Genetic variation in emerging multidrug-resistant Salmonella enterica 4,[5],12:I:- from seven european countries
Comunicación presentada en Antimicrobial Resistance in Zoonotic Bacteria and Foodborne Pathogens in Animals, Humans and the Environment
8 de junio de 2010
Hopkins K., Nair S., Kirchner M., Guerra B., Granier SA., Lucarelli C., Porrero MC., Jakubczak A., Threlfall EJ. y Mevius D.
In response to a marked increase in prevalence of Salmonella enterica with antigenic structure 4,[5],12:i:- expressing resistance to ampicillin, streptomycin, sulphonamides and tetracyclines (R-type ASSuT) noted in food-borne infections and pigs/pig meat from several European countries we characterized isolates to evaluate the possibility of clonal spread of this emerging multiresistant serotype. Methods: 116 S. enterica 4,[5],12:i:- isolates from humans and pigs/pig meat from England and Wales, France, Germany, Italy, Poland, Spain and The Netherlands were phage typed using the Typhimurium scheme, and subtyped by pulsed-field gel electrophoresis (PFGE) and variable-number tandem-repeat analysis (VNTR). Multilocus sequence typing (MLST) was performed on 6 representative isolates. PCR was used to identify resistance genes and screen for fljAB and hin (involved in phase-2 flagellum expression), iroB, STM2740, STM2757 and STM1053-1997, whose presence has been reported to vary between S. enterica 4,[5],12:i:- isolates from the United States and Spain. Results: Sixteen phage types, 36 PFGE profiles and 45 VNTR types were identified. MLST identified closely related types ST19 and ST34, which are typical of serotype Typhimurium. 91% of isolates exhibited deletions in fljA, fljB and/or hin. The presence of iroB, STM2740, STM2757 and STM1053-1997 varied, with new combinations of these genes in nearly 50% of isolates. The most frequent combination of characteristics was that 26/116 S. enterica 4,[5],12:i:- isolates were definitive phage type 193 (DT193), expressing R-type ASSuT encoded by blaTEM-like, strA-strB, sul2 and tet(B) (which was not integron-associated), and lacking fljAB and hin. These isolates belonged to PFGE profile STYMXB.0131, which represented 8 related VNTR types, and were from patients and pigs in England and Wales, France, Germany and The Netherlands. Conclusions: S. enterica 4,[5],12:i:-, DT193, R-type ASSuT has emerged in several European countries, with pigs a probable reservoir of infection. In order to prevent further spread of this strain appropriate intervention strategies need to be put in place as soon as possible. Strains of S. enterica 4,[5],12:i:- are emerging in both North America and Europe. In European isolates presence/absence combinations of fljAB, hin, iroB, STM2740, STM2757 and STM1053-1997 suggest this serotype represents several diverse strains that may have emerged independently, probably from serotype Typhimurium
 | Servicio de Zoonosis de Transmisión Alimentaria y Resistencia a Antimicrobianos (ZTA). Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM). |
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