Occurrence and characterization of urinary tract infection in patients with and without diabetes mellitus with special reference to Escherichia coli

The urinary tract is the second most common site for infection next to respiratory tract and urinary tract infection (UTI) occurs more frequently in persons with diabetes mellitus. The factors affecting UTI in diabetic patients are not well documented and there is lack of adequate surveillance information and characterization pertaining to urinary pathogens in diabetic cases in developing countries. Hence, the study aimed to look into the characterization and antibiotic susceptibility pattern of pathogens associated with UTI among diabetic and non-diabetic patients with special reference to Escherichia coli.

A total of 1695 non-repetitive urine samples were screened prospectively from symptomatic cases of diabetic and non-diabetic individuals by semi-quantitative calibrated loop culture technique between 2014 and 2016.

In our study, out of 1695 urine samples screened, 446 (24.9%) urine samples showed significant bacteriuria and Escherichia coli was accounted for 280 (62.7%) bacterial isolates. Though E.coli was the predominant organism, its occurrence was significantly high in non-diabetic subjects compared to diabetic subjects (70.6% Vs 55.2%, p<0.001). While Staphylococcus aureus (6.5% Vs 2.7%; p< 0.001) and Candida species (7% Vs 2.7%; p <0.001) were the more frequent cause of UTI in diabetic subjects. Among diabetic cases, 61% of the UTI cases were having long term diabetes of more than 10 years. The E.coli strains isolated from both groups showed increased resistance to ampicillin (86.7%), ceftazidime (63.2%), ciprofloxacin (52.5%) and trimethoprim/sulfamethoxazole (50%).

E.coli was predominant organisms isolated from UTI in both diabetic and non-diabetic groups. Microorganisms encountered in UTI did not differ by diabetic status except for Candida species and Staphylococcus aureus, which were more frequently isolated from diabetic patients. Among diabetics, age of the patient, long duration and poor glycemic control were associated risk factors in the development of UTI.