How cholera-causing bacteria respond to pressure

Cholera remains common in non-industrialized parts of the world today. It persists in part because V. cholera, the bacteria that causes the disease, is able to survive in diverse environments ranging from the intestinal lumen, to fresh water, to estuaries, to the sea. A study in The Journal of General Physiology provides new insights about the membrane components of V. cholera that enable it to withstand otherwise deadly increases in osmotic pressure resulting from changes in its surrounding environment.

Like other bacteria, V. cholera utilizes mechanosensitive channels to respond to rapid shifts in the external osmolarity. But the specific details of how it does so are unclear.

Now, researchers from the University of Maryland utilize techniques previously used on E. coli to analyze the functional properties of V. cholera. Sergei Sukharev and colleagues performed the first patch-clamp analysis of channels in the of V. cholera and compared them with those in E. coli.

They found that the gating and conductive properties of V. cholerae channels were comparable to those of their E. coli counterparts. A further comparison of the responses of channels in the two species indicated that, whereas small-conductance MscS-like channels were less dense in V. cholerae than in E. coli, large conductance MscL-type channels were present at higher density. Surprisingly, however, V. cholerae was more sensitive than E. coli to abrupt decreases in osmolarity.

The findings suggest that the increased number of MscL channels might help compensate for other traits rendering V. cholerae vulnerable to osmotic shock.

More information: Rowe, I., et al. 2013. J. Gen. Physiol. doi:10.1083/jgp.201310985 Adler, E.M. 2013 J. Gen. Physiol. doi:10.1083/jgp.201311041

add to favorites email to friend print save as pdf

Related Stories

Researchers work towards pharmacological targets for cholera

Jan 20, 2011

Just over a year after the earthquake in Haiti killed 222,000 people there's a new problem that is killing Haitians. A cholera outbreak has doctors in the area scrambling and the water-borne illness has already claimed 3600 ...

Recommended for you

What exactly is coronavirus?

5 hours ago

The conflicts in Syria and Iraq are straining public health systems and public health efforts meant to prevent and detect the spread of infectious diseases. This is generating a "perfect storm" of conditions for outbreaks. Among the infections raising concern is Middle East Respiratory Syndrome, caused by a type of coronavirus, which emerged in 2012. ...

Scientists find Ebola virus is mutating

5 hours ago

(Medical Xpress)—Researchers working at Institut Pasteur in France have found that the Ebola virus is mutating "a lot" causing concern in the African countries where the virus has killed over eight thous ...

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.