The Microbiome and a Bacterial Infection of Oxytricha trifallax

Abstract

The microbiome of O. trifallax has been a completely unexplored field of ciliate research. While other bacterial-ciliate relationships have been shown to have great effects on the lifecycles of these other ciliates, both harmful and necessary, no prior studies have yet been performed in O. trifallax. In order to rectify this, studies consisting of both high-throughput sequencing of the bacterial 16s rDNA locus and fluorescence in situ hybridization (FISH) against bacterial 16s rRNA within O. trifallax have been performed, and a great deal of variation has been found. Furthermore, a population of sick O. trifallax cells has been investigated, and this phenotype was determined to have been caused by a bacterial infection where one of the members is of the genus Ralstonia. Various experiments have also been performed in order to recreate this phenotype, and while this was not achieved, these studies have shown that O. trifallax is robust to the presence of some variant bacteria and to the absence of bacteria in general, while susceptible to the presence of others. This evidence suggests both a robustness and a susceptibility of O. trifallax to bacteria depending on which bacteria are present and at what levels they are present.