Friday, October 22, 2010

Cholera Has a Vacation Home

I'm quickly learning how challenging it is to keep up with even a weekly commitment to a blog entry, so this one is last week's entry, a few days late. I'm gonna keep plugging away at it though.

This week's paper is Kathryn L. Cottingham, Deborah A. Chiavelli, and Ronald K. Taylor. 2003. Environmental microbe and human pathogen: the ecology and microbiology of Vibrio cholerae. Frontiers in Ecology and the Environment 1: 80–86. It is a review of the state of research on Vibrio cholerae in its aqautic environment. I picked it because I got a tip that my advisor may ask me to repeat my current experiment on V. cholerae, and I thought I should start learning more about it. V. cholerae is in the same genus as my current experimental organism, Vibrio vulnificus, and they have a lot in common. They both inhabit two environments (human and aquatic) and they both can enter a Viable But Non-Culturable (VBNC) state. V. cholerae is more interesting to funds-granting organizations since it causes more infections, so it would be beneficial to include it in any papers we generate.

When in the aquatic environment, V. cholerae can be either free-swimming, or attached to a substrate. In the attached form, it may form a biofilm, an organized aggregation of many thousands of V. cholerae cells. Biofilms provide protection for the cells against predation and antibiotics, but the mechanism of their formation is not well-known. Cells may attach to phytoplankton or zooplankton, which provides a nutrient-rich environment in which V. cholerae can multiply.

The aim of the paper appears to be not to reveal any new information about V. cholerae, but to point out that very little is known about the aquatic state. The paper raises more questions than it answers, and concludes with a list of areas for new research. These include comparing gene expression between the aquatic both free-swimming and attached) and infectious forms, and determining what, if any, genes are responsible for transition into the VBNC state.

UPDATE: I started writing this blog entry last night; this morning Haitian officials confirmed that a cholera outbreak is plaguing an area of the country where many refugees headed after the earthquake to escape the conditions in Port-au-Prince. Since V. cholera is shed in the feces and vomit of infected individuals, and can be contracted from drinking contaminated water, outbreaks are common in areas with poor sanitation, such as the temporary housing in Haiti. Read more here:

No comments:

Post a Comment