Location: Egg Safety & Quality ResearchTitle: Assignment of serotype to Salmonella enterica isolates obtained from poultry and their environment in Southern Brazil. Author
Submitted to: Letters in Applied Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/24/2013
Publication Date: 6/24/2013
Citation: Pulido-Landinez, M., Sanchez-Ingunza, R., Guard, J.Y., Pinheiro Do Nascimen, T. 2013. Assignment of serotype to Salmonella enterica isolates obtained from poultry and their environment in Southern Brazil. Letters in Applied Microbiology. Available: http://www.ncbi.nlm.nih.gov/pubmed/23734786. Interpretive Summary: Variation occurring in the DNA of a group of poultry-associated Salmonella isolates from Southern Brazil provided evidence of mixtures of serovar Group D serotypes on-farm and in single samples from birds. This finding suggests that co-infection and inter-serotype competition of Salmonella enterica in poultry could impact the incidence of disease in animals or humans. In addition, unique serotypes were identified on-farm that escaped detection by antibody typing. Application of cost-efficient and highly discriminatory genomic methods for assigning serotype may alter concepts about the epidemiology of Salmonella enterica on-farm and in foods.
Technical Abstract: To assess diversity of Salmonella enterica serotypes present in poultry and their environment from Southern Brazil, the Kauffman-White-LeMinor (KWL) scheme was used to serotype a total of 155 isolates. Isolates were then re-examined with nested PCR and sequencing of the dkgB-linked Intergenic Sequence Ribotyping (ISR) region that assesses single nucleotide polymorphisms occurring around a 5S ribosomal gene. Serotypes identified were Heidelberg (40.6%), Enteritidis (34.2%), Hadar (8.4%), Typhimurium (3.9%), Gallinarum (3.2%), Agona (1.3%), Cerro (1.3%), Livingstone (1.3%), Infantis (0.6%), Isangi (0.6%), Mbandaka (0.6%), Montevideo (0.6%), and Senftenberg (0.6%). Three unique ISRs were detected from 4 strains. Day old chicks yielded only S. Enteritidis, whereas S. Heidelberg was most often associated with poultry carcasses. Overall agreement between KWL and ISR was 85.2%, with disagreement possibly due to the ability of ISR to detect mixtures of serotypes in culture. Overall, ISR provided more information than did KWL about the ecology of Salmonella enterica on-farm. The O-antigen group D Salmonella enterica serovars such as Pullorum, Gallinarum and Enteritidis appear susceptible to overgrowth by other serotypes. > > >