Phenotypic and molecular detection of Salmonella species with antimicrobial susceptibility patterns in clinical isolates

Objectives: Salmonella species are significant pathogens that cause a variety of clinical diseases. As antibiotic resistance increases, they are becoming a greater concern. Material and Methods: Conventional culture and biochemical techniques were used to isolate and identify 200 clinical samples for Salmonella species, and polymerase chain reaction (PCR) targeting a 796 bp gene fragment was used for molecular confirmation. The Kirby–Bauer disc diffusion technique was used to test for antimicrobial susceptibility. Results: Out of 200 samples, 7 (3%) included bacterial growth classified as Salmonella species. The isolates had normal cultural and biochemical characteristics, such as non-lactose fermenting colonies on MacConkey agar and black-centred colonies on xylose lysine deoxycholate and SalmonellaShigella agar. Salmonella was validated using PCR amplification, yielding, for molecular confirmation, the invA gene (796 bp fragment) as the target of PCR. Antibiotic susceptibility tests demonstrated perfect sensitivity to imipenem (100%), moderate sensitivity to ciprofloxacin (80%) and trimethoprim– sulfamethoxazole (60%), and high resistance to chloramphenicol (80%), azithromycin (80%), and ampicillin (60%). Conclusion: The investigation confirms the presence of multidrug-resistant Salmonella species in clinical samples. The significant resistance to conventional antibiotics emphasizes the importance of frequent antimicrobial monitoring, cautious antibiotic usage, and molecular confirmation in the identification and treatment of Salmonella infections.