Antibiotic susceptibility pattern of Pseudomonas aeruginosa expressing blaGES and blaPER genes in two different hospitals

Pseudomonas aeruginosa is intrinsically resistant to several antimicrobial drugs classes. Various extended-spectrum beta lactamases (ESBL) types have been found in P. aeruginosa such as Pseudomonas extended resistance (PER) and Guiana extended-spectrum (GES) enzymes. The study aimed to evaluate the susceptibility of the ESBL producing P. aeruginosa strains that express blaGES and blaPER genes to commonly used antibiotics. A total of 28 P. aeruginosa clinical isolates was identified as ESBL producers and subjected to polymerase chain reaction (PCR) technique for detection of blaGES, blaPER genes. Routine antimicrobial susceptibility was determined by the disc diffusion method. The highest resistance rate reached 71.4% for ciprofloxacin, while the lowest resistance rate (10.7%) was seen in imipenem followed by colistin (21.6%). blaGES gene was observed in 78.6% of the isolates, while blaPER appeared in 22.4%. It was concluded that imipenem and colistin showed good antipesuedomonal activity and blaGES was predominant gene among the ESBL producing P. aeruginosa in Makah hospitals. The results of the present study can help to prevent the mortality and morbidity associated with Pseudomonas infections in hospitals.   Key words: P. aeruginosa, extended-spectrum beta lactamases (ESBL), blaGES, blaPER, polymerase chain reaction (PCR).