Experimental evolution of Aeromonas ZOR0001 for host adaptation

Animals are colonized by dynamic communities of bacteria, largely acquired by transmission from the external environment and other hosts; however, the traits that promote a microbe's ability to be host-associated (i.e. to colonize or otherwise exist within a host) are not fully understood. We used the zebrafish as a tractable host-microbe model system to investigate how a zebrafish gut isolate, Aeromonas veronii (ZOR0001; Aer01), increases its ability to be host-associated. Our selection regime consisted of serially exposing larval zebrafish to Aer01, each time selecting for gut-associated populations. In this way, evolved isolates could be generated in order to identify adaptive mutations and discover the mechanisms of adaptation.