title: Molecular characterization of Salmonella enterica serovar Typhimurium isolated from human, food, and animal sources in Malaysia.
abstract: Salmonella Typhimurium is an important nontyphoidal Salmonella serovar associated with foodborne diseases in many parts of the world. This organism is the major causative agent of nontyphoidal salmonellosis in Malaysia. We aimed to investigate the genetic profiles of the strains isolated from clinical, zoonotic, and dietary sources in Malaysia using multilocus variable number tandem repeat analysis (MLVA) and pulsed-field gel electrophoresis (PFGE). By focusing on the 5 common variable number tandem repeat (VNTR) loci, we found that PFGE (D = 0.99) was more discriminative than MLVA (D = 0.76). The low MLVA score might be because of a lack of VNTR loci STTR6 (81.0%) and STTR10pl (76.2%). Both subtyping methods suggested that our S. Typhimurium strains were largely endemic with limited genetic variation. Furthermore, we observed that biphasic S. Typhimurium strains were dominant (99%) and multidrug resistance was prevalent (50%) within our sample pool. The most frequently observed phenotypes were resistance to compound sulfonamides (49%), tetracycline (51%), and streptomycin (52%). In this study, we documented the genetic relationship, antimicrobial resistance characteristics, and flagellar-phase dominance among S. Typhimurium strains found in Malaysia.
authors.affiliation: Institute of Biological Sciences, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Soo Tein
authors.initials: ST
authors.lastname: Ngoi
authors.forename: Bjørn-Arne
authors.initials: BA
authors.lastname: Lindstedt
authors.forename: Haruo
authors.initials: H
authors.lastname: Watanabe
authors.forename: Kwai Lin
authors.initials: KL
authors.lastname: Thong
mesh_terms: D000818:Animals; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D019353:Endemic Diseases; D005516:Food Microbiology; D014644:Genetic Variation; D006801:Humans; D008296:Malaysia / Q000453:epidemiology; D018598:Minisatellite Repeats; D017720:Molecular Epidemiology; D058889:Molecular Typing; D012480:Salmonella Infections / Q000453:epidemiology / Q000382:microbiology*; D012481:Salmonella Infections, Animal / Q000453:epidemiology / Q000382:microbiology*; D012486:Salmonella typhimurium / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification