Frequency of CTX-M gene isolated from E. coli in patients with suspected urinary tract infection in Semnan

Today, bacterial resistance is one of the greatest medical challenges and it annually serves a huge amount of public and private investments since late or false diagnosis endangers the lives of patients. Beta-lactamase genes are a major cause of this challenge. The aim of the current study was to investigate the pattern of bacterial resistance in patients with urinary tract infection (UTI) in Semnan and to determine the frequency of CTX-M gene. Throughout the study, 400 samples of urine were collected from healthcare centers and clinical laboratories in Semnan. Then, 151 E. coli positive samples were isolated through diagnostic and confirmatory tests. Antibiogram was performed using ampicillin, nalidixic acid, ceftriaxone, nitrofurantoin, co-trimoxazole, norfloxacin, amikacin, gentamicin and ciprofloxacin antibiotic discs. Ceftriaxone-resistant isolates were selected for the second stage of antibiogram. ESBL containing strains were identified and were investigated for CTX-M gene by PCR. The sensitivity to nitrofuratoeine antibiotic was 35.76%% (n = 54) and the lowest sensitivity was to ampicillin (7.28%, n = 11). The rate of ESBL containing strains was 33, of which 60.6% contained CTX-M gene. Among the ESBL containing strains, the highest resistance was seen to be for ampicillin (n = 30). Due to the high percentage of resistance to ampicillin in this area, prescribing by physicians must be prohibited; in addition, more attention should be paid to the use of other antibiotics, especially third generation of cephalosporins because of high prevalence of ESBL producers like blaCTX-M. •Bacterial resistance is one of the greatest medical challenges.•Prescription of ampicillin and third generation of cephalosporins must be carefully managed.•Resistance to gentamycin and nitrofurantoin is low among urinary tract infections in Semnan.•The prevalence of beta-lactamase gene blaCTX-M was 60.6%.