Streptococcus organisms include Streptococcus pneumoniae and Streptococcus pyogenes. S. pneumoniae is a leading cause of pneumonia, particularly in young and old individuals, and can also cause bacteremia, meningitis, and middle ear infections. It is normally found in the nasopharynx of 10-30% of healthy individuals. S. pyogenes causes pharyngitis and skin infections like impetigo and can lead to post-streptococcal diseases including rheumatic fever and glomerulonephritis. Both are gram-positive bacteria that are identified using culture, microscopy and serological techniques.
This document discusses streptococci and enterococci bacteria, including their classification, pathogenic properties, and roles in causing diseases. It focuses on Streptococcus pyogenes, Streptococcus pneumoniae, and their mechanisms of pathogenesis. Key points include:
1) S. pyogenes is β-hemolytic and a cause of pharyngitis and impetigo. Virulence factors include M protein, hyaluronic acid capsule, and exotoxins which aid adhesion, antiphagocytosis, and tissue damage.
2) S. pneumoniae is a gram-positive diplococcus and a cause of pneumonia. It is encapsulated in one of over 90 serotypes and uses this capsule to
This document discusses the genus Neisseria, focusing on Neisseria gonorrhoeae which causes gonorrhea. It describes the morphology, growth characteristics, antigenic structure, transmission, clinical manifestations, diagnosis and treatment of N. gonorrhoeae. Key points include: N. gonorrhoeae are gram-negative diplococci that grow best at 35-36C with 5-10% CO2; transmission occurs through sexual contact; symptoms vary depending on infection site but can include urethritis, cervicitis, and pelvic inflammatory disease; diagnosis involves microscopy, culture, biochemical tests and serology; and treatment guidelines are regularly updated due to increasing antibiotic resistance.
This document provides an overview of Streptococcus pneumoniae (pneumococcus). It is a gram-positive lance-shaped diplococcus that is a normal inhabitant of the upper respiratory tract. It causes pneumonia and other respiratory infections. Key characteristics include being bile soluble, optochin sensitive, and having a polysaccharide capsule that allows for serotyping. It is treated with penicillin but antibiotics resistance is a concern. Vaccines can help prevent pneumococcal disease.
Streptococcus pyogenes, also known as Group A Streptococcus, is a common human pathogen. It causes a variety of infections including pyogenic infections, pharyngitis, impetigo, erysipelas, necrotizing fasciitis, and can lead to post-infectious complications like rheumatic fever and glomerulonephritis. S. pyogenes is a Gram-positive coccus that grows in chains and produces several virulence factors like streptolysins and pyrogenic exotoxins that contribute to its pathogenicity. It is identified through culture, antigen detection, and serological tests. Treatment involves penicillin and prevention focuses on vaccination to reduce rheumatic fever
Staphylococcus epidermidis is an opportunistic pathogen that commonly forms biofilms on medical devices. These biofilms make infections very difficult to treat as bacteria in biofilms are up to 1000 times more resistant to antibiotics. The document discusses various strategies to control S. epidermidis biofilms, including using antibiotic combinations to prevent resistance development, targeting mechanisms of biofilm antibiotic resistance, and exploring natural compounds and their synergistic effects with antibiotics.
The document discusses Enterococci, including its natural habitats, morphology, general properties, medically important species, culture characteristics, virulence factors, pathogenicity, laboratory diagnosis, biochemical tests, Lancefield grouping, antibiotic resistance, and treatment options. Key points include that Enterococci normally inhabit the intestinal tract, oral cavity, and vaginal canal of humans and animals. The most common medically important species that cause nosocomial infections are Enterococcus faecalis and E. faecium. Laboratory identification involves culture, biochemical tests like catalase and sugar fermentation reactions, and determining Lancefield grouping. Antibiotic resistance is a concern, especially for vancomycin and penicillin.
Pathogenic mechanishm of group a streptococcusHamna Sadaf
Group A Streptococcus (GAS) causes infections ranging from mild to severe through multiple virulence mechanisms. GAS adheres to host surfaces using proteins like M protein and pili. It resists innate immunity through factors inhibiting complement deposition and neutrophil killing, like the hyaluronic acid capsule. GAS also degrades antibodies and antimicrobial peptides using enzymes like SpeB. Together, these redundant mechanisms allow GAS to colonize diverse tissues and spread through the host.
This document provides a taxonomic classification of various bacteria, organized by their gram staining characteristics and other properties. It discusses gram positive non-spore forming bacilli like Mycobacterium, Corynebacterium, Lactobacillus, Erysipelothrix, and Listeria. It also covers gram positive spore forming bacilli such as Bacillus, Clostridium, and anaerobic bacteria. Finally it summarizes some characteristics of gram negative bacilli.
This document discusses streptococci and enterococci bacteria, including their classification, pathogenic properties, and roles in causing diseases. It focuses on Streptococcus pyogenes, Streptococcus pneumoniae, and their mechanisms of pathogenesis. Key points include:
1) S. pyogenes is β-hemolytic and a cause of pharyngitis and impetigo. Virulence factors include M protein, hyaluronic acid capsule, and exotoxins which aid adhesion, antiphagocytosis, and tissue damage.
2) S. pneumoniae is a gram-positive diplococcus and a cause of pneumonia. It is encapsulated in one of over 90 serotypes and uses this capsule to
This document discusses the genus Neisseria, focusing on Neisseria gonorrhoeae which causes gonorrhea. It describes the morphology, growth characteristics, antigenic structure, transmission, clinical manifestations, diagnosis and treatment of N. gonorrhoeae. Key points include: N. gonorrhoeae are gram-negative diplococci that grow best at 35-36C with 5-10% CO2; transmission occurs through sexual contact; symptoms vary depending on infection site but can include urethritis, cervicitis, and pelvic inflammatory disease; diagnosis involves microscopy, culture, biochemical tests and serology; and treatment guidelines are regularly updated due to increasing antibiotic resistance.
This document provides an overview of Streptococcus pneumoniae (pneumococcus). It is a gram-positive lance-shaped diplococcus that is a normal inhabitant of the upper respiratory tract. It causes pneumonia and other respiratory infections. Key characteristics include being bile soluble, optochin sensitive, and having a polysaccharide capsule that allows for serotyping. It is treated with penicillin but antibiotics resistance is a concern. Vaccines can help prevent pneumococcal disease.
Streptococcus pyogenes, also known as Group A Streptococcus, is a common human pathogen. It causes a variety of infections including pyogenic infections, pharyngitis, impetigo, erysipelas, necrotizing fasciitis, and can lead to post-infectious complications like rheumatic fever and glomerulonephritis. S. pyogenes is a Gram-positive coccus that grows in chains and produces several virulence factors like streptolysins and pyrogenic exotoxins that contribute to its pathogenicity. It is identified through culture, antigen detection, and serological tests. Treatment involves penicillin and prevention focuses on vaccination to reduce rheumatic fever
Staphylococcus epidermidis is an opportunistic pathogen that commonly forms biofilms on medical devices. These biofilms make infections very difficult to treat as bacteria in biofilms are up to 1000 times more resistant to antibiotics. The document discusses various strategies to control S. epidermidis biofilms, including using antibiotic combinations to prevent resistance development, targeting mechanisms of biofilm antibiotic resistance, and exploring natural compounds and their synergistic effects with antibiotics.
The document discusses Enterococci, including its natural habitats, morphology, general properties, medically important species, culture characteristics, virulence factors, pathogenicity, laboratory diagnosis, biochemical tests, Lancefield grouping, antibiotic resistance, and treatment options. Key points include that Enterococci normally inhabit the intestinal tract, oral cavity, and vaginal canal of humans and animals. The most common medically important species that cause nosocomial infections are Enterococcus faecalis and E. faecium. Laboratory identification involves culture, biochemical tests like catalase and sugar fermentation reactions, and determining Lancefield grouping. Antibiotic resistance is a concern, especially for vancomycin and penicillin.
