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

• Published in: International journal of food microbiology Vol. 162; no. 2; pp. 174 - 181
• Main Authors: Campioni, Fábio, Davis, Margaret, Medeiros, Marta Inês C., Falcão, Juliana P., Shah, Devendra H.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-03-2013; Elsevier
• Subjects: Animal productions; Animals; Biological and medical sciences; Brazil; Chickens - microbiology; Cluster Analysis; Food industries; Food microbiology; Fundamental and applied biological sciences. Psychology; Genetic Variation; Genotype; Humans; Minisatellite Repeats - genetics; MLVA; North America; Salmonella Enteritidis; Salmonella enteritidis - classification; Salmonella enteritidis - genetics; Salmonella enteritidis - isolation & purification; Salmonella Infections - microbiology; Salmonellosis; Terrestrial animal productions; Vertebrates; South America; Brazil; America; North America; Salmonellosis; Salmonella Enteritidis; MLVA; Human; Salmonella enteritidis; Farming animal; Typing; American; Poultry; Strain; Vertebrata; Meat animals; Bacteria; Genetics; Isolate; Chicken; Aves; Comparative study; Enterobacteriaceae; Food
• ISSN: 0168-1605; 1879-3460
• DOI: 10.1016/j.ijfoodmicro.2013.01.008

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 24year 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.
► 288 S. Enteritidis isolates from Brazil and North America were genotyped by MLVA. ► Comparison of MLVA profiles led to classification of the strains into two major clusters. ► North American strains were genetically diverse whereas Brazilian strains were clonal. ► After 1993 a new and prevalent subtype of S. Enteritidis was introduced in Brazil.