Mannheimia indoligenes

Mannheimia indoligenes is a species of Gram-negative, facultatively anaerobic bacteria in the family Pasteurellaceae. It was first described in 2024 based on a collection of 25 strains belonging to clade V of the genus Mannheimia, primarily isolated from cattle.
The type strain, M14.4^T, was originally isolated from the tongue of a healthy cow in Scotland between 1959 and 1961. However, other strains included in the species were isolated from a variety of tissues and from cattle with clinical disease. This suggests that M. indoligenes may form part of both the commensal and pathogenic microbiota in cattle.

Morphology and physiology

Mannheimia indoligenes cells are Gram-negative, non-motile rods. They are facultatively anaerobic and non-spore-forming. The bacterium produces indole and displays a distinct fatty acid and polar lipid profile. It uses coenzyme Q-7 as its sole respiratory quinone.

Pathogenicity

Although the type strain was recovered from a healthy animal, several other strains were isolated from cattle with disease. This supports a possible role for M. indoligenes in various infections, though further studies are needed to confirm pathogenic mechanisms and prevalence.