Long-Term Dissemination of CTX-M-5-Producing Hypermutable Salmonella enterica Serovar Typhimurium Sequence Type 328 Strains in Russia, Belarus, and Kazakhstan

Abstract

e In this paper, we present evidence of long-term circulation of cefotaxime-resistant clonally related Salmonella enterica serovar Typhimurium strains over a broad geographic area. The genetic relatedness of 88 isolates collected from multiple outbreaks and sporadic cases of nosocomial salmonellosis in various parts of Russia, Belarus, and Kazakhstan from 1996 to 2009 was established by multilocus tandem-repeat analysis (MLVA) and multilocus sequence typing (MLST). The isolates belong to sequence type 328 (ST328) and produce CTX-M-5 ␤-lactamase, whose gene is carried by highly related non-self-conjugative but mobilizable plasmids. Resistance to nalidixic acid and low-level resistance to ciprofloxacin is present in 37 (42%) of the isolates and in all cases is determined by various single point mutations in the gyrA gene quinolone resistance-determining region (QRDR). Isolates of the described clonal group exhibit a hypermutable phenotype that probably facilitates independent acquisition of quinolone resistance mutations.

Molecular epidemiological characteristics of Salmonella enterica serovars Enteritidis, Typhimurium and Livingstone strains isolated in a Tunisian university hospital

“…This latter sequence type of Salmonella Typhimurium was recovered in Japan, Taiwan, Russia, United Kingdom and Scotland (25). As reported by Kozyreva et al, this strain was probably lacking the pSLT virulent plasmid of Salmonella Typhimurium (25). Three of the tested loci, STTR5, STTR6 and STTR10, displayed a high degree of polymorphism indicated by 0.611, 0.72, 0.597 indices respectively, which were comparable with previous reports.…”

“…Four loci were present in all tested isolates, while STTR10pl was absent from one isolate ST328. This latter sequence type of Salmonella Typhimurium was recovered in Japan, Taiwan, Russia, United Kingdom and Scotland . As reported by Kozyreva et al, this strain was probably lacking the pSLT virulent plasmid of Salmonella Typhimurium .…”

Burden of Food-Related Illness Caused by Resistant Salmonella spp. and Shigella spp.: Harbingers of Multistate Outbreaks in 2012 and 2013

“…were completely resistant to nalidixic acid and gentamycin during the 2012 and 2013 outbreaks in Iran; these findings are consistent with the data from other studies in Iran and neighboring countries (24)(25)(26). A study by Ashtiani et al (27) out of Iran showed that the resistance rate to nalidixic acid was 42.3%.…”

Applications of Genomics in Regulatory Food Safety Testing in Canada

“…Bacterial strains with a mutator phenotype have an elevated mutation rate, typically due to mutations in genes encoding components of DNA replication and repair pathways [49]. Mutator phenotypes are commonly found in clinical bacterial populations and may contribute significantly to the acquisition of antimicrobial resistance [50][51][52]. For example, the mutator phenotype has been attributed to the development of multidrug-resistant S. typhimurium [50].…”

“…Mutator phenotypes are commonly found in clinical bacterial populations and may contribute significantly to the acquisition of antimicrobial resistance [50][51][52]. For example, the mutator phenotype has been attributed to the development of multidrug-resistant S. typhimurium [50]. In E. coli, this phenotype has recently been shown to be induced in response to stress conditions [53].…”