Emergence of <i>Salmonella enterica</i> Serovar Infantis Harboring IncI1 Plasmid with <i>bla</i>_CTX-M-14 in a Broiler Farm in Japan

Abstract

ABSTRACT. Cefotaxime (CTX)-resistant and -susceptible Salmonella enterica serovar Infantis isolates obtained from broilers raised on a farm in January 2010 in Japan were characterized to establish their resistance determinants. The CTX-resistant isolates produced CTX-M-14 extended-spectrum β-lactamase and harbored 2 distinct plasmid of approximately 140-and 95-kb, whereas the CTX-susceptible isolates harbored one 140-kb plasmid. The 95-kb plasmids were replicon typed as IncI1 carrying the bla CTX-M-14 gene, while the 140-kb plasmids were IncP and harbored the aphA1, aadA1, tetA, and sul1 genes. Genetic fingerprinting by pulsed-field gel electrophoresis revealed similar macrorestriction profiles amongst CTX-resistant and susceptible isolates, suggesting a clonal relationship. The presence of CTX-resistant S. Infantis on a broiler farm has occurred through the acquisition of IncI1 resistance plasmid. KEY WORDS: β-lactamase, broiler, CTX-M-14, extended-spectrum plasmid replicon typing, Salmonella Infantis.doi: 10.1292/jvms.11-0488; J. Vet. Med. Sci. 74(9): 1213-1216, 2012 Amongst members of the Enterobacteriaceae family, Escherichia coli (E. coli) and Klebsiella pneumoniae have been implicated as potential producers of extendedspectrum β-lactamases (ESBLs) which possess hydrolyzing activity against third-generation cephalosporins. In recent years, several reports have described other bacterial species within the Enterobacteriaceae family capable of producing ESBLs. Of these, Salmonella spp. producing ESBLs have been detected in salmonellosis cases both in humans [9,10,17] and domestic animals [18].Salmonella enterica serovar Infantis (S. Infantis) is one of the predominant serotypes isolated from broilers in Japan [19]. In the late 1990s, S. Infantis isolates harboring ESBLs were recovered from hospitalized patients in South America [14]. More recently, S. Infantis producing ESBLs were found not only in human patients but also in domestic animals and commercial meats [3,5]. Most of these produced the CTX-M-type ESBLs, indicating the probability that dissemination of 3rd-generation cephalosporin-resistant S. Infantis associated with various types of β-lactamases is gradually expanding world-wide. In this article, we characterized S. Infantis isolates carrying CTX-M-14 ESBL derived from broiler chickens.Ten S. Infantis isolates obtained from 30 broiler cecal samples collected at a poultry processing plant in western Japan in January 2010 were used in this study. The broiler chickens involved in this survey were sampled from 3 different flocks raised on the same commercial farm. The isolation of the bacteria was done as follows; approximately 1 g of cecal contents was aseptically mixed with 5 ml of sterilized distilled water. Then, 1 ml of suspension was enriched in 10 ml of tetrathionate broth (Merck KGaA, Darmstadt, Germany) and incubated at 42°C. After 24 hr of incubation, a loopful from each of enriched broth was streaked onto plates of selective deoxycholate hydrogen sulfide lactose (DHL) agar (Oxoid Ltd., Basing...

High prevalence and molecular characteristics of multidrug-resistant Salmonella in pigs, pork and humans in Thailand and Laos provinces

“…The bla CTX-M-14 gene was previously found in Salmonella Enteritidis from a 4-year-old boy in Japan (Izumiya et al, 2005), patients in Argentina (Jure et al, 2010) and patients in Hong Kong (Jin & Ling, 2006). The gene was also found in other serovars, including Infantis from a broiler in Japan (Kameyama et al, 2012) and Typhimurium from patients in Hong Kong (Jin & Ling, 2006). These results highlight the horizontal transfer of the gene, in agreement with our results.…”

IncI1 Plasmids Carrying Various bla CTX-M Genes Contribute to Ceftriaxone Resistance in Salmonella enterica Serovar Enteritidis in China

“…Interestingly, the size of some of these plasmids (ϳ90 kb) was similar to the size of plasmids recoverable from the S. Enteritidis strains tested in this study. Importantly, such plasmids were also present in S. Enteritidis and S. enterica strains of other serovars isolated from both diarrheal patients and farm animals (27,28). In order to determine whether the IncI1 conjugative plasmids in this study were identical, pMLST was performed to determine the subtypes of those plasmids.…”

Whole-Genome Sequencing Identifies In Vivo Acquisition of a bla CTX-M-27 -Carrying IncFII Transmissible Plasmid as the Cause of Ceftriaxone Treatment Failure for an Invasive Salmonella enterica Serovar Typhimurium Infection

“…In the United States, most third-generation cephalosporin resistance among human Salmonella isolates has historically been due to a plasmidmediated bla CMY-2 (AmpC-type) ␤-lactamases (14,78,79), and while NTS with ESBL determinants (including bla CTX-M ) are increasingly common in other parts of the world (19,(80)(81)(82), they still remain rare in the United States (83). bla CTX-M determinants in NTS infections are now being reported in the United States (84) and have increased significantly in veterinary and food isolates in the rest of the world in recent years (85)(86)(87). bla CTX-M -encoding NTS were first isolated in the late 1980s in Tunisia (88) (53).…”