Pathogenic mechanishm of group a streptococcusHamna Sadaf
Group A Streptococcus (GAS) causes infections ranging from mild to severe through multiple virulence mechanisms. GAS adheres to host surfaces using proteins like M protein and pili. It resists innate immunity through factors inhibiting complement deposition and neutrophil killing, like the hyaluronic acid capsule. GAS also degrades antibodies and antimicrobial peptides using enzymes like SpeB. Together, these redundant mechanisms allow GAS to colonize diverse tissues and spread through the host.
This document provides a taxonomic classification of various bacteria, organized by their gram staining characteristics and other properties. It discusses gram positive non-spore forming bacilli like Mycobacterium, Corynebacterium, Lactobacillus, Erysipelothrix, and Listeria. It also covers gram positive spore forming bacilli such as Bacillus, Clostridium, and anaerobic bacteria. Finally it summarizes some characteristics of gram negative bacilli.
The document discusses various opportunistic mycoses caused by fungi that are normally present on the human body or in the environment. It notes that such infections typically occur in immunocompromised individuals. Specific mycoses covered include candidiasis caused by Candida albicans, aspergillosis caused by Aspergillus fumigatus, penicilliosis caused by Penicillium marneffei, and mucormycosis caused by fungi of the order Mucorales such as Mucor. The document also discusses mycotoxicosis caused by ingestion of toxins like aflatoxins produced by some fungi that contaminate foods like peanuts.
Streptococcus is a genus of gram-positive coccus or spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales, in the phylum Firmicutes. Cell division in streptococci occurs along a single axis, so as they grow, they tend to form pairs or chains that may appear bent or twisted
This document discusses Streptococcus, including:
1. It describes the morphology, classification, cultural characteristics, and biochemical reactions of Streptococcus.
2. It outlines several toxins and virulence factors produced by Streptococcus pyogenes, including streptolysins, pyrogenic exotoxins, streptokinase, deoxyribonucleases, and hyaluronidase.
3. It discusses the pathogenicity of Streptococcus in suppurative infections like pharyngitis, impetigo, and necrotizing fasciitis, as well as non-suppurative sequelae including acute rheumatic fever and acute glomerulonephritis.
Citrobacter is a genus of Gram-negative bacteria that is commonly found in soil, water, and the intestinal tract of humans and animals. While usually harmless, some Citrobacter species can cause opportunistic infections, especially in immunocompromised patients. Citrobacter freundii is one of the most clinically significant species, known to cause infections of the urinary tract, respiratory tract, blood, and central nervous system. It has developed resistance to many antibiotics. Citrobacter infections in neonates can be serious, with meningitis being particularly dangerous. Diagnosis involves blood and CSF cultures, while treatment requires a combination of antibiotics and sometimes surgery.
Pneumococcus, also known as Streptococcus pneumoniae, are normal inhabitants of the upper respiratory tract that can cause pneumonia and ear infections. They are gram-positive cocci arranged in pairs or chains. Identification involves testing for morphology, culture characteristics like alpha-hemolysis on blood agar and bile solubility. There are over 90 serotypes classified by their polysaccharide capsule which is a major virulence factor and basis for vaccines. Pneumonia results from inhalation of the bacteria when immunity is low, often following a viral infection.
Streptococcus is a genus of bacteria that includes several species that are pathogens. They are spherical, gram-positive cocci that can be α-hemolytic, β-hemolytic, or non-hemolytic. Important pathogenic species include Streptococcus pyogenes (group A streptococcus), a cause of pharyngitis and skin infections, and Streptococcus agalactiae (group B streptococcus), a cause of neonatal sepsis and meningitis. Enterococcus faecalis is a frequent cause of hospital-acquired infections like urinary tract infections. Viridans streptococci commonly cause infective endocarditis. Identification involves culturing samples and observing hemolysis and sensitivity to antibiotics like bac
Streptococcus are Gram-positive cocci that form chains. They include pathogenic and commensal species. S. pyogenes is a beta-hemolytic streptococcus of Lancefield group A that causes pyogenic infections like tonsillitis and scarlet fever. It produces toxins like streptolysins and pyrogenic exotoxins. Rheumatic fever and acute glombulonephritis are non-suppurative complications of S. pyogenes infections. S. pneumoniae is a common cause of pneumonia and meningitis. It is an alpha-hemolytic encapsulated diplococcus that is bile soluble and optochin sensitive. Identification involves culture, Gram stain, biochemical tests and serotyping
S. pyogenes, or group A streptococcus, is a gram-positive bacterium known to cause a variety of infections. It appears in chains and is capsulated. It is sensitive to bacitracin and produces positive reactions to PYR tests and negative reactions to catalase and ribose fermentation tests. It possesses M proteins and other antigens that allow it to evade the immune system. It produces various toxins and enzymes that contribute to its virulence. Common manifestations include pharyngitis, impetigo, cellulitis, erysipelas, necrotizing fasciitis, and non-suppurative complications like rheumatic fever and glomerulonephritis. Diagn
Streptococcus pneumoniae is a gram-positive diplococcal bacterium that is a normal resident of the upper respiratory tract. It can cause pneumonia as well as other infections when it spreads from the nose and throat to the lungs or other body sites. It has a polysaccharide capsule that allows it to evade phagocytosis by white blood cells. There are over 90 known serotypes based on differences in capsular antigens. S. pneumoniae was first isolated in the 1880s and techniques for identifying and typing strains based on capsular reactions were developed in the early 20th century. It remains an important cause of community-acquired pneumonia.
This document discusses the prevalence of vancomycin-resistant enterococci (VRE) in hospitalized patients in Islamabad and Rawalpindi, Pakistan. It describes how 133 clinical samples were collected from three hospitals and cultured to isolate enterococci species. The enterococci isolates were then tested for vancomycin resistance using selective media. Antibiotic susceptibility testing and minimum inhibitory concentration determination were performed on the vancomycin-resistant enterococci isolates to evaluate resistance patterns.
This document discusses Group B and D streptococci, including their taxonomy, description, epidemiology, clinical significance, and laboratory diagnosis. It focuses on Streptococcus agalactiae (Group B streptococcus) and Enterococcus (Group D streptreptococcus).
Group B streptococcus is a leading cause of neonatal infections. It commonly causes early-onset meningitis in newborns. Proper screening and treatment of colonized mothers during pregnancy can help prevent early-onset neonatal infections. Identification involves culturing vaginal/rectal swabs in selective broth followed by plating on blood agar. Phenotypic tests like CAMP and hippurate hydrolysis are used to identify S. agalactiae.
This document discusses the classification, morphology, culture characteristics, pathogenicity, and prevention of streptococci bacteria. It describes how streptococci are classified based on their hemolytic properties and cell wall antigens. Key points include that Group A streptococci cause diseases like strep throat, scarlet fever, and rheumatic fever, while enterococci can cause endocarditis. Prevention involves treating Group A strep pharyngitis with penicillin to prevent rheumatic fever.
This document summarizes information about streptococci and Streptococcus pneumoniae (pneumococcus). It describes their characteristics including being gram positive cocci that may appear in chains or pairs and are catalase negative. It discusses distinguishing streptococci from staphylococci and classifying streptococci based on hemolysis and groups A, B, C, D, F, and G. For pneumococcus, key points are that it is a normal respiratory tract commensal but an important cause of pneumonia and otitis media, having distinguishing morphology, optochin sensitivity, and a capsule visible with quellung reaction. Pneumococcal disease manifestations include pneumonia, bacteremia, and mening
This document discusses the classification, structure, virulence factors, and important pathogens of the genus Streptococcus. It describes how streptococci are classified based on their hemolytic properties and Lancefield grouping. Key pathogens like S. pyogenes and S. pneumoniae are then discussed in more detail, outlining their morphology, culture characteristics, toxins/enzymes, mechanisms of pathogenesis, associated diseases, and treatment approaches.
A 63-year-old male presents with worsening cough, wheezing, and shortness of breath over the past 5 days. On examination, he has a congested cough, wheezing on expiration, and rhonchi in the right lower chest. He has a history of smoking for 30 years and hypertension. Diagnostic testing is being considered to evaluate for possible pneumonia. Streptococcus pneumoniae is a leading cause of community-acquired pneumonia. It is a gram-positive cocci that can be identified through culture, antigen detection, and molecular methods to guide appropriate antibiotic treatment.
