Mountain Top University Library

Diarrhoea is one of the leading causes of childhood death worldwide. In Nigeria, acutegastroenteritis in children under five years is a major cause of mortality and morbidity. Salmonella and Shigella species are the most frequently isolated microbial agents causingacutegastroenteritis in patients, particularly in developing countries. This study examinedtheprevalence, molecular characterization and antibiotic resistance profiles of SalmonellaandShigella spp. isolated from children with diarrhoea and household potential sources of diarrhoea. A total of 300 clinical samples, 300 environmental samples, 48 meat samples and 252freshproduce samples (Cabbage, Carrot, Lettuce, Cucumber, Watermelon, Pineapple, and Pawpaw)were examined for the presence of Salmonella and Shigella spp. using media based method. Molecular characterization of isolated pathogens was carried out using multiplex polymerasechain reaction. Antibiotic susceptibility testing was performed using Kirk-Bauer disc diffusionmethod as well as the determination of resistant genes (tetA, qnrS, qnrB, qnrA, sul1, gyrA)exhibited by selected Salmonella strains. The respective prevalence of Salmonella and Shigellaspp. from the various sources include children (25%, 20.3%), environmental (24%, 25.7%), meat
(64.6%, 72.9%), and ready-to-eat fruit and vegetable (27.4%, 34.1%). Molecular typingconfirmed 193 serotypes of Salmonella enterica subsp. I group, 52.3%of Salmonella entericasubsp. I tested demonstrated resistance to at least three or more of the twelve antibiotics tested. Resistance to cefoperazone (90.1%), tetracycline (80.2%), cotrimoxazole (78.2%), ciprofloxacin(74.3%) and ceftriaxone (51.5%) was most prominent in strains tested. These strains wereconfirmed to possess the tetA, qnrS, qnrB, qnrA, sul1, gyrA`genes responsible for the resistance. The high prevalence of Salmonella and Shigella spp. reported in this study indicates that childrenare at risk of severe infections which could be difficult to treat during antibiotics therapy, therefore, attention should be taken in selecting antimicrobials in treating SalmonellaandShigella infection both in animals and humans based on antimicrobial susceptibility test. Keywords: diarrhoea, under 5 children, Salmonella, Shigella, antimicrobial resistance, PCR