.
The study evaluated the antimicrobial effects of the salivary proteins lactoferrin and lysozyme on Streptococcus mutans and Lactobacillus casei using broth macrodilution and agar diffusion methods. Lysozyme showed bactericidal and bacteriostatic effects on both microorganisms, with minimum inhibitory concentrations of 58.7 mg/mL for S. mutans and 43.1 mg/mL for L. casei. Lactoferrin did not have any inhibitory effects on either microorganism, even at a concentration of 200 mg/mL. There was also no observed synergistic antimicrobial effect when the proteins were tested together.
This document discusses various methods for enumerating and testing for microorganisms in food. It describes total plate counts, coliform tests, and tests for mesophilic bacteria, staphylococci, Salmonella, Shigella, and other pathogenic bacteria. Specific procedures are outlined, including enrichment, plating, screening, and confirmation steps. A variety of media are used, such as violet red bile agar, Baird-Parker agar, triple sugar iron agar, and lysine iron agar. Colonies are examined for characteristics like color, zone formation, and biochemical reactions to identify microorganisms.
Detection techniques for microorganisms in food of animalMANJEET RATHOUR
The detection and enumeration of microorganisms in food are an essential
part of any quality control or food safety plan. Traditional methods of detecting foodborne pathogenic bacteria are often time-consuming because of the need for growth
in culture media, followed by isolation, biochemical and/or serological identifi cation,
and in some cases, subspecifi c characterization. Advances in technology have made
detection and identifi cation faster, more sensitive, more specifi c, and more convenient than traditional assays. These new methods include for the most part antibodyand DNA-based tests, and modifi cations of conventional tests made to speed up
analysis and reduce handling.
Enumeration is counting of microorganisms present in a sample.
This is done to know the intense of presence of the spoilers in the spoiled food.
To detect which type of organism is responsible for the spoilage.
Mostly this is done two important methods.
Viable count
Total count
VIABLE COUNT:
A viable cell count allows one to identify the number of actively growing or dividing cells in a sample.
The plate count method or spread plate method relies on bacteria growing a colony on a nutrient medium.
Number of colonies can be counted.
Plate count agar is used for general count
MacConkey agar is used for Gram negative organisms.
TOTAL COUNT:
The initial analysis is done by mixing serial dilution of sample in liquid nutrient agar which is then poured into bottles.
The bottles are then sealed and laid on their sides to produce a slopping agar surface.
The colonies are then counted by eye.The total number of colonies are said as Total Viable Count. The initial analysis is done by mixing serial dilution of sample in liquid nutrient agar which is then poured into bottles.
The bottles are then sealed and laid on their sides to produce a slopping agar surface.
The colonies are then counted by eye.The total number of colonies are said as Total Viable Count.
Pour plate method:
The same procedure is done for this till serial dilution.
The serially diluted sample is then mixed with the molten nutrient agar.
Then poured onto the sterile petridish.
Incubated under appropriate temperature amd the colonies where counted.
ConclusionThe enumeration of these spoiled food samples are important to encounter the type of microbe is causing the spoilage.
And hence this is used to prevent the same type of spoilage.
This can be avoided by making the environmental changes which inhibits the organism which is responsible for the spoilage.
MPN AND INDIRECT METHODS OF MEASUREMENT OF MICROBIAL GROWTH microbiology Notes
This document discusses methods for measuring microbial growth, including the most probable number (MPN) method and indirect turbidity measurements. The MPN method involves inoculating water samples into multiple tubes containing growth media and observing results to statistically estimate microbial concentrations. It involves presumptive, confirmed, and completed tests to identify coliforms and E. coli. Turbidity measurements use a spectrophotometer to measure light passage through cultures, where increased microbial growth causes higher turbidity and lower light transmission. Both methods provide ways to quantify microbes in samples without direct microscopic counting.
Monica c. del moral and felix valles phages manuscript official draftfelixjvalles
This document describes the isolation and characterization of a mycobacteriophage (Musamodel) from soil samples collected in Puerto Rico. After screening six soil samples without success, a phage was isolated from the seventh sample collected near a plantain plant. The phage was purified through three rounds of plating and was found to infect Mycobacterium smegmatis. Initial characterization suggests the phage has a lytic life cycle based on clear plaque formation. Future work will further characterize the phage through empirical testing, sequencing, and bioinformatics analysis.
Epidemiological marker (serotyping and bacteriocin typing)Santosh Kumar Yadav
This document discusses various epidemiological marker typing methods used to differentiate bacterial strains, including serotyping, bacteriocin typing, and colicin typing. Serotyping is based on antigenic differences expressed on bacterial cell surfaces and has good reproducibility but poor discriminatory power. Bacteriocin typing examines bacteriocin production and susceptibility patterns to distinguish strains. It has fair reproducibility and discriminatory power but some strains are non-typeable. Colicin typing specifically examines colicin production in E. coli strains using a spot culture method with indicator strains. These typing methods can help epidemiological studies and hospital infection control.
The document discusses the Most Probable Number (MPN) technique, which is used to estimate the concentration of viable microorganisms in water samples. It works by inoculating water samples into broth at different dilutions and observing growth, based on the principle of extinction dilution. A positive/negative result is obtained from lactose fermentation tests in broth. These results are interpreted using an MPN table to estimate the number of bacteria per 100ml of water. The document outlines the materials, presumptive test procedure involving broth incubation, confirmatory test using EMB agar plates, and complete test of Gram staining suspicious colonies to identify bacteria like E. coli.
1. There are two main types of bacterial counts - total bacterial count and total viable count. Total bacterial count includes both living and dead cells while total viable count only measures living cells.
2. Bacterial enumeration is important for comparing growth under different conditions, and in industries like dairy, food, and water microbiology.
3. Methods of enumeration include direct counting using microscopy or Coulter counter, and indirect counting of viable cells using serial dilution plating or membrane filtration. Other methods determine cell mass through dry weight, nitrogen content, or turbidity measurements.
1.paola 5.anthony hernandez phages report pdf correctedpcaballero21
This study isolated and characterized a novel mycobacteriophage (bacterial virus) named Incognito from soil in Puerto Rico. Incognito was isolated from soil collected under a plantain tree and purified through plaque purification. Electron microscopy and SDS-PAGE gel electrophoresis were used to characterize the phage's morphology and protein profile. Incognito produced turbid plaques and had a concentration of 3 x 107 plaque forming units per mL. Its protein profile showed similarities to other mycobacteriophages. This study demonstrates that Puerto Rico's tropical environment supports diverse phage populations with potential applications in phage therapy.
