title: Effect of a Salmonella group H1 R factor on virulence and response of infections to antimicrobial therapy.
abstract: A group H1 R factor encoding resistance to chloramphenicol, streptomycin, sulfonamide, and tetracycline was transferred into Salmonella typhimurium LT-2. The virulence of LT-2 for mice, as assessed by intraperitoneal 50% lethal dose and the number of organisms in the spleen, was not affected by the R factor. On the other hand, the R factor conferred resistance in mouse infections to therapy with chloramphenicol and trimethoprim plus sulfamethoxazole.
mesh_terms: D000818:Animals; D051379:Mice; D011815:R Factors; D012480:Salmonella Infections / Q000188:drug therapy* / Q000382:microbiology; D012486:Salmonella typhimurium / Q000235:genetics* / Q000472:pathogenicity; D013997:Time Factors