Antimicrobial Resistance Patterns of Proteus Species Isolated from Various Clinical Samples at a Tertiary Care Hospital: A Retrospective Observational Study

Introduction: The alarming increase in antimicrobial resistance of Proteus spp. is underappreciated, despite the fact that it causes a wide array of infections, including urinary tract infections and wound infections. These infections can be controlled by species identification and surveillance of antimicrobial resistance. Aim: To determine the prevalence and antimicrobial susceptibility pattern of Proteus species isolated from various clinical samples. Materials and Methods: A retrospective observational study was conducted in the Department of Microbiology at Indira Gandhi Medical College and Research Institute, Puducherry, India from January to December, 2022. A total of 13,091 clinical samples received from inpatients and outpatients were processed, of which 76 isolates were identified as Proteus species. Demographic details such as age and sex were obtained from laboratory records. Identification was performed using conventional microbiological methods like Gram staining, catalase, oxidase test and standard biochemical tests. Antimicrobial susceptibility pattern was carried out by the Kirby‑Bauer disk diffusion method according to Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: Among the 76 Proteus isolates, 52 (68.42%) were recovered from the male patients.The predominant species isolated was P. mirabilis (49; 64.47%), followed by P. vulgaris (27; 35.53%). The majority of isolates was obtained from wound swabs (37; 48.68%). The higher resistance rates were observed for cefepime (78.85%) followed by imipenem (63.46%) and ciprofloxacin (58.49%), whereas lower resistance rates were noted for piperacillin-tazobactam (12.16%), amikacin (19.12%) and meropenem (17.86%). Overall, Multidrug Resistance (MDR) was detected in 29 out of 76 Proteus isolates (38.15%). Conclusion: This study emphasises the clinical significance of Proteus species and the increasing prevalence of multidrugresistant strains. Based on the observed susceptibility pattern, aminoglycosides, meropenem and piperacillin-tazobactam remain treatment options for Proteus infections. Continuous antimicrobial surveillance and rational usage of antibiotic are essential to combat the antimicrobial resistance of Proteus species in future.