TLC Bioautography (TLC as highthrough put screening). Kunal Shimpi
TLC bioautography is technique to isolate compound by chromatography and follow by biological detection system. It content its method, How they work, it's mechanism, advantages, disadvantages, applications and much more.
Onion (Allium Cepa) Genotoxicity Test
Laboratory of Ecotoxicology and LCA
Department of Environmental Chemistry, ICT Prague
References:
1. FERETTI, D., ZERBINI, I., ZANI, C., CERETTI, E., MORETTI,M.,MONARCA, S. (2007): Allium cepa chromosome
abberation and micronucleus tests applied to study genotoxicity of extracts from pesticide-treated vegetables and
grapes. Food Addit. Contam. 24 (6): 561-572.
2. RANK, J., NIELSEN, M.H. (1997): Allium anaphase-telophase genotoxicity assay. Department of Environment,
Technology and Social Studies, Roskilde University, Denmark.
This document describes the development and evaluation of a new medium called Makka medium for screening gram negative bacteria like coliforms in drinking water samples. The researchers developed Makka medium as an economical and safer alternative to the commonly used m-Endo agar medium. Makka medium uses methylene blue as an indicator to inhibit gram positive bacteria and allow growth of gram negatives. Tests showed that Makka medium was comparable to m-Endo agar in detecting coliforms, with coliforms appearing as blue-green colonies on Makka medium. The researchers concluded that Makka medium is recommended for use instead of m-Endo agar for detection of coliforms and gram negative bacteria in water samples due to its low cost
This document summarizes a study conducted by researchers at the University of Puerto Rico at Cayey to identify soil bacteria capable of producing novel antibiotics. Soil samples were collected from two sites and diluted to isolate individual bacterial colonies. Colonies were purified, stained, and had their DNA analyzed. The isolated bacteria were tested for antibiotic resistance and their ability to inhibit the growth of other bacteria, which could indicate antibiotic production. The goal was to find bacteria producing compounds similar to teixobactin, a potent antibiotic discovered from uncultured soil bacteria.
This document describes several methods for enumerating or counting bacteria in a sample, including viable plate count, direct microscopic count, and turbidity count. The viable plate count method involves making serial dilutions of a sample and counting the number of colonies that grow on an agar plate, then multiplying by the dilution factor to determine the concentration in the original sample. The direct microscopic count uses a counting chamber to directly view and count bacteria under a microscope. The turbidity count uses spectrophotometry to measure the turbidity or cloudiness of diluted samples, which correlates to the number of bacteria present based on a generated standard curve. Procedures for each method are provided.
Dióxido de Cloro desinfectant against bacillus anthracisricguer
This document summarizes a study that tested the sporicidal activity of chlorine dioxide disinfectant against Bacillus anthracis spores. When B. anthracis spores were mixed with aqueous chlorine dioxide solution in sealed tubes, there was a high reduction of viable spores of 8 log10 in only 3 minutes. However, spraying or spreading the solution onto surfaces only achieved a 1 log10 reduction, because the chlorine dioxide gas was rapidly vaporized from the solutions. Supplementing the chlorine dioxide solution with 5% bleach restored its full potency and increased its stability for surface decontamination when sprayed.
Identification and Detection of Microorganism esraa alaa
Molecular detection of pathogens (molecular microbiology)
is a new, dynamic and progressive spinoff of classic microbiology. It plays an important role in those clinical situations when standard microbiology (relying on the successful cultivation of potential pathogens) produces suboptimal results or completely fails.
OR
Modern approach for identification and quantification of microorganisms (pathogens) in the diagnostics of infections or foodborne illness using molecular microbiology. Broadest range of available tests and tailor-made packages.
All clinical isolates of Salmonella enterica serovars Typhi and Paratyphi tested were capable of biofilm formation in vitro. The optimized conditions for maximum biofilm formation were adherence test medium incubated at 37°C and 150 rpm for 48 hours. Of the Salmonella Typhi isolates tested, 61% were very strong biofilm producers, 29% were strong producers, and 11% were moderate producers. For Salmonella Paratyphi isolates, 69% were very strong producers, 23% were strong producers, and 8% were moderate producers. The ability of these clinical isolates to form biofilms is concerning from a public health perspective as it could facilitate transmission to new hosts and cause disease.
The document describes three methods for enumerating bacteria: standard plate count, turbidity, and direct microscopic count. The standard plate count method involves serially diluting a bacterial sample, plating the dilutions on agar, incubating the plates, and counting the colonies to calculate colony-forming units (CFUs) per mL. Turbidity measures light absorption by a bacterial suspension to estimate cell concentration. Direct microscopic count directly counts cells in a known volume under a microscope but cannot distinguish live from dead cells.
Bacteriological analysis of drinking water by MPN method.prakashtu
This document describes the MPN (Most Probable Number) method for analyzing drinking water bacteriologically. The MPN method involves inoculating water samples in multiple dilutions into lactose broths to detect coliform bacteria presence. Positive samples are then cultured on EMB agar to isolate and identify E. coli. Confirmed E. coli colonies produce acid and gas when cultured in lactose broth at 44.5°C. The number of positive samples at each dilution level is used with statistical tables to estimate the MPN of coliform bacteria per 100ml of water. This provides a statistical analysis of bacteria levels in drinking water samples.
Chrlorine dioxide inactivation of cryptosporidium parvum oocysts and bacteria...ricguer
This study evaluated the inactivation of Cryptosporidium parvum oocysts and bacterial spore indicators by chlorine dioxide. Two viability methods, in vitro excystation and cell culture infectivity assay, produced significantly different results for C. parvum inactivation, suggesting excystation is not an adequate viability assay. Purified oocysts from three suppliers showed marked differences in resistance to chlorine dioxide inactivation. Ct values required for a 2-log inactivation ranged from 75 to 1,000 mg-min/L depending on the oocyst source. Bacterial spores were more sensitive to chlorine dioxide than C. parvum oocysts and could not be used
Microbiology is the study of microbes that infect humans and cause disease. Sensitivity testing helps determine the most effective antibiotic to treat an infection by testing which antibiotics can inhibit or kill the bacteria causing the infection. The sensitivity test involves culturing bacteria from a sample, identifying the bacteria species, and exposing it to different antibiotics to see which ones prevent its growth. This helps doctors select the appropriate antibiotic for treatment.
