Vibrio cholerae: Model Organism to Study Bacterial Pathogenesis - Interview

I am Es.In MindUP, we study biology of human pathogens in non hosts environments. Many human pathogens after exiting their human host have to survive in the environment before infecting another host. So our goal is to better understand processes that control survival of human pathogens in the environment.

And our goal is to then better understand transmission dynamics of infectious agents. So we are using Vibrio cholera, the cost of agent of diarrhea, disease, cholera as a model organism. Vibrio cholera is a facultative human pathogen and it has an aquatic lifecycle.

Therefore, it provides us great opportunity to study the survival of human pathogen in a natural environment. There are many tools to study this organism. Its genome is completely sequenced and there are micro array representing every gene in the genome.

And furthermore, there are many tools that we can manipulate the genome of this organism. My research program takes advantage of these tools and integrates them to study aquatic lifecycle of cholera. So in our experiments, we try to simulate the aquatic environments that organism lives in.

And then we would like to know how does this organism so senses fluctuations in its environment with respect to nutrient load, temperature, salinity, or other biological stressors such as pages and tzo? So in aquatic environment, RIA cholera is found either in a free living form or in a surface attached form. And the surface attached forms are known as biofilms, which are simply composed of microorganisms and their extra polymeric substances, which can be exo polysaccharide and proteins and sometimes DNA.

And this matrix acts as a glue and hold the organism together. And when grown in biofilm mode, these organisms are actually resistant to fluctuating parameters of their environments and they can be better protected from, for example, phage and proteasome probations. And these are factors that are controlling abundance of microorganisms in the environment.

Some of the recent techno technological advance that helped us in our studies are the completion of the genome sequence of the organism and development of microray technology. Using these technologies, we can determine at the whole genome level how this organism responds to major fluctuations in its environment such as nutrient deprivation or changes in temperature. Or one of our major goal is to integrate our whole genome expression studies to a network analysis.

So we would like to identify genetic regulatory network that controls response of to fluctuating environmental parameters. We would like to be able to model behavior of organism in the environment. And also we still do not know when in the environment with whom Vibra Cide interacts with.

We do not know much about ecology of this organism, and we also do not know relevance of the genes and processes we identified to be important for survival of this organism in the laboratory to the real world. No are the genes that we identified express when Ria cholera is present in natural environment. We also would like to be able to identify and culture organisms that Vibrio Cora interacts with because in the environment, Vibrio Cora is a part of the complex microbial community.

So I think understanding biology of Vibrio Cora in natural environment would be a, it's a challenging and it's critical for us to understand biology of the organism. Within the next five years, I hope that we would be able to better characterize op polysaccharide components of biofilms. For example, in Vibrio cholera, we still do not know structure of the op polysaccharide that is holding the cells together.

We also do not know all the components of biofilm metrics. Eventually I think it be great to be able to quantify components of the biofilm metrics in natural biofilms of these organisms. I think another major challenge is to study, be OC in natural environment.

And I hope that we would be able to take advantage of comparative genomic studies and combine whole genomic expression profiling comparative genomics to better understand evolution of IBR cholera as a pathogen.