Moraxella pluranimalium is a Gram-negative, aerobic, catalase- and oxidase-positive, non-spore-forming bacterium in the genus Moraxella. It was originally isolated from the nasal turbinate of a pig in Spain.
The species name pluranimalium is derived from the Latin pluri- (many) and animalium (of animals), referring to its isolation from multiple animal species.
In a survey of bacteria from healthy pigs in Great Britain (2014âÂÂ2015), one isolate of M. pluranimalium was found to carry the chromosomally-encoded mcr-6.1 gene, a variant of the colistin resistance determinant. Phenotypic testing showed reduced susceptibility to colistin.
The type strain (248-01) has been shown to harbor the chromosomal gene mcr-2.2, a close variant of mcr-2, conferring high-level resistance to colistin (MIC 16â¯mg/L). This strain is considered a likely natural source of mcr-2-type genes before their mobilization into plasmids circulating in Enterobacteriaceae.