Bacterial Isolates and Antibiotic Susceptibility Patterns in Sterile Body Fluids in Patients Attending a Tertiary Care Hospital: A Two-Year Retrospective Study

Introduction Infections of sterile body fluids are caused by various bacterial agents and are usually associated with high morbidity and mortality. Timely microbiological culture and sensitivity testing of clinical specimens can identify the etiological agent, guide the targeted antibiotics, and reduce further complications. Knowledge of local antimicrobial susceptibility patterns is essential for selecting appropriate empirical therapy. The present study aimed to determine the profile of bacterial pathogens and their antimicrobial resistance patterns isolated from normally sterile body fluids at a tertiary care center in Odisha, India. Methods A retrospective laboratory-based observational study was carried out in the Department of Microbiology, Kalinga Institute of Medical Sciences, Bhubaneswar, Odisha. Culture and sensitivity records from the previous two years (January 2021 to December 2022) were retrieved and analyzed after getting approval by the Institutional Ethics Committee (KIIT/KIMS/IEC/1098/2023, date: January 1, 2023). A total of 2307 sterile body fluid samples (CSF, pleural, ascitic, and synovial fluids) were processed using standard microbiological procedures. Isolate identification and antimicrobial susceptibility testing were carried out using the VITEK-2 system and interpreted according to Clinical and Laboratory Standards Institute (CLSI) guidelines. Data were analyzed using SPSS version 26.0 (IBM Corp., Armonk, NY). Results Out of 2307 samples, 291 yielded bacterial growth, giving an overall culture positivity rate of 12.6%. Pleural fluids showed the highest positivity rate (18.5%), followed by synovial fluid (16.4%). Gram-positive bacteria outnumbered (54%), with Staphylococcus aureus as the most common isolate (31.6%). Among Gram-negative isolates, Klebsiella pneumoniae (13.7%) was predominant. Enterobacterales showed higher susceptibility to aminoglycosides and carbapenems, with high resistance to ciprofloxacin. Pseudomonas spp. and Acinetobacter spp. exhibited limited susceptibility to the commonly used antibiotics. Multidrug-resistant (MDR), extensively drug-resistant (XDR), and pandrug-resistant (PDR) among Gram-negative bacilli (GNB) were 21.6%, 14.2%, and 3%, respectively. Methicillin-resistant Staphylococcus aureus (MRSA) constituted 48.9% of Staphylococcus aureus. Conclusion Sterile body fluid infections due to bacterial agents at our center were found to be 12.6% and showed a diverse bacterial profile with a substantial burden of antimicrobial resistance. The high prevalence of MDR GNB and MRSA underscores the importance of continuous local surveillance and antimicrobial stewardship to guide empirical therapy and improve patient outcomes.