Streptococcus pyogenes is a Gram-positive bacterium that can cause a variety of infections in humans. It commonly colonizes the throat and skin. It produces toxins and enzymes that contribute to its virulence and ability to cause disease. S. pyogenes can cause suppurative infections like pharyngitis, impetigo, and necrotizing fasciitis. It can also cause non-suppurative sequelae after infection like acute rheumatic fever and glomerulonephritis. Diagnosis involves culturing samples on blood agar and testing for sensitivity to bacitracin. Treatment involves antibiotics like penicillin. Prevention focuses on proper treatment of streptococcal infections to reduce risk of
Stenotrophomonas is a genus of Gram-negative, aerobic bacteria. It includes the species S. maltophilia, S. africana, and S. nitritireducens. S. maltophilia is an opportunistic pathogen that can cause various infections in humans. It is resistant to many antibiotics but susceptible to trimethoprim-sulfamethoxazole and ticarcillin-clavulanic acid. Laboratory diagnosis of S. maltophilia involves culturing on MacConkey agar and testing for biochemical properties such as being catalase-positive and oxidase-negative.
This document discusses Streptococcus pneumoniae, the bacterium that causes pneumococcal infections. It describes the gram-positive diplococcal morphology of S. pneumoniae and its requirement for enriched media and CO2 for growth. Key virulence factors include an encapsulating polysaccharide that is antiphagocytic. S. pneumoniae can cause infections of the respiratory tract as well as meningitis, endocarditis, and peritonitis. Laboratory diagnosis involves isolating the bacteria from sputum, CSF, or blood samples and identifying alpha-hemolytic colonies that are sensitive to optochin, confirming S. pneumoniae. Treatment involves various antibiotics like penicillins, cephalosporins, and
HIV is a retrovirus with an RNA genome that causes AIDS. It has two types, HIV-1 which causes the worldwide pandemic and HIV-2 which is found mainly in West Africa. HIV-1 has many subtypes that differ in their geographic distribution. The virus has an outer membrane with glycoprotein spikes that allow it to bind to and enter host cells. It contains enzymes like reverse transcriptase and integrase that help its replication cycle of binding to host cells, integrating its genetic material into the host DNA, producing new viral proteins and particles, and ultimately destroying CD4 cells and weakening the immune system. Antiretroviral drugs target specific stages of this replication cycle to suppress the virus.
The document discusses various opportunistic mycoses caused by fungi that are normally present on the human body or in the environment. It notes that such infections typically occur in immunocompromised individuals. Specific mycoses covered include candidiasis caused by Candida albicans, aspergillosis caused by Aspergillus fumigatus, penicilliosis caused by Penicillium marneffei, and mucormycosis caused by fungi of the order Mucorales such as Mucor. The document also discusses mycotoxicosis caused by ingestion of toxins like aflatoxins produced by some fungi that contaminate foods like peanuts.
Streptococcus is a genus of gram-positive coccus or spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales, in the phylum Firmicutes. Cell division in streptococci occurs along a single axis, so as they grow, they tend to form pairs or chains that may appear bent or twisted
This document discusses Streptococcus, including:
1. It describes the morphology, classification, cultural characteristics, and biochemical reactions of Streptococcus.
2. It outlines several toxins and virulence factors produced by Streptococcus pyogenes, including streptolysins, pyrogenic exotoxins, streptokinase, deoxyribonucleases, and hyaluronidase.
3. It discusses the pathogenicity of Streptococcus in suppurative infections like pharyngitis, impetigo, and necrotizing fasciitis, as well as non-suppurative sequelae including acute rheumatic fever and acute glomerulonephritis.
Citrobacter is a genus of Gram-negative bacteria that is commonly found in soil, water, and the intestinal tract of humans and animals. While usually harmless, some Citrobacter species can cause opportunistic infections, especially in immunocompromised patients. Citrobacter freundii is one of the most clinically significant species, known to cause infections of the urinary tract, respiratory tract, blood, and central nervous system. It has developed resistance to many antibiotics. Citrobacter infections in neonates can be serious, with meningitis being particularly dangerous. Diagnosis involves blood and CSF cultures, while treatment requires a combination of antibiotics and sometimes surgery.
Pneumococcus, also known as Streptococcus pneumoniae, are normal inhabitants of the upper respiratory tract that can cause pneumonia and ear infections. They are gram-positive cocci arranged in pairs or chains. Identification involves testing for morphology, culture characteristics like alpha-hemolysis on blood agar and bile solubility. There are over 90 serotypes classified by their polysaccharide capsule which is a major virulence factor and basis for vaccines. Pneumonia results from inhalation of the bacteria when immunity is low, often following a viral infection.
Streptococcus is a genus of bacteria that includes several species that are pathogens. They are spherical, gram-positive cocci that can be α-hemolytic, β-hemolytic, or non-hemolytic. Important pathogenic species include Streptococcus pyogenes (group A streptococcus), a cause of pharyngitis and skin infections, and Streptococcus agalactiae (group B streptococcus), a cause of neonatal sepsis and meningitis. Enterococcus faecalis is a frequent cause of hospital-acquired infections like urinary tract infections. Viridans streptococci commonly cause infective endocarditis. Identification involves culturing samples and observing hemolysis and sensitivity to antibiotics like bac
Streptococcus are Gram-positive cocci that form chains. They include pathogenic and commensal species. S. pyogenes is a beta-hemolytic streptococcus of Lancefield group A that causes pyogenic infections like tonsillitis and scarlet fever. It produces toxins like streptolysins and pyrogenic exotoxins. Rheumatic fever and acute glombulonephritis are non-suppurative complications of S. pyogenes infections. S. pneumoniae is a common cause of pneumonia and meningitis. It is an alpha-hemolytic encapsulated diplococcus that is bile soluble and optochin sensitive. Identification involves culture, Gram stain, biochemical tests and serotyping
S. pyogenes, or group A streptococcus, is a gram-positive bacterium known to cause a variety of infections. It appears in chains and is capsulated. It is sensitive to bacitracin and produces positive reactions to PYR tests and negative reactions to catalase and ribose fermentation tests. It possesses M proteins and other antigens that allow it to evade the immune system. It produces various toxins and enzymes that contribute to its virulence. Common manifestations include pharyngitis, impetigo, cellulitis, erysipelas, necrotizing fasciitis, and non-suppurative complications like rheumatic fever and glomerulonephritis. Diagn
Streptococcus pneumoniae is a gram-positive diplococcal bacterium that is a normal resident of the upper respiratory tract. It can cause pneumonia as well as other infections when it spreads from the nose and throat to the lungs or other body sites. It has a polysaccharide capsule that allows it to evade phagocytosis by white blood cells. There are over 90 known serotypes based on differences in capsular antigens. S. pneumoniae was first isolated in the 1880s and techniques for identifying and typing strains based on capsular reactions were developed in the early 20th century. It remains an important cause of community-acquired pneumonia.
This document discusses the prevalence of vancomycin-resistant enterococci (VRE) in hospitalized patients in Islamabad and Rawalpindi, Pakistan. It describes how 133 clinical samples were collected from three hospitals and cultured to isolate enterococci species. The enterococci isolates were then tested for vancomycin resistance using selective media. Antibiotic susceptibility testing and minimum inhibitory concentration determination were performed on the vancomycin-resistant enterococci isolates to evaluate resistance patterns.
This document discusses Group B and D streptococci, including their taxonomy, description, epidemiology, clinical significance, and laboratory diagnosis. It focuses on Streptococcus agalactiae (Group B streptococcus) and Enterococcus (Group D streptreptococcus).
Group B streptococcus is a leading cause of neonatal infections. It commonly causes early-onset meningitis in newborns. Proper screening and treatment of colonized mothers during pregnancy can help prevent early-onset neonatal infections. Identification involves culturing vaginal/rectal swabs in selective broth followed by plating on blood agar. Phenotypic tests like CAMP and hippurate hydrolysis are used to identify S. agalactiae.
