ABSTRACT
Fifty-three Salmonella 1,4,[5],12:i:- and 45 Salmonella Typhimurium strains were characterised using phage typing, plasmid profiles and pulsed-field gel electrophoresis (PFGE) for comparison. The majority of the strains were subdivided into definitive type (DT) 41 (22.6 percent) and DT 193 (18 percent) and the 60-MDa plasmid was detected in 94.3 percent and 84.4 percent of strains, respectively. Genetic diversity was observed among all strains and 90 percent presented a > 70 percent similarity through PFGE analysis. These results suggest a close relationship between Salmonella 1,4,[5],12:i:- and Salmonella Typhimurium at the serotype level.
Subject(s)
Animals , Salmonella enterica/genetics , Brazil , Bacterial Typing Techniques/methods , Electrophoresis, Gel, Pulsed-Field , Genetic Markers , Salmonella enterica/classification , Salmonella typhimurium/classification , Salmonella typhimurium/geneticsABSTRACT
Bacteriophage MB78 is a virulent phage of Salmonella typhimurium. The viral DNA is 42 kb in size and seems to be circularly permuted. We show that viral DNA replication is through concatemeric DNA formation which is subsequently converted into full length DNA through headful packaging. A restriction map of MB78 DNA for six restriction endonucleases e.g. BgIII, PvuII, ECORI, ClaI, SalI and SmaI has been constructed. The yield of certain fragments in less than molar amount is explained in terms of permutation and the headful mechanism of packaging. The packaging site (pac site) has been suggested.