Infection and Drug Resistance (Dec 2019)
PAU-1, a Novel Plasmid-Encoded Ambler Class A β-Lactamase Identified in a Clinical Pseudomonas aeruginosa Isolate
Abstract
Jian Wang,1,2,* Teng Xu,3,4,* Jun Ying,1,* Wangxiao Zhou,1 Qianqian Chen,1 Changrui Qian,1 Xinyi Zhu,1 Kai Shen,1 Peizhen Li,1 Kewei Li,1 Qiyu Bao,1 Junwan Lu1,5 1Institute of Biomedical Informatics, School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, 325035, People’s Republic of China; 2Department of Laboratory Medicine, Ningbo First Hospital, Ningbo 315010, People’s Republic of China; 3Research Center for Translational Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200120, People’s Republic of China; 4Institute of Translational Medicine, Baotou Central Clinical Hospital of Inner Mongolia Medical University, Baotou 014040, People’s Republic of China; 5School of Medicine and Health, Lishui University, Lishui 323000, People’s Republic of China*These authors contributed equally to this workCorrespondence: Qiyu Bao; Junwan LuInstitute of Biomedical Informatics, School of Laboratory Medicine and Life Science, Wenzhou Medical University, Chashan University Town, Ouhai District, Wenzhou 325035, People’s Republic of ChinaTel/Fax +86 577 86689779; +86 577 86689358Email [email protected]; [email protected]: The aim of this work was to identify a novel β-lactamase gene blaPAU-1 encoded on the plasmid of a clinical Pseudomonas aeruginosa isolate.Materials and methods: The clinical P. aeruginosa isolates were isolated from a hospital in southern China. Molecular cloning was performed to analyze the function of the resistance gene. The minimum inhibitory concentration (MIC) was determined by means of the agar dilution method to determine the antimicrobial susceptibilities of the strains. Whole-genome sequencing and comparative genomics analysis were performed to analyze the structures of the resistance gene-related sequences.Results: PAU-1 is a molecular class A, Bush-Jacoby group 2be enzyme which encoded 293 amino acids and shared 74% amino acid identity with a putative class A β-lactamase from Rhodoferax saidenbachensis. Cloned blaPAU-1 in Escherichia coli and P. aeruginosa conferred resistance to piperacillin and ampicillin, and elevated the MIC with a 2–3 dilution for some oxyimino-β-lactams in P. aeruginosa. The genetic environment of blaPAU-1 is tnpA-res-hp-relE-blaPAU-1-lysR, which is in accordance with the structure of a Tn3 transposon. Epidemiological investigation of blaPAU-1 in the same district did not show any evidences of molecular dissemination associated with this determinant.Conclusion: A novel class A β-lactamase gene, blaPAU-1, associated with the mobile genetic element was identified on a transferable plasmid in a clinical P. aeruginosa isolate. Strict surveillance for the emergence of the new determinant should be established and an effort should be made to block the dissemination of this determinant.Keywords: Pseudomonas aeruginosa, antimicrobial resistance, β-lactamase, PAU-1