This document discusses the classification, morphology, culture characteristics, pathogenicity, and prevention of streptococci bacteria. It describes how streptococci are classified based on their hemolytic properties and cell wall antigens. Key points include that Group A streptococci cause diseases like strep throat, scarlet fever, and rheumatic fever, while enterococci can cause endocarditis. Prevention involves treating Group A strep pharyngitis with penicillin to prevent rheumatic fever.
This document summarizes information about streptococci and Streptococcus pneumoniae (pneumococcus). It describes their characteristics including being gram positive cocci that may appear in chains or pairs and are catalase negative. It discusses distinguishing streptococci from staphylococci and classifying streptococci based on hemolysis and groups A, B, C, D, F, and G. For pneumococcus, key points are that it is a normal respiratory tract commensal but an important cause of pneumonia and otitis media, having distinguishing morphology, optochin sensitivity, and a capsule visible with quellung reaction. Pneumococcal disease manifestations include pneumonia, bacteremia, and mening
This document discusses the classification, structure, virulence factors, and important pathogens of the genus Streptococcus. It describes how streptococci are classified based on their hemolytic properties and Lancefield grouping. Key pathogens like S. pyogenes and S. pneumoniae are then discussed in more detail, outlining their morphology, culture characteristics, toxins/enzymes, mechanisms of pathogenesis, associated diseases, and treatment approaches.
A 63-year-old male presents with worsening cough, wheezing, and shortness of breath over the past 5 days. On examination, he has a congested cough, wheezing on expiration, and rhonchi in the right lower chest. He has a history of smoking for 30 years and hypertension. Diagnostic testing is being considered to evaluate for possible pneumonia. Streptococcus pneumoniae is a leading cause of community-acquired pneumonia. It is a gram-positive cocci that can be identified through culture, antigen detection, and molecular methods to guide appropriate antibiotic treatment.
Streptococcus pyogenes is a Gram-positive bacterium that can cause a variety of infections in humans. It commonly colonizes the throat and skin. It produces toxins and enzymes that contribute to its virulence and ability to cause disease. S. pyogenes can cause suppurative infections like pharyngitis, impetigo, and necrotizing fasciitis. It can also cause non-suppurative sequelae after infection like acute rheumatic fever and glomerulonephritis. Diagnosis involves culturing samples on blood agar and testing for sensitivity to bacitracin. Treatment involves antibiotics like penicillin. Prevention focuses on proper treatment of streptococcal infections to reduce risk of
Stenotrophomonas is a genus of Gram-negative, aerobic bacteria. It includes the species S. maltophilia, S. africana, and S. nitritireducens. S. maltophilia is an opportunistic pathogen that can cause various infections in humans. It is resistant to many antibiotics but susceptible to trimethoprim-sulfamethoxazole and ticarcillin-clavulanic acid. Laboratory diagnosis of S. maltophilia involves culturing on MacConkey agar and testing for biochemical properties such as being catalase-positive and oxidase-negative.
This document discusses Streptococcus pneumoniae, the bacterium that causes pneumococcal infections. It describes the gram-positive diplococcal morphology of S. pneumoniae and its requirement for enriched media and CO2 for growth. Key virulence factors include an encapsulating polysaccharide that is antiphagocytic. S. pneumoniae can cause infections of the respiratory tract as well as meningitis, endocarditis, and peritonitis. Laboratory diagnosis involves isolating the bacteria from sputum, CSF, or blood samples and identifying alpha-hemolytic colonies that are sensitive to optochin, confirming S. pneumoniae. Treatment involves various antibiotics like penicillins, cephalosporins, and
HIV is a retrovirus with an RNA genome that causes AIDS. It has two types, HIV-1 which causes the worldwide pandemic and HIV-2 which is found mainly in West Africa. HIV-1 has many subtypes that differ in their geographic distribution. The virus has an outer membrane with glycoprotein spikes that allow it to bind to and enter host cells. It contains enzymes like reverse transcriptase and integrase that help its replication cycle of binding to host cells, integrating its genetic material into the host DNA, producing new viral proteins and particles, and ultimately destroying CD4 cells and weakening the immune system. Antiretroviral drugs target specific stages of this replication cycle to suppress the virus.
The document discusses the classification, identification, and clinical significance of streptococci and enterococci bacteria. It describes how they are classified based on their hemolysis, Lancefield grouping, and other biochemical tests. Key genera include Streptococcus, Enterococcus, and Streptococcus milleri group. Identification involves cultural characteristics, catalase testing, and antibiotic sensitivity patterns. Clinically important species are S. pyogenes (GAS) which can cause strep throat, scarlet fever, and rheumatic fever.
1. A Punnett square is used to predict the possible combinations of alleles in offspring from known parental genotypes. It represents the gametes and possible zygotes from a genetic cross.
2. A Punnett square example shows a cross between a heterozygous parent (Tt) and a homozygous recessive parent (tt). It predicts that the offspring will be in a 3:1 ratio of tall to short phenotypes.
3. Probabilities from Punnett squares predict averages over many genetic crosses, not the exact outcomes of individual crosses, which may vary. The more offspring, the closer the observed ratios will be to the expected probabilities.
Staphylococcus is a genus of gram-positive bacteria that includes 35-40 species. The most common disease-causing species are S. aureus, S. epidermidis, and S. saprophyticus. Staphylococci are spherical cells arranged in clusters that are catalase-positive and facultative anaerobes. They are distinguished from Micrococcus through tests like coagulase production and modified oxidase, and from streptococci by their catalase positivity.
This document is a PowerPoint presentation about microbial diseases of the nervous system. It covers various bacterial infections that can cause meningitis (inflammation of the meninges) or encephalitis (inflammation of the brain), including those caused by Haemophilus influenzae, Neisseria meningitidis, Streptococcus pneumoniae, Listeria monocytogenes, Clostridium tetani, and Clostridium botulinum. It also discusses viral infections like poliomyelitis, rabies, and arboviral encephalitis. Diagnostic techniques and treatments for these diseases are explained. The presentation concludes by covering leprosy caused by Mycobacterium leprae.
This document appears to be a quiz on microbial diseases of the skin and eyes from a textbook. It consists of 25 multiple choice questions divided into 5 topics: skin, bacterial diseases, viral diseases, fungal and parasitic diseases, and infectious diseases of the eye. Each question is worth $100-$500 and includes the question, 4 possible answers, and then the correct answer. The questions cover a range of microbes that can cause infections of the skin and eyes, such as bacteria, viruses, fungi and parasites.
Potential virulence factors of Streptococcus dysgalactiae associated with bov...Shoaib Ahmad Shakhes
S. dysgalactiae is an environmental pathogen capable of causing bovine mastitis. It possesses several potential virulence factors that allow it to infect the mammary gland and evade the host immune system, including IgG and fibronectin binding proteins, MAG protein, α2-macroglobulin binding, LTA, capsule, extracellular enzymes like fibrinolysin and hyaluronidase, and streptokinase. S. dysgalactiae can also adhere to and invade mammary epithelial cells, potentially establishing a persistent infection. Further research on these virulence mechanisms could aid in developing new prevention and treatment strategies for S. dysgalactiae mastitis.
This document contains a quiz on microbial diseases of the nervous system. It is divided into sections on the nervous system, bacterial diseases, fungal and protozoan diseases, viral diseases, and prion diseases. Each section contains multiple choice questions on topics related to specific pathogens that can infect the nervous system, their symptoms, modes of transmission, and sterilization methods. The questions range in value from $100 to $500 and provide the answers when selected.
This document provides an overview of the digestive system through multiple sections:
1) An introduction covering the anatomy and histology of the alimentary canal.
2) Sections on the functional anatomy of the upper GI tract, small intestine, and large intestine describing their roles in digestion.
3) A section on chemical digestion and absorption outlining the enzymes and processes involved.
The document quizzes the reader with multiple choice questions at the end of each section.
