Biochemical and Molecular Identification of Escherichia coli and Salmonella spp. Isolated from Milk and Fermented Milk Products Vended in Sabon-Gari and Zaria Local Government Area, Kaduna State, Nigeria

Abstract

Salmonella spp. and Escherichia coli are two of the most prevalent food-poisoning organisms. As part of this investigation, Escherichia  coli and Salmonella spp. were isolated from some fresh milk and fermented milk products in Zaria. This study aimed to investigate the  prevalence and molecular characterisation of Salmonella spp. and Escherichia coli in fresh milk and fermented milk products vended  Sabon-Gari and Zaria Local Government Area, Kaduna State, Nigeria. Four hundred (400) samples were used consisting of one hundred  (100) samples of milk, 100 samples of Kindirimo, 100 samples of Nono, and 100 samples of yoghurt. In addition, a routine microbiological  isolation detected 11% of the samples positive for Escherichia coli and 16% for Salmonella spp. All isolates were biochemically  characterised and identified; however, none of the selected isolates of Escherichia coli or Salmonella spp. possessed the virulence genes  rfbE or invA. Thus, 16S ribotyping was utilised to authenticate the isolates' identities as Escherichia coli strain NCCP 14540, Escherichia coli  strain E57, Salmonella bongori and Salmonella enterica subsp. enterica serovar Typhimurium. However, more molecular research is  required to determine which other Salmonella and Escherichia coli serotypes were present in the study region.