|1157-1||MULTILOCUS VARIABLE-NUMBER TANDEM REPEAT ANALYSIS OF Salmonella Enteritidis STRAINS ISOLATED FROM HUMANS, FOOD AND ANIMALS IN BRAZIL|
|Autores:||Fábio Campioni (FCFRP-USP - Faculdade de Ciências Farmacêuticas de Ribeirão Preto-USP) ; Devendra Shah (WSU - Washington State University) ; Marta I.c. Medeiros (IALRP - Adolfo Lutz Institute of Ribeirão Preto) ; Juliana Pfrimer Falcão (FCFRP-USP - Faculdade de Ciências Farmacêuticas de Ribeirão Preto-USP) |
Background: Salmonella infections are one of the major health problems worldwide. Serovar Enteritidis became the most isolated worldwide after 1980s and currently remains the most frequent isolated serovar in African, Asian, European and Latin American countries and the second most common in North American and Oceania regions. In Brazil, this upsurge was observed during the 1990s and up to now few molecular typing studies have been conducted with this serovar in this country. The aim of this study was to type S. Enteritidis strains isolated from human feces, food and animals from outbreaks and/or sporadic cases by Multilocus Variable-Number Tandem Repeat Analysis (MLVA) in order to assess the genetic diversity of them, as well as, verify the prevalence of possible genomic types.
Methods: A total of 188 Salmonella Enteritidis strains isolated in Brazil from human feces (67), food (61) and animals (60) between 1986 and 2010 was typed by MLVA. The loci SENTR1, SENTR2, SENTR3, SENTR4, SENTR5, SENTR6, SENTR7, SE-3 and SE-7 were amplified by PCR and submitted to capillary electrophoresis. The size of the peaks were analysed by the software GeneMarker and the dendrogram of genomic similarity constructed by the software BioNumerics.
Results: The dendrogram of genomic similarity showed that 152 (80,85%) of the strains were clustered together with more than 85% of similarity. Additionally, 34 (18,09%) strains were clustered with a similarity above 75%. Interestingly, two strains isolated in 1986 and 1992 showed less than 40% of similarity with all the other 186 strains isolated after 1993 and were the most diverse strains of the study.
Conclusions: The majority of the S. Enteritidis strains studied presented a high genomic similarity which suggests that those strains descended from a common ancestor that differed little over the years and have been contaminating food, humans and animals during decades in Brazil. Also, the low similarity between the strains isolated in 1986 and 1992 with the other strains isolated after 1993, showed a change in the prevalent clone in Brazil during the 1990s. Thus, this work contributed for a better understanding on the epidemiology of S. Enteritidis in Brazil and in the world.
Palavras-chave: Genotyping, MLVA, Salmonella Enteritidis