Antimicrobial resistance pattern and prevalence of metallo-β-lactamases in Pseudomonas aeruginosa from Saudi Arabia
African Journal of Microbiology Research
To determine the prevalence of metallo-β-lactamases (MBLs) in Pseudomonas aeruginosa and to investigate whether MBL genes have spread in MBL-producing isolates. A total of 350 clinical isolates of P. aeruginosa were screened for production of MBL. Antibiotic susceptibility testing was determined by E-test strips. Six MBL genes and class 1 integron were tested by polymerase chain reaction (PCR). Positive MBL genes were subjected to sequencing. Matting out assay was carried out. The resistance
... . The resistance rates of 350 P. aeruginosa isolates to piperacillin, piperacillin/tazobactam, cefotaxime, ceftazidime, cefepime, aztreonam, imipenem, and ciprofloxacin were 54, 50.3, 48.3, 45.14, 40.3, 30.57, 38.6 and 36.85%, respectively. The results of MBL screening revealed that 20.57% (72/350) of P. aeruginosa produced MBL. Sixty three (46.46%) of 135 imipenem-resistant isolates were not found to produce MBL. MBL-producing isolates were 100% resistant to β β β β-lactams except aztreonam, which showed resistance rate of 63.88%. Only 20.3 and 5.42% of the MBL-producing isolates were resistant to amikacin and polymyxin B, respectively. PCR and deoxyribonuleic acid (DNA) sequencing investigated revealed that all MBL isolates harbour bla VIM-2 gene . High prevalence of imipenem resistant and MBL-producing P. aeruginosa isolates was reported. Imipenem resistance is in increasing and MBL is responsible for 20.57% of the resistance. The bla VIM-2 is the dominant MBL gene in MBL-producing isolates in Saudi Arabia.