Prevalence of Extended-spectrum beta-lactamase-producing Pseudomonas aeruginosa in Clinical samples, collected from patients in Tabriz hospitals.

Background and Aim : Pseudomonas aeruginosa is one of the most bacteria involved in nosocomial infections. Presence of Extended-spectrum Beta-lactamases (ESBLs) genes, play an important role in induction of resistance in beta-lactamase producing species to beta lactam antibiotics. Frequency of resistance to these antibiotics is increasing. The aim of this study was to determine the antimicrobial susceptibility pattern and prevalence of ESBLs in clinical isolates of Pseudomonas aeruginosa collect from Tabriz hospitals by phenotypic methods Methods : In this analytic-descriptive study, ۷۸ Pseudomonas aeruginosa isolates, collected from different clinical specimens in Tabriz Sina, Madani and Emam Reza Hospitals, were used. The pattern of antimicrobial resistance was determined by disk diffusion (Kirby-buer) method. The ESBL production was determined by combination disk method using disks containing ceftazidim and cefotaxim alone and in combination with Clavulanic acid. Results : In this study the most effective antibiotics against isolates were amikacin and colistin with ۹۵% susceptibility whereas the highest resistance was to Amoxicillin and Co-trimoxazole and with ۹۲% and ۹۱%. Combine disc test s results indicated that ۴۷ of isolates (۶۱%) were ESBL producers Conclusion : Considering high resistance rate of Pseudomonas aeruginosa to majority of antibiotics and increasing frequency of ESBLs producing isolates, we need for infection control criteria and use of appropriate therapeutic protocols according to antibiogram

Keywords:

Pseudomonas aeruginosa , Antibiotic resistance , ESBL