Antibiotic Susceptibility Patterns of Enteric Fever Salmonella Isolates from Infected Patients Blood Samples within Enugu, Nigeria

Abstract

Background: Salmonella enterica enterica serovar typhi/paratyphi is the causative agent of enteric (typhoid) fever, a life-threatening systemic illness, significantly impacting global health especially the developing nations. Although enteric fever can be treated effectively with antibiotics, it is becoming increasingly challenging due to the rising incidence of drug resistance. Aim: The aim was investigate the prevalence and antibiotic susceptibility patterns of Salmonella isolates from typhoid fever patients in order identify the multidrug-resistant trends. Methodology: The study was carried out between March and June, 2024. Venous blood samples were obtained from 200 randomly selected subjects, aged 5-70 years made up of 95 males and 105 females. The samples were allowed to coagulate and the clots were aseptically inoculated in bile salt broth and incubated for 18-48 hours at 37°C and then sub-cultured unto Salmonella- Shigella Agar. The suspected colonies were identified by biochemical tests involving the urea hydrolysis and typical reaction in Triple Sugar Iron Agar. Antibiotic susceptibility was evaluated using the Kirby-Bauer disc diffusion method. The antibiotics used included pefloxacin, ofloxacin, azithromycin, levofloxacin, cefotaxime, sparfloxacin, ciprofloxacin, amoxacillin, augmentin and gentamicin. Results: This study showed that 95 (47.5%) samples were positive for Salmonella enterica enterica species, predominantly Salmonella Typhi (54.7%). A higher infection rate was observed among males (68.4%) and individuals aged 16-26 years (64.7%). Antibiotic susceptibility testing showed high sensitivity to pefloxacin and azithromycin (100% each) and levofloxacin(94.7%), while  resistances were noted against amoxacillin and augmentin with the rates of 68.4% and 63.2%, respectively Conclusions: This study emphasizes the importance of proper diagnosis and antimicrobial susceptibility testing to guide effective treatment in each patient. The findings also highlight the emergence of multi-drug resistance (MDR) Salmonella Typhi/Paratyphi, necessitating revised treatment protocols and stringent antibiotic stewardship. However, the high rates of sensitivity to fluroquinolones antibiotics make allowance for choices and alternatives during treatment.