News & Events
Deciphering the ecological niches of Vibrio cholerae
Speaker(s): A/Prof. Yan Boucher, Biological Sciences, University of Alberta, Canada
When: 17 May 2017 (3:00 - 4:00pm)
Where: SBS CR2 (Level 1)
Type: Seminars

Abstract

Vibrio cholerae is an enteric pathogen that can cause acute diarrhoea, leading to tens of thousands of deaths every year. It is a waterborne bacterium, ubiquitous in coastal ecosystems, but also one of the few causative agents of pandemic disease without an identified vector and defined life cycle. To gain insight into its ecology, we used a combination of culture-based and culture-independent techniques, exhaustively sampling populations in both non-endemic (USA) and endemic (Bangladesh) areas. Population genomics and massively parallel amplicon sequencing of a protein-coding gene unique to this species (viuB) revealed considerable variation in the relative abundance of various strains over the course of two years. Most notably, viuB alleles corresponding to the O1 serogroup responsible for pandemics were identified in non-endemic areas when no isolates of this group could be recovered, suggesting a lack of culturability. Furthermore, the O1 viuB alleles were strikingly absent from size fractions corresponding to free living cells, indicating a particle/host associated lifestyle. Sporadic blooms of O1 strains could be observed, providing a possible cause for the initiation of cholera outbreaks before transmission via the faecal-oral route.