Introduction: The rising prevalence of carbapenem-resistant Enterobacteriaceae (CRE) poses a major public health threat, impacting the efficacy of last-resort antibiotics. In the United Arab Emirates (UAE), camels, vital to culture and the economy, may act as CRE reservoirs. However, the CRE carriage in farm animals across the UAE and Gulf Cooperation Council countries remains largely unexplored.
Objectives: This pilot study aimed to evaluate the prevalence and genetic characteristics of carbapenem-resistant Enterobacteriaceae in camels in the UAE.
Methods: Fecal samples from 12 camels on a Dubai farm were screened for carbapenem- and extended-spectrum β-lactamase-producing Gram-negative bacilli using selective culture techniques. The antimicrobial susceptibility testing followed the CLSI guidelines, while multiplex PCR was used to identify Carbapenemase genes. Whole-genome sequencing (WGS) revealed detailed genetic profiles, including the sequence types and global relatedness of the isolates. In total, 20 bacterial isolates were tested, and based on their plasmid profiles, WGS of 4 isolates was performed.
Results: CR Escherichia coli was found in 8.33% (1/12 ) of the camels. The isolates carried the blaNDM gene, conferring carbapenem resistance, but lacked the other tested Carbapenemase genes. Antimicrobial susceptibility testing showed multidrug resistance to multiple antibiotic classes. Among the four isolates, the S101-C1 isolate (the ST648 complex) displayed an extensive resistance profile, harboring blaNDM-5, blaCTX-M-15, blaOXA-1, blaTEM-1, and resistance genes for aminoglycosides (aac(6')-Ib-cr5, aadA5), sulfonamides (sul1), tetracyclines (tet(B)), and macrolides (mph(A)). Resistance was augmented by efflux-associated genes (acrF/emrD/emrE) and mutations (ftsI_N337NYRIN, gyrA_D87N/S83L). Another isolate, S101-E1 (ST155 complex), exhibited MDR, with the resistance genes blaCTX-M-15, blaTEM-1, tet(A), qnrS1 and a colistin resistance mutation (pmrB_Y358N). Efflux-related genes (acrF/mdtM) were also present.
Conclusion: This study is the first to report the presence of blaNDM-positive E. coli in camels in the UAE, suggesting that camels may serve as reservoirs for antimicrobial-resistant bacteria, including CRE. It highlights the potential risks of zoonotic transmission through direct contact or via the food chain.
