蛋鸡生产行业的抗菌素耐药性已成为严重的公共卫生问题。蛋鸡生产链上常见条件致病菌肠球菌的耐药性和系统发育关系尚未系统阐明。从115个环境样品中获得了105个肠球菌分离株(空气,灰尘,粪便,苍蝇,污水,和土壤)沿着蛋鸡生产链收集(种鸡,小鸡,幼鸡,和商业蛋鸡)。这些肠球菌分离株对一些临床相关抗生素表现出耐药性,如四环素(92.4%),链霉素(92.4%),和红霉素(91.4%),所有菌株均具有多药耐药表型。全基因组测序表征了29个获得性抗生素抗性基因(ARGs),这些基因在51个对截短侧耳素耐药的肠球菌分离株中对11类抗生素产生了抗性,和lsa(E),介导对胸膜木素的抗性,总是与lnu(B)共同发生。与移动遗传元素数据库的比对确定了四个转座子(Tn554,Tn558,Tn6261和Tn6674)与几个ARG(erm(A),蚂蚁(9)-la,fex(A),和optrA)介导对许多临床重要抗生素的耐药性。此外,我们在Tn554家族中鉴定出两个携带ARGs的新转座子,命名为Tn7508和Tn7492.基于常规多位点序列分型和全基因组单核苷酸多态性分析的互补方法表明,系统发育相关的截短侧耳素抗性肠球菌分离株广泛分布在不同生产农场的各种环境中。我们的结果表明,耐抗菌肠球菌的环境污染需要更多的关注,他们强调了耐截短侧耳素的肠球菌和ARGs在蛋鸡生产链上传播的风险,从而保证有效的消毒。
Antimicrobial resistance in the laying hen production industry has become a serious public health problem. The antimicrobial resistance and phylogenetic relationships of the common conditional pathogen Enterococcus along the laying hen production chain have not been systematically clarified. 105 Enterococcus isolates were obtained from 115 environmental samples (air, dust, feces, flies, sewage, and soil) collected along the laying hen production chain (breeding chicken, chick, young chicken, and commercial laying hen). These Enterococcus isolates exhibited resistance to some clinically relevant antibiotics, such as tetracycline (92.4%), streptomycin (92.4%), and erythromycin (91.4%), and all strains had multidrug resistance phenotypes. Whole genome sequencing characterized 29 acquired antibiotic resistance genes (ARGs) that conferred resistance to 11 classes of antibiotics in 51
pleuromutilin-resistant Enterococcus isolates, and lsa(E), which mediates resistance to pleuromutilins, always co-occurred with lnu(B). Alignments with the Mobile Genetic Elements database identified four transposons (Tn554, Tn558, Tn6261, and Tn6674) with several ARGs (erm(A), ant(9)-la, fex(A), and optrA) that mediated resistance to many clinically important antibiotics. Moreover, we identified two new transposons that carried ARGs in the Tn554 family designated as Tn7508 and Tn7492. A complementary approach based on conventional multi-locus sequence typing and whole genome single nucleotide polymorphism analysis showed that phylogenetically related
pleuromutilin-resistant Enterococcus isolates were widely distributed in various environments on different production farms. Our results indicate that environmental contamination by antimicrobial-resistant Enterococcus requires greater attention, and they highlight the risk of
pleuromutilin-resistant Enterococcus and ARGs disseminating along the laying hen production chain, thereby warranting effective disinfection.