title: Characterization of Salmonella enterica subsp. enterica serovar 4,[5],12:i:- clones isolated from human and other sources in Switzerland between 2007 and 2011.
abstract: Salmonella enterica subsp. enterica serovar 4,[5],12:i:- is a monophasic variant of Salmonella Typhimurium. In this study, a total of 651 human and 107 food and environmental isolates of serovar 4,[5],12:i:- recovered from 2007 through 2011 in Switzerland were characterized by antibiotic resistance profiles and pulsed-field gel electrophoresis (PFGE). In addition, a selection of isolates belonging to the most frequent PFGE patterns was further subjected to multilocus variable-number tandem-repeat analysis (MLVA) and phage typing. Over the years 2007-2011, the reports of salmonellosis caused by Salmonella enterica serovar 4,[5],12:i:- significantly increased. A high prevalence of multidrug-resistant isolates, mainly showing an ampicillin-streptomycin-sulfonamide-tetracycline resistance pattern (ASSuT), was observed. In addition, four extended spectrum beta lactamase (ESBL) (CTX-M-55)-producing isolates were found. XbaI PFGE analysis of all isolates revealed over 150 different pulsotypes, and generally showed a considerable diversity within the monophasic isolates. Nevertheless, among these we identified seven dominant profiles, which encompassed 66% of all isolates tested. The PFGE type STYMXB.0131 dominated among human as well as food isolates. Multilocus variable-number tandem-repeat analysis profile 3-12-10-0-0211, which, in many cases, coincided with PFGE type STYMXB.0131 and phage type DT193 were the most prevalent types found for the isolates further characterized by these typing methods. Our data provide strong evidence for a spread of two specific Salmonella serovar 4,[5],12:i:- clones (PFGE pattern STYMXB.0131, resistance type ASSuT) and (PFGE pattern STYMXB.0131, resistance type SSuT). In contrast to the human isolates, the pork/poultry isolates expressed predominantly the SSuT resistance type.
authors.affiliation: Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
authors.forename: Christine
authors.initials: C
authors.lastname: Gallati
authors.forename: Roger
authors.initials: R
authors.lastname: Stephan
authors.forename: Herbert
authors.initials: H
authors.lastname: Hächler
authors.forename: Burkhard
authors.initials: B
authors.lastname: Malorny
authors.forename: Andreas
authors.initials: A
authors.lastname: Schroeter
authors.forename: Magdalena
authors.initials: M
authors.lastname: Nüesch-Inderbinen
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001434:Bacteriophage Typing; D001435:Bacteriophages / Q000145:classification / Q000254:growth & development / Q000302:isolation & purification; D002645:Chickens / Q000382:microbiology; D024901:Drug Resistance, Multiple, Bacterial; D004784:Environmental Monitoring; D005243:Feces / Q000382:microbiology; D006801:Humans; D008460:Meat / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D012480:Salmonella Infections / Q000382:microbiology*; D019779:Salmonella enterica / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification / Q000821:virology; D012486:Salmonella typhimurium / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification / Q000821:virology; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000235:genetics / Q000378:metabolism; D034421:Sus scrofa / Q000382:microbiology; D013557:Switzerland; D014871:Water Microbiology
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C059639:DNA modification methylase XbaI; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific)