Background: Nowadays, the resistance to antibiotics in bacteria encountered many physicians around the world; it is an issue that has created numerous problems in the treatment, like urinary tract infection, as a common infection. The aim of this study was to evaluate prevalence of tetracycline resistant genes in Enterobacteriaceae family (Proteus, Enterobacter and Klebsiella) isolated from urine samples.

Materials and methods: In this descriptive study, 230 samples of urinary infection were collected from patients. They were identified by using diagnostic biochemical tests and then antibiotic susceptibility tests were used by ticarcillin, ceftriaxone, cefoxitin, streptomycin, erythromycin and tetracycline antibiotics. Afterwards, DNA plasmids were extracted and PCR was performed by coding proprietary primers resistant to tetracycline (TetA, TetB).

Results: Of 230 suspicious samples, 120 were confirmed after biochemical tests, including 88 Kebsiella, 20 Proteus and 12 Enterobacter. The antibiotic susceptibility test of tetracycline showed 38.33% sensitivity and 34.99% resistance for Klebsiella, 6.66% sensitivity and 3.33% resistance for Enterobacter, and 2.5% sensitivity and 14.16% resistance for Proteus. Out of the 120 samples, 25 Tet(A) gene and 36 Tet(B) were detected.

Conclusion: The comparison between the results of cultures and PCR method for the genes Tet(A) and Tet(B) showed that PCR method confirmed antibiogram tests, but for improving sensitivity, accuracy and specificity, other coding tetracycline resistance genes should be studied to reach more conclusive results.

Keywords: Tetracycline resistance, Tet(A), Tet(B), Klebsiella, Proteus, Enterobacter, PCR.