Urinary tract infection (UTI) is one of the most common infectious diseases and nosocomial infections worldwide, and uropathogenic Escherichia coli is the primary cause of UTI. Due to increased antibiotic resistance and the emergence of multidrug resistant (MDR) UPEC clones, the treatment of UTI is difficult. The occurrence of MDR in E. coli has been attributed to the AcrAB-TolC complex of efflux pumps.
The aim of this study was to complete a frequency evaluation of acrA and acrB genes among UPEC MDR strains isolated from patients with UTI who were admitted to Milad hospital in Tehran.
For 123 UPEC strains that were isolated and diagnosed from the urine samples of patients using biochemical tests, antibiotic susceptibility was carried out using the disc diffusion method according to CLSI guidelines. Isolates that were resistant to at least one antimicrobial agent in three or more of the categories were considered to be MDR. The presence and frequency of acrA and acrB genes was determined using PCR.
The rates of antibiotic resistance to ampicillin, cefalotin, tetracycline, cefazolin, ceftriaxone, ceftizoxime, ceftazidime, ciprofloxacin, and cotrimoxazole were 82.9%, 78.1%, 61.1%, 49.5%, 38.2%, 30.2%, 26.1%, 42.2%, and 60.1%, respectively. The isolates were most sensitive to nitrofurantoin (95.9%), gentamicin (77.2%), and amikacin (71.5%). A total of 78% of the isolates were MDR. The frequency of the acrA gene was 82.90%, the acrB gene was 95.90% and acrA + acrB was 95.90%. There was no significant difference between acrA and acrB frequency relating to bacterial antibiotic resistance.
Our results showed that ways to control the treatment of UTI for the prevention of MDR occurrence should be sought. For a better study of efflux pumps, a comprehensive and detailed study regarding the presence of efflux pumps gees is required.