In addition to motility, which test best differentiates Acinetobacter spp. from Alcaligenes spp.?

The oxidase test is crucial for distinguishing between Acinetobacter spp. and Alcaligenes spp. because these two genera exhibit notably different responses to this test. Acinetobacter spp. are typically oxidase-negative, meaning they do not produce the enzyme cytochrome c oxidase. In contrast, Alcaligenes spp. are oxidase-positive, demonstrating the presence of this enzyme.

This difference is significant in clinical microbiology for identifying and classifying bacterial species. Understanding this biochemical property allows microbiologists to make more accurate diagnoses and choose appropriate treatment options based on the type of infection or condition caused by the bacteria.

While tests like TSI (Triple Sugar Iron), catalase, and flagellar staining can provide useful information about bacterial metabolism and structural characteristics, they do not offer the same level of clarity in differentiating these two groups as the oxidase test does.