Phylogenetic analysis and molecular identification of bacteria isolated from fresh cow milk

Abstract

The study's purpose was to identify bacteria in raw cow's milk using molecular methods. 90 milk samples were gathered from three distinct sources in Al- Diwaniya city: Taj Al-Nahrain Company for Agricultural Production and Livestock, breeders, and super markets. Milk samples were cultured on various culture media to isolate microorganisms. Staining features, cultural properties on various selective medium, biochemical tests, catalase and coagulase tests, and ultimately PCR were used to identify the isolated bacteria. Ten (11.1%) of the 90 milk samples tested positive for E. coli, whereas the other eight were negative (8.8 percent) 16 Proteus spp., 16 (17.7%) Klebsiella spp., 3 (3.3%) Salmonella spp., and 10 (11.1%) Staphylococcus spp. was found. A 16S rRNA gene-based PCR was used to amplify 20 isolates. The polymerase chain reaction (PCR) and DNA sequencing were used to detect and identify every suspect isolate. The PCR was directed toward the 16S rRNA gene. The sequencing results revealed that the strains belonged to Citrobacter spp., E. coli spp., Staphylococcus spp., Klebsiella spp., Proteus spp., Enterobacter spp., and Streptococcus spp., and that all of the tested isolates had a similarity of 93 percent to 99 percent to those in the Gen Bank of The National Centre for Biotechnology.