The document contains a quiz about topics related to birth control, pregnancy, reproduction, and infertility. It includes multiple choice questions on subjects like the hormone detected in home pregnancy tests, diseases that can affect pregnant women, weight gain norms during pregnancy, stages of labor, various contraceptive methods, causes of infertility, and complications of pregnancy like preeclampsia. The quiz is divided into sections for pregnancy, reproduction, birth control, and infertility, with questions ranging from $100 to $400 in each section and a final round question.
This document appears to be a quiz on microbiology presented as a game show with questions worth $100, $200, $300, $400, or $500 on various topics related to microbial growth. It covers physical and chemical requirements for microbial growth, how bacterial cultures grow, and different types of culture media. Each question is followed by possible multiple choice answers and then the correct answer. The document aims to test understanding of key concepts in microbiology.
This document contains a quiz on microbial diseases of the cardiovascular and lymphatic systems. It is divided into topics on bacteria, vectors, viruses, and protozoa/helminths. Each topic contains multiple choice questions about various pathogens, with answers provided after each question. The quiz covers information about causative agents, transmission methods, signs and symptoms, and life cycles.
The document provides an overview of the urinary system including:
1) The gross anatomy of the kidneys and nephrons, including structures like the renal medulla, renal cortex, renal columns, renal sinus, ureters, and calyces.
2) The process of filtration through the glomerulus and nephron, including factors that influence glomerular filtration rate.
3) The role of renal tubules in reabsorbing nutrients and regulating water, electrolyte, and acid-base balance as urine is formed.
The document describes the structure and functions of the digestive system, including the organs of the digestive tract from mouth to anus and accessory organs. It details the layers of the digestive tract wall and the roles of the different cell types in the stomach lining. The stomach secretes hydrochloric acid and enzymes to begin breaking down food through both mechanical and chemical digestion.
This document contains a series of questions and answers about antimicrobial drugs and antibiotic resistance. It is formatted as a quiz with multiple choice questions on topics like the history of antibiotic discovery, modes of antibiotic action, resistance development, and strategies for combating resistance. The questions progress from $100 to $500 in value and cover five main topics: history, antimicrobials, mode of action, resistance, and the future of antimicrobial drugs.
This document appears to be a quiz on microbiology topics related to respiratory diseases. It consists of multiple choice questions divided into topics including the upper respiratory tract, lower respiratory tract, bacteria, and viruses. For each question there is an answer option selected from A-D. The document aims to test knowledge of infectious agents, transmission, symptoms, and treatments of various respiratory illnesses.
This document contains a quiz on cellular biology with questions and answers about prokaryotic and eukaryotic cell structures. It is formatted as a game with multiple choice questions in various topics worth $100-$500 each. The topics covered include prokaryotic cells, bacterial cell walls, external structures like flagella and capsules, internal structures like plasmids and ribosomes, and an introduction to eukaryotic cells.
This document contains a quiz on viruses, viroids, and prions from a textbook chapter. It consists of multiple choice questions divided into topics including viral characteristics, cultivation, infections, relationships to cancer, and properties of prions and viroids. For each question, the multiple choices are listed and the correct answer identified when the user selects their choice. The quiz covers details about viral structure, life cycles, diseases caused, and molecular mechanisms of infection and pathogenesis.
The document provides information about Streptococcus pneumoniae (pneumococci) and Streptococcus viridans. It describes the typical morphology, culture characteristics, pathogenicity and laboratory identification of these two types of bacteria. S. pneumoniae is a leading cause of community-acquired pneumonia and other infections. It is distinguished from S. viridans by being optochin-sensitive, bile soluble and able to ferment inulin.
Introduction to streptococcus and a brief review on its speciesBandita Panigrahi
Streptococcus is a genus of bacteria that can cause diseases like mastitis, meningitis, and arthritis in animals and humans. They are gram-positive cocci that grow in chains and are facultative anaerobes. S. agalactiae is the cause of contagious mastitis in ruminants. Its virulence factors include an antiphagocytic polysaccharide capsule and surface proteins that help it evade the immune system and colonize the mammary gland. The infection can become chronic if left untreated.
This document provides information on various bacteria including Streptococcus, Staphylococcus, Mycobacterium tuberculosis, and others. It describes their characteristics, habitats, methods of transmission, methods of culture and identification, pathogenicity, and treatments. Key points covered include that Streptococcus is gram-positive and forms chains, Staphylococcus forms grape-like clusters, and Mycobacterium tuberculosis is acid-fast and causes tuberculosis. Culture methods and identification of each organism is outlined along with diseases they can cause.
Staphylococci are gram positive cocci that commonly inhabit the skin and nasal passages. The most pathogenic species are Staphylococcus aureus and S. epidermidis. S. aureus can cause skin infections, pneumonia, toxic shock syndrome and food poisoning. Diagnosis involves gram staining, culturing on selective media like blood agar, and biochemical tests for catalase and coagulase production. Treatment depends on infection severity and involves drainage, fluid replacement, and antibiotics like methicillin or vancomycin for resistant strains. Prevention involves proper hygiene, wound care, isolation of infected patients, and sterilization of medical equipment.
This document discusses several types of streptococci that are medically important, including Streptococcus pyogenes, Streptococcus pneumoniae, and viridans streptococci. S. pyogenes causes diseases like strep throat, impetigo, and necrotizing fasciitis. S. pneumoniae is a major cause of pneumonia and meningitis. Viridans streptococci can cause endocarditis following bacteremia from dental procedures. The document covers characteristics, diseases caused, diagnostic tests, and treatments for these different streptococci.
Staphylococcus aureus and Staphylococcus epidermidis are common pathogenic Gram-positive cocci that can cause opportunistic infections. S. aureus is more virulent and can produce a variety of conditions depending on the site of infection, while S. epidermidis normally inhabits human skin and can cause infection in immunocompromised individuals. These bacteria employ various virulence factors like protein A, clumping factor, and toxins to evade the immune system and cause disease. Common infections include skin infections, food poisoning, toxic shock syndrome, bacteremia, endocarditis, and pneumonia. Treatment involves antibiotics like methicillin, but many strains have developed resistance including MRSA.
The document discusses Staphylococcus bacteria, including S. aureus, S. epidermidis, and S. saprophyticus. S. aureus is a common cause of skin infections and abscesses. It produces toxins that can cause food poisoning, scalded skin syndrome, and toxic shock syndrome. Treatment involves draining infections and antibiotics like penicillins, though antibiotic resistance is a problem. Prevention focuses on hygiene and proper wound care.
Mycoplasmas are the smallest free-living organisms that can cause diseases in humans. They lack cell walls and have minimal genetic material. Several Mycoplasma species can cause respiratory illnesses like pneumonia from M. pneumoniae or urogenital infections from M. hominis, U. urealyticum, and M. genitalium. They are difficult to culture but can be identified using PCR or serological tests. Mycoplasma pneumonia is most common in children aged 5-15 years old and is typically treated with tetracyclines or macrolides.
This document provides information on Staphylococcus, including:
- It is a gram positive coccus that occurs in grape-like clusters and was first observed in human lesions.
- Major species that colonize human skin include S. epidermidis and S. aureus.
- It is a facultative anaerobe that grows well on blood agar and produces beta hemolytic colonies. Identification involves gram staining and tests like catalase and coagulase.
- It can cause a variety of infections like skin abscesses, pneumonia, osteomyelitis and toxic shock syndrome. Virulence factors include adhesins, enzymes, and exotoxins. Antibiotic resistance is common.
bacterial skin and soft tissue infections.pptRamaGupta28
This document discusses various bacterial skin infections including erysipelas, impetigo, folliculitis, ecthyma, furuncles, carbuncles, cellulitis, necrotizing fasciitis, and pyomyositis. Erysipelas is a bacterial skin infection of the upper dermis caused by Streptococcus pyogenes. Impetigo is a superficial infection that presents as crusting or bullous lesions caused by Staphylococcus aureus or streptococcus. Folliculitis presents as pustules in hair-bearing skin and is usually caused by S. aureus. Cellulitis is a spreading skin infection of the deeper dermis and subcutaneous tissues caused by streptococci
This document provides information on Group B Streptococcus (GBS) and Enterococcus. For GBS, it discusses the pathogenisis, including virulence factors like the polysaccharide capsule and beta-hemolysin. It also covers epidemiology, risk factors, clinical manifestations of early vs late onset disease, and the gold standard test for diagnosis. For Enterococcus, it introduces the two common species, describes increasing importance as nosocomial pathogens and vancomycin resistance, and lists common sites of infection.
