title: MLVA typing reveals higher genetic homogeneity among S. Enteritidis strains isolated from food, humans and chickens in Brazil in comparison to the North American strains.
abstract: Salmonella Enteritidis (S. Enteritidis) is a major causative agent of food-borne gastroenteritis associated with the consumption of contaminated poultry products. In this study we used multilocus variable number of tandem repeats (VNTRs) analysis (MLVA) to discriminate a total of 188 S. Enteritidis strains recovered from human (n=67), food (n=61) and chickens (n=60) during a 24 year period (1986 through 2010) in Brazil. MLVA profiles of the 188 strains from Brazil were compared to the MLVA profiles of 100 human clinical (n=52) and poultry-associated (n=48) strains isolated in North America between 1986 and 2008. MLVA typing led to classification of the 288 strains from Brazil and North America into two major clusters named A and B with 35% of similarity. Cluster A consisted of a vast majority of strains isolated from North America (n=71) and only three strains isolated from Brazil which included two pre-pandemic strains (SE5 and SE4). In contrast, cluster B consisted of all of the post-pandemic strains isolated from Brazil (n=185) and fewer strains isolated from North America (n=29). In general, MLVA typing showed that the North American strains were more genetically diverse whereas Brazilian strains were more genetically clonal. The clustering of pre-pandemic strains from Brazil with the North American strains suggests the possibility that the pre-pandemic strains were more likely genetically diverse; however after 1993 a new and prevalent subtype of S. Enteritidis was introduced in this country. This is the first study describing MLVA genotyping of the S. Enteritidis strains isolated from Brazil.
authors: Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, USP, Av. do Café, s/n, 14040-903, Ribeirão Preto, SP, Brazil.
authors: Fábio
authors: F
authors: Campioni
authors: Margaret
authors: M
authors: Davis
authors: Marta Inês C
authors: MI
authors: Medeiros
authors: Juliana P
authors: JP
authors: Falcão
authors: Devendra H
authors: DH
authors: Shah
mesh_terms: D000818:Animals; D001938:Brazil; D002645:Chickens / Q000382:microbiology*; D016000:Cluster Analysis; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D018598:Minisatellite Repeats / Q000235:genetics*; D009656:North America; D012480:Salmonella Infections / Q000382:microbiology*; D012477:Salmonella enteritidis / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification