Co-existence of a novel RND efflux pump tmexC6D6.2-toprJ1b and blaOXA-4 in the extensively drug-resistant Pseudomonas aeruginosa ST233 clone

Xuan Wu; Guorong Chen; Panpan Wang; Lu Yang; Yige Wu; Guoquan Wu; Hui Li; Bing Shao

doi:10.1016/j.ijfoodmicro.2024.110984

Co-existence of a novel RND efflux pump tmexC6D6.2-toprJ1b and bla_OXA-4 in the extensively drug-resistant Pseudomonas aeruginosa ST233 clone

Int J Food Microbiol. 2024 Nov 16:428:110984. doi: 10.1016/j.ijfoodmicro.2024.110984. Online ahead of print.

Authors

Xuan Wu¹, Guorong Chen², Panpan Wang³, Lu Yang⁴, Yige Wu⁵, Guoquan Wu⁶, Hui Li⁷, Bing Shao⁸

Affiliations

¹ School of Public Health, Capital Medical University, Beijing 100069, PR China; Beijing Key Laboratory of Diagnostic and Traceability Technologies for Food Poisoning, Beijing Center for Disease Prevention and Control, Beijing 100013, PR China.
² Beijing Key Laboratory of Diagnostic and Traceability Technologies for Food Poisoning, Beijing Center for Disease Prevention and Control, Beijing 100013, PR China; Department of Gastroenterology, China-Japan Friendship Hospital (Institute of Clinical Medical Sciences), Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100029, PR China.
³ Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou 225009, Jiangsu Province, PR China.
⁴ Shanghai Institute of Doping Analyses, Shanghai University of Sport, Shanghai 200438, PR China.
⁵ Beijing Key Laboratory of Diagnostic and Traceability Technologies for Food Poisoning, Beijing Center for Disease Prevention and Control, Beijing 100013, PR China; National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing 100193, PR China.
⁶ National Center for Veterinary Drug Safety Evaluation, College of Veterinary Medicine, China Agricultural University, Beijing 100193, PR China.
⁷ School of Public Health, Capital Medical University, Beijing 100069, PR China; Beijing Key Laboratory of Diagnostic and Traceability Technologies for Food Poisoning, Beijing Center for Disease Prevention and Control, Beijing 100013, PR China. Electronic address: lihui@bjcdc.org.
⁸ School of Public Health, Capital Medical University, Beijing 100069, PR China; Beijing Key Laboratory of Diagnostic and Traceability Technologies for Food Poisoning, Beijing Center for Disease Prevention and Control, Beijing 100013, PR China. Electronic address: shaobingch@sina.com.

PMID: 39579523
DOI: 10.1016/j.ijfoodmicro.2024.110984

Abstract

The emergence of RND efflux pump gene cluster tmexCD-toprJ threats the clinical use of tigecycline as a last-resort antibiotic. Co-existence of extended spectrum β-lactamases and tmexCD-toprJ can accelerate the emergence of multidrug resistant or extensively drug-resistant Pseudomonas aeruginosa, leading to the production of high-risk clones. This study identified a novel gene cluster, tmexC6D6.2-toprJ1b, on the chromosome of a high-risk ST233 XDR P. aeruginosa from Chinese retail chicken samples. Genetic feature analysis revealed that a tnfxB6-tmexC6D6.2-toprJ1b-strBA-floR-tet(G)-IS6100-sul1-aadA2-int1-intA structure formed a putative transposition unit. tmexC6D6.2-toprJ1b shared high similarity at the nucleotide level with other tmexCD-toprJ gene clusters. tnfxB6 regulator was located downstream from the tmexC6D6.2-toprJ1b gene cluster and it did not affect bacterial resistance phenotype. The expression of tmexC6D6.2-toprJ1b could reduce the growth of E. coli and bring a moderate fitness cost. Further studies are needed to decipher the mechanism of the silencing of tnfxB6 in mediating the high-level resistance of tmexC6D6.2-torpJ1b and continuously monitor the coexistence of the novel tmexCD-toprJ gene cluster and the ESBLs-related resistance genes.

Keywords: Pseudomonas aeruginosa; RND efflux pump gene cluster; ST233; Tigecycline; bla(OXA-4).