Clinical and microbiological profile of invasive Salmonella disease in Mexico: a single-center retrospective study

Salmonella gastrointestinal infections are common in low- and middle-income countries; however, there is limited data on the clinical presentation and microbiological characteristics of invasive Salmonella disease in Latin America.

A cross-sectional study was conducted, including all patients with Salmonella spp. isolated from usually sterile sites at our center from May 2016 to June 2025. Data on demographics, comorbidities, immunological status, symptoms, treatment, and outcomes were collected from medical records. The isolated serogroups and their antimicrobial resistance patterns were analyzed using historical data from the Bacteriology Laboratory electronic database. Descriptive statistical methods were used for data analysis.

A total of 77 cases of invasive Salmonella infection were identified. Most patients were male (76.6%), with a median age of 33 years. HIV infection was present in 80.5% of cases, and 88.7% of these individuals had advanced disease. Fever was the most frequent symptom (85.7%), and 10.4% required admission to the intensive care unit. Overall mortality was 13%, and all fatal cases occurred among people living with HIV (PWH). The most common treatment was third-generation cephalosporins (58.4%). Resistance to aminoglycosides was documented in all isolates; 52.3% were resistant to trimethoprim-sulfamethoxazole and 6% to ceftriaxone. Ciprofloxacin non-susceptibility reached 64.8%. Multidrug resistance was observed in 12.6% of isolates.

Invasive Salmonella disease primarily affected immunocompromised individuals, particularly PWH, with fever and bacteremia being the predominant clinical manifestations. Although multidrug resistance was relatively low, the high prevalence of ciprofloxacin non-susceptibility highlights the need to revise regional empirical treatment strategies.