Does Phage Predation Shape Typhoid Ecology in Urban Water?

Jason Andrews of Stanford University in the U.S. will study the association between the typhoid fever-causing bacterium Salmonella Typhi and its bacteriophage in both aquatic environments and the human gastrointestinal tract to see if they influence geographic and seasonal disease outbreaks in Bangladesh. The ecology and evolution of many know bacterial pathogens including V. cholerae are affected by the viruses (bacteriophage) that infect them. Indeed, seasonal cholera epidemics are inversely correlated with phage prevalence in water. They will study this relationship in S. Typhi, which contaminates half of city water supplies in Bangladesh. They will generate a library of local phage strains infecting S. Typhi and use a computational approach to identify indicator S. Typhi strains that may be susceptible to these phage, which they will then test experimentally. They will also characterize the abundance and strains of phage in municipal water supplies, and in stool samples from typhoid cases, and compare these with clinical cases of typhoid to determine if they shape temporal and spatial patterns of typhoid.