Serotypes and Antimicrobial Resistance Patterns of Invasive Non-Typhoidal Salmonella in Uganda

Abstract

Drug-resistant invasive non-typhoidal Salmonella poses a significant challenge to the management of acute febrile illnesses in Uganda. However, the characteristics of invasive non-typhoidal Salmonella strains are not yet well understood. This study aimed to determine the serotypes and antimicrobial resistance patterns of invasive non-typhoidal Salmonella isolates from a local health center in Uganda. Invasive non-typhoidal Salmonella isolates archived over 5 years from febrile patients at a local health center were characterized for serotypes and antimicrobial susceptibility patterns using conventional methods. Among the 80 archived isolates, 18 serotypes of invasive non-typhoidal Salmonella were identified, with Salmonella Typhimurium (42.5%), Salmonella Enteritidis (20%), and Salmonella Haifa (8.8%) being the most prevalent. A total of 81.3% (65/80) of the isolates exhibited resistance to at least one antibiotic, with the highest resistance rates observed for streptomycin (72.5%), trimethoprim-sulfamethoxazole (66.2%), and ampicillin (56.2%). The most common antimicrobial resistance profile, found in 23.1% (15/65) of resistant isolates, was Amp-C-S10-S300-SXT. Notably, 81.5% of the drug-resistant isolates were multi-drug resistant. Invasive non-typhoidal Salmonella in this setting have a high rate of antimicrobial resistance to commonly used antibiotics. Improved treatment guidelines could be adapted for better clinical outcomes.