Antibiotics resistance profile and bla-TEM genes in Salmonella serotypes associated with typhoidal salmonellosis in selected hospitals in Katsina State, Nigeria

Abstract

Typhoidal salmonellosis is common illness and remains a serious public health problem in many regions of the world especially in developing countries, where it became endemic. About 80% of deaths due to Salmonella serovars are found in Africa. Recently multi-drug resistant (MDR) strains of Salmonellae have emerged apparently due to the extensive use of antimicrobial agents in clinical and veterinary practices. The present research work was carried out to evaluate the antibiotic resistance profile and detect beta lactamase genes present in Salmonella serotypes associated with enteric fevers in selected hospitals in Katsina State, Nigeria. A total of 300 blood samples were collected from febrile patients, followed by isolation, biochemical and serological characterization of recovered isolates. Moreover, the isolates were evaluated for antibiotic susceptibility using the Kirby-Bauer disc diffusion method. The presence of β-lactamase (bla-TEM) resistance genes was evaluated by polymerase chain reaction. Biochemical characterization revealed the presence of Salmonella Typhi and Salmonella paratyphi A from 14 samples only. Result of serotyping (slide agglutination) of the isolates indicate that nine (09) were Salmonella Typhi serotypes belonging to D serogroup while five (05) were Salmonella Paratyphi A belonging to the A serogroup. The antibiogram pattern revealed that all the Salmonella enterica serovar Typhi were 100% resistance to Sulfomethaxazole- trimethoprim, Chloramphenicol, Cephalexin, Ofloxacin, Gentamicin, and Penicillin G and followed by 88.9% resistance to Ampicillin. The PCR analysis confirmed the presence of bla-TEM gene in eight (8) serovars of Salmonella enterica serovar Typhi only. Findings of the study have indicated a high prevalence of antimicrobial resistance among Salmonella serovars especially the Salmonella enterica serovar Typhi. This implies a great threat to public health, therefore appropriate measures and new guidelines should be established to address the rational use of antibiotics and to prevent their abuse.