Bacteria Flashcards
(40 cards)
What is different about the capsule of Bacillus anthracis?.
It contains D-glutamate instead of polysaccharide
Which bacteria stains with PAS?
Tropheryma whipplei
What is found in Thayer-Martin media?
Vancomycin, Polymixin, and Nystatin
Which bacteria are encapsulated?
SHiNE SKiS
Streptococcus pneumoniae
Haemophilus influenzae type B
Neisseria meningitidis
Escheria coli
Salmonella
Klebsiella pneumoniae
Group B Strep
Which bacteria are catalase positive?
- PLACESS for your CATs
- Pseudomonas
- Listeria
- Aspergillus
- Candida
- E. Coli
- S. Aureus
- Serratia
Which bacteria produces a yellow pigment?
Which produces a red pigment?
Yellow: S.Aureus
Red: Serratia marcesens
Where is the gene location in…
Exotoxins?
Endotoxins (Gram negative)?
- Exotoxins: Plasmid or bacteriophage
- Endotoxins: Bacterial chromosome
Which toxins are ADB ribosylating toxins?
- Diptheria toxin
- Exotoxin A
- Shiga toxin
- Shiga-like toxin (EHEC)
- Heat labile toxin (ETEC)
- Cholera toxin
- Pertussis toxin
What toxins are released by ETEC and what are their functions?
Heat labile toxin: Overactivates adenylate cyclase leading to increased cAMP and increased Cl secretion in the gut and H2O efflux
Heat stable toxin: Overactivates guanylate cyclase leading to increased cGMP and decreased resorption of NaCl and H2O in the gut
What toxin is associated with bacillus anthracis? What is its function?
What is characterisitic of bacillus anthracis?
Edema factor - mimics adenylate cyclase enzyme and increases cAMP
Black eschar in cutaneous anthrax
What is the function of Streptolysin O from Strep Pyogenes?
Protein that degrades cell membrane: Lyses RBCs, contributes to beta hemolysis; antibodies against toxin (ASO) used to diagnose rheumatic fever
What are the functions of Exotoxin A (Strep pyogenes) and Toxic shock syndrome toxin (S. Aureus)?
Bring MHCII and TCR in proximity to outside of antigen binding site to cause overwhelming release of IFN-gamma and IL-2
In what populations does strep pneumo cause sepsis?
Sickle cell anemia and splenectomy
What are the two types of viridans group streptococci and which makes dextrans that bind to fibrin-platelet aggregates on damaged heart valves?
Streptococcus mutans and Streptococcus sanguinis
S. Sanguinis affects the damaged heart valves
S. Mutans causes dental caries
What are the features of scarlet fever?
Scarlet rash with sandpaper-like texture, strawberry tongue, circumoral pallor
What is the classification of bacillus anthracis?
Gram positive, spore-forming rod
What is caused by cutaneous anthrax?
What is caused by pulmonary anthrax?
Cutaneous: Boil like lesion - ulcer with black eschar
Pulmonary anthrax: Inhalation of spores - flu like symptoms that rapidly progress to fever, pulmonary hemorrhage, mediastinitis, and shock
What toxin in bacillus cereus causes nausea and vomiting (within 1-5 hours)?
Cereulide
How is nocardia treated?
Sulfonamides (TMP-SMX)
What tests are used to diagnose TB?
- PPD: Positive if current infection, past exposure, or BCG vaccinated
- Negative is no infection, anergic, or sarcoidoses
- Interferon-y release assay - more specific test (fewer false positives from BCG vaccination)
What is the function of cord factor in TB?
Inhibits macrophage maturation and induces release of TNF-α
What is the pattern of sensation loss in leprosy?
Glove and stocking loss of sensation (skin and superficial nerves)
What type of T-cell response occurs in the Lepromatous form? The Tuberculoid form?
Lepromatous: HumoralTh2 response
Tuberculoid: Th1 type immune response
Which lactose fermenting enteric bacteria is a weak fermenter?
Serratia
