Whole-Genome Sequencing of an Escherichia coli ST69 Strain Harboring blaCTX-M-27 on a Hybrid Plasmid

Abstract

Ling Wang,1,* Yuee Guan,2,* Xu Lin,3,* Jie Wei,4 Qinghuan Zhang,4 Limei Zhang,5 Jing Tan,1 Jie Jiang,1 Caiqin Ling,1 Lei Cai,1 Xiaobin Li,5 Xiong Liang,1 Wei Wei,6 Rui-Man Li7 1Department of Obstetrics, Zhuhai Hospital Affiliated with Jinan University (Zhuhai People’s Hospital), Zhuhai, 519000, People’s Republic of China; 2Department of Cardiology, Zhuhai Hospital Affiliated with Jinan University (Zhuhai People’s Hospital), Zhuhai, 519000, People’s Republic of China; 3Department of Gastrointestinal Surgery, Zhuhai Hospital Affiliated with Jinan University (Zhuhai People’s Hospital), Zhuhai, 519000, People’s Republic of China; 4Department of Clinical Laboratory, Zhuhai Hospital Affiliated with Jinan University (Zhuhai People’s Hospital), Zhuhai, 519000, People’s Republic of China; 5Guangdong Provincial Key Laboratory of Tumor Interventional Diagnosis and Treatment, Zhuhai Hospital Affiliated with Jinan University (Zhuhai People’s Hospital), Zhuhai, 519000, People’s Republic of China; 6Department of Cardiothoracic Surgery, Zhuhai Hospital Affiliated with Jinan University (Zhuhai People’s Hospital), Zhuhai, 519000, People’s Republic of China; 7Department of Gynaecology and Obstetrics, The First Affiliated Hospital of Jinan University, Guangzhou, 510630, People’s Republic of China*These authors contributed equally to this workCorrespondence: Rui-Man Li; Wei Wei, Email [email protected]; [email protected]: Escherichia coli is a common Gram-negative human pathogen. The emergence of E. coli with multiple-antibiotic-resistant phenotypes has become a serious health concern. This study reports the whole-genome sequences of third-generation cephalosporin-resistant (3GC-R) and multidrug-resistant (MDR) E. coli EC6868 and explores the acquired antibiotic-resistance genes (ARGs) as well as their genetic contexts.Methods: E. coli EC6868 was isolated from a vaginal secretion sample of a pregnant patient in China. The antimicrobial susceptibility was assessed, and whole-genome sequencing was conducted. The acquired ARGs, insertion sequence (IS) elements, and integrons within the genome of E. coli EC6868 were identified, and the genetic contexts associated with the ARGs were analyzed systematically.Results: E. coli EC6868 was determined to belong to ST69 and harbored a 144.9-kb IncF plasmid (pEC6868-1) with three replicons (Col156, IncFIBAP001918, and IncFII). The ESBL gene blaCTX-M-27 was located on the structure “∆ISEcp1-blaCTX-M-27-IS 903B”, which was widely present in the species of Enterobacteriales. Other ARGs carried by plasmid pEC6868-1 were mainly located on the 18.9-kb IS 26-composite transposon (five copies of intact IS 26 and one copy of truncated IS 26) composing of IS 26-mphA-mrx(A)-mphR(A)-IS 6100, ∆TnAs3-eamA-tet(A)-tetR(A)-aph(6)-Id-aph(3”)-Ib-sul2-IS 26, and a class 1 integron, which was widely present on IncF plasmids of E. coli, mainly distributed in ST131, ST38, and ST405. Notably, pEC6868 in our study was the first report on a plasmid harboring the 18.9-kb structure in E. coli ST69 in China.Conclusion: The 3GC-R E. coli ST69 strain with an MDR IncF plasmid carrying blaCTX-M-27 and other ARGs, conferring resistance to aminoglycosides, macrolides, sulfonamides, tetracycline, and trimethoprim, was identified in a hospital in China. Mobile genetic elements including ISEcp1, IS 903B, IS 26, Tn 3, IS 6100 and class 1 integron were found within the MDR region, which could play important roles in the global dissemination of these resistance genes.Keywords: Escherichia coli, vaginal secretion, plasmid, blaCTX-M-27, genetic context

Keywords

• escherichia coli
• vaginal secretion
• plasmid
• blactx-m-27
• genetic context