Wang Yan, Hou Naxin, Rasooly Reuven, Gu Yongqiang, He Xiaohua
Western Regional Research Center, Agricultural Research Service, United States Department of Agriculture, Albany, CA, United States.
State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.
Front Microbiol. 2021 Apr 30;12:667406. doi: 10.3389/fmicb.2021.667406. eCollection 2021.
The prevalence of -positive bacteria in 5,169 domestic animal-derived samples collected by USDA Food Safety and Inspection Service between October 2018 and May 2019 was investigated. A procedure including enriched broth culture and real-time PCR targeting to were used for the screening. Fifteen positive isolates were identified, including one plasmid-borne -positive strain, EC2492 (reported elsewhere) and 14 -positive strains from poultry (1), catfish (2), and chicken rinse (11) samples, resulting in an overall prevalence of -positive bacteria 0.29% in all meat samples tested. Analysis of 16S rRNA and whole genome sequences revealed that all 14 strains belonged to . Data from phylogenetic analysis of seven housekeeping genes, including , and , indicated that nine strains belonged to and five strains belonged to . Antimicrobial tests showed that almost all -positive strains exhibited high resistance to colistin with MICs ≥ 128mg/L, except for one strain, which showed a borderline resistance with a MIC of 2 mg/L. A segment containing two adjacent and lik genes was found in two and one strains and a variety of IS-like elements were found in the flanking regions of this segment. A -related lipid A phosphoethanolamine transferase gene was present in all 14 strains, while an additional -related lipid A phosphoethanolamine transferase gene was found in 5 strains only. In addition to genes, other antimicrobial resistance genes, including , , , , , , , , and were observed in chromosomes of some strains. The relative high prevalence of chromosome-borne genes and the close proximity of various IS elements to these genes highlights the need for continued vigilance to reduce the mobility of these colistin-resistance genes among food animals.
美国农业部食品安全与检验局在2018年10月至2019年5月期间收集的5169份家畜来源样本中，对阳性细菌的流行情况进行了调查。采用包括富集肉汤培养和针对的实时PCR在内的程序进行筛选。鉴定出15株阳性分离株，包括1株质粒携带的阳性菌株EC2492（已在其他地方报道）以及14株来自家禽（1株）、鲶鱼（2株）和鸡肉冲洗液（11株）样本的阳性菌株，在所检测的所有肉类样本中，阳性细菌的总体流行率为0.29%。对16S rRNA和全基因组序列的分析表明，所有14株菌株均属于。对包括、和在内的7个管家基因进行系统发育分析的数据表明，9株菌株属于，5株菌株属于。抗菌试验表明，除1株MIC为2mg/L的菌株表现出临界耐药性外，几乎所有阳性菌株对黏菌素均表现出高耐药性，MIC≥128mg/L。在2株和1株菌株中发现了一个包含两个相邻的和lik基因的片段，并且在该片段的侧翼区域发现了多种类IS元件。在所有14株菌株中均存在一个与相关的脂多糖A磷酸乙醇胺转移酶基因，而仅在5株菌株中发现了另一个与相关的脂多糖A磷酸乙醇胺转移酶基因。除了基因外，在一些菌株的染色体中还观察到其他抗菌抗性基因，包括、、、、、、、和。染色体携带的基因相对较高的流行率以及各种IS元件与这些基因的紧密相邻，凸显了持续保持警惕以降低这些黏菌素抗性基因在家禽中移动性的必要性。
