Urinary tract infections (UTIs) are among the most common bacterial infections encountered in both community and hospital settings. They represent a significant health burden globally, particularly among patients with diabetes mellitus (DM). Individuals with diabetes are more susceptible to UTIs due to multiple factors, including impaired immune responses, autonomic neuropathy leading to incomplete bladder emptying, and persistent glycosuria that promotes bacterial growth (1,2). These factors not only increase the frequency of infection but also contribute to a higher risk of complications such as pyelonephritis, renal abscesses, and urosepsis. Furthermore, diabetic patients often experience atypical or asymptomatic presentations, which can lead to delayed diagnosis and treatment (3).

The burden of diabetes is rapidly escalating in India, with over 77 million people currently affected, making it one of the countries with the highest number of diabetic individuals globally (4). This demographic shift has also led to an increased incidence of infection-related complications, including UTIs. Diabetic women, in particular, have a higher predisposition due to both metabolic and anatomical factors (5). In addition to being more frequent, UTIs in diabetics are often more severe, recurrent, and caused by multidrug-resistant organisms (6). While Escherichia coli continues to be the most prevalent uropathogen, other Gram-negative organisms such as Klebsiella pneumoniae, Pseudomonas aeruginosa, and fungal pathogens like Candida species are also frequently isolated in this population (7,8).

The increasing trend of antibiotic resistance in uropathogens poses a major challenge in the management of UTIs, especially in diabetic patients. The irrational use of antibiotics, lack of prescription regulation, and inadequate infection control practices in many parts of India have contributed to this growing resistance (9). Resistance to commonly used antibiotics such as fluoroquinolones, co-trimoxazole, and third-generation cephalosporins is now widespread, making empirical treatment increasingly difficult (10). In many cases, effective treatment now relies on last-resort antibiotics such as carbapenems, which further raises concerns about antimicrobial stewardship and the risk of resistance escalation (11).

Understanding the regional variations in the microbial profile and antimicrobial susceptibility patterns is essential for formulating effective empirical therapy. However, most studies available from India are either single-center or have limited sample sizes, which may not accurately represent the microbial spectrum and resistance trends across broader geographic areas (12). Central India, with its unique mix of urban, semi-urban, and rural healthcare settings, lacks adequate multicentric data regarding UTIs in diabetic patients. In this context, timely and accurate data are needed to inform treatment guidelines and improve patient outcomes (13).

The present study was undertaken to fill this gap by conducting a prospective multicentric analysis across three tertiary care hospitals in Central India over a one-year period. The objectives of the study were to determine the prevalence and etiology of UTIs in diabetic patients, to assess the antibiotic sensitivity patterns of isolated uropathogens, and to evaluate the burden of multidrug-resistant infections in this high-risk population. The findings are expected to contribute valuable insights for clinicians, microbiologists, and policymakers involved in the management of diabetic patients with suspected urinary tract infections.

This prospective, multicentric observational study was conducted over a period of one year (from June 2023 to May 2024) across three tertiary care teaching hospitals located in Central India. The study aimed to evaluate the etiology and antibiotic sensitivity patterns of urinary tract infections (UTIs) in patients with diabetes mellitus. Ethical clearance was obtained from the institutional ethics committees of all participating centers prior to initiation.

Diabetic patients (both type 1 and type 2) aged 18 years and above, presenting to outpatient departments or admitted to wards with clinical features suggestive of UTI—such as dysuria, increased frequency, urgency, lower abdominal pain, suprapubic tenderness, or fever—were included in the study. Informed consent was obtained from all participants. Patients with recent urological interventions, those on prolonged antibiotic therapy (>7 days), pregnant women, catheterized individuals, and those unwilling to participate were excluded to avoid confounding factors.

A midstream clean-catch urine sample was collected aseptically from each patient in a sterile, wide-mouthed container. For patients who were critically ill or unable to collect the sample themselves, urine was collected via sterile catheterization under strict aseptic precautions. The samples were transported immediately to the microbiology laboratory of each center and processed within two hours of collection.

Urine cultures were performed using standard microbiological procedures. Samples were inoculated onto Cysteine Lactose Electrolyte Deficient (CLED) agar and MacConkey agar using a calibrated loop delivering 0.001 mL of urine. The plates were incubated aerobically at 37°C for 18–24 hours. A colony count of ≥10⁵ colony-forming units (CFU)/mL was considered significant bacteriuria. Isolates were identified using conventional biochemical tests and, where required, automated identification systems (such as VITEK 2 Compact).