Most probable number or multiple tube fermentation techniqueSamsuDeen12
multiple tube fermentation or most probable number is a microbiological technique used to check the portability of water. microbial analysis of water is determined, and distinguished between faecal and non faecal contaminated water.
Isolation of bacteria is a significant step in diagnosing and managing bacterial infections. It involves collecting specimens, preserving and transporting them to the lab, examining samples microscopically, and using various culture and non-culture methods to isolate bacteria. Culture methods include using solid or liquid media, and automated systems, to allow bacterial colonies to grow. Non-culture methods involve molecular techniques like PCR. Proper specimen handling and use of appropriate culture conditions and media allow isolation of pathogenic bacteria to enable treatment and control of infections.
The document summarizes a study conducted by a biology student that found antibiotic-resistant bacteria present in higher numbers in February compared to October at a local daycare center in North Carolina. Swabs were taken from various surfaces in a toddler room in the fall and winter. Five bacterial species showing resistance to multiple antibiotics were identified in October, compared to fourteen species in February. The student used microscopy, biochemical testing, and DNA sequencing to identify the bacteria isolated. The results indicate antibiotic-resistant bacteria pose a legitimate health threat in daycare centers.
The document discusses several methods for enumerating and quantifying bacteria in samples, including viable plate counts, direct microscopic cell counts, and turbidity counts. The viable plate count method involves making serial dilutions of a sample and counting the number of colonies that grow on an agar plate, then calculating the concentration in the original sample. The direct microscopic count method uses a counting chamber to directly examine and count bacteria under a microscope. The turbidity count method uses spectrophotometry to measure the light absorbed by a bacterial suspension, which is proportional to the concentration of cells.
This document describes a study conducted by researchers at the University of Puerto Rico at Cayey to identify soil-collected bacteria that could produce novel antibiotic compounds. Soil samples were collected from two sites and diluted to isolate individual bacterial colonies. Colonies showing growth were purified and analyzed using gram staining, freezing, electrophoresis, and tests for antibiotic resistance and production. Initial results identified distinct colony morphologies from the soil samples and showed growth from the undiluted, but not highly diluted, samples. Further analysis of purified colonies is planned to characterize the bacteria and determine their antibiotic properties.
This study investigated methods for detecting biofilm formation in Staphylococcal isolates from neonatal infections. Staphylococci were the most common cause of infection. Three phenotypic methods (tube method, microtiter plate method, Congo red agar) and a genotypic PCR method were used to detect biofilm formation. The tube method had the highest sensitivity and specificity compared to the PCR method. Strong biofilm formers showed higher resistance to vancomycin and meropenem. Both genotypic and phenotypic methods should be used to fully identify biofilm formation in Staphylococci.
Epidemiological marker (serotyping and bacteriocin typing)Santosh Kumar Yadav
This document discusses various epidemiological marker typing methods used to differentiate bacterial strains, including serotyping, bacteriocin typing, and colicin typing. Serotyping is based on antigenic differences expressed on bacterial cell surfaces and has good reproducibility but poor discriminatory power. Bacteriocin typing examines bacteriocin production and susceptibility patterns to distinguish strains. It has fair reproducibility and discriminatory power but some strains are non-typeable. Colicin typing specifically examines colicin production in E. coli strains using a spot culture method with indicator strains. These typing methods can help epidemiological studies and hospital infection control.
The document discusses the Most Probable Number (MPN) technique, which is used to estimate the concentration of viable microorganisms in water samples. It works by inoculating water samples into broth at different dilutions and observing growth, based on the principle of extinction dilution. A positive/negative result is obtained from lactose fermentation tests in broth. These results are interpreted using an MPN table to estimate the number of bacteria per 100ml of water. The document outlines the materials, presumptive test procedure involving broth incubation, confirmatory test using EMB agar plates, and complete test of Gram staining suspicious colonies to identify bacteria like E. coli.
1. There are two main types of bacterial counts - total bacterial count and total viable count. Total bacterial count includes both living and dead cells while total viable count only measures living cells.
2. Bacterial enumeration is important for comparing growth under different conditions, and in industries like dairy, food, and water microbiology.
3. Methods of enumeration include direct counting using microscopy or Coulter counter, and indirect counting of viable cells using serial dilution plating or membrane filtration. Other methods determine cell mass through dry weight, nitrogen content, or turbidity measurements.
1.paola 5.anthony hernandez phages report pdf correctedpcaballero21
This study isolated and characterized a novel mycobacteriophage (bacterial virus) named Incognito from soil in Puerto Rico. Incognito was isolated from soil collected under a plantain tree and purified through plaque purification. Electron microscopy and SDS-PAGE gel electrophoresis were used to characterize the phage's morphology and protein profile. Incognito produced turbid plaques and had a concentration of 3 x 107 plaque forming units per mL. Its protein profile showed similarities to other mycobacteriophages. This study demonstrates that Puerto Rico's tropical environment supports diverse phage populations with potential applications in phage therapy.
TLC Bioautography (TLC as highthrough put screening). Kunal Shimpi
TLC bioautography is technique to isolate compound by chromatography and follow by biological detection system. It content its method, How they work, it's mechanism, advantages, disadvantages, applications and much more.
Onion (Allium Cepa) Genotoxicity Test
Laboratory of Ecotoxicology and LCA
Department of Environmental Chemistry, ICT Prague
References:
1. FERETTI, D., ZERBINI, I., ZANI, C., CERETTI, E., MORETTI,M.,MONARCA, S. (2007): Allium cepa chromosome
abberation and micronucleus tests applied to study genotoxicity of extracts from pesticide-treated vegetables and
grapes. Food Addit. Contam. 24 (6): 561-572.
2. RANK, J., NIELSEN, M.H. (1997): Allium anaphase-telophase genotoxicity assay. Department of Environment,
Technology and Social Studies, Roskilde University, Denmark.
This document describes the development and evaluation of a new medium called Makka medium for screening gram negative bacteria like coliforms in drinking water samples. The researchers developed Makka medium as an economical and safer alternative to the commonly used m-Endo agar medium. Makka medium uses methylene blue as an indicator to inhibit gram positive bacteria and allow growth of gram negatives. Tests showed that Makka medium was comparable to m-Endo agar in detecting coliforms, with coliforms appearing as blue-green colonies on Makka medium. The researchers concluded that Makka medium is recommended for use instead of m-Endo agar for detection of coliforms and gram negative bacteria in water samples due to its low cost
This document summarizes a study conducted by researchers at the University of Puerto Rico at Cayey to identify soil bacteria capable of producing novel antibiotics. Soil samples were collected from two sites and diluted to isolate individual bacterial colonies. Colonies were purified, stained, and had their DNA analyzed. The isolated bacteria were tested for antibiotic resistance and their ability to inhibit the growth of other bacteria, which could indicate antibiotic production. The goal was to find bacteria producing compounds similar to teixobactin, a potent antibiotic discovered from uncultured soil bacteria.
