Analysis of Metallo-β-lactamases, oprD Mutation, and Multidrug Resistance of β-lactam Antibiotic-Resistant Strains of Pseudomonas aeruginosa Isolated from Southern China

Abstract

The purpose of this study was to analyze the metallo-β-lactamases (MBLs) genotype and oprD mutations of the β-lactam antibiotic-resistant Pseudomonas aeruginosa (PA) strains isolated from southern China. We collected 110 strains of β-lactam antibiotic-resistant PA from 2 hospitals during January 2016–December 2017 from Dongguan, South China. MBLs were detected, amplified, and typed using EDTA disc synergy test, PCR, and Sanger gene sequencing. The mutations and expression levels of oprD were detected using Sanger gene sequencing and qPCR. A total of 16.36% (18/110) β-lactam antibiotic-resistant PA strains produced MBLs, and the main genotypes of MBLs were IMP-25, VIM-2, and SIM-2. Sanger gene sequencing results showed that 107 of the 110 strains harbored mutations in oprD sequence, while 3 strains were negative for oprD amplification (2.73%). Among the 107 strains with positive amplification (97.27%), the rate of intentional mutations (including deletions, insertions, and premature stop codons) was 93.46% (100/107) and that of no disrupted mutation was 6.54% (7/107). qPCR analysis confirmed that the expression level of the OprD protein in the 7 strains of no disrupted mutation was significantly reduced. Among the β-lactam antibiotic-resistant PA strains in southern China, 16.36% were positive for MBLs. The loss rate of oprD was 2.73%, and almost all PA strains showed oprD amplification variation or transcription downregulation. Thus, impaired oprD expression and MBLs production may be some of the mechanisms of β-lactam antibiotic-resistance of PA strains in southern China.

Evaluation of β-lactamases and Molecular Typing of Pseudomonas aeruginosa Clinical Strains Isolated from Hospitalized Children in Tehran, Iran

“…It seems that the resistance to imipenem in these bacteria depends on mechanisms other than the production of carbapenemase enzyme. As reported in other studies, the frequency of MBLs was approximately 8.2 to 35.1% (44)(45)(46). Contrary to some reports, VIM was the predominant MBL gene associated with the outbreaks due to MBL-producing P. aeruginosa (47,48).…”

Evolution of Antimicrobial Resistance Levels of ESKAPE Microorganisms in a Peruvian IV-Level Hospital

“…P. aeruginosa is an opportunistic pathogen frequently involved in nosocomial infections, often showing high levels of antibiotic resistance [ 14 36 ]. In this sense, the levels of resistance ranging from ~50 to ~75% (except colistin) found in the present study were to be expected and are in the line of previous reports in Peru [ 14 ].…”