Association of <I>Vibrio cholerae</I> O1 El Tor and O139 Bengal with the copepods <I>Acartia tonsa</I> and <I>Eurytemora affinis</I>

Abstract

The association of <I>Vibrio cholerae</I> with zooplankton has been<SUP> </SUP>suggested as an important factor in transmission of human epidemic<SUP> </SUP>cholera, and the ability to colonize zooplankton surfaces may<SUP> </SUP>play a role in the temporal variation and predominance of the<SUP> </SUP>two different serogroups (<I>V. cholerae</I> O1 El Tor and O139) in<SUP> </SUP>the aquatic environment. To date, interactions between specific<SUP> </SUP>serogroups and species of plankton remain poorly understood.<SUP> </SUP>Laboratory microcosm experiments were carried out to compare<SUP> </SUP>quantitatively the colonization of two copepod species, <I>Acartia</I><I><SUP> </SUP></I><I>tonsa</I> and <I>Eurytemora affinis</I>, by each of the epidemic serogroups.<SUP> </SUP><SUP>V. cholerae</SUP> O1 consistently achieved higher abundances than<SUP> </SUP><SUP>V. cholerae</SUP> O139 in colonizing adults of each copepod species<SUP> </SUP>as well as the multiple life stages of <I>E. affinis</I>. This difference<SUP> </SUP>in colonization may be significant in the general predominance<SUP> </SUP>of <I>V. cholerae</I> O1 in cholera epidemics in rural Bangladesh where<SUP> </SUP>water supplies are taken directly from the environment.<SUP> </SUP>