Deck 27: Moraxella

Question 1

Differentiation of Moraxella lacunata from other Moraxella species can best be done by testing for

A)the ability to utilize acetate.
B)the ability to liquefy serum.
C)glucose utilization tests.
D)growth on MacConkey agar.

Answer 1

B
M. lacunata is able to liquefy serum, so depressions are formed on the surface of Loeffler's serum agar slants.

Question 2

Differentiation of Neisseria elongata subsp.glycolytica from other Moraxella species can best be done by testing for

A)the ability to utilize acetate.
B)the ability to liquefy serum.
C)glucose utilization tests.
D)growth on MacConkey agar.

Answer 2

B
Most of the species considered in this chapter do not utilize glucose; Neisseria elongata subsp. glycolytica, which produces acid from glucose in the rapid sugar test used for Neisseria spp., is the only exception.

Question 3

The species of Moraxella that is most commonly associated with human infections, primarily of the respiratory tract, is

A)Moraxella catarrhalis.
B)Moraxella lacunata.
C)Moraxella canis.
D)Moraxella atlantae.

Answer 3

A
Moraxella catarrhalis is the species most commonly associated with human infections, primarily of the respiratory tract.

Question 4

In Gram-stained preparations, Moraxella lincolnii will appear as

A)either gram-negative coccobacilli or short, broad rods that tend to resist decolorization and may appear gram-variable.
B)gram-negative cocci in pairs or short chains.
C)coccobacilli or medium-sized rods.
D)coccobacilli that may appear in chains.
E)either coccobacilli or short, straight rods.

Question 5

In Gram-stained preparations, Moraxella lacunata will appear as

A)either gram-negative coccobacilli or short, broad rods that tend to resist decolorization and may appear gram-variable.
B)gram-negative cocci in pairs or short chains.
C)coccobacilli or medium-sized rods.
D)coccobacilli that may appear in chains.
E)either coccobacilli or short, straight rods.

Question 6

In Gram-stained preparations, Moraxella atlantae will appear as

A)either gram-negative coccobacilli or short, broad rods that tend to resist decolorization and may appear gram-variable.
B)gram-negative cocci in pairs or short chains.
C)coccobacilli or medium-sized rods.
D)coccobacilli that may appear in chains.
E)either coccobacilli or short, straight rods.

Question 7

Differentiation of Moraxella nonliquefaciens and M.osloensis can best be done by testing for

A)the ability to utilize acetate.
B)the ability to liquefy serum.
C)glucose utilization tests.
D)growth on MacConkey agar.

Question 8

True cocci, such as most Neisseria spp.and Moraxella (Branhamella) catarrhalis, can be differentiated from morphologically similar Moraxella species by

A)comparing the penicillin susceptibility testing results of the bacteria.
B)subjecting the bacterium to noninhibitory concentrations of penicillin.
C)the resistance of Moraxella to many beta-lactam antimicrobials.
D)performing the DNA test.

Question 9

In Gram-stained preparations, Moraxella elongata appears as

A)either gram-negative coccobacilli or short, broad rods that tend to resist decolorization and may appear gram-variable.
B)gram-negative cocci in pairs or short chains.
C)coccobacilli or medium-sized rods.
D)coccobacilli that may appear in chains.
E)either coccobacilli or short, straight rods.