PREVALENCE OF VIRULENCE AND RESISTANCE GENES IN Salmonella Typhi AMONG INTERNALLY DISPLACED PERSONS IN TWO LOCAL GOVERNMENT AREAS OF BENUE STATE

An internally displaced person (IDP) is someone who is forced to leave his/her home due to a crisis, conflict, or natural disaster to find safety within their country's borders. Internal displacement has significant effects on public health, including the prevalence of typhoid fever. Following decades of several crises in Benue State, there has been an increasing number of internally displaced persons (IDPs). The aim of this study was to assess the prevalence of virulent and resistant genes of Salmonella typhi among internally displaced persons in two local government areas of Benue State, Nigeria. Four hundred (400) stool samples were collected alongside with a well-structured questionnaires, 200 stool samples were collected from each IDP camp (Logo and Guma). The samples were screened for Salmonella Typhi following standard bacteriological procedures. Salmonella isolates were subjected to antibiotic susceptibility test on Muller-Hinton agar following the Kirby-Bauer disk diffusion technique. Plasmid gel electrophoresis was used to screen the isolates for plasmids. Acridine orange was used for curing experiment. Polymerase chain reaction was used to detect virulent and resistant genes: inVA, FliC-d, tetA and blaTEM, respectively. The identification of Salmonella Typhi was done by using PCR the STY0307- specific gene primers. The results of this study showed a higher prevalence [50(12.5%)] of S. typhi infection in Logo LGA compared to Guma LGA, with 30(7.5%). Salmonella typhi infection was highest 5.0% amongst IDPs aged ≤10 years in Logo LGA and 3.0% in Guma LGA. Female IDPs had a significantly (P<0.05) higher prevalence rate (8.75%) in Logo LGA than males, with 3.75%. Female IDPs in Guma LGA had a higher infection rate 5.0% in comparison to males with 2.5%. Concerning duration in camps, IDPs who lived longer than 2years had a higher Salmonella Typhi infection rate (4.25% in Guma LGA and 9.5% in Logo LGA). Salmonella Typhi isolates exhibited resistance to ceporex (cephalexin), ciprofloxacin (cipro), ampicillin (omnipen), streptomycin (trobicin), gentamycin (gentamicin) and tetracycline (doxycycline). The isolates' multiple antibiotic resistance index (MARI) ranges from 0.4 to 0.7. The study demonstrated a high prevalence of plasmid mediated multidrug resistant potentially virulent strains of xvii Salmonella Typhi amongst the sample IDP dwellers. The antibiotic resistance was borne on lasmids following the post-curing experimentation. The isolates showed presence of the blaTEM resistant gene of 100.00% isolates and tetA resistant gene 50.00% isolates. Polymerase chain reaction analysis revealed that 80% of the isolates harboured the inVA gene. The FliC-d virulent gene was not detected in the isolates. A total of 75.00% of the isolates showed amplification of the STY0307 gene, for Salmonella Typhi. The presence of typhoid fever and high levels of antimicrobial resistance plasmid-mediated in this study implies a significant threat to public health. It is therefore imperative for stakeholders and policymakers to prioritize healthcare infrastructure, routine screening, and education within IDP settings to curb the spread of resistant and virulent S. typhi strains.