Non-typhoidal Salmonella infections: Clinical spectrum and antimicrobial susceptibility from western India...

Non-typhoidal Salmonella (NTS) causes illnesses ranging from gastroenteritis to invasive bloodstream infection, particularly in vulnerable hosts. We describe the clinical profile and antimicrobial susceptibility of NTS isolates recovered at a tertiary-care hospital in Navi Mumbai.

We conducted a retrospective case series of consecutive NTS isolates recovered from blood and stool between January 2022 and December 2025. Identification and MIC-based susceptibility testing were performed using automated platforms; azithromycin and chloramphenicol were tested by gradient diffusion or disc diffusion. Results were interpreted according to CLSI M100.

Eighteen isolates were recovered from 17 patients (15 blood and 3 stool). The median age of patients with invasive infection was 57 years (range, 0.5-84). Among adults with invasive NTS (n = 12), 11 (91.7%) had comorbidities. Three invasive cases occurred in children aged 6 months to 2 years; one had a structural urinary tract abnormality. Among invasive cases, 7/15 (46.7%) required intensive care, 3/15 (20.0%) developed septic shock, and 5/15 (33.3%) developed acute kidney injury. No in-hospital mortality occurred; one late death was unrelated to the index episode. Ciprofloxacin non-susceptibility occurred in 6/15 (40.0%) blood isolates, comprising 2 intermediate and 4 resistant isolates; one of three stool isolates was intermediate. One blood isolate was ceftriaxone-resistant with a presumptive ESBL phenotype detected by VITEK 2 AES. All isolates were susceptible to meropenem and trimethoprim-sulfamethoxazole. All tested isolates were susceptible to chloramphenicol (15/15). Azithromycin results (15/15) fell within the susceptible range using S. Typhi criteria because NTS-specific CLSI breakpoints are unavailable.

In this small single-centre series, most adults with invasive NTS had comorbidities, and bloodstream infections were frequently severe. Ciprofloxacin non-susceptibility and a ceftriaxone-resistant isolate with a presumptive ESBL phenotype support culture-guided therapy, local antibiogram review, antimicrobial stewardship, and continued surveillance.