Antibiotics Resistance and Molecular Detection of Virulence Genes in Salmonella Spp Isolated from Ready to Eat Fruits Salad in Nasarawa and Benue State in North Central, Nigeria

Abstract

Foodborne illnesses, particularly those caused by Salmonella, constitute a significant public health concern in Nigeria, where the increasing consumption of ready-to-eat fruit salads heightens the risk of microbial contamination due to often inadequate hygienic practices. This study investigated the molecular characterization and detection of virulence genes in Salmonella spp. isolated from ready-to-eat fruit salads obtained from Nasarawa and Benue States in North Central Nigeria. A total of 200 fruit salad samples were randomly collected from major markets. Isolation and identification of Salmonella spp. were conducted using standard microbiological techniques, while antibiotic susceptibility was assessed using the disk diffusion method in accordance with Clinical and Laboratory Standards Institute guidelines. Detection of virulence genes was performed using the polymerase chain reaction (PCR) following a boiling extraction method. Of the 200 samples analyzed, Salmonella spp. were detected in 12 samples (6.0%), with a higher prevalence observed in Nasarawa State (7.0%) compared to Benue State (5.0%). The antibiotics resistance of Salmonella sp isolated from ready to eat fruit salads sold in Nasarawa State showed that the isolates were more resistance to, cefexime (42.8 %) and had low resistance to ampicillin (14.2 %). Salmonella sp isolated from Benue were highly resistance to nalidixic acid and cefexime (60.0 %) but less resistant to nitrofurantoin (20.0 %). The commonest MAR in Salmonella sp isolated from Nasarawa was 0.3, with a percentage of occurrence of 42.8 %. The commonest MAR in Salmonella serovars isolated from Benue was 0.4 and 0.5, with a percentage of occurrence of 40.0 %. Out of six isolates evaluated for virulence genes, the order of virulence genes detected was, spi A and sp vB genes (33.3 %) from Salmonella sp isolated from Nasarawa; The blasted sequences of Salmonella sp showed the isolates were related to Salmonella enterica sub sp. enterica serovar Typhimurium, it was observed that the ready to eat fruit-salads sold 2 in major cities in North Central Nigeria were contaminated with Salmonella and are resistance to commonly use antibiotic in treatment of infection cause by these Salmonella.