Opossums and Cat Fleas: New Insights in the Ecology of Murine Typhus in Galveston, Texas.

Murine typhus is an acute undifferentiated febrile illness caused by Rickettsia typhi The classic reservoir (Rattus spp.) and flea vector (Xenopsylla cheopis) were once culprits of murine typhus in the United States. Vector and rodent control efforts have drastically decreased the prevalence of disease, except in a few endemic foci where opossums and cat fleas play a role in transmission.

Novel determinants of intestinal colonization of Salmonella enterica serotype typhimurium identified in bovine enteric infection.

Cattle are naturally infected with Salmonella enterica serotype Typhimurium and exhibit pathological features of enteric salmonellosis that closely resemble those in humans. Cattle are the most relevant model of gastrointestinal disease resulting from nontyphoidal Salmonella infection in an animal with an intact microbiota. We utilized this model to screen a library of targeted single-gene deletion mutants to identify novel genes of Salmonella Typhimurium required for survival during enteric infection.