Salmonellosis in poultry is one of the most significant bacterial infections causing mortality, reduced production, and serious economic losses. This study aimed to study the molecular diversity among Salmonella isolates and investigate the epidemiological spread of these bacteria in broiler and layer chicken flocks in five different farms in Karbala, Iraq, using random amplified polymorphic DNA (RAPD) polymerase chain reaction (PCR). In total, 217 cloac a swabs were collected from the farms, out of which 129 and 88 swabs were taken from broiler and layer chickens. The samples were screened by PCR for S. enterica subsp. enterica using primers specific for the invA gene. Afterward, RAPD-PCR with uniplex or multiplex octamer primers was applied to genotype the isolates. The incidence rate of Salmonella infections in broilers and layers was estimated to be 27.9% and 12.5%. The uniplex primers P2 and P3, along with the multiplex primers yielded discriminatory patterns. Moreover, the RAPD typing showed a diverse range of banding patterns of Salmonella spp. Dendrograms created through GelJ software revealed various Salmonella genotypes in broilers and layers. The RAPD-PCR could be used as an accurate and fast tool to identify genetic relatedness among Salmonella spp. The obtained results would assist researchers in epidemiological studies and controlling salmonellosis in poultry fields.
