Likely to survive in the oral cavity, bacteria evolved to divide along their longitudinal axis without parting from one another. A research team co-led by environmental cell biologist Silvia Bulgheresi from the University of Vienna and microbial geneticist Frédéric Veyrier from the Institut national de la recherche scientifique (INRS) just published their new insights in Nature Communications. In their work, they described the division mode of these caterpillar-like bacteria and their evolution from a rod-shaped ancestor. They propose to establish Neisseriaceae oral bacteria as new model organisms that could help pinpoint new antimicrobial targets.
Although our mouth houses over 700 species of bacteria and its microbiota is, therefore, as diverse as that of our gut, not much is known about how oral bacteria grow and divide. The mouth is a tough place to live in for bacteria. The epithelial cells lining the inner surface of the oral cavity are constantly shed and, together with salivary flow, organisms that inhabit this surface will therefore struggle for attachment. It is perhaps better to stick to our mouth that bacteria of the family Neisseriaceae have evolved a new way to multiply. Whereas typical rods split transversally and then detach from each other, some commensal Neisseriaceae that live in our mouths, however, attach to the substrate with their tips and divide longitudinally – along their long axis. In addition to that, once cell division is completed, they remain attached to one another forming caterpillar-like filaments. Some cells in the resulting filament also adopt different shapes, possibly to perform specific functions to the benefit of the whole filament. The researchers explain: "Multicellularity makes cooperation between cells possible, for example in the form of division of labor, and may therefore help bacteria to survive nutritional stress."








