Frequency of Class 1 Integrons among Escherichia coli Isolates of Patients with Urinary Tract Infection

Recent studies demonstrated an increased pattern of drug resistance in uropathogenic Escherechia coli (E. coli) which is considered as the most common cause of urinary tract infections (UTIs). Present investigation was undertaken to evaluate antibiotic resistance pattern of E. coli causing UTIs obtained from urine samples and their relationship with integron class1. Apart from that, special emphasis was given on mediated and transferable antibiotic resistance in E. coli as well as the mobilized integrons that contribute to dissemination of antibiotic resistance. Methods and Materials: Susceptibility of isolates to 12 antibiotics was tested by the Kirby -Bauser disk diffusion method. The sensitivity was monitored by zone of inhibition according to the clinical and laboratory standard institute (CLSI) guidelines. Plasmid DNA from E. coli strains was tested for class 1 integron by PCR. Rate of resistance to the 12 antibiotics is as follows: Ampicillin (89.4%), Cefotaxim (31%), Ciprofloxacin (22.4%), Aztreonam (21.7%), Ceftazidim (21.1%), Ceftriaxon (20.5%), Co-trimoxazole (19.9%), Gentamicin (15.5%), Amikacin (7.5%), Cefepim (11.8%), Nitrofurantoin (6.2) and Imipenem (1.9%). Existence of integron was confirmed in 41.9% of isolates. Significant association was evaluated by PCR between resistance to Gentamicin, Amikacin, Gentamicin, Amikacin, Cefotaxim, Ceftazidim, Ceftriaxon, Aztreonam, Ciprofloxacin and Co-trimoxazole with the existence of class 1 integrons. Imipenem could be used as the initial therapy for E. coli in UTIs. Similar studies are essential to determine appropriate guidelines for empirical therapy which vary by location.