Prevalence and Antimicrobial Characteristics of Shiga Toxin-Producing Escherichia coli Isolates from Pork in Korea
FOODBORNE PATHOGENS AND DISEASE
Authors: Heo, Eun Jeong; Ko, Eun Kyung; Kang, Hye Jeong; Kim, Young Jo; Park, Hyun Jeong; Wee, Sung-Hwan; Moon, Jin San
Abstract
Shiga toxin-producing Escherichia coli (STEC) strains are important food-borne pathogens that can be transmitted through the consumption of food products derived from pigs. Moreover, antimicrobial resistance in STEC has been a matter of increasing concern. The aim of this study was to investigate the prevalence and antimicrobial characteristics of STEC isolates from pork in Korea. We isolated 131 isolates of E. coli from 334 pork samples collected from slaughterhouses and retail markets from 2008 to 2009. Among the 131 isolates, 6 (4.58%) were confirmed to belong to 6 different serotypes of STEC. All six STEC isolates contained stx1 and eaeA virulence genes, and four of them additionally carried the hly gene. The minimum inhibitory concentration (MIC) of 15 antibiotics (amoxicillin/clavulanic acid, ampicillin, cephalothin, cefoxitin, ceftiofur, gentamicin, neomycin, streptomycin, nalidixic acid, ciprofloxacin, colistin, chloramphenicol, florfenicol, tetracycline and sulfamethoxazole/trimethoprim) toward the STEC isolates was determined. As a result, three strains were associated with high MICs for florfenicol and chloramphenicol (64 mu g/mL). Furthermore, all three strains were found to contain the florfenicol-resistant gene (floR) but not the chloramphenicol-resistant gene (cat). Sequence alignment and BLAST analysis of the polymerase chain reaction products of the floR gene indicated that they contained sequences with homology to the floR gene of E. coli or Salmonella enterica serovar, Heidelberg. This is the first report on the detection of floR in STEC isolated from pork obtained from retail markets in Korea.
Risk of Antimicrobial Resistant Non-TyphoidalSalmonelladuring Asymptomatic Infection Passage between Pet Dogs and Their Human Caregivers in Khon Kaen, Thailand
ANTIBIOTICS-BASEL
Authors: Wu, Xin; Angkititrakul, Sunpetch; Richards, Allen L.; Pulsrikarn, Chaiwat; Khaengair, Seri; Keosengthong, Amphone; Siriwong, Supatcharee; Suksawat, Fanan
Abstract
To explore the risk of antimicrobial resistant (AMR) non-typhoidalSalmonelladuring asymptomatic infection passage between pet dogs and human caregivers in Khon Kaen, Thailand, one hundred forty paired fecal samples (n= 280) were obtained from companion dogs and their human caregivers, interviewed from 140 households during 2019-2020. The purifiedSalmonellaisolates were serotype-identified and tested for antimicrobial resistance against ampicillin, ciprofloxacin, chloramphenicol, nalidixic acid, streptomycin, sulfamethoxazole-trimethoprim, and tetracycline. The homologousSalmonellaisolate pairs (suggestingSalmonellainfections may have been due to passage between each one of the pair, or derived from the same source) were subsequently characterized by serotype screening, pulsed field gel electrophoresis (PFGE), and Synchrotron Fourier transform infrared spectroscopy (SR-FTIR). TheSalmonellaprevalence observed in dogs, 12.86% (18/140), was not significantly different from that observed in humans, 17.86% (25/140) using McNemar's test. The AMR patterns (the patterns among the isolates of pet dogs and caregivers) and the serotypes (thirteen serotypes with 18 isolates from pet dogs plus thirteen serotypes with 25 isolates from humans) between pet dogs and humans were not significantly different using Pearson's chi-squared test. The homologousSalmonellaisolates from theSalmonella-present households was 5.13% (2/39). This study demonstrated that the hypothesis that there is a high risk ofSalmonellainfection passage between dogs and humans with close contact in Khon Kaen is doubtful. Only 5.13% of homologousSalmonellaisolates fromSalmonella-present households were found in Khon Kaen, Thailand, although the prevalence ofSalmonella-positive samples, serotypes, and antimicrobial resistance patterns were quite similar among the two populations.