In this study, 155 isolates of E. coli isolated from patients with urinary tract infection were evaluated. Of them (133 cases) were females and 10.5% (18 cases) were males. The level of UTI in the age group of less than 20 years, 20–40 years and over 40 years was obtained 22%, 46.7% and 31.3%, respectively .According to the results of this study, the highest level of antibiotic resistance in patients with urinary tract infection was related to ampicillin and doxycycline and the lowest level of resistance was related to gentamicin, cefotaxime and nitrofurantoin. In a study by Abdulaziz Qassim (2018), the highest level of antibiotic resistance was related to ampicillin, amoxicillin clavulanate and the lowest level of drug resistance was for imipenem, gentamicin, cefotaxime, and nitrofurantoin[7].
In this study, by evaluating the symptoms of urinary tract infection, it was determined that the prevalence of clinical symptoms showed the most prevalence in dysuria 46.4%, flank pain 27.2% and frequency 26.5% in the patients, respectively. Hematuria, diarrhea, vomiting, and fever were observed in less than 15% of cases. In the study of Mishra (2010), dysuria, frequency, and frequent urination (Orgency) were the most common symptoms, which are consistent with our study[8] .
Among the laboratory factors, nitrite in 41.7%, pyuria in 47% and hematuria in 15% of cases were positive. In the Schippmann's (2018) study, the prevalence of nitrite and pyuria was reported 41% and 38%, respectively[9]. Also in a study by Jennifer (2001) pyuria and nitrite was obtained 47.5% and 44%, respectively[10]. There is a little difference between these studies and the conducted study, according to comparing the results.
In this study, 30 E. coli isolates were productive of ESBL from 155 isolates. Among the strains with positive ESBL, 19.5% were related to females (26 cases of 133 female patients) and 22.5% were related to males (4 cases of 18 male patients) male. In the Shakia's study (2017), the prevalence of ESBL was 81.8% in females and 18.2% in males[11]. In the Sakina's study (2018), the prevalence of ESBL has been reported 40% in females and 30% in males[12]. Also in a study by Stefano (2014), the prevalence of ESBL in females was reported 15% higher than males[13]. One reason for the discrepancy between the results of our study and the conducted study was the overuse of antibiotics, which may result in a higher prevalence of ESBL.
The prevalence of ESBL in the age group of over 40 years, 20–40 years and less than 20 years was 31.9%, 24.2% and 10%, respectively. In the Sakina's study (2018), the level of ESBL in the age groups of 16–30 years, 31–45 years and 46–60 years were reported 34.6%, 37.5% and 30%, respectively[12]. In the Shakia's study (2017), the most prevalence of ESBL was reported 27.3% and 24.2%, respectively, in the two age groups of 21–30 years and 31–40 years[11]. In this study, 11.5% of people with positive ESBL were employees, 0% workers, 22.5% housewives, 17.5% students, and 31.3% had other jobs. The results show that there is no relationship between job and prevalence of ESBL and all strata get the ESBL. In the statistical population under study, among those who had ESBL positive, 28% were under diploma (14 cases of 50 patients), 19.4% were diploma (6 cases of 31 patients) and 17.3% were bachelor (9 cases of 52 patients) and 5.6% had master's degree or higher (1 case of 18 patients).The results show that the level of ESBL in people with higher education is significantly lower than people with low education. The prevalence of ESBL in the urban population is 19.1% (25 cases of 131 patients) and in the rural population is 25% (5 cases of 20 patients), this issue indicated a higher ESBL prevalence in the rural population.
According to the results of this study, in ESBL-producing E. coli strains, 31.6% of patients reported a history of UTI (6 cases of 30 patients). History of hospitalization in patients with ESBL-producing E. coli strains has been reported 29.9% (20 out of 67 patients) and 12.3% of the patients (10 cases of 81 patients) did not report hospitalization history.
In this study, 38.9% (7 cases of 18 patients) reported a history of antibiotic use during one past month. In the study of Abyaneh (2018), the recurrent urinary tract infection and the use of more than two antibiotics per year have been proven as the factors risk of ESBL-producing[14]. In the koksal's study (2019), the prevalence of ESBL in patients with a history of hospitalization in the past 3 months was 27.3%, while it was 8% in other patients[15], which is consistent with the results of our study.
The most level of resistance in ESBL-producing E. coli strains was related to cefazolin, ampicillin, co-trimoxazole, ceftriaxone and ceftazidime with 83.3%, 83.3%, 80%, 80% and 73.3%, respectively, and the lowest level of resistance was related to nitrofurantoin and gentamicin with 6.7% and 10%, respectively. In the study of Abdulaziz Qassim (2018), the most level of resistance in ESBL-producing E. coli strains was related to ampicillin, amoxicillin clavulanate and ceftazidime with 100%, 88% and 85%, respectively, and the lowest level of resistance was for imipenem, nitrofurantoin and gentamicin with 0%, 21% % and 27%, respectively[7]. In the study of Dash (2018), ampicillin, cefuroxime and ceftriaxone showed the most level of resistance and meropenem, amikacin and nitrofurantoin showed the lowest level of resistance[16]. In the koksal's study (2019), the most level of resistance in ESBL-producing E. coli strains, was related to ceftriaxone, ceftazidime, and cefepime with 100% resistance and ampicillin with 95.5% resistance. The lowest level of resistance was reported for imipenem, meropenem and nitrofurantoin[15]. The results of conducted study are consistent with our study and indicate a high level of family of β-lactam antibiotics resistance in ESBL-producing E. coli strains.
Evaluating the genes generated in ESBL specimens using PCR in this study showed that CTX-M gene was found in 86.7% and CTX-M15 gene was found in 53.3% of the strains (16 from 28). The TEM gene and the SHV gene were not found in any of the strains. In the study of Haba Maged (2018), TEM, SHV and CTX-M genes were found in 42.8%, 36.7% and 38.6% of cases, respectively[17]. According to the study by Elizabeth Gaviral (2018), 92% of ESBL-containing strains had the CTX-M 15 gene and the SHV gene was found in only two isolates, which indicates a high degree of consistent with this study[18]. In the Abdulaziz Qassim (2018) study, 93.94% of the strains also contained the CTX-M gene, and TEM was found in 12.12% of the strains, which is opposed with the results of this study regarding the TEM gene[7]. Al-Jami et al., identified the distribution of ESBL-producing genes on 121 isolates in 2019[19]. Among the 75 ESBL-producing strains, the SHV gene was in 30.7% and the TEM gene in 20.7% of cases, which is not consistent with our study.
In this study, the most response to treatment in antibiotics was reported for nitrofurantoin (100%), ciprofloxacin (94%), cefexime (80%), cotrimoxazole (80%) and doxycycline (64%), respectively. According to Ghazala's study (2019), nitrofurantoin was introduced as the first treatment with 100% response[20]. Thomas Hutton in 2012 also introduced nitrofurantoin, fosfomycin, and trimethoprim-sulfamethoxazole as the first treatment[21].
Overall, the conducted study shows that overuse of antibiotics and recurrent infections and timely and inadequate non-treatment can lead to ESBL-producing E. coli strains in urinary tract infections and the following drug resistance will have a serious challenge. Patients' awareness and education about the principles of hygiene, referring to a physician and not arbitrary use of antibiotics are effective in reducing multidrug resistance.
The antibiotic use, hospitalization, and UTIs history lead to increasing ESBL-producing E. coli strains in urinary tract infections.