Gram positive bacteria

Question 1

Streptococci pyogenes (strep A)

Answer 1

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

Question 2

Streptococci agalactiae (strep B)

Answer 2

cocci in chains Facultative or obligate anaerobes Catalase - encapsulated neonatal septicemia, meningitis, and pneumonia Culture

Question 3

Streptococci bovis/equinus (strep D)

Answer 3

cocci in chains Facultative or obligate anaerobes Catalase - Urinary tract infections Culture

Question 4

Streptococci pneumoniae

Answer 4

Lancet-shaped diplococcus Facultative or obligate anaerobes Catalase -, optochin sensitive encapsulated #1 bacterial pneumonia in adults (capsule), #1 otitis media in children Culture

Question 5

Streptococci viridans

Answer 5

cocci in chains Facultative or obligate anaerobes Catalase - dental caries, subacute endocarditis Culture

Question 6

Enterococci faecalis

Answer 6

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

Question 7

Staphylococci aureus

Answer 7

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

Question 8

Staphylococci epidermidis

Answer 8

cocci in clusters Facultative anaerobe Catalase +, Coagulase - biofilm covers prosthetics endocarditis Culture

Question 9

Staphylococci saprophyticus

Answer 9

cocci in clusters Facultative anaerobe Catalase +, Coagulase - UTI Culture

Question 10

Bacillus cereus

Answer 10

Boxcar rod (spore former) Aerobe to facultative anaerobe Heat stable enterotoxin (vomiting), heat labile enterotoxin (diarrhea) food poisoning PCR, gram stain, immunofluorescence

Question 11

Bacillus anthracis

Answer 11

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

Question 12

Clostridia tetani

Answer 12

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

Question 13

Clostridia perfringens

Answer 13

rod (spore former) Anaerobic Foul odor Exotoxins Gas gangrene Anaerobic culture

Question 14

Clostridia botulinum

Answer 14

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

Question 15

Clostridia difficile

Answer 15

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

Question 16

Corynebacteria diphtheriae

Answer 16

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)

Question 17

Listeria monocytogenes

Answer 17

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

Question 18

Gardnerella vaginalis

Answer 18

coccobacilli Facultative anaerobe Bacterial vaginosis - clue cells and fishy odor culture

Question 19

Peptostreptococcus magnus

Answer 19

cocci Anaerobic Opportunistic Skin and soft tissue infections, deep organ abscesses Anaerobic culture

Question 20

Peptostreptococcus anaerobius

Answer 20

cocci Anaerobic Opportunistic Oral infections Anaerobic culture

Question 21

Mycobacteria tuberculosis & bovis

Answer 21

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

Question 22

Mycobacteria leprae

Answer 22

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

Question 23

Nocardia asteroides

Answer 23

filamentous Aerobic Opportunistic intracellular pathogen Found in soil and gingiva Pleurocutaneous nocardiosis (resembles tuberculosis and CNS infections) Cultures

Question 24

Nocardia brasilienses

Answer 24

filamentous Aerobic Opportunistic intracellular pathogen Found in soil and gingiva Primary cutaneous nocardiosis (cellulitis, lymphocutaneous disease, actinomycetoma) Cultures

Question 25

Actinomycosis

Answer 25

filamentous Anaerobic Sulfur granules Live in mouth and tonsils Painful abscesses in the mouth, lungs, GI tract Anaerobic culture