大肠杆菌(E.大肠杆菌)起着重要的生态作用,并且是识别人类抗性进化的有用生物指示剂,动物与环境最近,产超广谱β-内酰胺酶(ESBL)的大肠杆菌对公众健康构成了威胁。一般来说,圈养的健康大熊猫不接触抗生素;然而,他们仍然获得抗微生物细菌。为了了解圈养大熊猫生态系统中是否存在抗性基因交换,本研究探索了330株大熊猫粪便中共生大肠杆菌的耐药性特征,周围的环境,和饲养员。不同来源的分离株表现出相似的抗性表型,产ESBL/AmpC的分离株对抗生素的耐药性高于非产ESBL/AmpC的分离株(P<0.05)。此外,检测到广谱β-内酰胺酶相关耐药基因和粘菌素耐药基因的发生,本研究应用了分离株系统发育分型和多位点序列分型(MLST)。在68个产生ESBL/AmpC的分离株中发现了7种不同的β-内酰胺酶抗性基因(blaCTX-M-55,blaCTX-M-15,blaCTX-M-27,blaCTX-M-65,blaTEM-1,blaOXA-1和blaCMY)和mcr-1。blaCTX-M-55(48.53%)被发现是最主要的抗性基因,其次是blaTEM-1(19.12%)和blaCTX-M-27(16.18%)。尽管如此,blaCTX-M-55在大熊猫分离株中普遍检出(63.16%),周围环境(43.48%),和饲养员(33.33%)。然而,在这项研究中没有检测到碳青霉烯酶基因。mcr-1只与大熊猫隔离。在缀合实验中成功获得了45个tanscapants。在缀合物中观察到抗微生物剂抗性和相关抗性基因的存在。结果表明,52.63%的大熊猫分离株来自周围环境的73.91%,从育种者中分离的100%为系统组A。MLST从分离物中识别出27种序列类型(ST),发现ST48(19/68;27.94%)是主要的ST型,特别是在大熊猫和周围环境的分离物中。总之,共生产ESBL/AmpC的大肠杆菌成为ESBL抗性基因的储库,这是对大熊猫健康的潜在威胁。大熊猫之间的相互作用,环境和育种者有助于抗性表型和基因型的发展,这些表型和基因型可能容易在物种或环境中转移;因此,建议采用基于“OneHealth”方法的严格监控。
Escherichia coli (E. coli) plays an important ecological role, and is a useful bioindicator to recognize the evolution of resistance in human, animal and environment. Recently, extended-spectrum β-lactamases (ESBL) producing E.coli has posed a threat to public health. Generally, captive healthy giant pandas are not exposed to antibiotics; however, they still acquire antimicrobial resistant bacteria. In order to understand whether there is an exchange of resistance genes within the ecosystems of captive giant pandas, this study explored resistance characteristics of 330 commensal E. coli isolates from feces of giant pandas, the surroundings, and breeders. Isolates from different sources showed similar resistance phenotype, and ESBL/
AmpC-producing isolates showed more profound resistance to antibiotics than non-ESBL/
AmpC-producing isolates (P<0.05). Furthermore, the occurrence of broad-spectrum β-lactamase related resistance genes and colistin resistance genes was detected, and isolates phylogenetic typing and multilocus sequence typing (MLST) were applied in this study. Seven different β-lactamase resistance genes (blaCTX-M-55, blaCTX-M-15, blaCTX-M-27, blaCTX-M-65, blaTEM-1, blaOXA-1 and blaCMY) and mcr-1 were found in 68 ESBL/
AmpC-producing isolates. blaCTX-M-55 (48.53 %) was found the most predominant resistance genes, followed by blaTEM-1 (19.12 %) and blaCTX-M-27 (16.18 %). Nonetheless, blaCTX-M-55 was commonly detected in the isolates from giant pandas (63.16 %), the surroundings (43.48 %), and breeders (33.33 %). However, there were no carbapenemase genes detected in this study. mcr-1 was harbored in only one isolate from giant panda. Forty-five tansconjugants were successfully obtained in the conjugation experiments. The presence of antimicrobial resistance and related resistance genes tested were observed in the transconjugants. The results indicated that 52.63 % of the isolates from giant panda 73.91 % of the isolates from surroundings, and 100 % of the isolates from breeders were phylogroup A. Total of 27 sequence types (ST) were recognized from the isolate by MLST and found that ST48 (19/68; 27.94 %) was the predominant ST type, especially in the isolates from giant pandas and the surroundings. In conclusion, commensal ESBL/
AmpC-producing E. coli becomes a reservoir of ESBL resistance genes, which is a potential threaten to health of giant pandas. The interaction between giant pandas, surroundings and breeders contribute to development of resistant phenotypes and genotypes which might transfer across species or the surroundings easily; hence, strict monitoring based on a \"One Health\" approach is recommended.