This document describes several methods for enumerating or counting bacteria in a sample, including viable plate count, direct microscopic count, and turbidity count. The viable plate count method involves making serial dilutions of a sample and counting the number of colonies that grow on an agar plate, then multiplying by the dilution factor to determine the concentration in the original sample. The direct microscopic count uses a counting chamber to directly view and count bacteria under a microscope. The turbidity count uses spectrophotometry to measure the turbidity or cloudiness of diluted samples, which correlates to the number of bacteria present based on a generated standard curve. Procedures for each method are provided.
Dióxido de Cloro desinfectant against bacillus anthracisricguer
This document summarizes a study that tested the sporicidal activity of chlorine dioxide disinfectant against Bacillus anthracis spores. When B. anthracis spores were mixed with aqueous chlorine dioxide solution in sealed tubes, there was a high reduction of viable spores of 8 log10 in only 3 minutes. However, spraying or spreading the solution onto surfaces only achieved a 1 log10 reduction, because the chlorine dioxide gas was rapidly vaporized from the solutions. Supplementing the chlorine dioxide solution with 5% bleach restored its full potency and increased its stability for surface decontamination when sprayed.
Identification and Detection of Microorganism esraa alaa
Molecular detection of pathogens (molecular microbiology)
is a new, dynamic and progressive spinoff of classic microbiology. It plays an important role in those clinical situations when standard microbiology (relying on the successful cultivation of potential pathogens) produces suboptimal results or completely fails.
OR
Modern approach for identification and quantification of microorganisms (pathogens) in the diagnostics of infections or foodborne illness using molecular microbiology. Broadest range of available tests and tailor-made packages.
All clinical isolates of Salmonella enterica serovars Typhi and Paratyphi tested were capable of biofilm formation in vitro. The optimized conditions for maximum biofilm formation were adherence test medium incubated at 37°C and 150 rpm for 48 hours. Of the Salmonella Typhi isolates tested, 61% were very strong biofilm producers, 29% were strong producers, and 11% were moderate producers. For Salmonella Paratyphi isolates, 69% were very strong producers, 23% were strong producers, and 8% were moderate producers. The ability of these clinical isolates to form biofilms is concerning from a public health perspective as it could facilitate transmission to new hosts and cause disease.
The document describes three methods for enumerating bacteria: standard plate count, turbidity, and direct microscopic count. The standard plate count method involves serially diluting a bacterial sample, plating the dilutions on agar, incubating the plates, and counting the colonies to calculate colony-forming units (CFUs) per mL. Turbidity measures light absorption by a bacterial suspension to estimate cell concentration. Direct microscopic count directly counts cells in a known volume under a microscope but cannot distinguish live from dead cells.
Bacteriological analysis of drinking water by MPN method.prakashtu
This document describes the MPN (Most Probable Number) method for analyzing drinking water bacteriologically. The MPN method involves inoculating water samples in multiple dilutions into lactose broths to detect coliform bacteria presence. Positive samples are then cultured on EMB agar to isolate and identify E. coli. Confirmed E. coli colonies produce acid and gas when cultured in lactose broth at 44.5°C. The number of positive samples at each dilution level is used with statistical tables to estimate the MPN of coliform bacteria per 100ml of water. This provides a statistical analysis of bacteria levels in drinking water samples.
Chrlorine dioxide inactivation of cryptosporidium parvum oocysts and bacteria...ricguer
This study evaluated the inactivation of Cryptosporidium parvum oocysts and bacterial spore indicators by chlorine dioxide. Two viability methods, in vitro excystation and cell culture infectivity assay, produced significantly different results for C. parvum inactivation, suggesting excystation is not an adequate viability assay. Purified oocysts from three suppliers showed marked differences in resistance to chlorine dioxide inactivation. Ct values required for a 2-log inactivation ranged from 75 to 1,000 mg-min/L depending on the oocyst source. Bacterial spores were more sensitive to chlorine dioxide than C. parvum oocysts and could not be used
Microbiology is the study of microbes that infect humans and cause disease. Sensitivity testing helps determine the most effective antibiotic to treat an infection by testing which antibiotics can inhibit or kill the bacteria causing the infection. The sensitivity test involves culturing bacteria from a sample, identifying the bacteria species, and exposing it to different antibiotics to see which ones prevent its growth. This helps doctors select the appropriate antibiotic for treatment.
Most probable number or multiple tube fermentation techniqueSamsuDeen12
multiple tube fermentation or most probable number is a microbiological technique used to check the portability of water. microbial analysis of water is determined, and distinguished between faecal and non faecal contaminated water.
Isolation of bacteria is a significant step in diagnosing and managing bacterial infections. It involves collecting specimens, preserving and transporting them to the lab, examining samples microscopically, and using various culture and non-culture methods to isolate bacteria. Culture methods include using solid or liquid media, and automated systems, to allow bacterial colonies to grow. Non-culture methods involve molecular techniques like PCR. Proper specimen handling and use of appropriate culture conditions and media allow isolation of pathogenic bacteria to enable treatment and control of infections.
The document summarizes a study conducted by a biology student that found antibiotic-resistant bacteria present in higher numbers in February compared to October at a local daycare center in North Carolina. Swabs were taken from various surfaces in a toddler room in the fall and winter. Five bacterial species showing resistance to multiple antibiotics were identified in October, compared to fourteen species in February. The student used microscopy, biochemical testing, and DNA sequencing to identify the bacteria isolated. The results indicate antibiotic-resistant bacteria pose a legitimate health threat in daycare centers.
The document discusses several methods for enumerating and quantifying bacteria in samples, including viable plate counts, direct microscopic cell counts, and turbidity counts. The viable plate count method involves making serial dilutions of a sample and counting the number of colonies that grow on an agar plate, then calculating the concentration in the original sample. The direct microscopic count method uses a counting chamber to directly examine and count bacteria under a microscope. The turbidity count method uses spectrophotometry to measure the light absorbed by a bacterial suspension, which is proportional to the concentration of cells.
