Other Fermenting GNRs

Question 1

Genera that are considered unusal fermenters

Answer 1

• Vibrio
• Aeromonas
• Plesiomonas
• Campylobacter

Question 2

Inflammation of the stomach and intestines, resulting from bacterial toxins or viral infection and causing vomiting and diarrhea

Answer 2

Gastroenteritis

Question 3

Infection of the intestines rsulting in severe diarrhea w/ the presence of blood and mucous in the feces

Answer 3

Dysentery

Question 4

Stool specimen collection requirements

Answer 4

Stool or rectal swab has a 2 hour window if placed in a sterile cup

Question 5

Stool specimen preservatives

Answer 5

• Cary Blair
• Buffered glycerol saline
• Alkaline peptone water
• Modified Stuart’s

Question 6

Oxidase positive, fermenters of glucose, isolated in coastal areas (fresh, brackish, and salt water), associated w/ seafood consumption

Answer 6

Vibrio sp. characteristics

Question 7

Describe vibrio morphology

Answer 7

• Curved, comma shaped GNRs,
• Polar flagella,
• Halophilic (requires Na)

Question 8

Caused by Vibrio, spread by fecal-oral route, severity variable but usually severe diarrhea, death results from massive fluid loss/shock/acidosis

Answer 8

Cholera

Question 9

Notorious pathogen, no tissue invasion, enterotoxin production (adheres to small intestine), “rice water” stools

Answer 9

Vibrio cholera

Question 10

Treatment of cholera

Answer 10

• Fluid/electrolyte replacement

- Tetracycline in severe cases

Question 11

Collection/transport requirements for stool/wounds (cholera)

Answer 11

Stool
- Susceptible to desiccation, w/in first 24 hours of infection
- Cary Blair at room temp (no buffered glycerol saline transport)
Wounds
- Sterile swabs

Question 12

What do we use to isolate cholera?

Answer 12

• Thiosulfate Citrate Bile Salts Sucrose Agar (TCBS agar)
• SBA
• MAC

Question 13

Describe TCBS agar

Answer 13

• Green plate
• Selective and differential
• Sucrose fermenters (yellow colonies) vs. non-sucrose fermenters (green colonies)

Question 14

Hemolysis present on SBA from cholera

Answer 14

Beta

Question 15

MAC results in cholera

Answer 15

Most lactose negative

Question 16

Incubation requirements for cholera

Answer 16

Ambient air at 35C

Question 17

What methods can we use to identify cholera?

Answer 17

• String test
• Vibriostatic test
• KIA and Phase II
• Automation
• MALDI-TOF
• O1 ro O139 antisera

Question 18

List 3 non-cholera vibrios

Answer 18

• V. parahaemolyticus
• V. vulnificus
• V. alginolyticus

Question 19

Endemic to Japan, mild gastroenteritis (ingestion of raw fish), wound infections (contaminated water), Kanagawa Phenomenon, does NOT ferment glucose

Answer 19

V. parahaemolyticus

Question 20

More wound infections than diarrhea (contaminated seawater), septicemia, invasive, liver disease, non-sucrose fermenting

Answer 20

V. vulnificus

Question 21

Wound infections, infections of ears and eyes, infrequently isolated in clinical laboratory, ferments sucrose

Answer 21

V. alginolyticus

Question 22

Straight, coccobacillary GNR, polar flagellum, inhabitants of aquatic ecosystems (fresh and brackish); obtained from fresh produce, meat, and dairy products or exposure to aquatic source

Answer 22

Aeromonas sp

Question 23

Causes gastroenteritis (mild watery, self-limiting diarrhea, spring to fall seasons) and extraintestinal infections

Answer 23

Aeromonas sp

Question 24

Specimen collection and transport for Aeromonas sp

Answer 24

Stool: Cary-Blair or buffered glycerol saline as transport; process w/in 2 hours
Wounds: sterile swabs

Question 25

Media to isolate Aeromonas

Answer 25

SBA, MAC, CIN, KIA and Phase II, automation, MALDI-TOF

Question 26

Oxidase positive, fermenter, vibriostatic agent of O129 test, inability to grow in 6% NaCl

Answer 26

Aeromonas sp

Question 27

CIN media characteristics

Answer 27

Cefsulodin-irgasan-novobiocin (CIN)

- inhibits normal flora in stool

Question 28

Straight GNR, single species (one organism), polar flagellum, ubiquitous natural habitat in soil and fresh water, oxidase positive, glucose fermenter, lysine/ornithin/arginine positive

Answer 28

Plesimonas shigelloides

Question 29

Causes gastroenteritis (mild, chronic, or invasive), extraintestinal infections

Answer 29

P. shigelloides

Question 30

Isolation of P. shigelloides

Answer 30

SBA or MAC (enteric media)

Question 31

Curved or S-shaped, seagull wing GNRs, polar flagellum, microaerophilic and capnophilic (37-42C), normal habitats in GI tracts of poultry, dogs, cats, sheep, cattle,a nd humans; zoonotic (animal to human)

Answer 31

Campylobacter sp

Question 32

Causes gastroenteritis (C. jejuni), transmitted by contaminated food, self-limiting (similar to acute appendicitis), late summer/early fall occurrence, most common enteric pathogen

Answer 32

Campylobacter sp

Question 33

Cuases febrile systemic disease (Guillain-Barre’s syndrome) and periodontal disease

Answer 33

Campylobacter sp

Question 34

Methods to isolate and identify Campylobacter

Answer 34

Selective blood-based media (Campy-CVA) or charcoal-based (CSM); incubate at 42C, 5% O2, 10% CO2, 85% N for 48 hours

Question 35

Hippurate hydrolysis positive, oxidase positive, catalase positive, curved GNR

Answer 35

Campylobacter sp

Question 36

Spiral shaped GNR, natural habitat is human gastric mucosa (Dr. Barry Marshall’s experiment)

Answer 36

Helicobacter pylori

Question 37

Causes gastric and duodenal ulcers, peptic ulcer disease, and gastric cancer, rarely found in stool specimens

Answer 37

Helicobacter pylori

Question 38

Diagnosed by Ag detection, biopsy, urease testing, brucella agar w/ 5% horse blood, and ELISA tests for IgG

Answer 38

Helicobacteri pylori