Prevalence and Antimicrobial Susceptibility Profile of Salmonella spp. Isolated from Blood Cultures of Patients with Suspected Enteric Fever at a Specialized Laboratory in North India

Introduction: Enteric fever, caused by Salmonella enterica serovars Typhi and Paratyphi A, is a prevalent infection in developing countries. Although highly endemic in India, data on the prevalence and antimicrobial resistance patterns of this pathogen in Kashmir remain scarce. Therefore, this study aimed to determine the prevalence and antimicrobial susceptibility profile of Salmonella isolates from blood cultures of patients with suspected enteric fever. Methods: A total of ۹۷۰ blood culture samples from patients with suspected enteric fever were processed at Dr. Qadri’s Hematology Centre & Clinical Laboratory, Srinagar, between October ۲۰۲۲ and September ۲۰۲۴. Samples were inoculated into the BacT/ALERT® culture media. Positive cultures were subcultured on standard agar plates, and the resulting isolates were identified and subjected to antimicrobial susceptibility testing using the VITEK® ۲ system according to the latest Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: Of the ۹۷۰ blood cultures processed, ۳۷ (۳.۸%) were positive for Salmonella spp., with ۲۳ (۶۲.۲%) isolates identified as S. Typhi and ۱۴ (۳۷.۸%) as S. Paratyphi A. All isolates showed ۱۰۰% susceptibility to cefepime, piperacillin/tazobactam, carbapenems, azithromycin, tetracyclines, co-trimoxazole, and polymyxins. Susceptibility to ceftriaxone and tigecycline was ۹۷.۳%. In contrast, susceptibility rates were markedly low for the fluoroquinolones ciprofloxacin (۲.۷%) and levofloxacin (۵.۴%). Furthermore, no multidrug-resistant (MDR) isolates were detected in this study. Conclusions: This study demonstrates that S. enterica remains a significant cause of bloodstream infections in this resource-limited setting. However, the high prevalence of fluoroquinolone resistance, despite the absence of MDR strains, represents the primary therapeutic challenge in managing these infections. Therefore, extensive surveillance, enhanced diagnostics, and treatment protocols guided by antimicrobial susceptibility testing (AST) reports are crucial to optimize patient outcomes and combat emerging resistance in the region.

کلیدواژه ها:

Antimicrobial resistance ، Salmonella ، Fluoroquinolone resistance ، North India ، Minimum inhibitory concentration