Antimicrobial susceptibility testing (AST) was performed using the Kirby-Bauer disk diffusion method on Mueller-Hinton agar, and results were interpreted according to the Clinical and Laboratory Standards Institute (CLSI) guidelines, 2023 update. For Gram-negative isolates, antibiotics tested included ampicillin, ceftriaxone, cefepime, piperacillin-tazobactam, amikacin, gentamicin, nitrofurantoin, fosfomycin, ciprofloxacin, cotrimoxazole, and meropenem. For Gram-positive isolates, antibiotics such as ampicillin, nitrofurantoin, vancomycin, and linezolid were tested. Candida species, if isolated, were identified by germ tube test and confirmed with CHROMagar Candida; antifungal susceptibility was assessed using fluconazole, voriconazole, and amphotericin B.

Data were collected on patient demographics, clinical features, duration of diabetes, glycemic control (based on HbA1c levels), culture results, and antimicrobial resistance patterns. Multidrug resistance (MDR) was defined as resistance to at least one agent in three or more antimicrobial categories. Data were compiled and analyzed using Microsoft Excel and SPSS (version 25). Descriptive statistics were used to summarize demographic and clinical variables. Categorical data were expressed as frequencies and percentages, and comparisons between groups were made using the chi-square test. A p-value of <0.05 was considered statistically significant.

Study Population Characteristics

Out of 1,250 diabetic patients presenting with symptoms suggestive of UTI, 364 (29.1%) had culture-positive urinary tract infections. The mean age of culture-positive patients was 58.3 ± 12.4 years, with a female predominance (60.4%).

Table 1: Demographic Profile of Culture-Positive Diabetic UTI Patients (n=364)

Microbial Etiology of UTI

A total of 364 isolates were recovered. Escherichia coli was the most frequent uropathogen (48.9%), followed by Klebsiella pneumoniae and Enterococcus spp.

Table 2: Distribution of Uropathogens (n=364)

Distribution of Uropathogens by Sex

Table 3: Sex-wise Distribution of Common Uropathogens

Antibiotic Sensitivity Patterns

Antibiotic susceptibility varied by pathogen. Gram-negative isolates showed high resistance to fluoroquinolones and co-trimoxazole.

Table 4: Antibiotic Susceptibility Pattern of E. coli (n=178)

Table 5: Antibiotic Susceptibility Pattern of K. pneumoniae (n=79)

Table 6: Antibiotic Susceptibility Pattern of Pseudomonas aeruginosa (n=26)

Multidrug Resistance (MDR) Profile

MDR was defined as resistance to ≥3 antibiotic classes. Overall, 141 isolates (38.7%) were MDR.

Table 7: MDR Prevalence by Organism

Sensitivity Pattern of Candida spp. (n=16)

Table 8: Antifungal Susceptibility of Candida spp.

The present multicentric study highlights the microbiological spectrum and antimicrobial resistance patterns of urinary tract infections (UTIs) among diabetic patients in Central India. With a culture positivity rate of 29.1%, our findings are consistent with earlier reports indicating that 25–35% of diabetic patients presenting with urinary symptoms have microbiologically confirmed UTIs (1,2). The increased susceptibility of diabetic individuals to UTIs can be attributed to impaired immune responses, poor glycemic control, bladder dysfunction, and glycosuria which collectively create a favorable environment for microbial colonization and persistence (3,4).

In the present study, the majority of UTI cases were seen in individuals aged above 60 years, with a female predominance (60.4%). This aligns with previous literature which states that women with diabetes have a significantly higher risk of developing UTIs compared to their non-diabetic counterparts, especially in older age groups (5–7). The anatomical proximity of the urethra to the anus, reduced estrogen levels in postmenopausal women, and impaired local immunity contribute to this gender-based predisposition (8).