This presentation cover brief discussion of morphological features, cultural characteristics, virulence factors, pathogenesis, epidemiology and lab diagnosis of staphylococcus aureus .
#MedicalMicrobiology
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3. The summary also discusses their diagnosis through microscopy, culture, molecular and imaging techniques as well as challenges in treatment.
This document provides information about Chlamydia species, including their taxonomy, life cycle, diseases they cause, and methods for laboratory diagnosis. It describes Chlamydia as obligate intracellular parasites that infect humans, animals, and birds. They have both a replicative, reticulate body form and an infective, elementary body form. Key diagnostic methods discussed are microscopy using stains like Giemsa to identify inclusion bodies, culture isolation, antigen detection by ELISA or PCR, and antibody detection by tests like complement fixation. Treatment involves antibiotics like tetracyclines or azithromycin.
This document summarizes information about Staphylococci and Streptococci bacteria. It discusses their microscopic morphology, cultivation characteristics, biochemical features, virulence factors, clinical presentations, and treatment. Key points include:
- Staphylococci are Gram-positive cocci that can be coagulase-positive like S. aureus or coagulase-negative like S. epidermidis. S. aureus is an important human pathogen able to cause both localized and invasive infections.
- Streptococci are Gram-positive cocci arranged in chains. Important species include S. pyogenes (Group A Strep) which causes pharyngitis and can lead to post-stre
This document discusses diseases of mammary glands in dairy animals, focusing on mastitis. It defines mastitis as an inflammation of the udder and outlines its economic impacts. Mastitis can be clinical or subclinical, contagious or environmental. The major causes of mastitis are Staphylococcus aureus, Mycoplasma bovis, and E. coli bacteria. S. aureus is the leading cause and is difficult to treat once established. M. bovis spreads between quarters and causes clinical mastitis in multiple quarters. E. coli infections generally result from unhygienic conditions. The document outlines diagnostic techniques and measures to control spread, focusing on hygiene and culling infected animals.
Background &Objective: Klebsiella pneumonia causes different serious nosocomial infections for human and several strains became multiple drug resistance .This study was conducted to describe the epidemiology and molecular typing of Klebsiella pneumonia with the extended spectrum of B lactamase enzyme in Gaza strip .Methods :A cross-sectional survey was conducted during the period of December 2008 to November2009. One hundred and fifty clinical specimens were collected from patients admitted in different wards . Results : Sixty six percentage of the isolates were K.pneumonia .These were isolated from different infected sites : urine 24% , sputum 14%, wound 11% , stool11% , blood14% , cerebrospinal fluid 11% , skin16% . The ESBLs was detected in 67% of the strains ,53% strains were resistant for more than eight antibiotics , PCR demonstrated different patterns for the presence of SHV(80%) , TEM(60%) enzyme and CTX-M(20%), PFGE Showed 10 clusters of genetically unrelated strains with high prevalence of polyclonal strains of Klebsiella pneumonia. Antibiotic resistance was found against Cephalothin(95.0%),Cefotaxime(82.0%),Ceftazidime(59.0%),Ceftriaxone(86.0%),Gentamicin(56.0%),Trimethoprim/sulphamethoxazole(47.0%)..Chloramphenicol(42%),Amikacin(33%),Aztreonam (32%) and Imipenem(0%). Interpretation, Conclusion : our findings showed that genetically-related isolates of K. pneumoniae producing SHV and TEM and CTX-M were present in Gaza Strip. Larger studies need to be done to better define the molecular epidemiology of ESBL producing K. pneumoniae and its clinical implications
Gram-positive cocci include Staphylococcus (catalase-positive), which grows clusters, and Streptococcus (catalase-negative), which grows in chains. The staphylococci further subdivide into coagulase-positive (S. aureus) and coagulase-negative (S. epidermidis and S. saprophyticus) species. Streptococcus bacteria subdivide into Strep. pyogenes (Group A), Strep. agalactiae (Group B), enterococci (Group D), Strep viridans, and Strep pneumonia.
Gram-positive bacilli (rods) subdivide according to their ability to produce spores. Bacillus and Clostridia are spore-forming rods while Listeria and Corynebacterium are not. Spore-forming rods that produce spores can survive in environments for many years. Also, the branching filament rods encompass Nocardia and actinomyces.
Gram-positive organisms have a thicker peptidoglycan cell wall compared with gram-negative bacteria. It is a 20 to 80 nm thick polymer while the peptidoglycan layer of the gram-negative cell wall is 2 to 3 nm thick and covered with an outer lipid bilayer membrane.
Bloodstream infection mortality rates have increased by 78% in just two decades[1]. Gram-positive organisms have highly variable growth and resistance patterns. The SCOPE project (Surveillance and Control of Pathogens of Epidemiologic Importance) found that gram-positive organisms in those with an underlying malignancy accounted for 62% of all bloodstream infections in 1995 and 76% in 2000 while gram-negative organisms accounted for 22% and 14% of infections for these years.[2]
This document discusses Staphylococci bacteria, including their general features and important medical species. Staphylococci are gram-positive cocci that form grape-like clusters and are facultative anaerobes. Three medically important species are described: Staphylococcus aureus, S. epidermidis, and S. saprophyticus. S. aureus is the most virulent and causes a variety of infections through various cell-associated and secreted virulence factors. Laboratory diagnosis involves culturing specimens on selective media and performing tests like catalase, coagulase, and DNase.
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Histololgy of Female Reproductive System.pptxAyeshaZaid1
Dive into an in-depth exploration of the histological structure of female reproductive system with this comprehensive lecture. Presented by Dr. Ayesha Irfan, Assistant Professor of Anatomy, this presentation covers the Gross anatomy and functional histology of the female reproductive organs. Ideal for students, educators, and anyone interested in medical science, this lecture provides clear explanations, detailed diagrams, and valuable insights into female reproductive system. Enhance your knowledge and understanding of this essential aspect of human biology.
5-hydroxytryptamine or 5-HT or Serotonin is a neurotransmitter that serves a range of roles in the human body. It is sometimes referred to as the happy chemical since it promotes overall well-being and happiness.
It is mostly found in the brain, intestines, and blood platelets.
5-HT is utilised to transport messages between nerve cells, is known to be involved in smooth muscle contraction, and adds to overall well-being and pleasure, among other benefits. 5-HT regulates the body's sleep-wake cycles and internal clock by acting as a precursor to melatonin.
It is hypothesised to regulate hunger, emotions, motor, cognitive, and autonomic processes.
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1. Streptococcus organisms
Streptococus pneumoniae
and Streptococus pygene
Presentation
By
Ivan Kamulasi
2013-bmls-ft-008
School of allied health sciences
(c) ivankamulasi BMLS student,
CMLT 1
5. The serology subdivision is based on the
difference in group specific polysaccharide
antigens in the cell wall.
(c) ivankamulasi BMLS student,
CMLT 5
6. Rebecca Lancefield working with various
streptococcal species discovered proteins in
the cell wall of β-streptococcus organism that
was unique to certain organisms. She later
said streptococci produce group specific
carbohydrates that can be identified using
group specific antiserum
(c) ivankamulasi BMLS student,
CMLT 6
7. Grouped Streptococci
A, B and D (frequent)
C, G, F (less frequent)
Un grouped organisms
S. pneumoniae (pneumonia)
viridans streptococci (e.g. S. mutans ie dental
caries)
(c) ivankamulasi BMLS student,
CMLT 7
8. α (alpha)
◦ partial hemolysis
◦ green color
β (beta)
◦ complete clearing
γ (gamma)
- no lysis
8
White colonies
(c) ivankamulasi BMLS student,
CMLT
9. Groups A an B
◦β
Group D
◦ α or γ
S. pneumoniae and viridans
◦α
9
(c) ivankamulasi BMLS student,
CMLT
10. Is a spherical, gram positive bacterium
It displays Streptoccocal group A antigen on
its cell wall.
