Bacterial Disease Division, Animal and Plant Quarantine Agency, 177 Hyeksin 8-ro, Gimcheon-si, Gyeongsangbuk-do 39660, Republic of Korea.
Jeonnam National Veterinary Service Laboratory, 619 Geumgang-ro, Jakcheon-myeon, Gangjingun, Jeonnam 59213, Republic of Korea.
Int J Food Microbiol. 2019 Mar 16;293:53-59. doi: 10.1016/j.ijfoodmicro.2019.01.002. Epub 2019 Jan 6.
The heavy use or abuse of antimicrobials in food animals has caused an increase in antimicrobial resistance in enterococci of animal origin, which could get transmitted to those of human origin via the food chain. Since duck meat consumption has been on the rise in Korea, we conducted this study to provide information about the antimicrobial resistance of the enterococci obtained from healthy ducks and their carcasses. A total of 82 Enterococcus faecium and 174 E. faecalis isolated from duck fecal and carcass samples were investigated for antimicrobial resistance to 16 agents, using broth dilution method, and were further characterized using molecular methods. Most of E. faecium (84.1%) and E. faecalis (87.9%) isolates were resistant to one or more antimicrobials. Multi-drug resistant (MDR) isolates were observed in both E. faecium (40.2%) and E. faecalis (33.9%) with high frequencies. High rate of resistance was observed for tetracycline, ciprofloxacin, chloramphenicol, and erythromycin in both E. faecium and E. faecalis. Resistance to gentamicin, vancomycin, and daptomycin, in both E. faecium and E. faecalis, was, if at all, very rare. However, linezolid resistance was observed in nine E. faecium (11.0%) and one E. faecalis (0.6%). All, but one, Linezolid resistant (LR) isolates were also resistant to chloramphenicol and florfenicol. The novel transferable oxazolidinone and phenicol resistant gene, optrA, was found in six E. faecium isolates. All of them co-carried phenicol exporter gene fexA. None of the LR isolates had mutation in the 23S ribosomal RNA and in the ribosomal protein L3. Six LR E. faecium isolates had Asn130Lys mutation in the ribosomal protein L4, of which five also carried optrA gene. None of the isolates carried the multi-resistance gene cfr. Transfer of oxazolidinone and phenicol resistance was observed in five among the 10 LR isolates; two of them had optrA and fexA genes. Multi-drug resistant Enterococcus that also carried the resistance gene to a last-resort antimicrobial is a major concern for public health. Thus, to prevent the introduction of last-resort antimicrobial resistance into food chain, continuous surveillance of antimicrobial resistance in duck is imperative.
由于食品动物中大量或滥用抗菌药物，导致动物源肠球菌的抗菌药物耐药性增加，这些耐药性可能通过食物链传播到人类源肠球菌。由于韩国鸭肉消费呈上升趋势，我们进行了这项研究，以提供有关健康鸭及其胴体来源肠球菌的抗菌药物耐药性信息。使用肉汤稀释法对从鸭粪便和胴体样本中分离的 82 株屎肠球菌和 174 株粪肠球菌进行了对 16 种抗菌药物的耐药性检测，并进一步采用分子方法进行了特征分析。大多数屎肠球菌（84.1%）和粪肠球菌（87.9%）分离株对一种或多种抗菌药物具有耐药性。屎肠球菌（40.2%）和粪肠球菌（33.9%）均观察到多药耐药（MDR）分离株，频率较高。屎肠球菌和粪肠球菌对四环素、环丙沙星、氯霉素和红霉素的耐药率均较高。屎肠球菌和粪肠球菌对庆大霉素、万古霉素和达托霉素的耐药率均较低。然而，屎肠球菌中有 9 株（11.0%）和粪肠球菌中有 1 株（0.6%）对利奈唑胺耐药。除一株外，所有利奈唑胺耐药（LR）分离株对氯霉素和氟苯尼考也有耐药性。在 6 株屎肠球菌分离株中发现了新型可转移的噁唑烷酮和苯乙酰胺类耐药基因 optrA。它们均携带苯乙酰胺类外排基因 fexA。所有 LR 分离株的 23S 核糖体 RNA 和核糖体蛋白 L3 均无突变。6 株 LR 屎肠球菌分离株的核糖体蛋白 L4 中有天冬酰胺 130 赖氨酸突变，其中 5 株还携带 optrA 基因。分离株均未携带多耐药基因 cfr。在 10 株 LR 分离株中有 5 株表现出噁唑烷酮和苯乙酰胺类耐药性转移，其中 2 株携带 optrA 和 fexA 基因。携带最后一道防线抗菌药物耐药性的多药耐药肠球菌是公共卫生的主要关注点。因此，为了防止最后一道防线抗菌药物耐药性引入食物链，必须对鸭的抗菌药物耐药性进行持续监测。
