Microbiological Profile and Antibiotic Susceptibility Pattern of Bacterial Infections in Patients with Chronic Kidney Disease at a Tertiary Care Hospital

Abstract

Background: Patients with chronic kidney disease (CKD) are highly susceptible to bacterial infections because of uraemia-related immune dysfunction, comorbidities, vascular access and repeated hospitalisation. The emergence of multidrug-resistant (MDR) organisms narrows the therapeutic options further, because many antimicrobials are nephrotoxic or need dose adjustment. Local data on pathogens and their susceptibility patterns are essential for rational empirical therapy.
Aim and objectives: To determine the microbiological profile and antibiotic susceptibility pattern of bacterial infections in patients with CKD, to detect important resistance phenotypes, and to identify factors associated with culture-proven infection.
Materials and methods: A prospective, hospital-based observational study was conducted in the Department of Microbiology of a tertiary care teaching hospital from June 2025 to May 2026. Three hundred adult patients with CKD (KDIGO stages 3–5D) and clinically suspected bacterial infection were enrolled. Urine, blood, respiratory samples, pus/wound swabs, catheter tips/exit-site swabs and sterile body fluids were processed by standard microbiological methods. Identification was by conventional biochemical tests and VITEK 2 Compact. Antimicrobial susceptibility was determined by Kirby–Bauer disk diffusion according to CLSI M100 (33rd edition); colistin MIC was determined by broth microdilution. ESBL, carbapenemase production, MRSA and high-level aminoglycoside resistance were detected phenotypically. MDR, XDR and PDR were defined by international consensus criteria. Data were analysed with SPSS version 25.
Results: Mean age was 52.4 ± 14.6 years and 62.0% of patients were male. Culture was positive in 214 patients (71.3%), yielding 226 isolates; positivity rose from 58.3% in stage 3 to 80.0% in stage 5D (p = 0.018). Urine was the commonest sample (46.0%). Gram-negative bacilli constituted 69.9% of isolates, led by Escherichia coli (27.4%), Klebsiella pneumoniae (15.9%), Pseudomonas aeruginosa (10.6%) and Acinetobacter baumannii (8.0%); Staphylococcus aureus (12.4%) and Enterococcus species (11.5%) were the main Gram-positive pathogens. ESBL production occurred in 61.3% of E. coli and 66.7% of K. pneumoniae; carbapenem resistance was seen in 17.2% of Enterobacterales, 25.0% of P. aeruginosa and 66.7% of A. baumannii. MRSA accounted for 46.4% of S. aureus and VRE for 11.5% of enterococci. Overall, 72.6% of isolates were MDR. Colistin (94.4–100% among Gram-negatives), linezolid (100%) and vancomycin (100% for staphylococci) retained the highest activity. Prior antibiotic use, indwelling catheters, age above 60 years, hypoalbuminaemia and diabetes mellitus were independent predictors of culture-proven infection. In-hospital mortality was higher in culture-positive patients (14.5% vs 5.8%; p = 0.037).
Conclusion: Gram-negative, multidrug-resistant bacteria dominate infections in CKD patients at our centre, and resistance increases with advancing CKD stage. Empirical therapy should follow locally validated, CKD-specific antibiograms with renal dose adjustment, and should be de-escalated promptly on culture results. Strengthening infection control, catheter care and antimicrobial stewardship is essential.