It’s a beta hemolytic
Has an incubation period of 1-3 days
(c) ivankamulasi BMLS student,
CMLT 10
11. Domain : Prokaryotes
Kingdom : bacteria
Phylum : Firmicutes
Class : Bacilli
Order : Lactobacillalees
Family : Streptococcacae
Genera : Streptococcus
Species : S pyogenes
(c) ivankamulasi BMLS student,
CMLT 11
12. S pyogenes is widely distributed in nature
Can be found in water, dust, vegetation, milk
products, and also as a commensal in the
upper respiratory tract.
(c) ivankamulasi BMLS student,
CMLT 12
13. Are gram positive and spherical
They measure 0.7-0.9 um in diameter
The cells occur in chains of varying lengths
and are best demonstrated in fluid cultures
where long chains are found
They are capsulated in young cultures
(c) ivankamulasi BMLS student,
CMLT 13
14. Suitable culture media
Blood agar, serum agar and MacConkey ( they
don’t grow on MacConkey due to salt present
in the media )
Growth temperature ranges from 22-420c
with optimum at 37oC
They measure 0.1-1mm in diameter after 24
hours of incubation
(c) ivankamulasi BMLS student,
CMLT 14
15. They are semi transparent, low convex,
desecrate and with matt or glossy surface ,
grey white or colorless, dry or shiny and
usually irregular outline on a Blood agar
When freshly isolated, the colonies are
mucoid i.e heavily capsulated
They are beta hemolytic on blood agar
(c) ivankamulasi BMLS student,
CMLT 15
16. • Adherence to the epithelial cells
• Invasion into the epithelial cells - important for
persistent infections and invasion into deep
tissues
• Avoiding opsonization and phagocytosis;
• Producing enzymes and toxins
Streptococcus pyogenes Pathogenesis ( via
invasiveness and production of toxins
(c) ivankamulasi BMLS student,
CMLT 16
17. Enzymes and toxins
Streptokinase (fibrinolysin)
Can lyse blood clots and may be responsible for the rapid spread
of the organism.
Used (IV injection) for treatment of pulmonary emboli, coronary
artery thrombosis and venous thrombosis.
Streptodornase (DNases A to D)
Decreases viscosity of DNA suspension.
Hyaluronidase (spreading factor):
Destroys connective tissue and aids in spreading infecting bacteria.
C5a peptidase
Prevents streptococci from activation of phagocytes and is
important for survival of S. pyogenes in tissue and blood.
Streptococcus pyogenes
(c) ivankamulasi BMLS student,
CMLT 17
18. Hemolysins
Streptolysin O: O2-labile; causes hemolysis deep in blood
agar plates. ASO (antistreptolysin O) titer >160-200 units
suggests recent infection or exaggerated immune
response to an earlier respiratory infection. However, skin
infection does not induce ASO.
Streptolysin S: O2-stable. Causes b-hemolysis on the
surface of blood agar plates. Cell-bound, not antigenic.
Produced in the presence of serum. Kills phagocytes by
releasing the lysosomal contents after engulfment.
(c) ivankamulasi BMLS student,
CMLT 18
19. Specimen
Throat swab, pus, exudates, blood for culture
and serum for estimation of ASO titres
Micoscopy
Gram stain techniques;
They are gram positive cocci showing short or
long chains
Non motile and non sporing, however some
strain are capulated if prepared rom fresh
cultures
(c) ivankamulasi BMLS student,
CMLT 19
20. Suitable media
Blood agar, chocolate agar, Macconkey
Incubate in 5-10% Co2 or aerobically at 37oc
On BA colonies are beta hemolytic measuring
0.5- 1 mm in diameter, grey white or colorless
with irregular shapes
On MacConkey the organisms show no growth
(c) ivankamulasi BMLS student,
CMLT 20
22. Lancefield grouping. This is done by rapid
and simple techniques such as streptex which
is a latex particle agglutination test.
Organism is Lancefield group A
Serological test. The group antigens are
extracted using HCl and the antigens are then
tested with group specific antisera by one of
the following methods
Precipitation test, Elisa, Fluorescent antibody
test (FAT), Slide agglutination test (SAT)
(c) ivankamulasi BMLS student,
CMLT 22
23. ASOT investigates post streptococcal diseases
such as rheumatic fever which give rise to
ASO level to 80-85% and this can be done by
ASO latex slide agglutination test which is a
screening test or ASO micro titration or tube
haemolysis test to titrate the antibody.
(c) ivankamulasi BMLS student,
CMLT 23
24. DNase B antibody to investigate acute
glomerulonephritis following a streptococcal skin
infection
Antimicrobial sensitivity. Antibiotics with
activities against Streptococcus Pyogenes include
penicillin, erythromycin, Ampicillin, gentamycin,
ciprofloxacilin.
Biochemical reactions
They are Catalase negative, Bacitracin test
sensitive at a concentration of 0.05 units, Bile
solubility test negative, Camp test negative,
Litmus milk reduction test negative
(c) ivankamulasi BMLS student,
CMLT 24
26. S. pyogenes can transiently colonize the oropharynx and skin.
Diseases are caused by recently acquired strains that can
establish an infection of the pharynx or skin.
S. pyogenes causes pharyngitis mainly in children of 5 to 15
years old.
The pathogen is spread mainly by respiratory droplets.
Crowding increases the opportunity for the pathogen to spread,
particularly during the winter months.
Soft tissue infections are preceded by skin colonization and the
organisms are introduced into the superficial or deep tissue
through a break in the skin.
Epidemiology
(c) ivankamulasi BMLS student,
CMLT 26
27. Clinical Diseases
1. Local infection with S. pyogenes
Streptococcal sore throat (pharyngitis), and scarlet fever.
Streptococcal pyoderma (impetigo, local infection of
superficial layers of skin).
Strains that cause skin infections are different from those
that cause pharyngitis.
Additional notes
(c) ivankamulasi BMLS student,
CMLT 27
28. 2. Invasion by S. pyogenes
Invasion from respiratory tract: otitis media, sinusitis,
pneumonia, meningitis, osteomyelitis, and arthritis.
Invasion from skin: erysipelas, cellulitis, and necrotizing
fasciitis. Diffuse and rapidly spreading infection that
extends along lymphatic pathways with only minimal local
suppuration.
Sepsis (streptococcal toxic shock syndrome, STSS):
the organism is introduced into the subcutaneous tissue
through a break in the skin cellulitis necrotizing
fasciitis systemic toxicity, multiple organ failure, and
death (mortality > 40%).
(c) ivankamulasi BMLS student,
CMLT 28
29. 3. Poststreptococcal diseases (occurs 1-4 weeks after
acute S. pyogenes infection, hypersensitivity responses)
Rheumatic fever: most commonly preceded by infection of the
respiratory tract. Inflammation of heart (pancarditis), joints,
blood vessels, and subcutaneous tissue. Results from cross
reactivity of anti-M protein Ab and the human heart tissue.
Acute glomerulonephritis: preceded by infection of the skin
(more commonly) or the respiratory tract. Symptoms: edema,
hypertension, hematuria, and proteinuria. Initiated by Ag-Ab
complexes on the glomerular basement membrane.
* Rheumatic fever can be reactivated by recurrent streptococcal
infections, whereas nephritis does not.
(c) ivankamulasi BMLS student,
CMLT 29
31. leading cause of pneumonia
◦ particularly young and old
bacteremia
meningitis
middle ear infections (otitis media) -
children
(c) ivankamulasi BMLS student,
CMLT 31
32. Domain : Prokaryotes
Kingdom : bacteria
Phylum : Firmicutes
Class : Bacilli
Order : Lactobacillalees
Family : Streptococcacae
Genera : Streptococcus
Species : S pneumoniae
(c) ivankamulasi BMLS student,
CMLT 32
33. member normal flora, nasopharynx of 10 – 30 %
healthy individuals
replication and spread after damage to upper
respiratory tract (e.g. after the flu)
(c) ivankamulasi BMLS student,
CMLT 33
34. MORPHOLOGY:
Pneumococci are Gram
positive small(1μm),
slightly elongated cocci,
with one end broad &
other end pointed,
presenting a flame
shaped or lanceolate
appearance.