This document describes a study conducted by researchers at the University of Puerto Rico at Cayey to identify soil-collected bacteria that could produce novel antibiotic compounds. Soil samples were collected from two sites and diluted to isolate individual bacterial colonies. Colonies showing growth were purified and analyzed using gram staining, freezing, electrophoresis, and tests for antibiotic resistance and production. Initial results identified distinct colony morphologies from the soil samples and showed growth from the undiluted, but not highly diluted, samples. Further analysis of purified colonies is planned to characterize the bacteria and determine their antibiotic properties.
This study investigated methods for detecting biofilm formation in Staphylococcal isolates from neonatal infections. Staphylococci were the most common cause of infection. Three phenotypic methods (tube method, microtiter plate method, Congo red agar) and a genotypic PCR method were used to detect biofilm formation. The tube method had the highest sensitivity and specificity compared to the PCR method. Strong biofilm formers showed higher resistance to vancomycin and meropenem. Both genotypic and phenotypic methods should be used to fully identify biofilm formation in Staphylococci.
The document describes a lab experiment that tests how the addition of a pGLO plasmid affects the growth and characteristics of E. coli bacteria. The experiment involves transforming E. coli bacteria with the pGLO plasmid by adding it to a solution containing the bacteria. One solution receives the pGLO plasmid (+pGLO) while the other does not (-pGLO). The bacteria are then observed under UV light and incubated under various conditions to analyze effects on growth and gene expression.
This lab report summarizes an experiment that tested the effectiveness of various antibiotics and antiseptics against different bacterial species using the Kirby-Bauer disk diffusion method. Bacterial lawns of four species were created on agar plates. Filter paper disks soaked in different antibiotics were placed on one set of plates, while disks soaked in antiseptics (betadine, glycerol, hydrogen peroxide) were placed on another set. The experiment aimed to observe variations in susceptibility between bacterial species and antimicrobial agents. The results showed differing zones of inhibition providing data on each microbe's response to specific antibiotics and antiseptics.
Antimicrobial susceptibility of isolated E.coli from different water sources ...Sulieman Bahar
This study tested the antimicrobial susceptibility of E.coli isolated from different water sources in Nyala Town, Sudan. E.coli was isolated from 50 water samples using standard methods and tested against 12 commonly used antimicrobial agents. The results showed that the E.coli strains were most sensitive to Ciprofloxacin, Co-Trimoxazole and Chloramphenicol and most resistant to Tetracycline and Ampicillin/Sulbactam. This indicates multiple antibiotic resistant E.coli exist in the water sources of the study area, making the water potentially unsafe for drinking.
Mycobacteriophage Isolation from Tropical Soil Sample: SerotinusKenko95
1. Researchers isolated and purified a mycobacteriophage named Serotinus from a soil sample in Puerto Rico using Mycobacterium smegmatis as the host bacterium.
2. They performed three rounds of plaque purification to obtain a pure phage population, which was then stored at 4°C.
3. Future work will include identifying the phage's genetic information and characteristics, which may lead to important discoveries in modern medicine such as alternative treatments to antibiotic resistant bacteria.
Virulence Phenotype, Physicochemical Properties and Biofilm Formation of Pseu...IJERA Editor
This document summarizes a study characterizing Pseudomonas aeruginosa strains isolated from drinking water distribution systems in Morocco. The study examined the virulence phenotypes, biofilm formation ability, and physicochemical properties of the P. aeruginosa isolates.
The results showed that the isolates expressed a range of virulence factors including proteases, lipases, and hemolysins. Most isolates were motile and able to form biofilms on polyethylene surfaces within 8-12 hours. Physicochemical characterization found the isolates possessed a range of surface properties like hydrophobicity/hydrophilicity that influence their ability to adhere to surfaces. Scanning electron microscopy images showed cell adhesion and biofilm formation on polyethylene over time.
In summary, the study
This document discusses methods for determining cell viability. It defines viability as the capacity for replication over a given timeframe. Methods for counting viable cells include indirect dilution-based techniques where colonies are counted after culturing, and direct techniques like nalidixic acid treatment, fluorogenic dyes, and microradiography that identify viable cells without culturing. A variety of assays can also assess properties of viable cells like integrity, permeability, enzyme content, and energy status to evaluate effects on cell viability.
The study aimed to test the specificity of two antibodies (033 and 1-9E10) for binding the c-myc protein. Human colon carcinoma cells were extracted to obtain cytosolic, nuclear, and nuclear pellet extracts. The 033 antibody bound c-myc in the cytosolic extract at approximately 110 kDa, but the 9E10 antibody did not bind c-myc. This suggests c-myc is not restricted to the nucleus and more research is needed to fully understand c-myc and its role in cancer.
The document describes experiments conducted to identify an unknown microorganism. Samples from two patients, labeled Culture A and Culture B, were tested using a Gram stain. Culture A showed pink rod-shaped bacteria, while Culture B showed round purplish-pink bacteria. An antibiotic test found that chloramphenicol and tetracycline were most effective at inhibiting the growth of both bacterial cultures. Based on the morphological and antibiotic test results, the unknown microorganism was identified as Citrobacter Freundii.
This laboratory report summarizes three experiments conducted by a group of students:
1. Media preparation demonstration - The group prepared two types of nutrient agar media.
2. Isolation of soil bacteria - The group determined the viable titer of soil bacteria by serial dilution and plating, then isolated pure cultures.
3. Staining techniques - The group demonstrated endospore staining of Bacillus and gram staining of an unknown bacterium to identify cell structure.
Two novel mycobacteriophages, dubbed Mikriplithari and Ususindagari, were isolated from a soil sample in Puerto Rico. The soil sample was enriched with Mycobacterium smegmatis to amplify any phages present. Two distinct phage populations were purified through plaque purification and titrated, with Mikriplithari having a titer of 6.00 × 108 pfu/mL and Ususindagari having a titer of 2.60 × 108 pfu/mL. The isolated phages show potential for novel genotypes and phenotypes that could be useful in biomedical applications due to increasing antibiotic resistance.
A mycobacteriophage was isolated from a soil sample collected in Puerto Rico and named Serotinus. The soil sample was enriched with Mycobacterium smegmatis bacteria to encourage phage growth. Plaques were observed, indicating the presence of phages, and three rounds of plaque purification were performed to isolate a pure phage population. Clear plaques formed after the third purification, suggesting Serotinus is a lytic phage. Future work will characterize Serotinus to contribute to the Mycobacteriophage Database.
