Week 5 Canvas Questions

Which of the following might lead one to suspect that an organism is a nonfermenter?

A) Pink colonies on MacConkey agar

B) Cytochrome oxidase negative

C) Gram-negative bacillus

D) Alkaline slant and deep in TSI

D) Alkaline slant and deep in TSI

Which virulence factor of P. aeruginosa is associated with capsule production and resistance to phagocytosis?

A) Elastase

B) Alginate

C) Exotoxin A

D) Collagenase

B) Alginate

The most frequently isolated nonfermenter is:

A) Pseudomonas aeruginosa.

B) Acinetobacter lwoffi.

C) Alcaligenes faecalis.

D) Stenotrophomonas maltophilia.

A) Pseudomonas aeruginosa.

Nonfermentative gram-negative bacilli associated with environmental infections from contaminated medical devices that are oxidase-positive, oxidize glucose, and produce yellow-pigmented colonies include which of the following genera?

A) Chryseobacterium and Elizabethkingia

B) Chromobacterium and Comamonas

C) Sphingomonas and Oligella

D) Pseudomonas and Acidovorax

A) Chryseobacterium and Elizabethkingia

Indicate the correct group for each species listed.

P. aeruginosa Stutzeri group

P. mendocina Fluorescent group

B. cepacia Pseudomallei group

B. pseudomallei

P. putida

P. aeruginosa Fluorescent group

P. mendocina Stutzeri group

B. cepacia Pseudomallei group

B. pseudomallei Pseudomallei group

P. putida Fluorescent group

True or False? OF media has a high content of peptone and a low content of carbohydrate.

False

True or False? Both Pseudomonas aeruginosa and Burkholderia cepacia have been implicated in cases of pneumonia in those with cystic fibrosis.

True

The aspirated sputum collected from a patient on a ventilator showed a Gram stain with many Gram-negative bacilli and a moderate amount of neutrophils. The specimen was plated onto blood, chocolate, and MacConkey agars. There was a moderate amount of growth on each plate. The colonies on blood agar were shiny, resembling ground lead, with a zone of beta hemolysis. The colonies on MacConkey agar were colorless. The Gram stain indicates that the sputum

A) is contaminated

B) contains normal microbiota

C) seems to indicate an infectious state

D) was collected improperly

C) seems to indicate an infectious state

A gram-negative non fermentative gram-negative bacillus which had the odor of over ripened grapes, a green pigment, and was ADH +, LDC -, and ODC+. is most likely:

A) Proteus vulgaris

B) Pseudomonas aeruginosa

C) Burkholderia cepacia

D) Stenotrophomonas maltophilia

B) Pseudomonas aeruginosa

Define Halophilic

Preferring increased NaCl for growth

Define Capnophilic

Growth is enhanced in increased CO2

Define Microaerophilic

Preferring an environment with small amounts of oxygen

Define Zoonosis

infection transmitted from animals to humans

True or False? Vibrio cholerae is halophilic.

False

True or False? Aeromonas hydrophilia is found in fresh water, sea water, and tap water.

True

The classic strain of Vibrio cholerae 01:

A) is associated with more recent pandemics.

B) is resistant to polymyxin.

C) is nonhemolytic on sheep blood agar.

D) agglutinates chicken red blood cells.

C) is nonhemolytic on sheep blood agar.

Helicobacter is differentiated from Campylobacter by its rapid:

A) lactose fermentation.

B) urease production.

C) hydrolysis of bile esculin.

D) catalase production

B) urease production

Darting motility in wet preps is characteristic of:

A) Vibrio cholerae.

B) Campylobacter jejuni.

C) Aeromonas hydrophilia.

D) Plesiomonas

B) Campylobacter jejuni.

Which of the following Campylobacter species is an emerging periodontal pathogen?

A) C. coli

B) C. curvus

C) C. jejuni subsp. jejuni

D) C. fetus subsp. fetus

B) C. curvus

All of the following Vibrio would be expected to grow in salt water, except:

A) V. fluvialis.

B) V. parahaemolyticus

C) V. vulnificus.

D) V. mimicus.

D) V. mimicus.

Campylobacter jejuni ssp. jejuni has been identified as the cause of gastroenteritis in a small child. The child had eaten barbecued chicken, a hamburger, potato salad, and ice cream at a picnic. Based on the incidence of Campylobacter is these foods, which item was the most likely cause of the infection?

A) chicken

B) hamburger

C) potato salad

D) ice cream

A) chicken

The Gram stain of Campylobacter would most likely show:

A) Gram-negative curved rods

B) Gram-negative rods with bipolar staining

C) Gram-negative coccobacilli

D)Gram-negative S-shaped forms that resemble gull wings

D)Gram negative S-shaped forms that resemble gull wings

OF reactions show a yellow color in both the open and closed tubes for glucose, which would indicate:

A) the organism is oxidizing glucose.

B) the organism cannot utilize glucose.

C) the organism is fermentative.

D) the organism is a facultative aerobe.

C) the organism is fermentative.

