Environmental Microbe and Human Pathogen: The Ecology and Microbiology of Vibrio cholerae

Vibrio cholerae, the bacterium that causes cholera, is a fascinating microorganism that occupies two distinct habitats: aquatic environments and human intestines. Although its activity in human hosts has received a great deal of attention because of its effect on human health, the microbe's behavior in natural ecosystems has received much less consideration. In this paper we briefly review the microbiology and ecology of V. cholerae, before highlighting four important areas for further research. First, V. cholerae acts as a typical heterotrophic bacterium while in aquatic environments, mineralizing organic matter for reuse within the food web. In addition, three key processes affect the microorganism's population dynamics and therefore its role in ecosystem processes: a viable-but-non-culturable (VBNC) state, attachment to environmental substrates, and bacterivory. Several factors link V. cholerae in its human and aquatic habitats, especially human activities that influence its growth conditions while outside the body. These activities create feedbacks between humans and the environment that are at present not well understood, but which are likely to alter the persistence and spread of the resulting disease.