Characterization of Extended-Spectrum β-Lactamase-Producing Enterobacteriaceae From Retail Food in China

Abstract

In this study, we characterized the β-lactamase genes and phenotypic resistance of cephalosporin-resistant Enterobacteriaceae isolated from retail foods in China. Of 1,024 Enterobacteriaceae isolates recovered from raw meat products, aquatic products, raw vegetables, retail-level ready-to-eat (RTE) foods, frozen foods, and mushrooms from 2011 to 2014, 164 (16.0%) showed cefotaxime (CTX) and/or ceftazidime (CAZ) cephalosporin resistance, and 96 (9.4%) showed the extended-spectrum β-lactamase (ESBL) phenotype. More than 30% isolates were resistant to all antimicrobial agents except carbapenems (MEM 3.1% and IPM 5.2%), cefoxitin (FOX 6.3%), and amoxicillin/clavulanic acid (AMC 26%), and 94.8% of the strains were resistant to up to seven antibiotics. Polymerase chain reaction analysis showed that blaTEM (81.9%) was the most common gene, followed by blaCTX-M (68.1%) and blaSHV (38.9%). Moreover, 16.8% (72/429) of food samples contained ESBL-positive Enterobacteriaceae, with the following patterns: 32.9% (23/70) in frozen foods, 27.2% (5/29) in mushrooms, 17.6% (24/131) in raw meats, 13.3% (4/30) in fresh vegetables, 11.1% (8/72) in RTE foods, and 9.3% (9/97) in aquatic products. In addition, 24 of 217 foods collected in South China (11.1%), 25 of 131 foods collected in North of the Yangtze River region (19.1%), and 23 of 81 foods collected in South of the Yangtze River region (28.4%) were positive for ESBL- Enterobacteriaceae. Conjugation experiments demonstrated that the 22 of 72 isolates were transconjugants that had received the β-lactamase gene and were resistant to β-lactam antibiotics as well as some non-β-lactam antibiotics. These findings demonstrated that retail foods may be reservoirs for the dissemination of β-lactam antibiotics and that resistance genes could be transmitted to humans through the food chain; and the predominant ESBL-producing Enterobacteriaceae in China was isolated from in frozen chicken-meat, followed by frozen pork, cold noodles in sauce, cucumber, raw chicken meat, frozen pasta, brine-soaked chicken and tomato.

Antimicrobial resistance pattern in Salmonella enterica from clinical and poultry sources in Calabar, Nigeria

“…All 55 isolates demonstrated 100% resistance to nalixidic acid and 100% susceptible to ciprofloxacin and norflaxacin antibiotics. This agrees with several studies carried out in India where salmonella isolates demonstrated 100% resistance to nalixidic acid with susceptibility to ciprofloxacin (Crump et al, 2003;Kownhar et al, 2007;Ye et al, 2018). These antibiotics belong to the quinolone/fluoroquiniolone drug class.…”

Isolation, genotyping and antimicrobial susceptibility of pathogenic Escherichia coli serotypes in ready to eat foods

“…Of the 7 E. coli isolates examined, we found an overall prevalence of 42% (n=3) isolates showed resistance rate to AMC (29%), CIP (29%) and GEN (14%) ( Table 4). AMC, CIP and GEN resistance has been reported in studies performed worldwide, concerning RTE foods (Rasheed et al 2014;Kochakkhani et al 2016;Baloch et al 2017;Ye et al 2018). Our results were lower than those found by Kochakkhani et al (2016) (100% for AMC and CIP) and Baloch et al (2017) (80.9% for AMC and 18% for GEN).…”

“…Results of this study demonstrated that MER and STX were the most effective agents against E. coli with susceptibility rate of 100%. Recent studies have also been describing STX and MER resistant E. coli isolates (Campos et al, 2013;Rasheed et al 2014;Lima et al 2017;Ye et al, 2018) in RTE foods. Of the 7 E. coli isolates examined, we found an overall prevalence of 42% (n=3) isolates showed resistance rate to AMC (29%), CIP (29%) and GEN (14%) ( Table 4).…”

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“…It is guaranteed. The drug resistance levels of positive ESBL types producing 13 antibiotics are much lesser than China CHINET's surveillance for bacterial drug resistance 15 .…”