Methods of collectons of water samples and microbiological (1)Kamal Singh Khadka
This document discusses methods for analyzing drinking water quality by testing for indicator bacteria. It describes the Most Probable Number (MPN) method and Membrane Filtration (MF) method. The MPN method involves diluting water samples and incubating them in growth media to detect coliforms over multiple tubes and steps. The MF method filters water through a membrane to retain bacteria, which are then cultured and counted. Both methods provide quantitative microbiological testing to detect indicator bacteria and assess drinking water safety.
Bioconversion of Penicillin to CephalosporinIOSR Journals
Cephalosporins are known as 3rd generation broad spectrum Beta lactam antibiotics, which can also be produced synthetically. Commonly, chemical ring expansion followed by an enzymatic removal of the phenylacetyl side chain is commonly employed to convert penicillin G into 7-aminodeacetoxycephalosporanic acid, the precursor for the manufacture of semisynthetic cephalosporins. This process requires several steps, is expensive and highly polluting. Thus there is a need to device a simple biological route to replace the chemical process. A mutant of Streptomyces clavuligerus NP1 was reported to converts Penicillin G to Deacetoxycephalosporin G (DAOG;phenylacetyl-7-aminodeacetoxycephalosporanic acid) enzymatically[5,8] . This enzyme, deacetoxycephalosporin synthase has the potential for the large scale transformation of Penicillin G to deacetoxycephalosporin. The present work studies the conditions required for efficient transformation of Penicillin G to Deacetoxycephalosporin using the wild type strain Streptomyces clavuligerus . Detection of cephalosporin was carried out using various methods. Additionally succinic acid formation was also studied as it could be used as a commercially important by product of the transformation. Deacetoxycephalosporin synthase also extracted and partially purified and characterised.
Presentation based on a research article published in the journal scientific reports in 2017, entitled as "A Novel Pathogen Capturing Device for Removal and Detection"
Preliminary evaluation of the larvicidal efficacy of coelomic fluid of Eudril...inventionjournals
International Journal of Pharmaceutical Science Invention (IJPSI) is an international journal intended for professionals and researchers in all fields of Pahrmaceutical Science. IJPSI publishes research articles and reviews within the whole field Pharmacy and Pharmaceutical Science, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
Compact Dry is a ready-to-use test method for counting microorganisms that helps reduce testing time. The plates can be used to test raw materials and finished products for food, beverages, cosmetics, and pharmaceuticals. They can also be used for surface monitoring, especially in hard to reach areas. Colonies grow with different pigmented colors depending on the type of bacteria, allowing for identification. The plates have a long shelf life of up to 24 months and can be easily stored, transported, and incubated within a range of temperatures. Compact Dry combines the features of traditional agar plates with the benefits of dehydrated film media to shorten testing time and increase lab efficiency.
This study examined the differences in biofilm formation capabilities between vancomycin-resistant and ciprofloxacin-resistant Staphylococcus aureus clinical isolates. Six S. aureus isolates from urine samples were tested for antibiotic resistance to vancomycin and ciprofloxacin. Two isolates were resistant to ciprofloxacin and three were resistant to vancomycin based on standard guidelines. A variety of assays were used to analyze biofilm formation, finding that ciprofloxacin-resistant isolates showed moderate biofilm formation, while vancomycin-resistant isolates showed strong biofilm formation. The study concluded that antibiotic-resistant S. aureus clinical isolates displayed differences in their ability to form biofilms.
Anti-Adhesion and Anti-Biofilm Effectiveness of Disinfectants Used In Hemodia...IJERA Editor
Biofilms are communities of microorganisms attached to a surface and included in an extracellular matrix making it resistant to exogenous deleterious agents. The aim of this study is to evaluate the anti-adhesive and anti-biofilm effect of five commercials disinfectants having different active principles (hydrogen peroxide, sodium hypochlorite, isopropyl alcohol and ethanol) on four Staphylococcus strains isolated from hemodialysis unit surfaces. The disinfectants anti-adhesive effect was estimated to an exceeding rate 70% for the various studied dilutions and 90% towards the pure products. Whereas the anti-biofilm effect showed an elimination rate varying between 10 % and 95 % according to the following parameters: active principle, time of contact, concentration and bacterial strain. Our study demonstrated that all tested products have an interesting anti-adhesive effect and that the peroxide of hydrogen is endowed with important anti-biofilm efficiency, followed by the alcoholic products and the sodium hypochlorite.
Similar to EWMA Conference-Ep442-MODELLING WOUND BIOFILMS IN A THERMO-REVERSIBLE MATRIX WITH FLORESCENT MARKERS (20)
EWMA 2014 - EP502 A LABORATORY EVALUATION OF THE BLOOD ABSORPTION PROPERTIES ...EWMA
This study compared the blood absorption properties of 5 surgical dressings (A-E). An in vitro experiment added bovine blood to dressings at a constant rate, measuring absorption capacity and dispersion. Dressing A (Mepilex Border Post-Op) absorbed the largest volume of blood before reaching the dressing edges or leaking, with good dispersion throughout. The results indicate Dressing A will require fewer dressing changes and better protect wounds from contamination compared to the other dressings tested.
EWMA 2014 - EP499 MANAGEMENT OF AN INFECTED DIABETIC FOOT WITH SPECIALIZED DR...EWMA
This document presents two case studies of patients with diabetic foot infections. Both patients, aged 29 and 52, underwent surgical debridement and partial amputation of the infected toes. Controlling the infection and exudate levels in the wounds proved difficult, requiring the use of various antimicrobial dressings over a 4-month period. Through a combination of wound bed preparation, surgical debridement, and specialized dressings, the treatment was ultimately successful in controlling the infections and promoting wound healing.
EWMA 2014 - EP498 USE OF NEGATIVE PRESSURE THERAPY IN CONJUNCTION WITH A PROT...EWMA
Este documento describe el caso de un paciente diabético con una ulcera grave en el pie que fue tratada con éxito mediante la aplicación combinada de terapia de presión negativa y una matriz moduladora de proteasas. El tratamiento promovió el rápido crecimiento de tejido de granulación, permitiendo cubrir las estructuras óseas expuestas y prevenir infecciones. La matriz aceleró la epitelización y contracción de la herida, logrando su cierre total en 60 días. El uso combinado de estas tecnologías es una altern
EWMA 2014 - EP496 CONTEMPORARY SILVER DRESSINGS IN THE TREATMENT OF INFECTED ...EWMA
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This study evaluated two total contact casting (TCC) systems for offloading diabetic foot ulcers and stabilizing Charcot feet in South Africa. System B, which used a washable, water resistant inner lining, demonstrated better patient adherence and aeration compared to System A. Both systems effectively reduced plantar pressures and healed wounds within 36 days on average. The study concluded that TCC is the gold standard for offloading but more training is needed for healthcare professionals to incorporate it widely in practice.
