Prevalence of blaoxa-1 and blashv Genes in E. coli Isolates from Hospitalized Patients in Rasht

Extended-spectrum beta-lactamases (ESBL) are widely produced by Escherichia coli strains. The aim of this study was to determine frequency of blaOXA-1 and blaSHV genes in E.coli strains isolated from patients hospitalized in city of Rasht, Iran.
In this cross-sectional study, 200 samples were collected from patients. The E. coli strains were identified using morphological characteristics and biochemical tests. Antimicrobial susceptibility testing was performed. The prevalence of the blaOXA-1 and blaSHV genes in the E. coli isolated was assessed by PCR method.
Overall, 160 E. coli strains were isolated. Of these, 83 (51.9%) showed ESBL activity while 71 (48.1%) did not. All positive strains were resistant to cephalothin. Moreover, 98.8% of ESBL-producing strains were resistance to amoxicillin, cefotaxime and ceftriaxone. The prevalence of the blaOXA-1 and blaSHV genes in ESBL-producing strains were 45% and 17%, respectively. In addition, 28.9% of the strains had both genes while the genes were absent in 9.6% of the strains.
Prevalence of the blaOXA-1gene is higher than that of the blaSHV gene. The absence of both genes in some isolates indicates the possible role of other genes in the ESBL activity.