摘要
      最近的研究表明，从圈养大熊猫身上分离出的大肠杆菌（E.coli）菌株对抗生素具有严重耐药性，并携带各种抗生素耐药性基因（ARGs）。抗生素耐药性大肠杆菌携带的ARGs或毒力相关基因（VAGs）被认为是对大熊猫、人类、其他动物和环境的潜在健康威胁。在本研究中，我们从临床健康圈养大熊猫中分离出的84株抗生素耐药大肠杆菌菌株中筛选了ARGs和VAGs，确定了ARGs-VAGs之间的关联，并分析了大肠杆菌分离株的系统发育聚类。我们的研究结果表明，从大熊猫分离的大肠杆菌菌株中最常见的ARG是blaTEM（100.00%，84/84），而最常见的VAG是fimC（91.67%，77/84）。30对ARGs之间存在显著的正相关，其中sul1/tetC最强（OR，133.33）。14对VAG之间存在显著正相关，fyuA/iroN最强（OR（294.40））。45对ARG和VAG之间也存在正相关，其中最强的是sul1/eaeA（OR，23.06）。进一步分析了ARGs与移动基因元件（MGE）的相关性，发现flor和intI1最强（OR，79.86）。系统发育聚类结果显示，最常见的组是B2组（67.86%，57/84），其次是A组（16.67%，14/84）、D组（9.52%，8/84）和B1组（5.95%，5/84）。这项研究表明，从圈养大熊猫中分离出的抗生素耐药性大肠杆菌是ARGs和VAGs的宿主，并且ARGs、VAGs和MGE之间存在显著的相关性。监测大熊猫大肠杆菌携带的ARGs、VAGs和MGE有利于控制抗菌药物耐药性的发展。
Abstract
Recent studies showed that Escherichia coli (E. coli) strains isolated from captive giant pandas have serious resistance to antibiotics and carry various antibiotic resistance genes (ARGs). ARGs or virulence-associated genes (VAGs) carried by antibiotic-resistant E. coli are considered as a potential health threat to giant pandas, humans, other animals and the environment. In this study, we screened ARGs and VAGs in 84 antibiotic-resistant E. coli strains isolated from clinically healthy captive giant pandas, identified the association between ARGs and VAGs and analyzed the phylogenetic clustering of E. coli isolates. Our results showed that the most prevalent ARG in E. coli strains isolated from giant pandas is blaTEM (100.00%, 84/84), while the most prevalent VAG is fimC (91.67%, 77/84). There was a significant positive association among 30 pairs of ARGs, of which the strongest was observed for sul1/tetC (OR, 133.33). A significant positive association was demonstrated among 14 pairs of VAGs, and the strongest was observed for fyuA/iroN (OR, 294.40). A positive association was also observed among 45 pairs of ARGs and VAGs, of which the strongest was sul1/eaeA (OR, 23.06). The association of ARGs and mobile gene elements (MGEs) was further analyzed, and the strongest was found for flor and intI1 (OR, 79.86). The result of phylogenetic clustering showed that the most prevalent group was group B2 (67.86%, 57/84), followed by group A (16.67%, 14/84), group D (9.52%, 8/84) and group B1 (5.95%, 5/84). This study implied that antibiotic-resistant E. coli isolated from captive giant pandas is a reservoir of ARGs and VAGs, and significant associations exist among ARGs, VAGs and MGEs. Monitoring ARGs, VAGs and MGEs carried by E. coli from giant pandas is beneficial for controlling the development of antimicrobial resistance.

https://www.mdpi.com/2306-7381/9/12/705