Este estudio buscó detectar factores de riesgo de pie diabético en personas con diabetes mediante consultas de enfermería. Se evaluó a 56 pacientes con diabetes tipo 1 o 2 sin lesiones en los pies. Más del 30% presentaron alto riesgo de desarrollar pie diabético debido a factores como baja escolaridad, falta de educación sobre el cuidado de los pies, antecedentes de úlceras y amputaciones, y calzado y corte de uñas inadecuados. El estudio concluye que es necesario fortalecer
EWMA 2014 - EP490 THE CHARACTERISTICS OF WOUND PAIN ASSOCIATED WITH DIABETES-...EWMA
This study examined the prevalence and characteristics of wound pain in diabetes-related foot ulcers. It found that over 50% of patients reported experiencing wound pain based on formal pain assessment tools, even though some did not report pain to their podiatrist. Pain was described as tender, brief, or intermittent. Both neuropathic and neuroischaemic ulcers had low reported pain intensity and little effect on quality of life. The study concludes wound pain may be underassessed clinically and more research is needed to understand differences in pain between ulcer types.
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This study assessed foot self-care knowledge and practices in 350 Saudi patients with diabetes referred to a specialized diabetes care center. While 42.6% had excellent knowledge of how diabetes affects foot health, only 17.7% demonstrated good ability to identify and apply appropriate foot self-care practices. Most patients acquired knowledge through media rather than primary health care clinics. The quality of knowledge from primary care clinics did not translate to better ability to practice self-care compared to other sources of knowledge. The study concludes current foot self-care education and knowledge is unsatisfactory and calls for a national diabetes control program delivering unified, evidence-based education through healthcare providers and media to prevent limb loss.
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Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
These lecture slides, by Dr Sidra Arshad, offer a quick overview of the physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar lead (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
6. Describe the flow of current around the heart during the cardiac cycle
7. Discuss the placement and polarity of the leads of electrocardiograph
8. Describe the normal electrocardiograms recorded from the limb leads and explain the physiological basis of the different records that are obtained
9. Define mean electrical vector (axis) of the heart and give the normal range
10. Define the mean QRS vector
11. Describe the axes of leads (hexagonal reference system)
12. Comprehend the vectorial analysis of the normal ECG
13. Determine the mean electrical axis of the ventricular QRS and appreciate the mean axis deviation
14. Explain the concepts of current of injury, J point, and their significance
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. Chapter 3, Cardiology Explained, https://www.ncbi.nlm.nih.gov/books/NBK2214/
7. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
Knee anatomy and clinical tests 2024.pdfvimalpl1234
This includes all relevant anatomy and clinical tests compiled from standard textbooks, Campbell,netter etc..It is comprehensive and best suited for orthopaedicians and orthopaedic residents.
Rasamanikya is a excellent preparation in the field of Rasashastra, it is used in various Kushtha Roga, Shwasa, Vicharchika, Bhagandara, Vatarakta, and Phiranga Roga. In this article Preparation& Comparative analytical profile for both Formulationon i.e Rasamanikya prepared by Kushmanda swarasa & Churnodhaka Shodita Haratala. The study aims to provide insights into the comparative efficacy and analytical aspects of these formulations for enhanced therapeutic outcomes.
Local Advanced Lung Cancer: Artificial Intelligence, Synergetics, Complex Sys...Oleg Kshivets
Overall life span (LS) was 1671.7±1721.6 days and cumulative 5YS reached 62.4%, 10 years – 50.4%, 20 years – 44.6%. 94 LCP lived more than 5 years without cancer (LS=2958.6±1723.6 days), 22 – more than 10 years (LS=5571±1841.8 days). 67 LCP died because of LC (LS=471.9±344 days). AT significantly improved 5YS (68% vs. 53.7%) (P=0.028 by log-rank test). Cox modeling displayed that 5YS of LCP significantly depended on: N0-N12, T3-4, blood cell circuit, cell ratio factors (ratio between cancer cells-CC and blood cells subpopulations), LC cell dynamics, recalcification time, heparin tolerance, prothrombin index, protein, AT, procedure type (P=0.000-0.031). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and N0-12 (rank=1), thrombocytes/CC (rank=2), segmented neutrophils/CC (3), eosinophils/CC (4), erythrocytes/CC (5), healthy cells/CC (6), lymphocytes/CC (7), stick neutrophils/CC (8), leucocytes/CC (9), monocytes/CC (10). Correct prediction of 5YS was 100% by neural networks computing (error=0.000; area under ROC curve=1.0).
Basavarajeeyam is an important text for ayurvedic physician belonging to andhra pradehs. It is a popular compendium in various parts of our country as well as in andhra pradesh. The content of the text was presented in sanskrit and telugu language (Bilingual). One of the most famous book in ayurvedic pharmaceutics and therapeutics. This book contains 25 chapters called as prakaranas. Many rasaoushadis were explained, pioneer of dhatu druti, nadi pareeksha, mutra pareeksha etc. Belongs to the period of 15-16 century. New diseases like upadamsha, phiranga rogas are explained.
- Video recording of this lecture in English language: https://youtu.be/kqbnxVAZs-0
- Video recording of this lecture in Arabic language: https://youtu.be/SINlygW1Mpc
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
EWMA Conference-Ep442-MODELLING WOUND BIOFILMS IN A THERMO-REVERSIBLE MATRIX WITH FLORESCENT MARKERS
1. MODELLING WOUND BIOFILMS IN A
THERMO-REVERSIBLE MATRIX WITH
FLUORESCENT MARKERS
Benjamin Taylor1, 2, David Williams1 & Jon Nosworthy3.
1Cardiff University School of Dentistry
2Knowledge Transfer Partnership Associate
3Advanced Medical Solutions plc
2. Fluorescent probes
Today ‘off the shelf’ molecular markers are readily
available to assess bacterial viability.
SYTO®9 (Life Technologies Ltd, Paisley, UK) is a
fluorescent marker which binds nucleic acid
within live cells where it fluoresces green (light
wavelength 500 nm in live microorganisms) when
excited by light at 480nm.
