Isolation and identification of Salmonella from diarrheagenic infants and young animals, sewage waste and fresh vegetables

Abstract

Aim: This study was carried out to determine the prevalence, distribution, and identification of Salmonella serotypes in diarrheagenic infants and young animals, including sewage waste and fresh vegetables. Materials and Methods: A total of 550 samples were processed for the isolation of Salmonella spp., using standard microbiological and biochemical tests. Further polymerase chain reaction (PCR) detection of Salmonella genus was carried out using self-designed primers targeting invA gene and thereafter identification of important serotypes namely Salmonella Enterica serovar Typhimurium, Salmonella Enterica serovar Enteritidis, Salmonella Enterica serovar Typhi was performed using published standardized multiplex PCR. Results: An overall low prevalence of 2.5% (14/550) was observed. The observed prevalence of Salmonella spp. in diarrheagenic infants was 1.2% (05/400), diarrheagenic young animals 4% (02/50), sewage waste 10% (05/50), and fresh vegetables 4% (02/50), respectively. In diarrheagenic infants, of the five Salmonella isolates identified, two were Salmonella Typhimurium, two Salmonella Enteritidis, and one was unidentified and hence designated as other Salmonella serovar. All the Salmonella isolates identified from diarrheagenic young animals and sewage waste belonged to other Salmonella serovar, whereas, of the two isolates recovered from fresh vegetables, one was identified as other Salmonella serovar, and one as Salmonella Typhimurium, respectively. Conclusion: Isolation of Salmonella spp. especially from sewage waste and fresh vegetable is a matter of great concern from public health point of view because these sources can accidentally serve as a potential vehicle for transmission of Salmonella spp. to animals and human beings.

Keywords

• inv A
• isolation
• multiplex polymerase chain reaction
• Salmonella