Get Full Government Meeting Transcripts, Videos, & Alerts Forever!
Get email alerts on the Vibrio Environmental Reservoirs topic
No spam. Unsubscribe anytime.
Lecturer reports deep-sea copepods carry Vibrio cholerae nearly identical to known strains
Summary
A university lecture presented sequencing data showing Vibrio cholerae isolated from deep‑sea copepods at hydrothermal vents closely match previously sequenced V. cholerae, suggesting broad environmental reservoirs and prompting ongoing genomic analysis.
A lecturer at the President's Lecture Series told the seminar that Vibrio cholerae bacteria isolated from deep‑sea copepods were “practically identical” to V. cholerae found in near‑shore and human‑associated samples.
The finding matters because it supports an environmental reservoir model for cholera: the bacterium can persist in a range of aquatic habitats and associate with zooplankton, which may help explain biogeography and evolution of pathogenic strains.
The lecturer described samples collected from around hydrothermal vents on the East Pacific Rise at about 2,500 meters. Copepods recovered during Alvin dives were plated on TCBS (thiosulfate‑citrate‑bile salts) agar, yielding colonies that were phenotypically consistent with Vibrio. Subsequent genetic testing and genome sequencing — work done in collaboration with teams including researchers at Los Alamos — showed high similarity between the vent isolates and reference V. cholerae genomes across both chromosomes. The lecturer said the team has sequenced about 27 V. cholerae isolates and is analyzing their global biogeography by source (for example, Africa, South America, Chesapeake Bay, Asia).
Comparative analysis also showed strong similarity between the vent isolates and other Vibrio species such as V. vulnificus and V. parahaemolyticus, the lecturer said, noting this could reflect an ancestral environmental lineage and active lateral gene transfer in open pan‑genome bacteria. The lecturer attributed the outcome to full‑chromosome sequencing led in part by collaborators including John Heidelberg and earlier mapping by James Kaper’s group.
The lecturer cautioned that genomic comparisons are ongoing and described planned analyses to define core genes, species‑specific genes and laterally transferred elements that distinguish pathogenic from nonpathogenic strains. She said these comparisons could help trace divergence timelines by comparing Vibrio from geographically separated deep‑sea hosts.
The lecturer concluded that the results point to complex environmental reservoirs for human pathogens and said additional sequencing and comparative genomics are underway to clarify evolutionary relationships and possible transmission pathways.
