PDF(Pubmed)
Abstract：
Carbapenems are atypical β-lactam antibiotics with a broade antibacterial spectrum and strong antibacterial activity; however, the emergence and spread of carbapenemases have led to a decline in their effectiveness. New Delhi metallo-β-lactamase (NDM) is an important carbapenemase that has attracted widespread attention and poses a major threat to public health. To investigate the epidemiological characteristics of blaNDM in swine and chicken farms in southwestern China, we isolated 102 blaNDM-positive Enterobacterales strains from 18 farms in Sichuan and Yunnan provinces in 2021, with Escherichia coli and Klebsiella spp. being the main reservoirs of blaNDM, variant blaNDM-5 being the most prevalent, and all strains being multi-drug resistant. Whole-genome sequencing analysis of 102 blaNDM-positive Enterobacterales strains revealed that blaNDM had spread primarily through its carriers on the same farm and among the 18 farms in this study. A high degree of genetic similarity between animal-derived blaNDM-positive Escherichia coli strains and human-derived strains was also identified, suggesting a potential mutual transmission between them. Nanopore sequencing results indicated that blaNDM is predominantly present on the IncX3 plasmid, that an insertion sequence might be important for recombination in the blaNDM genetic environment, and that most of the plasmids carrying blaNDM are transferable. Collectively, our results enrich the current epidemiological information regarding blaNDM in pig and chicken farms in Southwest China, revealing its transmission pattern, as well as the potential risk of transmission to humans, which could help to better understand and control the spread of blaNDM.
摘要：
碳青霉烯类是非典型的β-内酰胺类抗生素,抗菌谱广,抗菌活性强,碳青霉烯酶的出现和传播导致其有效性下降。新德里金属β-内酰胺酶（NDM）是一种重要的碳青霉烯酶，已引起广泛关注，并对公众健康构成重大威胁。调查中国西南地区养猪场blaNDM的流行病学特征,2021年，我们从四川和云南两省的18个农场中分离出102株blaNDM阳性肠杆菌，其中大肠杆菌和克雷伯菌属。作为blaNDM的主要水库，变种blaNDM-5是最普遍的，所有菌株都具有多重耐药性。对102株blaNDM阳性肠杆菌菌株的全基因组测序分析表明，blaNDM主要通过其携带者在同一农场和本研究的18个农场中传播。还鉴定了动物来源的blaNDM阳性大肠杆菌菌株与人源菌株之间的高度遗传相似性，暗示他们之间潜在的相互传播。纳米孔测序结果表明，blaNDM主要存在于IncX3质粒上，插入序列对于blaNDM遗传环境中的重组可能很重要，并且大多数携带blaNDM的质粒是可转移的。总的来说，我们的研究结果丰富了当前中国西南地区养猪场和养鸡场有关blaNDM的流行病学信息，揭示了它的传播模式，以及传播给人类的潜在风险，这有助于更好地理解和控制blaNDM的传播。
