Gram Positive Bacteria Flashcards
What are some defining characteristics of Staphylococus Aureus? Virulence factors
Normal human microbiota, but opotunistic pathogens.
Gram-positive, nonmotile, cocci. Evades phagocytosis, produces enzymes and toxins.
What are the diseases S. Aureus can cause?
- Food poisoning by enterotoxin production.
- Colitis if during antibiotic treatment they overgrow and produce enterotoxin B.
- Impetigo (Furnuncle, Carbuncle).
- Scalded skin syndrome.
- Toxic shock syndrome, Bacteremia (blood), endocarditis, pneumonia, Osteomyelitis (bone marrow)
What are some defining characteristics of Streptococcus Pyogenes? Virulence factors?
Gram-possitive cocci. White colonies surrounded by zone of beta-hemolysis. Often has a capsule. Depletes normal microbiota, established before antibodies form, and impairs specific immunity.
What are some Diseases caused by S. Pyogenes?
Pharyngitis (strep throat), Scarlet fever, Impetigo, Erysipelas, TSS, Necrotizing Fasciitis.
What are postreptococcal Sequelae examples?
- Rheumatic fever linked to GAS pharyngitis. leads to damage of heart valves. Type II HS
- Glomerulonephritis linked to GAS-pharyngitis or skin infection. Leads to inflammation of glomeruli and nephrons and obstruct blood flow to kidneys. Type II or Type III HS.
What are some characteristics of Alpha-Hemolytic Strep (The viridans)? what can they cause?
Can’t be grouped in lancefield system. Produce green discoloration when brown on blood media. Major role in dental caries and plaque.
Can cause Meningitis and Endocarditis.
What are some characteristics of S. Pneumoniae? Virulence factors?
Gram-positive cocci. Forms unpigmented colonies when grown on blood agar. Leading cause of death before antibiotics. Large polysaccharide capsule that protects from immune system.
What are some diseases caused by S. Pneumoniae?
Pneumococcal pneumonia, Sinusitis and otitis media, Bacteremia and endocarditis, meningitis.
What are some characteristics of Enterrococcus? Virulence factors?
Gram-possitive, lack a capsule. Found in colon. Resistant to a lot of treatments.
What are some diseases Enterococcus can cause?
UTI, Bateremia, endocarditis, wound infections.
What are some characteristics of Bacillus Anthracis? Virulent factor?
Gram-positive bacilli, forms endospores. Virulence due to 3 component toxin and protein capsule.
What are some characteristics of Clostridium perfringens?
Gram-possitive, anaerobic, endospore forming. In soil, water, and GI tract of animals and humans. produces 11 toxins.
C. Perfringens causes what diseases?
Food poisoning by enterotoxin.
Gas gangrene.
What are some characteristics of Clostridium Difficile? Causes what?
Common intestinal microbiota. Opportunistic. Fecal Transplants for treatment. Causes Pseudomembranous Colitis.
What are some characteristics of C. Botulinum? Causes?
Forms a preformed toxin that can be ingested or open wound. Causes botulism.
What are some characteristics of Clostridium tetani? Causes.
Endospore forming, gram positive rod. Soil, dust, GI tract. Endospores germinate and form tetanus toxin. Causes tetanus.
What are some characteristics of Listeria Monocytogenes?
Gram-positive, non spore forming, coccobacillus. found in soil, water, mammals, birds, fish, insects, Enters by contaminated food and drink. Produces no toxins or enzymes, but virulent through its ability to live in cells.
Polymerizes host cell actin to move around quickly.
What are some characteristics of Corynebacterium Diphtheriae?
Transmitted thorugh respiratory droplets. Forms a pseudomembrane from dead cells and fluid that can block the respiratory tract.
What are some characteristics of Propionibacterium? Causes?
Small, gram-positive rods found on skin. P. Acnes is most common and causes acne.
What are some characteristics of Actinomyces?
Anaerobic gram positive filamentous bacilli. Major component of dental plaque and associated with gingivitis and root caries.
What are Nocarida?
Soil saprophytes that cause nocardiosis.
What are Streptomyces?
Filmamentous branching soil bacilli that make most of our antibiotics.
