Evolutionary and Epidemiological Characterization of Multidrug-Resistant Escherichia coli Isolated From Pangolins in China.

Malayan pangolin populations have fallen to a critically endangered level, and illegal trafficking of wild pangolins is a global problem. Little is known about antimicrobial-resistant bacteria (MDRB) harbored by pangolins, although pangolins are frequently consumed as food or used in traditional medicine. In this study, we report for the first time that strains of multidrug-resistant Escherichia coli were found in a captured Malayan pangolin in Shenzhen, China (December 2018). Antibiotic resistance genes (ARGs) were found in great diversity and abundance on conjugative plasmids, according to genomic analysis. IncX1-type replicon plasmids carrying numerous ARGs and conserved mobile genetic elements predominated in MDR E. coli isolates. Their ability to transport genes horizontally was further strengthened by structural characteristics such class 1 integron-like gene clusters, IS26, and Tn1721, which may have made cross-species dissemination easier. Overall, our findings suggest that illegal transboundary trafficking of Malayan pangolins may contribute to the dissemination of MDRB and highlight the potential public health risks associated with uncontrolled wildlife trade.