VIRULENCE OF A SALMONELLA-TYPHIMURIUM OMPD MUTANT

An ompD mutation caused by a Tn10 insertion was transduced into Salmon ella typhimurium SL1344 and UK-1. The adherence and invasion capabilit ies of the resultant ompD mutants were examined by tissue culture anal ysis. The virulence of the S. typhimurium ompD mutants was ascertained by a 50% lethal dose (LD50) study and by determining colonization abi lity,vith BALB/c mice. We found no statistically significant differenc e in adherence and invasion capacities between the S. typhimurium wild type strains and their corresponding ompD mutants. Furthermore, the L D,, and colonization studies revealed that there is no statistically s ignificant difference in virulence between the S. typhimurium wild typ e strains and their corresponding ompD mutants. These results differ f rom those reported previously (C. J. Dorman, S. Chatfield, C. F. Higgi ns, C. Hayward, and G. Dougan, Infect. Immun. 57:2136-2140, 1989).