Gram positive bacteria Flashcards
Streptococci pyogenes (strep A)
cocci in chains Facultative or obligate anaerobes Catalase - M protein resist phagocytosis, encapsulated, hyaluronic acid capsule, erythrogenic exotoxin causes scarlet fever #1 bacterial pharyngitis, impetigo, rheumatic fever, streptococcal glomerulonephritis, necrotizing fascitis, toxic shock syndrome Culture
Streptococci agalactiae (strep B)
cocci in chains Facultative or obligate anaerobes Catalase - encapsulated neonatal septicemia, meningitis, and pneumonia Culture
Streptococci bovis/equinus (strep D)
cocci in chains Facultative or obligate anaerobes Catalase - Urinary tract infections Culture
Streptococci pneumoniae
Lancet-shaped diplococcus Facultative or obligate anaerobes Catalase -, optochin sensitive encapsulated #1 bacterial pneumonia in adults (capsule), #1 otitis media in children Culture
Streptococci viridans
cocci in chains Facultative or obligate anaerobes Catalase - dental caries, subacute endocarditis Culture
Enterococci faecalis
diplococci or short chains Facultative anaerobe Catalase - encapsulated, can be VRE and transfer B-lactam resistance to other bacteria Normal intestinal flora - can cause UTI, bacteremia, and endocarditis (other itis’ as well) Culture
Staphylococci aureus
cocci in clusters Facultative anaerobe Catalase +, Coagulase + resistant to b-lactams and vancomycin, clumping factor, polysaccharide capsule, surface protein A (Ig blocker), Exfoliative A&B toxins (scalded skin syndrome), Toxic shock syndrome toxin (TSST1), heat stable enterotoxin (gastroenteritis) scaled skin syndrome, pneumonia, meningitis, endocarditis, osteomyelitis, food poisoning Culture
Staphylococci epidermidis
cocci in clusters Facultative anaerobe Catalase +, Coagulase - biofilm covers prosthetics endocarditis Culture
Staphylococci saprophyticus
cocci in clusters Facultative anaerobe Catalase +, Coagulase - UTI Culture
Bacillus cereus
Boxcar rod (spore former) Aerobe to facultative anaerobe Heat stable enterotoxin (vomiting), heat labile enterotoxin (diarrhea) food poisoning PCR, gram stain, immunofluorescence
Bacillus anthracis
Boxcar rod (spore former) Aerobe to facultative anaerobe antigenic capsule (polyglutamyl) and several exotoxins (factor A) Cutaneous (red lesions followed by necrosis), inhalation (mild pneumonia with hemorrhagic mediastinitis and ARDS), GI (bloody diarrhea) PCR, gram stain, immunofluorescence
Clostridia tetani
Tennis racket shaped rod (spore former) Anaerobic Foul odor tetanospasmin (spasmogenic toxin or tetanus toxin) which blocks inhibitory neurotransmitter release Muscle spasms and convulsions (tetanus) Anaerobic culture
Clostridia perfringens
rod (spore former) Anaerobic Foul odor Exotoxins Gas gangrene Anaerobic culture
Clostridia botulinum
rod (spore former) Anaerobic Foul odor 8 botulinum exotoxins (A, B…), A is most potent exotoxin known, block ACh release Flaccid paralysis, diplopia, dysarthria, dysphonia, dysphagia, respiratory failure, infant (honey), wound (penetrating) difficult - give botulinum antitoxin
Clostridia difficile
rod (spore former) Anaerobic Foul odor Toxin A (enterotoxin), toxin B (cytopathic which kills GI cells) Pseudomembranous enterocolitis (replacement of normal flora), watery diarrhea Anaerobic culture
Corynebacteria diphtheriae
rod-like to club-shaped Aerobe to facultative anaerobe Catalase +, mycolic acid Tox (diphtheria toxin) - B allows A(ctive) fragment to enter stopping protein synthesis (Elongation Factor 2) Pseudomembrane in upper airway, edema Schick test (previous immunity), Tellurite media (black colonies)
Listeria monocytogenes
bacilli Facultative anaerobe Catalase +, intracellular parasite Listeriolysin O to survive in macrophage phagolysosome, can polymerize actin to transfer to new cells Listeriosis (food-borne in meats, raw vegetables, etc.), miscarriage, stillbirth, neonatal sepsis culture from blood or CSF, motile
Gardnerella vaginalis
coccobacilli Facultative anaerobe Bacterial vaginosis - clue cells and fishy odor culture
Peptostreptococcus magnus
cocci Anaerobic Opportunistic Skin and soft tissue infections, deep organ abscesses Anaerobic culture
Peptostreptococcus anaerobius
cocci Anaerobic Opportunistic Oral infections Anaerobic culture
Mycobacteria tuberculosis & bovis
Rod-like filamentous Aerobic Catalase +, mycolic acid, peptidoglycan Cord factors prevent phagocytosis Tuberculosis (airborne or unpasteurized cow milk), M. bovis BCG for vaccine Ziehl-Neelsen stain
Mycobacteria leprae
Rod-like filamentous Aerobic Catalase +, mycolic acid, peptidoglycan Cord factors prevent phagocytosis Tuberculoid (5 or fewer lesions with no organisms) or lepromatous leprosy (6 or more with bacilli) - Hansen disease Ziehl-Neelsen stain
Nocardia asteroides
filamentous Aerobic Opportunistic intracellular pathogen Found in soil and gingiva Pleurocutaneous nocardiosis (resembles tuberculosis and CNS infections) Cultures
Nocardia brasilienses
filamentous Aerobic Opportunistic intracellular pathogen Found in soil and gingiva Primary cutaneous nocardiosis (cellulitis, lymphocutaneous disease, actinomycetoma) Cultures