They occur in pairs,
with the broad ends
opposing each other.
They are capsulated &
the capsule encloses
each pair.
They are nonmotile &
nonsporing.
(c) ivankamulasi BMLS student,
CMLT 34
35. CULTURE & CULTURAL CHARACTERISTICS:
They grow only in enriched media.
They are aerobes & facultative anaerobes
The optimum temperature being 37ºC & pH 7.8.
Growth is improved by 5-10% CO2.
On BA, the colonies are small, smooth and
transparent low convex, may be white, tiny and
become flattened and measure 1mm in diametre
(doom shape)
(c) ivankamulasi BMLS student,
CMLT 35
36. Media used: Blood agar
Colony morphology: On blood agar, after
incubation for 18 hours, the colonies are small,
dome shaped & glistening, with an area of
α-haemolysis.
On further incubation the colonies
become flat with raised edges & central
umbonation called as Draughtsman or carrom
coin appearance.
(c) ivankamulasi BMLS student,
CMLT 36
38. PATHOGENICITY:
Source of infection:
i) Endogenous- from the colonized area.
ii) Exogenous- patients or carriers.
Mode of infection: By inhalation.
(c) ivankamulasi BMLS student,
CMLT 38
39. Antigenic structure:
1. Capsular polysaccharide:
It is the most important antigen & type
specific.
Since it diffuses into infective tissue & culture
medium it is called as specific soluble
substance(SSS).
Pneumococci are classified into types based
on the nature of capsular polysaccharide &
more than 90 serotypes are recognised &
named 1,2,3…...
(c) ivankamulasi BMLS student,
CMLT 39
40. 2. M protein: It is not associated with virulence.
3. ‘C’ Carbohydrate antigen:
- It is present in all pneumococci so species
specific.
- Virulance factors
1. Capsule: It is antiphagocytic.
2. Pneumolysin: It is a membrane damaging
toxin has cytotoxic and complement
activating properties.
(c) ivankamulasi BMLS student,
CMLT 40
42. D. Determinants of Pathogenicity
Toxins
a) Pneumolysin O (Ply)
A 53-kDa protein that is cytolytic to eukaryotic cells
that have cholesterol as a component of their cell
membranes particularly the respiratory epithelium;
also activates complement
b) Autolysin (LytA)
Causes lysis of pneumococci in the presence of
surface-active agents or antimicrobials that inhibit cell
wall synthesis
Release toxic proteases
Cell wall components
Teichoic acid & peptidoglycan beneath the capsular
polysaccharide
(c) ivankamulasi BMLS
student, CMLT 42
43. D. Determinants of Pathogenicity
Hydrogen peroxide –
• causes damage to host cells (can cause apoptosis
in neuronal cells during meningitis) and has
bactericidal effects against competing bacteria
(Haemophilus influenzae, Neisseria meningitidis,
Staphylococcus aureus)
Pili –
• hair-like structures that extend from the surface
• contributes to colonization of upper respiratory
tract and increase the formation of large amounts
of TNF by the immune system during sepsis,
raising the possibility of septic shock
(c) ivankamulasi BMLS
student, CMLT 43
44. Mechanism of Pathogenesis:
Entry of pneumococci into nasopharynx
Colonization of nasopharynx
May cause infection of the middle ear,
paranasal
sinuses & respiratory tract by direct spread
Infection of meninges can also occur, by
contiguity or
through blood
Enters blood causing bacteremia, which may
also
lead to disseminated infections as in the
heart,
peritoneum or joint(c) ivankamulasi BMLS student,
CMLT 44
45. LABORATORY DIAGNOSIS:
Specimens to be collected:
Sputum,
CSF,
Blood,
Synovial fluid,
In children laryngeal swab can be taken if sputum
can not be collected.
(c) ivankamulasi BMLS student,
CMLT 45
49. 4. Culture:
a) Media used:
Blood agar
b) Colony morphology:
Are small, smooth and transparent, low convex,
may be white, tiny and become flattened or
depressed centrally showing draughts-man’s
shape and measure up to 1mm in diameter
(doom shape)
c) Indirect Gram’s smear:
Smears are examined
from the culture plate
and reveals Gram
positive lanceolate
shaped diplococci.
(c) ivankamulasi BMLS student,
CMLT 49
50. Streptococcus pneumoniae is a fermentative
aerotolerant anaerobe.
It is usually cultured in media that contain blood.
On blood agar, colonies characteristically
produce a zone of alpha (green) hemolysis, which
differentiates S. pneumoniae from the group A
(beta hemolytic) streptococcus, but not from
commensal alpha hemolytic (viridans)
streptococci which are co-inhabitants of the
upper respiratory tract.
Special tests such as inulin fermentation, bile
solubility, and optochin (an antibiotic) sensitivity
must be routinely employed to differentiate the
pneumococcus from Streptococcus viridans.
(c) ivankamulasi BMLS student,
CMLT 50
51. d) Capsular swelling reaction: Positive.
It is done by mixing the suspension of colonies
from the culture plate and a loopful of type
specific antiserum & a drop of methylene blue
solution on a slide.
e) Biochemical reactions:
(c) ivankamulasi BMLS student,
CMLT 51
52. OPTOCHIN TEST (ethylhydrocupreine HCl)
• Inhibits growth of pneumococci but not viridans
(c) ivankamulasi BMLS
student, CMLT 52
Optochin positive Optochin negative
54. BILE SOLUBILITY TEST
• Bile or bile salts (surface-active agents)
activate an autolytic AMIDASE which
cleaves the bond between alanine &
muramic acid in the peptidoglycan
resulting in lysis of microorganism
• Amidase is present in pneumococcus
but not in viridans streptococci
(c) ivankamulasi BMLS
student, CMLT 54
55. (Neufeld) QUELLUNG (capsular
precipitation) REACTION
• Most rapid & most useful: identifies & specifies type
of pneumococci in sputum, spinal fluid, exudates, or
culture
• Pneumococcal specimen mixed with (polyvalent)
antipneumococcal serum & methylene blue:
Positive result: refractile & swollen capsules on oil
immersion
(c) ivankamulasi BMLS
student, CMLT 55
56. 2. Quellung( capsular swelling ) reaction:
It is described by Neufeld.
On a slide the sputum is mixed with type specific
antiserum against capsular antigen & a loopful of
methylene blue solution. The capsule becomes
swollen & refractile.
(c) ivankamulasi BMLS student,
CMLT 56
57. 5. Animal inoculation: From specimens where
organisms are expected to be scanty, isolation
may be obtained by intraperitoneal inoculation
in mice.
6. Serology: Antibodies can be demonstrated by
agglutination & precipitation test.
(c) ivankamulasi BMLS student,
CMLT 57
58. Catalase test
Facultative anaerobe
Catalase-negative:
accumulation of hydrogen
peroxide kills microorganism
in culture medium
(c) ivankamulasi BMLS
student, CMLT 58
59. • MANAGEMENT
– CHEMOTHERAPY:
• Based on sensitivity teating
• DOC: IM PCN G (uncomplicated pneumonia) OR
oral PCN V (milder URTI)
• PCN-allergic alternatives: cephalosporin or
erythromycin (pneumonia),chloramphenicol
(meningitis), quinolones
– PREVENTIVE:
• Pneumococcal conjugate vaccine for high-risk cases
(c) ivankamulasi BMLS
student, CMLT 59
60. Reservoir Human carriers
Transmission Respiratory
"Autoinoculation“
Temporal pattern Winter and early spring
Communicability Unknown
Probably as long as
organism in respiratory
secretions
(c) ivankamulasi BMLS
student, CMLT 60
61. Outbreaks uncommon
Generally occur crowded
environments (jails, nursing
homes)
Persons with invasive
disease often have
underlying illness
May have high fatality rate
(c) ivankamulasi BMLS
student, CMLT 61