Investigation of metallo-beta-lactamase production in carbapenem-resistant Pseudomonas aeruginosa isolated in Kastamonu Training and Research Hospital, Turkey

Aims@#The detection of the metallo-beta-lactamase (MBL) producing Pseudomonas aeruginosa isolates is crucial for infection control and public health. The present study aimed to investigate the MBL production in carbapenem-resistant P. aeruginosa isolated from various clinical samples in Kastamonu Training and Research Hospital, Turkey. @*Methodology and results@#Seventy-three carbapenem-resistant P. aeruginosa isolates were recovered from different patients between April 2018 and November 2020. Identification of the isolates was performed by conventional methods (culture examination, determination of Gram reaction, and oxidase test) and an automated system (Vitek 2). Antibiotic susceptibility patterns were determined using the Vitek 2 and the results were interpreted based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) standards. The MBL production was phenotypically investigated using the imipenem-EDTA combined disk test. The presence of beta-lactamase IMP (blaIMP), beta-lactamase VIM (blaVIM) and beta-lactamase GIM (blaGIM) genes were determined using PCR to confirm the MBL production. Seventy-one isolates (97%, n=71/73) were resistant to imipenem, sixty-four isolates (88%, n=64/73) to meropenem and sixty-two isolates (85%, n=62/73) to both imipenem and meropenem. Sixty-five isolates (89%, n=65/73) were defined as multidrug-resistant. The MBL production was detected in 57 isolates (78%, n=57/73) phenotypically. However, the blaIMP, blaVIM and blaGIM genes were not detected in all the isolates.@*Conclusion, significance and impact of study@#It was determined that there were no imipenemase (IMP), Verona integron-encoded metallo-beta-lactamase (VIM) and German imipenemase (GIM) type MBLs in carbapenem-resistant P. aeruginosa isolated from Kastamonu Training and Research Hospital. MBL production in carbapenem-resistant P. aeruginosa strains can be investigated phenotypically. However, confirmation of results with molecular tests is especially significant for epidemiological studies.

Investigation of beta-lactamases in carbapenem-resistant a. baumannii isolates

To investigate the prevalence of PER-1, PER-2, GES, IMP-1, VIM-2, OXA-23, and OXA-24 type beta-lactamases in carbapenem-resistant Acinetobacter baumannii isolates, in view of the fact that Beta-lactamase production is the most important mechanism of acquired beta-lactam resistance in Gram-negative pathogens. Experimental study. Department of Medical Microbiology, School of Medicine, Pamukkale University, Denizli, Turkey. From January 2009 to December 2009, a total of 98 carbapenem-resistant A. baumannii bacteria were isolated from patients. In-house PCR was performed for the detection of PER-1, PER-2, GES, IMP-1, VIM-2, OXA-23, and OXA-24 beta-lactamase genes in those clinical carbapenem-resistant A. baumannii isolates. Prevalence rate of beta-lactamase genes in carbapenem-resistant A. baumannii isolates Results: GES beta-lactamase was found in 59 isolates [60.20%]. PER-1 was found in eight isolates [8.16%]. IMP-1 was found in five isolates [5.10%]. OXA-24 was detected in two isolates [2.04%]. No isolate possessed VIM-2, PER-2, or OXA-23 beta-lactamase genes. This study indicates that the GES type beta-lactamases are the most prevalent among carbapenem-resistant A. baumannii isolates in our hospital. Screening for beta-lactamases and strict infection control for these isolates will help prevent further spread of resistance