Final Exam (new info)

Question 1

Non-branching, catalase positive

Answer 1

Bacillus, Listeria, Corynebacterium

Question 2

Non-branching, catalase negative

Answer 2

Erysipelothrix, Lactobacillus

Question 3

Branching or Partially Acid Fast

Answer 3

Nocardia

Question 4

Confirmatory “test” for Bacillus species

Answer 4

Endospore staining

Question 5

Virulence factors of Bacillus anthracis

Answer 5

Polypeptide capsule, potent endotoxins, edema toxin, lethal toxin

Question 6

Most common form of anthrax

Answer 6

Cutaneous anthrax

Question 7

How can anthrax be acquired?

Answer 7

contamination of wound (cutaneous anthrax), inhalation of spores (pulmonary anthrax/wool sorter’s disease), ingestion (gastrointestinal anthrax)

Question 8

Clinical presentation of Bacillus cereus

Answer 8

food poisoning, diarrheal syndrome, is associated with rice, meat, poultry, and soups

Question 9

Differentiation between Listeria monocytogenes and Group B Strep

Answer 9

Catalase positive (Group B Strep is catalase negative)

Question 10

Listeria monocytogenes biochemical results

Answer 10

Catalase positive
Bile esculin positive
Umbrella motility
Block-type hemolysis on CAMP test
Beta hemolytic

Question 11

Clinical presentation of diphtheria

Answer 11

respiratory: acquired by droplet spray, can cause demyelinating peripheral neuritis, cardiac failure, paralysis
cutaneous: infections occur at the site of minor abrasions; nonhealing ulcers with a dirty gray membrane

Question 12

Corynebacterium diphtheriae biochemical results

Answer 12

Catalase positive
Bile esculin negative

Question 13

Erysipelothrix rhusiopathiae biochemical results

Answer 13

Catalase negative
production of H2S on TSI

Question 14

Erysipelothrix rhusiopathiae clinical presentation

Answer 14

infection through occupational exposure: farmers, butches, fishermen
Erysipeloid: produces painful swelling usually on the hands or fingers
Endocarditis may occur in patients with valve replacements

Question 15

Gardnerella vaginalis clinical presentation

Answer 15

Bacterial vaginosis (BV): malodorous (fishy) discharge, vaginal pH greater than 4.5

Question 16

How can Nocardia species be identified?

Answer 16

Using paraffin bait test: only Nocardia can break it down as a substrate

Question 17

Nonselective anaerobic culture media

Answer 17

Cooked meat broth, Anaerobic blood agar, Egg-yolk agar (EYA), Peptone-yeast extract glucose broth (PYG), Thioglycolate broth

Question 18

Selective anaerobic culture media

Answer 18

Bacteroides bile esculin agar (BBE), Laked Kanamycin-vancomycin blood agar (LKV), Anaerobic phenylethyl alcohol agar (PEA), Cycloserine cefoxitin fructose agar (CCFA)

Question 19

Clostridium perfringens clinical presentation

Answer 19

Type A and C most common for disease
Acute gastrointestinal infections: diarrhea to necrotizing enterocolitis
Most common cause of Gas Gangrene (myonecrosis)

Question 20

Clostridium difficile clinical presentation

Answer 20

Most common cause of nosocomial infections associated with antibiotic use
Causes watery diarrhea, pseudomembranous colitis with destruction of intestinal lining, toxic colon

Question 21

Propionibacterium acnes clinical presentation

Answer 21

Infections of human skin (pimples), intestines, corneal ulcers, heart valves, prosthetic devices (artificial joints), ventricular shunts
Can present as osteomyelitis, bacteremia, endocarditis, meningitis

Question 22

Difference between Nocardia and Anaerobic Actinomyces species

Answer 22

Nocardia grows aerobically and stain acid fast
Actinomyces does not!

Question 23

Actinomyces biochemical results

Answer 23

CAMP -
Catalase -
No hemolysis
Indole -
Nitrate reduction +

Question 24

Actinomyces species clinical presentation

Answer 24

“lumpy jaw”, sulfur granules in fluid, abdominal GI lesions, colonization of female genital tract, indistinguishable from pelvic inflammatory disease, associated with long term use of IUDs

Question 25

Bacteroides spp. virulence factors

Answer 25

pili, fimbriae, adhesins, peroxidase, superoxide dismutase, lipopolysaccharide endotoxin, capsular polysaccharide toxin

Question 26

Bacteroides fragilis group biochemical results

Answer 26

Esculin hydrolysis + Indole - Urease - Catalase + Oxidase +/- Ferments glucose, sucrose, lactose, maltose

Question 27

Bacteroides fragilis group clinical presentation

Answer 27

GI mucosal barrier breach, diarrhea from enterotoxigenic B fragilis (ETBF), produces beta-lactamase

Question 28

Porphyromonas species biochemical results

Answer 28

Esculin hydrolysis + Catalase - Indole -

Question 29

Porphyromonas species clinical presentation

Answer 29

Periodontal disease, inflammatory bowel disease

Question 30

Fusobacterium species biochemical results

Answer 30

Catalase +/- Lipase - Indole +/- Esculin hydrolysis -

Question 31

Fusobacterium species clinical presentation

Answer 31

Lemierre's syndrome: thrombophlebitis of the internal jugular vein Abscesses, bacteremia, puerperal infections, septic shock

Question 32

Veillonella species biochemical results

Answer 32

Non-motile Ferments lactate Reduces nitrate to nitrite

Question 33

Peptostreptococcus species biochemical results

Answer 33

Urease +/- Catalase - Indole - Nonhemolytic

Question 34

Common isolates of Peptostreptococcus species

Answer 34

P. magnus P. anaerobius P. asaccharolyticus