Gram Positive Bacteria Flashcards
SHiN
Streptococcus pneumoniae, Haemophilus influenzae type B, Neisseria meningitidis
Encapsulated
IgA protease - cleaves IgA to colonize resp. mucosa
Transformation - can takue up DNA from environment
Staphylococci
Catalase +
Coagulase + :S. aureus
Coagulase - :Novobiocin-Saprophyticus is Resistant; Epidermis is Sensitive
(On the office’s staph retreat, there was NO StRES)
Streptococcus
alpha hemolysis
Green ring on blood agar Strep pneumoniae (Optochin sens) Viridans streptococci (Optochin res) Optochin - Viridans is Resistant; Pneumoniae is Sensitive (OVRPS-overpass)
Streptococcus
Beta hemolysis
Clear area on blood agar
Group A - Strep pyogenes (Bacitracin sens)
Group B - Strep agalactiae (Bacitracin res)
B-BRAS
Streptococcus
gamma hemolysis
Enterococcus (E. faecalis)
Nonenterococcus (Strep bovis)
Beta-hemolytic bacteria
form clear area of hemolysis on blood agar Staph aureus Strep pyogenes - Group A Strep agalactiae - Group B Listeria monocytogenes
Staphylococcus aureus
Gram + cocci in clusters, Catalase +, Coagulase +
Virulence Factor is Protein A - binds Fc-IgG
1. Superantigen/Exotoxin is TSST -> toxic shock syndrome
Exfoliative toxin -> scalded skin syn
Enterotoxin -> food poisoning in meat, mayonaise, custard (starts and ends quickly)
2. Inflamm dz - skin infxns, abscesses, pneum, endocarditis, osteomylitis
3. MRSA infxn
Staphylococcus epidermidis
Gram + cocci, Catalase +, Coagulase -, Novobiocin sensitive
uses biofilms to infect prosthetics and intravenous catheters
Streptococcus pneumoniae
Gram + diplococci, Catalase -, encapsulated, IgA protease, alpha hemolytic Most common cause of: Meningitis Otitis media (children) Pneumonia Sinusitis MOPS are Most OPtochin Sensitive Rusty Sputum, sepsis in sickle cell anemia, and splenectomy
Viridans group streptococcus
Gram + Catalse -, alpha hemolytic, Optochin res
Normal flora of OROPHARYNX
Strep mutans - dental caries
Strep sanguis - endocarditis at damaged valves (sanguis is latin for blood)
“Viridans group strep live in the mouth bc they are not afraid of-the-chin (op-to-chin res)”
Streptococcus pyogenes
Group A strep
Gram +, Beta hemolysis, bacitracin sens
Pyogenic - pharyngitis, cellulitis, impetigo
Toxigenic - scarlet fever, toxic shock-like syndrome
Immunologic - rheumatic fever, acute glomerulonephritis
ASO titer detects recent infxn
“PHaryngitis can result in rheumatic PHever and glomerulonePHritis”
“No rheum for SPECCulation: Subcutaneous plaques, Polyarthritis, Erythema marginatum, Chorea, Carditis”
Streptococcus agalactiae
Group B strep
Gram +, Beta hemolysis, bacitracin res
CAMP factor - enlarges S. aureus hemolysis
Colonizes the vagina
Causes pneumonia, meningitis, sepsis (B for Babies)
Screen pregnant women at 35-37 wks
Enterococci
Group D strep
Enterococcus faecalis and E. faecium
Normal colonic flora that are pen G res and cause UTI and endocarditis
VRE - nosocomial infxns
Streptococcus bovis
Group D strep
Colonize the gut and can cause bacteremia and endocarditis in colon cancer patients
Corynebacterium diphtheriae (coryne = club shaped)
Gram + rods with metachromatic granules and Elek test for toxin, grows in tellurite agar Diptheria Toxin -> pseudomembranous pharyngitis with lymphadenopathy ABCDEFG ADP ribosylation Beta-prophage Corynebacterium Diphtheria Elongation Factor 2 Granules
Spore-forming Gram + Bacteria formed in soil
Clostridium perfringes, C. tetani, B. cereus, C. botulinum, Coxiella burnetti
Clostridia
Gram +, spore-forming, obligate anaerobic bacilli
TETanus is TETanic paralysis (spastic paralysis)
BOTulinum is from BOTtles (cans) of food and honey (flaccid paralysis)
PERFringens PERForates a gangrenous leg
DIfficile causes DIarrhea
Listeria monocytogenes
Facultative intracellular microbe, acquired by ingestion of unpasteurized milk/cheese and deli meats or by vaginal transmission
Causes - Amnionitis, septicemia, spontaneous abortion, granulomatosis infantiseptica, neonatal meningitis, immunocompromised meningitis, gastroenteritis
Self-Limited
Actinomyces & Nocardia
Long Branching filaments resembling fungi
Actinomyces israelii (gram+ anaerobe) causes oral/facial abscesses that drain thru sinus tracts in skin (yellow sulfur granules)
Nocardia asteroides (gram+ acid-fast aerobe) causes pulmonary infxn in immunocompromised
SNAP
Sulfa for Nocardia
Actinomyces uses Penicillin
Mycobacteria
Gram +, Acid-Fast, with mycolic acid and high lipid content
M. tuberculosis -> TB (fever, night sweats, weight loss, hemoptysis)
Ghon Complex - primary TB
Caseating Granulomas - secondary TB
M. kansasii -> pulmonary TB-like symptoms
M. avium-intracellulare -> disseminated dz in AIDS, multi drug resistant (use azithromycin for prophylactic tx)
M. leprae -> skin infxn (Leprosy - Hansen’s Dz)
Mycobacterium leprae
Hansen’s Dz
1) Lepromatous - diffuse and communicable with low cell-mediated immunity with a humoral Th2 resp
(LEpromatous can be LEthal)
2) Tuberculoid - limited to a few hypoesthetic skin plaques with high cell-mediated immunity with large Th1 resp
Tx - Oral Dapsone, Rifampin, Clofazimine
Bacillus cereus
Beta hemolytic gram + rod
Food poisoning in reheated rice
Starts quickly and ends quickly
