Distribution of Class A Extended-Spectrum β-Lactamases Among Pseudomonas aeruginosa Clinical Strains Isolated from Ardabil Hospitals

Fereshteh Hasanpour, Nima Ataei, Amirhossein Sahebkar, Farzad Khademi

Research output: Contribution to journalArticlepeer-review


Background: 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 detection 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.

Original languageEnglish
Article numbere135726
Number of pages6
JournalJundishapur Journal of Microbiology
Issue number4
Publication statusE-pub ahead of print - 11 Jun 2023

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