Prevalence and characterization of Salmonella serotypes isolated at the National Reference Hospital of N'Djamena in Chad

Abstract

Salmonella spp are among the pathogens and multi-resistant agents that are causing great concern at the National Reference General Hospital (HGRN) in N'djamena. They are responsible for food poisoning and typhoid fever. This study has aimed to update knowledge on the presence, diversity and antibiotic resistance of Salmonella spp in hospitals in Chad. A total of 341 stool specimens from inpatients and outpatients were collected between August 2018 and February 2019. The identification of Salmonella strains was carried out using the Api 20E gallery and confirmed by the VITEK® 2TM 15 compact automaton in Chad and on the XLT4 medium at the Pasteur Institute in France. Isolates were characterized by serotyping using the Kauffmann-White Kit. Antimicrobial susceptibility testing was performed according to EUCAST guidelines. Extended-spectrum beta-lactamase (ESBL) resistance phenotype was reported in 42% of isolates. About 2% (6/314) of the samples were positive for Salmonella. Among the 6 sérovars identified, Salmonella enteritidis (50%) was the most common, followed by S. colindale (33.3%) and S. grampian (16.7). 100% of isolates (6) were resistant to at least one antimicrobial. Resistance was most frequently observed to amoxicillin-clavulanic acid, Cotrimoxazole and Tetracycline (100%). Moreover, a decrease in sensitivity to ceftriaxone (83.3%) and aztreonam (83.3%) was observed. Our results indicated an increase in Salmonella contamination and the appearance of isolates resistant to several antimicrobials in the CHU. © 2023 International Formulae Group. All rights reserved.