Question

Motility is a key initial assessment in the presumptive identification of the nonfermentative gram-negative bacilli. All of the following organisms are motile except

a) Pseudomonas aeruginosa
b) Acinetobacter baumannii
c) Burkholderia cepacia
d) Escherichia coli

Answer 1

Among the options given, Acinetobacter baumannii is the non-motile organism that will not demonstrate motility in a semi-solid medium, while Pseudomonas aeruginosa, Burkholderia cepacia, and Escherichia coli are motile.

Step-by-step explanation:

In the context of identifying nonfermentative gram-negative bacilli, motility is an essential characteristic for the presumptive identification. Among the bacteria listed, Pseudomonas aeruginosa, Burkholderia cepacia, and Escherichia coli are all motile, possessing flagella that allow them to move through semi-solid media and appear cloudy around the stab line. However, Acinetobacter baumannii is the non-motile organism in the list, characterized by its growth restricted to the stab line only.