Gram Positive Bacteria

Question 1

SHiN

Answer 1

Streptococcus pneumoniae, Haemophilus influenzae type B, Neisseria meningitidis

Encapsulated
IgA protease - cleaves IgA to colonize resp. mucosa
Transformation - can takue up DNA from environment

Question 2

Staphylococci

Answer 2

Catalase +
Coagulase + :S. aureus
Coagulase - :Novobiocin-Saprophyticus is Resistant; Epidermis is Sensitive
(On the office’s staph retreat, there was NO StRES)

Question 3

Streptococcus

alpha hemolysis

Answer 3

Green ring on blood agar
Strep pneumoniae (Optochin sens)
Viridans streptococci (Optochin res)
Optochin - Viridans is Resistant; Pneumoniae is Sensitive 
(OVRPS-overpass)

Question 4

Streptococcus

Beta hemolysis

Answer 4

Clear area on blood agar
Group A - Strep pyogenes (Bacitracin sens)
Group B - Strep agalactiae (Bacitracin res)
B-BRAS

Question 5

Streptococcus

gamma hemolysis

Answer 5

Enterococcus (E. faecalis)

Nonenterococcus (Strep bovis)

Question 6

Beta-hemolytic bacteria

Answer 6

form clear area of hemolysis on blood agar
Staph aureus
Strep pyogenes - Group A
Strep agalactiae - Group B
Listeria monocytogenes

Question 7

Staphylococcus aureus

Answer 7

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

Question 8

Staphylococcus epidermidis

Answer 8

Gram + cocci, Catalase +, Coagulase -, Novobiocin sensitive

uses biofilms to infect prosthetics and intravenous catheters

Question 9

Streptococcus pneumoniae

Answer 9

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

Question 10

Viridans group streptococcus

Answer 10

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)”

Question 11

Streptococcus pyogenes

Group A strep

Answer 11

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”

Question 12

Streptococcus agalactiae

Group B strep

Answer 12

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

Question 13

Enterococci

Group D strep

Answer 13

Enterococcus faecalis and E. faecium
Normal colonic flora that are pen G res and cause UTI and endocarditis
VRE - nosocomial infxns

Question 14

Streptococcus bovis

Group D strep

Answer 14

Colonize the gut and can cause bacteremia and endocarditis in colon cancer patients

Question 15

Corynebacterium diphtheriae
(coryne = club shaped)

Answer 15

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

Question 16

Spore-forming Gram + Bacteria formed in soil

Answer 16

Clostridium perfringes, C. tetani, B. cereus, C. botulinum, Coxiella burnetti

Question 17

Clostridia

Answer 17

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

Question 18

Listeria monocytogenes

Answer 18

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

Question 19

Actinomyces & Nocardia

Answer 19

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

Question 20

Mycobacteria

Answer 20

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)

Question 21

Mycobacterium leprae

Answer 21

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

Question 22

Bacillus cereus

Answer 22

Beta hemolytic gram + rod
Food poisoning in reheated rice
Starts quickly and ends quickly