About
Nearly all motile bacteria are able direct their motility to actively seek out favorable conditions (Hazelbauer et al., 2008). Most commonly, these bacterial cells use flagella to swim through liquid environments or swarm on surfaces. These whip-like appendages are anchored to a rotary motor in the cell envelope. For many pathogens, this type of motility is the first step in host invasion and is essential for survival within host tissues (Matilla and Krell, 2018; Shi et al., 1998). However, many pathogens are non-motile, such as viruses or bacteria that lack a motility apparatus. So how do they reach infection sites without the means to move themselves? Emerging evidence shows that non-motile entities can attach to motile species to benefit from motility without investing energy themselves (Muok and Briegel, 2020). For example, my lab discovered that non-motile bacterial spores are transported to beneficial environments by chemotactic soil bacteria via ‘hitchhiking’ (Muok et al., 2020a).
We hypothesize that such interspecies interaction is ubiquitous in nature, for example during host invasion of non-motile pathogens. In fact, dispersal of pathogenic, non-motile Staphylococci and Aspergilli via motile bacteria has been previously observed on abiotic surfaces, but the precise mechanism and impact on pathogenicity are unknown (Ingham et al., 2011; Samad et al., 2017). In this emerging research line, we are determining the structural interactions that enable hitchhiking behavior between motile bacteria and non-motile bacterial species, phages and viruses, and the implications for microbial distributions on pathogenicity.