What is a thermo-reversible matrix?
Poloxamer (Poloxamer 407: Sigma-Aldrich
company Ltd, Dorset, UK) is an inert powdered
polymer which can be dissolved into standard
bacteriological culture broth such as Muller-
Hinton or Tryptone Soya Broth.
The dissolved Poloxamer forms a semi-firm gel
matrix at temperatures > ≈ 15oC and liquefies < ≈
15oC.
It has been suggested that organisms inoculated
and suspended in a Poloxamer matrix form
microcolonies with a biofilm phenotype (Gilbert
et al., 1998; Clutterbuck et al., 2007; Yamanda et
al., 2011).
Aims:
• Develop a simple fluorescent in vitro model
able to support bacterial cells as a biofilm
phenotype.
• Use the test model to examine potential
antibiofilm compounds for antibiofilm activity
using fluorescence as an indicator.
Introduction
Image 1: Confocal image of P. aeruginosa stained
with SYTO®9 fluorescing at 500 nm.
3. Preparing Poloxamer biofilms
A B
C
D
1 2
A) 1) A standardised culture of P. aeruginosa (ATCC 9027) and 2)
Tryptone Soya Broth (TSB) + 30 % Poloxamer was prepared.
B) A sample of P. aeruginosa was inoculated into cooled (<15oC) TSB +
Poloxamer and thoroughly homogenised.
C) A 250-µL sample was then added to 1.5ml centrifuge tubes, avoiding
the formation of air bubbles.
D) All centrifuge tubes were incubated (with lids open) at 35oC for 24
hours in 60% relative humidity to prevent drying.
4. Extracting biofilm cells from Poloxamer
E F G
H
E) The ‘biofilm tubes’ were removed from the incubator and
‘flash cooled’ at -70oC for 2-3 minutes to liquefy the poloxamer.
F) A 500-µL volume of chilled (5-6oC) sodium chloride peptone
broth was added and homogenised into each biofilm tube.
G) All tubes were centrifuged at 3000 g for 5 minutes.
H) The supernatant was discarded and procedure F, G and H
repeated if necessary.
5. Testing novel antibiofilm compounds against extracted cells
I J K
L
M
I) A 100-µL dilution of antibiofilm compound was
added to extracted cells for a given time.
J) The antibiofilm compounds were washed out
with neutralisers.
K) Cells were re-suspended in equal volumes of
buffer and SYTO 9® live fluorescent stain.
L) 100-µL samples were dispensed into a clear-
bottom black 96-well plate and incubated at 21oC
for 15 minutes in the dark.
M) Fluorescence and data was captured by
excitation/emission scanning at 480/500 nm
wavelengths .
Note: Steps D to M were repeated for P.
aeruginosa grown in TSB as a planktonic control.
6. Results
Anti-biofilm compound A
50 100 150 200 250 300 350 400 450 500 550
-50
-40
-30
-20
-10
0
10
20
30
Time (seconds)
%changeRFU*
(emissionat500nm)
Figure 1. Kill rates of P. aeruginosa when exposed to antibiofilm compound A.
Black line = biofilm control (TSB + 30% poloxamer + Sterile H2O). Blue line = biofilm test (TSB + 30%
poloxamer + compound A). Green line = planktonic control (TSB + Sterile H2O). Red line = planktonic
test (TSB + compound A). Error bars show ± SEM (n=14; 2 biofilm/planktonic samples read at 7
different spatial points). *Relative Florescent Units.
7. Anti-biofilm compound B
50 100 150 200 250 300 350 400 450 500 550
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
Time (seconds)
%changeRFU*
(emissionat500nm)
Figure 2. Kill rates of P. aeruginosa when exposed to antibiofilm compound B.
Black line = biofilm control (TSB + 30% poloxamer + Sterile H2O). Blue line = biofilm test (TSB + 30%
poloxamer + compound B). Green line = planktonic control (TSB + Sterile H2O). Red line = planktonic
test (TSB + compound B). Error bars show ± SEM (n=14; 2 biofilm/planktonic samples read at 7
different spatial points). *Relative Florescent Units.
8. Anti-biofilm compound C
50 100 150 200 250 300 350 400 450 500 550
-80
-70
-60
-50
-40
-30
-20
-10
0
10
Time (seconds)
%changeRFU*
(emissionat500nm)
Figure 3. Kill rates of P. aeruginosa when exposed to antibiofilm compound C.
Black line = biofilm control (TSB + 30% poloxamer + Sterile H2O). Blue line = biofilm test (TSB +
30% poloxamer + compound C). Green line = planktonic control (TSB + Sterile H2O). Red line =
planktonic test (TSB + compound C). Error bars show ± SEM (n=14; 2 biofilm/planktonic
samples read at 7 different spatial points). *Relative Florescent Units.
9. Anti-biofilm compound D
50 100 150 200 250 300 350 400 450 500 550
-70
-60
-50
-40
-30
-20
-10
0
Time (seconds)
%changeRFU*
(emissionat500nm)
Figure 4. Kill rates of P. aeruginosa when exposed to antibiofilm compound D.
Black line = biofilm control (TSB + 30% poloxamer + Sterile H2O). Blue line = biofilm test (TSB +
30% poloxamer + compound D). Green line = planktonic control (TSB + Sterile H2O). Red line =
planktonic test (TSB + compound D). Error bars show ± SEM (n=14; 2 biofilm/planktonic samples
read at 7 different spatial points). *Relative Florescent Units.
10. Summary
• The use of Poloxamer grown biofilm cells could be a useful tool for screening potential
antibiofilm compounds.
• Using Poloxamer grown biofilms enabled the examination of 4 novel compounds to be
assessed for potential activity against P. aeruginosa biofilms.
• Comparisons of biofilm and planktonic curves demonstrated that planktonic P. aeruginosa
had more rapid reduction in fluorescence compared to biofilm cells after exposure to
antimicrobials.
• This method highlights the known increased tolerance to antimicrobials observed in biofilm
developed cells.
• This method can readily be expanded to cover a wide range of pathogenic organisms from
wounds including multi-drug resistant organisms, anaerobes, yeasts and mixed culture
consortia.
Acknowledgements
• The authors wish to acknowledge the support received by a Knowledge Transfer Partnership (KTP)
program to facilitate this research.
References
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• Yamada H, Koike N, Ehara T & Matsumoto T (2011) Measuring antimicrobial susceptibility of Pseudomonas
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