What characteristic distinguishes Campylobacter jejuni from other bacteria?

Campylobacter jejuni is notably distinguished by its unique morphology and motility, characterized by a curved shape and the presence of polar flagella. This distinctive curve, often described as a "comma" or "S" shape, sets it apart from many other bacterial species, which may have straight or spherical forms. The polar flagella enable Campylobacter jejuni to exhibit a noteworthy motility pattern, aiding in its ability to navigate through the viscous environments of the intestinal tract where it commonly resides.

In contrast, the other characteristics presented do not accurately describe Campylobacter jejuni. For instance, this organism does not produce gas from glucose fermentation, a trait often associated with other types of bacteria, like Enterobacteriaceae. Additionally, Campylobacter jejuni is not considered an obligate anaerobe; it is a microaerophilic organism, requiring reduced oxygen levels for optimal growth. Lastly, it is classified as a Gram-negative bacterium and does not present as Gram-positive cocci, which refers to a different category of bacteria entirely. The curved shape and polar flagella uniquely identify Campylobacter jejuni in the context of microbiological classification.