Escherichia coli (E. coli) and Salmonella enterica (S. enterica) are Gram-negative bacteria commonly found in the gastrointestinal tract of animals and can cause illness in humans, particularly through contaminated meat products and their handling. Genetic identification techniques offer rapid and precise methods for characterizing these bacteria and revealing their genetic diversity. This study aimed to investigate the inter- and intra-genetic variations among E. coli and S. enterica strains isolated from meat and handling sources in Ghana using PCR-based DNA sequencing of the uidA and invA genes. Genomic DNA was extracted from cultured E. coli and S. enterica colonies, and PCR amplification of the uidA and invA genes was performed. The resulting amplicons from 24 uidA genes were identified as E. coli, while the five invA genes represented Salmonella enterica subsp. enterica. The most frequently identified Salmonella serovars based on BLASTN analysis were Typhimurium and Kentucky. Genetic analysis revealed the presence of seven haplotypes among the sequenced E. coli isolates (Hd = 0.504; ? = 0.007; Eta = 7), with a haplotype frequency ranging from 70.3% to 4.2%. The S. enterica isolates exhibited two haplotypes (Hd = 0.400; ? = 0.002; Eta = 1), with haplotype frequencies of 20% and 80%, respectively. Phylogenetic analysis demonstrated that all isolates of the present study formed a monophyletic clade, showing a close genetic relationship, while exhibiting a paraphyletic relationship with other isolates, except for one S. enterica isolate. These findings highlight the need for broader studies on the genomic characteristics of E. coli and S. enterica in the region. Furthermore, the observed intra- and inter-genetic variations emphasize the importance of developing local interventions to control the spread and reduce the virulence of these bacteria to mitigate potential health risks associated with contaminated meat products.

Keywords: E. coli, evolutionary studies, genetic diversity, meat, PCR, S. enterica