Which of the following is true of Chryseobacterium?

A) Grows well on MacConkey agar

B) Is motile

C) Is oxidase negative

D) Produces yellow colonies on sheep blood agar

D) Produces yellow colonies on sheep blood agar

A nonfermentative, gram-negative bacillus that was oxidase positive and grew on MacConkey agar was isolated from the blood culture from a leukemic patient. The bacterium oxidized glucose and xylose and was unable to grow in 6.5% NaCl. Which of the following is the most likely bacterium?

A) Alcaligenes faecalis

B) Achromobacter xylosoxidans

C) Elizabethkingia meningosepticum

D) Acinetobacter baumannii

B) Achromobacter xylosoxidans

An oxidative, gram-negative bacillus isolated from a wound infection of a diabetic patient grew on sheep blood agar, producing feathery, alpha hemolytic colonies with a fruity odor of pears. OF media were very alkaline. This organism is most likely:

A) Pseudomonas aeruginosa and will grow at 42ºC.

B) Moraxella lacunata and will give a negative oxidase reaction.

C) Pseudomonas fluorescens and will produce yoverdine pigment.

D)Alcaligenes faecalis and will grow in 6.5% NaCl.

D)Alcaligenes faecalis and will grow in 6.5% NaCl.

True or False? The oxidase reaction can be used to differentiate Moraxella from Acinetobacter.

True

True or False? Most nonfermentative gram-negative bacilli are facultative anaerobes.

False

True or False? Moraxella can be differentiated from Neisseria gonorrhoeae using carbohydrate testing, such as CTA reactions.

True

Colonies isolated on sheep blood agar were oxidase positive and were found to utilize glucose, fructose and xylose in the open OF tubes which would lead one to suspect

A) a lactose fermenter from the family Enterobacteriaceae

B) a nonlactose fermenter from the family Enterobacteriaceae

C) a glucose fermenter

D) an oxidative organism

D) an oxidative organism

Pseudomonas aeruginosa

A) Produces pyocyanin and pyoverdin pigments

B) Is susceptible to most antibiotics

C) Is unable to grow at 42oC

D) Is unable to convert nitrates to nitrites

A) Produces pyocyanin and pyoverdin pigments

True or False? There has been a decrease in the incidence of infections from unusual gram-negative bacilli in recent years.

False

True or False? An epidemic is a widespread infectious disease that affects an entire continent or the whole world.

False

True or False? Campylobacter is catalase positive and oxidase negative.

False

When grown on TCBS agar, Vibrio parahaemolyticus appears __________ because it cannot ferment __________.

A) green, glucose

B) orange, sucrose

C) pink, lactose

D) green, sucrose

D) green, sucrose

Which Vibrio species is found in marine sources and is the agent of wound infections and septicemia that produces a cytolysin, causing severe infections in those with liver disease.

A) V. mimicus

B) V. fluvialis

C) V. parahaemolyticus

D) V. vulnificus

D) V. vulnificus

Arcobacter species:

A) are isolated as significant human pathogens more often than Campylobacter.

B) prefer a temperature of 35ºC to 37ºC for growth.

C) are found in swine and bulls.

D) require a capnophilic environment and are intolerant to oxygen.

C) are found in swine and bulls.

Which of the following is true of choleragen?

A) It is an enterotoxin that causes hypersecretion of water and electrolytes.

B) It penetrates the bowel mucosa with red cells present in the stool.

C) It is produced by both toxigenic and nontoxigenic strains of Vibrio cholerae..

D) It is an exotoxin that causes dehydration and electrolyte imbalance.

A) It is an enterotoxin that causes hypersecretion of water and electrolytes.

A case of cellulitis in a fisherman produced large, opaque, beta hemolytic colonies on sheep blood agar. The organism also grew on MacConkey agar, but failed to grow in 6.5% NaCl. This gram-negative bacillus was oxidase positive, indole positive, and fermented and produced gas from glucose. Of the following choices, which organism is most likely described?

A) Aeromonas hydrophilia complex

B) Vibrio parahaemolyticus

C) Aeromonas caviae complex

D) Alcaligenes faecalis

A) Aeromonas hydrophilia complex

Campylobacter are isolated on _________________.

A) Sheep blood agar

B) TCBS agar

C) Blood agar with antibiotics, (vancomycin, trimethoprim, polymyxin B) added

D) MacConkey agar

C) Blood agar with antibiotics, (vancomycin, trimethoprim, polymyxin B) added

Campylobacter jejuni ssp. jejuni has been isolated in an outbreak of foodborne disease. Complete the set of reactions to correctly identify this organism.

Urease

Hippurate Hydrolysis

Growth at 25o C

Growth at 37oC

Growth at 42o C

Nalidixic Acid

Cephalothin

Urease - negative

Hippurate Hydrolysis - Positive

Growth at 25oC - negative

Growth at 37oC - Positive

Growth at 42o C - Positive

Nalidixic Acid - Susceptibile (S)

Cephalothin - Resistant (R)