distribution of class a extended-spectrum lactamases among pseudomonas aeruginosa clinical strains isolated from ardabil hospitals

Currently, the emergence of extended-spectrum β-lactamase (esbl)-producing bacteria is becoming a major threat to patients in the hospital and community. such enzymes have been recently detected in pseudomonas aeruginosa, but there is no epidemiological data on the prevalence of esbl-producing clinical isolates in the hospitals of ardabil city (iran).objectives: this study aimed to determine the phenotypic and genotypic prevalence of class a esbl-producing p. aeruginosa strains in ardabil city.methods: a total of 120 clinical isolates of p. aeruginosa collected from ardabil hospitals were used in this study. phenotypic detec-tion of class a esbl-producing p. aeruginosa isolates was performed using a double-disk synergy test. in addition, the detection of class a esbl-encoding genes, including pseudomonas extended resistant (per), vietnamese extended-spectrum β-lactamase (veb), temoniera (tem), sulfhydryl variable (shv), cefotaximase (ctx-m), guyana extended-spectrum β-lactamase (ges), and pseudomonas-specific enzyme (pse), was performed using the polymerase chain reaction (pcr).results: the prevalence of class a esbl-producing p. aeruginosa strains was 8.3% (10 out of 120) based on the double-disk synergy test. however, 40% (48 out of 120) of these isolates were found to carry genes encoding class a esbls based on pcr. among 48 class a esbl-positive strains, the prevalence of pse, tem, veb, ctx-m, and per genes were 64.6% (31/48), 25% (12/48), 4.2% (2/48), 4.2% (2/48), and 2% (1/48), respectively. however, the frequency of other class a esbl genes (shv and ges genes) was 0%.conclusions: our results confirmed the presence of class a esbl-producing p. aeruginosa strains in the hospital environment of ardabil. on the other hand, the use of molecular tests can be a more precise and reliable method than phenotypic ones to identify these resistant strains and prevent the emergence of antibiotic resistance and ensuing treatment failure.