Investigation of the presence of PER-1 and OXA-10 like extended spectrum βeta-lactamases in ceftazidime resistant Pseudomonas aeruginosa strains from Kastamonu training and research hospital

The detection of the extended-spectrum beta-lactamases (ESBL) resistance mechanism is significant for infection control and public health. This study was aimed to analyse the frequency of ESBL in ceftazidime-resistant P. aeruginosa isolates obtained from various clinical samples in Kastamonu Training and Research Hospital between April 2018-March 2020. Forty-two ceftazidime-resistant P. aeruginosa isolated from different patients were included in the study. Determination of the strains and antibiotic susceptibility patterns were made with conventional bacteriological methods as well as MicroScan WalkAway Plus until 01/06/2019, and VITEK 2 after this date. The antibiotic susceptibility tests were evaluated by the European Antimicrobial Susceptibility Test Committee (EUCAST) standards. The ESBL positivity of the strains was searched by the combined disk test phenotypically. The presence of blaPER-1 and blaOXA-10 group was revealed by the polymerase chain reaction (PCR) method. Of the 42 ceftazidime-resistant strains, 81%, 19%, 11.9%, 9.5%, 9.5%, 4.8%, and 4.8% were found susceptible to amikacin, gentamicin, meropenem, cefepime, imipenem, piperacillin-tazobactam, and ciprofloxacin, respectively, using the automated systems. The ESBL production was detected in 27 (64.3%) strains phenotypically. The blaPER-1 gene was determined in only a strain designed as P. aeruginosa KPA-10. The blaOXA-10 group gene was not identified in any strains. Phenotypic tests can be used as a screening test for the determination of ESBL activity in ceftazidime-resistant P. aeruginosa strains. Besides, verification of the results by molecular tests and identification of the genes related for resistance is considerable epidemiologically.