2016 ISME Meeting - Montréal, Quebec

Yan and Paul (here pictured in the amazing Montréal Convention Centre) safely returned from Quebec, where they attended the 16th International Symposium on Microbial Ecology hosted by the International Society for Microbial Ecology (ISME) on August 21-26, 2016. Yan and Paul presented posters titled "Relatives of Vibrio cholerae pandemic strains can be found in non-endemic areas using a novel culture-independent method" and "Mosaic evolution of the Vibrio cholerae Type VI secretion system," respectively. Both posters are projects of Paul, who has clearly been very busy.

At the beautiful Palais des congrès de Montréal

Tania is Back in Bangladesh for More Field Work

From June 29 to August 15, 2016, Tania worked in Dr. Munirul Alam's lab in the International Centre for Diarrhoeal Disease Research, Bangladesh. They worked on a collaborative project, "Genetic tracking and characterization of naturally occurring Vibrio cholerae causing endemic cholera in Bangladesh." There, she helped organize the last rounds of sampling of environmental water to isolate V. cholerae from eight different sites around Dhaka City.

Vibrio cidicii, a Novel Vibrio Species Closely Related to Vibrio navarrensis

The official species description paper of the novel Vibrio species, Vibrio cidicii, is now out. The paper is entitled "Characterization of clinical and environmental isolates of Vibrio cidicii sp. nov., a close relative of Vibrio navarrensis" and published in the International Journal of Systematic and Evolutionary Microbiology. Vibrio cidicii was initially identified by the group of Dr. Cheryl Tarr from the Centers for Disease Control and Prevention (CDC) while studying clinical isolates of V. navarrensis. Thus, the new species was named after the CDC.

Characterization of the isolates involved extensive biochemical and genotypic tests, including whole-genome comparisons with close relatives, V. navarrensis and Vibrio vulnificus. Metabolic profiling found one major phenotypic difference between V. cidicii from its closest relatives, the utilization of L-rhamnose, where the V. cidicii isolates are able to utilize the substrate. Genome comparisons and multilocus sequence analysis (MLSA) show that the V. cidicii genomes to belong to a species different from V. navarrensis and V. vulnificus.

This work was in collaboration with the teams of Dr. Cheryl Tarr (CDC), Dr. I. King Jordan (Georgia Institute of Technology), and Dr. Rebecca Case (Department of Biological Sciences). This is the second novel Vibrio species characterized from the Boucher Lab (Vibrio metoecus being the first one).

MLSA of housekeeping genes show distinct clustering of V. cidicii from its closest relatives (from Orata et al., 2016)

Genome Sequences of Bacteria in Close Association with Emiliania huxleyi

Yan and Fabini, in collaboration with the lab of Dr. Rebecca Case (also from the Department of Biological Sciences), released two Genome Announcements today on the genome sequences of bacterial strains isolated from the polymicrobial cultures of coccolith-bearing and naked (no coccolith) microalga Emiliania huxleyi. The Case Lab isolated multiple bacteria from these cultures, including strains of Balneola sp., Erythrobacter sp., Jannaschia sp., Marinobacter sp., Roseovarius sp., and Sulfitobacter spp. among others, which form a symbiotic relationship with E. huxleyi. The Boucher Lab sequenced the genomes of these isolates. This is part of an ongoing work with both labs. We are currently working on resolving the taxonomic inconsistencies within the Rhodobacteraceae family, specifically within the Rosobeacter clade, by comparative genomic analysis.

Population Structure of Single-Source Vibrio cholerae

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)

2016 CIFAR-IMB General Meeting – Toronto, Ontario

The Integrated Microbial Biodiversity (IMB) Program of the Canadian Institute for Advanced Research (CIFAR) held its annual conference for members (and their students) at the Intercontinental Hotel, Toronto, Ontario on June 1-4, 2016. The conference was remarkable, with amazing talks from distinguished scientists from different parts of the world, lively scientific discussions, and sharing of innovative ideas.

Yan was accompanied by Tareq this year. Yan gave a talk entitled "Relatives of Vibrio cholerae pandemic strains can be found in non-endemic areas using a novel culture-independent method," and Tareq presented a poster of his current work entitled "The elusive descendants of the pandemic Vibrio cholerae ancestor: a diverse and dangerous bunch."

Toronto skyline