Escherichia coli was the most frequently isolated uropathogen (48.9%), followed by Klebsiella pneumoniae (21.7%) and Enterococcus spp. (12.1%). These findings are in accordance with several Indian and international studies that identify E. coli as the principal uropathogen among both diabetic and non-diabetic populations (9–12). However, the relatively higher proportion of Klebsiella and Pseudomonas aeruginosa in our diabetic cohort underscores the potential for more complicated infections in this population. Studies by Shill et al. and Khosravi et al. also report similar findings, noting increased prevalence of non-E. coli Gram-negative organisms in diabetic patients (13,14). The emergence of Candida species (4.4%) in urine cultures further reflects the immunocompromised status of long-standing diabetics, particularly those with poor glycemic control or prior antibiotic exposure (15,16).

Antimicrobial resistance remains a key concern in the management of UTIs. In our study, E. coli isolates demonstrated high susceptibility to nitrofurantoin (83%), fosfomycin (89%), amikacin (87%), and meropenem (93%). Resistance to ciprofloxacin and co-trimoxazole was notably high (72% and 75%, respectively). Similar resistance trends have been reported across India and Southeast Asia, where irrational antibiotic use and self-medication practices are prevalent (17–20). According to the ICMR-AMRSN (Indian Council of Medical Research - Antimicrobial Resistance Surveillance Network), fluoroquinolone resistance among uropathogens has reached critical levels in several Indian states, particularly among diabetic patients who have frequent antibiotic exposure (21).

Klebsiella pneumoniae isolates in our study also showed high resistance to fluoroquinolones and co-trimoxazole, but retained good sensitivity to fosfomycin (77%), amikacin (81%), and carbapenems (90%). These findings are consistent with prior research from tertiary care centers in India (22,23). The rising trend of extended-spectrum beta-lactamase (ESBL) producing Klebsiella species in diabetic patients necessitates routine AST-guided therapy rather than empirical treatment. Likewise, Pseudomonas aeruginosa isolates showed moderate susceptibility to piperacillin-tazobactam (77%) and carbapenems (88%), underscoring their MDR nature, which has been previously documented in studies by Patil et al. and Dash et al. (24,25).

Multidrug resistance (MDR), defined as resistance to three or more antibiotic classes, was observed in 38.7% of the isolates in our study. The MDR rate was highest in K. pneumoniae (47.8%), followed by Pseudomonas (42.3%) and E. coli (33.1%). This is alarming and aligns with findings from other Indian studies, which report MDR rates ranging from 30% to 70% among diabetic UTI isolates, depending on regional antibiotic usage patterns and infection control practices (26–28). The World Health Organization (WHO) has identified carbapenem-resistant Enterobacteriaceae (CRE) and fluoroquinolone-resistant E. coli as critical priority pathogens, especially in high-burden countries like India (29).

Fungal urinary tract infections due to Candida spp. were detected in 4.4% of patients. These infections were more common in elderly females with uncontrolled diabetes and prior broad-spectrum antibiotic use. All Candida isolates in our study were sensitive to amphotericin B, and over 80% were sensitive to fluconazole. Our findings mirror reports by Acharya et al. and Sobel et al., which emphasize the need to consider fungal UTI in diabetics with persistent symptoms and sterile pyuria (30,31).

An important aspect of our study is its multicentric design, involving three tertiary care hospitals, which improves the generalizability of the findings. Notably, there were minor inter-center variations in MDR prevalence, reflecting differences in local prescribing practices, infection control policies, and laboratory capacities. This underscores the importance of establishing local antibiograms and implementing hospital-based antimicrobial stewardship programs (32,33).

While our study provides valuable insight, it has some limitations. First, we did not evaluate ESBL and carbapenemase production using molecular methods, which would have provided deeper understanding of resistance mechanisms. Second, the study did not stratify data based on HbA1c levels or duration of diabetes, which may influence the severity and recurrence of UTI. Third, recurrence and treatment outcomes were not evaluated prospectively.

Despite these limitations, this study reinforces the importance of targeted antimicrobial therapy guided by culture and sensitivity results, especially in diabetic patients who are at higher risk for treatment failure, recurrent infections, and hospitalizations due to MDR organisms. Rational antibiotic use, patient education, early detection of UTI symptoms, and good glycemic control are pivotal in reducing the burden of UTIs in this vulnerable group.

UTIs in diabetic patients are caused predominantly by Gram-negative bacilli, with a significant proportion showing multidrug resistance. Empirical therapy should prioritize nitrofurantoin or fosfomycin for uncomplicated infections, and carbapenems for severe or complicated cases. This study reinforces the importance of local antibiograms and regular microbiological surveillance.

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