Our lab's newest paper is finally out! Bacteria display a stunning array of diversity, from higher order groups all the way down to the subspecies level of endlessly differing strains. Our main organism of study, Vibrio cholerae, is no different. Only by deeply sampling groups of closely related organisms from the same environment can we begin to understand how this diversity arises – both for V. cholerae and bacteria in general. Using multi locus sequence typing and phylogenomics, we found that the scenic Oyster Pond and Lagoon ecosystem in Woods Hole, Massachusetts is dominated by a handful of distantly related V. cholerae strains, with many more found in much lower numbers, perhaps waiting for the right opportunity to rise to the top. The dominating strains show signs of ecological differentiation, but are likely in strong competition with each other, as evidenced by their different repertoires of type VI secretion system effectors that mediate fatal bacterial interactions. Oh, and some are bioluminescent!
The paper is entitled "A small number of phylogenetically distinct clonal complexes dominate a coastal Vibrio cholerae population" and published in Applied and Environmental Microbiology. The work is a carryover from Yan's postdoc at the Massachusetts Institute of Technology (as evidenced by having Dr. Kathryn Kauffman and Dr. Martin Polz from MIT as co-authors), so it has been a long time in the making!
Clonal backbone of V. cholerae sampled from different locations around Oyster Pond (from Kirchberger et al., 2016)