Antibiotic Resistance of Typhoidal Salmonella Isolated from Humans in Kaduna and its Associated Factors

Abstract

Background: Pathogenic Salmonella species cause various types of infections ranging from mild gastroenteritis to life- threatening typhoid fever caused by Salmonella typhi , or paratyphoid fever caused by S. paratyphi A, B or C; of which S . paratyphi A is prevalent. Currently, treatment of typhoid infection is being hampered by the emergence of multidrug-resistant strains, while vaccines provide only temporal or partial protection. Objective: The aim of the study was to determine antibiotic resistance of typhoid causing Salmonella isolated from human stool. Methodology: A cross-sectional descriptive study was carried out in the capital city of Kaduna State, Nigeria. Questionnaires were administered to 300 consenting individuals; comprising 250 patients and 50 volunteering healthy individuals, to obtain relevant socio demographic and clinical information. Stool specimens were equally collected in sampling containers for isolation of typhoidal Salmonella on Salmonella Shigella Agar. Suspected typhoidal Salmonella colonies were confirmed by biochemical tests as S. typhi or S. paratyphi A, before antimicrobial susceptibility test was done using Kirby-Bauer disk diffusion method. Diameters of zone of inhibitions were recorded and interpreted according to Clinical Laboratory Standards Institute guidelines. The data and results obtained were represented on tables and charts. Chi-square analysis was also used to determine statistical association among parameters and p-values ≤ 0.050 were considered significant. Results: Thirty-two (32) typhoidal Salmonella were isolated; 25 were S. typhi and seven S. paratyphi A. Thirty isolates came from patients while two were isolated among healthy individuals. High antibiotic resistance was observed with Augmentin (100%), Ceftazidime (87.5%), Cefuroxime (84.4%), Cefixime (84.4%) and Gentamicin (40.6%), while Ciprofloxacin (12.5%), Nitrofurantoin (12.5%) and Oflaxacin (18.8%) showed a lower resistance. Age, marital status and state of origin were socio demographic factors found to be associated with the antibiotic resistance. Also, frequency of infection, presenting symptoms and sampling duration were statistically associated with the antibiotic resistance. Conclusion: Multi-drug resistance, high antibiotic resistance of typhoidal Salmonella and factors associated with it in this study, should awaken public health concerns in curbing the excesses of typhoidal Salmonella.