Tetracycline Resistance Associated with tet Genes or Integrons among Enterobacter cloacae Strains Isolated from Patients with Urinary Tract Infections

Background: This study aimed to evaluate the prevalence of tet genes and Class I and ۲ integrons in Enterobacter cloacae strains isolated from patients with urinary tract infections (UTIs).Materials & Method: A total of ۵۰ E. cloacae isolates were collected. Antimicrobial susceptibility pattern and tetracycline MIC were determined. The presence of tet genes (tetA, tetB, tetC, tetD) and Class ۱ and ۲ integrons and the content of Class ۱ integron were determined.Findings: Tetracycline MIC pattern classified ۳۶ % of the E. cloacae isolates as resistant. The most common tet gene was tetC (۲۲%), followed by tetD, tetA, and tetB. Class ۱ integron was detected in ۶۴% of the isolates. Class ۱ integron content analysis showed two variable gene cassettes (aadA۱ and aadA۵/dfrA۱۷ genes). The frequency of aadA۵/dfrA۱۷ was ۱۸.۷۵%, which was more common than aadA۱ gene (۶.۲۵%).Conclusion: The most important genetic markers for tetracycline resistance in E. cloacae isolates were tetC and Class ۱ integron. Harboring Class ۱ integron and resistance to streptomycin and ciprofloxacin were significantly correlated.

Keywords:

Integron , Enterobacter cloacae , Tetracycline resistance genes , Urine , Integron content , Class ۱ and ۲ integrons