High frequency of integrons and efflux pump in Uropathogenic Escherichia coli isolated from Iranian kidney and non-kidney transplant patients

Abstract

Introduction: Due to the important role of integrons and efflux pumps in increasing drug resistance, the aim of this study was to investigate the frequency of integrons and efflux pump in Uropathogenic Escherichia coli (UPEC) isolated from Iranian kidney and non-kidney transplant patients. Materials and methods: A case-control study was performed on 111 UPEC isolates obtained from 46 kidney transplant patients (group A) and 65 non-kidney transplant patients (group B) who were diagnosed with a UPEC-associated urinary tract infection between June 2019 to October 2019 in Isfahan, Iran. In our study, isolates were further confirmed as E. coli based on phenotyping and genotyping test. Antimicrobial susceptibility was determined using the disc diffusion method, and the presence of integron and efflux pump genes was detected by polymerase chain reaction. Results: In this study, the frequency of integron genes was as follows: 60.9 and 28.3 isolates of group A and 47.7 and 21.6 isolates of group B carried int1 and int2, respectively. In both groups with int1-positive, the highest resistance was to co-trimoxazole with (89.3) and (67.7), respectively. The lowest antibiotic resistance rates in groups A and B with int1-positive were seen against piperacillin/tazobactam (14.3) and nitrofurantoin (9.7), respectively. There was a significant association between the presence of Class 1 integron and cefixime in group A, and resistance to co-trimoxazole in group B. All three genes acrA, acrB, and tolC were present simultaneously in 68.5 (76/111) isolates, 71.8 (33/46) isolates of group A, and 66.2 (43/65) isolates of group B. Among all isolates a significant correlation between the presence of the tolC gene and the resistance to nalidixic acid, ofloxacin, and piperacillin-tazobactam was observed. Conclusion: Our data indicated a significant relationship between the presence of integrons and several antibiotics such as co-trimoxazole and cefixime. Furthermore, RND efflux pumps such as AcrAB-TolC play an important role in gram-negative bacteria in the removal of toxic substances and antibiotics.