Low distribution of integrous among multidrug resistant E. coli strains isolated from children with community-acquired urinary tract infections in Shiraz, Iran

Although integrons by themselves are not mobile, due to their presence in plasmids and transposons, they can be transferred horizontally. For these reasons integrons are a major mechanism for the spread and maintenance of multidrug resistance (MDR). This study describes the distribution of integron gene cassette classes in a collection of uropathogenic Escherichia coli (UPEC) isolated from children with community acquired urinary tract infection in Jahrom, Iran. E. coli strains isolated from urine samples were tested for susceptibility to 14 different antibiotics using the disk diffusion method and for integron classes by RFLP-PCR. Totally 96 strains of E. coli were isolated from urine samples. High prevalence of resistance to ampicillin (80.2%), co-trimoxazole ((76%) and tetracycline (70.8%) was seen among the UPEC isolates. All isolates were 100% sensitive to imipenem. Sixteen strains (16.6%) had the evidence of integron sequences with the prevalence of 6.25% (n = 6) and 10.41% (n = 10) for intI1 and intI2, respectively. No intI3 was detected in the isolates. The presence of integrons was significantly associated with resistance to certain antibiotics including gentamicin and ampicillin. Considering the MDR patterns and the low prevalence of integrons among the E. coli strains under the study, we suggest that the antibiotic resistance cassettes in these strains presumably are mostly carried on the other transposable elements rather than integrons.