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

Sierra Leone faces criticism over Ebola shutdown

1 minute ago

Sierra Leone began the second day of a 72-hour nationwide shutdown aimed at containing the spread of the deadly Ebola virus on Saturday amid criticism that the action was a poorly planned publicity stunt.

Presence of peers ups health workers' hand hygiene

14 hours ago

(HealthDay)—The presence of other health care workers improves hand hygiene adherence, according to a study published in the October issue of Infection Control and Hospital Epidemiology.

Sierra Leone streets deserted as shutdown begins

22 hours ago

Sierra Leone's normally chaotic capital resembled a ghost town on Friday as residents were confined to their homes for the start of a three-day lockdown aimed at halting the deadly Ebola epidemic.

Sierra Leone launches controversial Ebola shutdown

Sep 19, 2014

Sierra Leone on Friday launched a controversial three-day shutdown to contain the deadly spread of the Ebola virus, as the UN Security Council declared the deadly outbreak a threat to world peace.

User comments