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Jing Wang,1– 3,* Yue Jiang,1,2,* Cai-Yue Mei,1,2 Zhen-Yu Wang,1,2 Fa-Gang Zhong,4 Xing-Xing Zhang,4 Lu-Chao Lv,5 Meng-Jun Lu,1,2 Han Wu,1,2 Xinan Jiao1– 3 1Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu Province, People’s Republic of China; 2Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou, Jiangsu Province, People’s Republic of China; 3Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou, Jiangsu Province, People’s Republic of China; 4State Key Laboratory for Sheep Genetic Improvement and Healthy Production, Institute of Animal Husbandry and Veterinary, Xinjiang Academy of Agricultural and Reclamation Science, Shihezi, Xinjiang Province, People’s Republic of China; 5College of Veterinary Medicine, South China Agricultural University, Guangzhou, Guangdong Province, People’s Republic of China*These authors contributed equally to this workCorrespondence: Xinan Jiao, Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, No. 48 Wenhui East Road, Yangzhou, Jiangsu 225009, People’s Republic of China, Tel +86-514-87971136, Fax +86-514-87991747, Email jiao@yzu.edu.cn

Salmonella spp. are important foodborne pathogens, and multidrug-resistant (MDR) Salmonella strains have become a serious threat to clinical therapy. MDR S .

Colistin is a last-resort antibiotic for severe infections caused by multidrug-resistant (MDR) Gram-negative pathogens. Colistin resistance genes mcr , particularly mcr-1 , have been found in Enterobacteriaceae around the world, mainly in Escherichia coli and Salmonella . Salmonella enterica is a major foodborne pathogen, with MDR Salmonella being considered a “Serious Threat Level pathogen” by the Centers for Disease Control and Prevention.

This study aimed to investigate the prevalence and genomic characteristics of the colistin resistance gene

This study aimed to investigate the prevalence and diversity of extended-spectrum β-lactamases (ESBL)-producing Escherichia coli isolates from healthy individuals in a community and to elucidate their dissemination mechanism. Cefotaxime-resistant E. coli were isolated from 95 samples of healthy persons from one community in Yangzhou, China, and were tested for minimal inhibitory concentrations of 14 antimicrobial agents. The isolates were subjected to whole genome sequencing by Illumina Hiseq or PacBio single-molecule real-time sequencing. A total of 30 cefotaxime-resistant E. coli isolates were obtained, carrying blaCTX-M (n=29) or blaDHA (n=1), of which the blaCTX-M-55 (n=19) was the most predominant genotype. One novel blaCTX-M variant blaCTX-M-252 was identified. Thirteen CTX-M-55-producing E. coli isolates belonged to ST8369 from nasal (n=12) or faecal (n=1) samples shared the identical cgMLST type, resistance profiles, resistance genes, plasmid replicons, and a 5,053-bp blaCTX-M-55 structure ΔIS26-ΔISEcp1-blaCTX-M-55-Δorf477-ΔTn2. The blaCTX-M-55 gene was located on IncHI2/ST3 plasmid in E. coli ST8369. The lengths of blaCTX-M/blaDHA-carrying contigs in the remaining 17 E. coli strains ranged from 1,663 to 382,836 bp, located on chromosome (n=4) or plasmids (n=5); the location of the other eight contigs could not be determined due to incomplete assembly. The blaCTX-M was associated with ISEcp1 as previously reported. Nasal colonization of CTX-M-55-producing ST8369 E. coli strains has occurred among healthy individuals in one community. There is a potential risk of antimicrobial resistance dissemination between humans within one community through close contact or environment via aerosols or dust. Therefore, surveillance of nasal carriage of blaCTX-M in communities is warranted to further monitor the spread of the antimicrobial resistance genes in China.

This study aimed to investigate the prevalence and diversity of extended-spectrum β-lactamases (ESBL)-producing

This study aimed to investigate the prevalence and characterization of