Phylogenetic Analysis and Public Health Implications of Salmonella Strains in Southwestern States of Nigeria Using InvA Gene Sequences

Salmonella is a significant public health concern in Nigeria causing foodborne illnesses. Genetic diversity and prevalence of Salmonella are poorly understood in Nigeria. This study assessed the occurrence of Salmonella in various poultry houses in Nigeria and explored the evolutionary relationships among the isolates by analysis of invA gene. A total number of 314 samples (feces, feed, dust, waters, and palm swab) were collected from 49 farms in Abeokuta (18), Ibadan (20) and Oshogbo (11). Salmonella were detected with a prevalence of 2.75% in Ogun, 6.0% in Osun and 5.71%, in Oyo States, respectively. The overall prevalence of Salmonella in poultry farms sampled was 15/314 (4.78%). Sequence analysis revealed two sequences 01 and 02 to have 99.59% and 89.04 homologies with sequence of Paratyphi serovar (LC320032) and Enteritidis serovar (LC318423) in GenBank, respectively. Sequence 01 clustered with S. serovar Enteritidis from the USA, whereas Sequence 02 formed a distinct clade near S. serovar Typhimurium from Egypt. These findings underscore the public health significance of S. enterica in Nigeria, particularly in relation to food animals. The study highlights the need for improved farm management practices, stringent food safety regulations, and robust surveillance systems to mitigate the risk of Salmonella outbreaks.