Clinical, Bacterial, and Antibiogram Profiles of Infections Among Type 2 Diabetes Mellitus Patients in a Tertiary Care Center.

Background Patients with type 2 diabetes mellitus (T2DM) have an increased susceptibility to infection because of hyperglycemia-related immune dysfunction, vascular impairment, and associated comorbidities. Characterization of bacterial isolates and their antimicrobial susceptibility patterns is essential for selecting appropriate empirical therapy and limiting antimicrobial resistance. Methodology This hospital-based, cross-sectional study included 150 adults with T2DM and culture-positive infections admitted to a tertiary care hospital in Bengaluru, India, between April 2023 and November 2024. Clinical and microbiological characteristics, HbA1c levels, intensive care unit (ICU) admission, and in-hospital mortality were assessed. Bacterial identification, antimicrobial susceptibility testing, and extended-spectrum beta-lactamase (ESBL) assessment were performed by the hospital microbiology laboratory as part of routine clinical care, with susceptibility results reported according to the applicable Clinical and Laboratory Standards Institute criteria. Results Urinary tract infection was the most frequent infection, affecting 55/150 patients (36.67%). Escherichia coli was the predominant isolate (54/150 (36.00%)), followed by Klebsiella spp. (26/150 (17.33%)) and Pseudomonas spp. (24/150 (16.00%)). Multidrug-resistant (MDR) organisms were identified in 53/150 patients (35.33%), while ESBL production was recorded in 50/118 isolates with an evaluable ESBL result (42.37%); 32 isolates were classified as not applicable. Resistance was highest to meropenem (64/150 (42.67%)), followed by amoxicillin (60/150 (40.00%)) and ciprofloxacin (58/150 (38.67%)). Although glycemic control status differed between the MDR and non-MDR groups (p = 0.033), uncontrolled glycemia was less frequent in the MDR group; therefore, this finding does not establish poor glycemic control as a predictor of MDR infection. MDR infections were associated with higher ICU admission rates (26/53 (49.06%) versus 13/97 (13.40%); p < 0.001) and in-hospital mortality (9/53 (16.98%) versus 5/97 (5.15%); p = 0.017). Conclusions MDR bacterial infections were common among hospitalized patients with T2DM and were associated with higher rates of ICU admission and in-hospital mortality. Institution-specific antibiograms, prompt culture-guided therapy, and strengthened antimicrobial stewardship are needed given the observed resistance, including resistance to meropenem.