Departamento de Análises Clínicas, Toxicológicas e Bromatológicas - Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café s/n°, Ribeirão Preto, SP, Brazil.
Division of Microbiology, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland, USA.
Sci Rep. 2018 Jul 11;8(1):10478. doi: 10.1038/s41598-018-28844-6.
Salmonella Enteritidis became the main serovar isolated from gastroenteritis cases in Brazil after the 90's. In this study we used whole genome sequence analysis to determine the phylogenetic relationships among a collection of strains isolated in Brazil to identify possible genomic differences between the strains isolated in the pre and post-epidemic period. Also, we compared our data from strains isolated in Brazil to strains available in the public domain from other South American countries. Illumina technology was used to sequence the genome of 256 Salmonella Enteritidis strains isolated over a 48 year-period in Brazil, comprising the pre- and post-epidemic period. Phylogenetic analyses revealed distinct lineages for strains isolated before and after 1994. Moreover, the phage region SE20 that may be related to the emergence of Salmonella Enteritidis worldwide was present only in strains of the post-epidemic cluster. In conclusion, our results showed that the genomic profile of Salmonella Enteritidis strains isolated in Brazil shifted after 1994, replaced by a global epidemic group of strains. It may be hypothesized that the presence of the prophage SE20 might have conferred to these strains a better ability to colonize chicken and consequently to infect and cause disease in humans, which might better explain the increase in the number of S. Enteritidis cases in Brazil and other South American countries. However, to verify this hypothesis further studies are needed.
肠炎沙门氏菌在 90 年代后成为巴西肠胃炎病例中主要分离的血清型。在这项研究中，我们使用全基因组序列分析来确定在巴西分离的一组菌株之间的系统发育关系，以确定流行前和流行后时期分离株之间可能的基因组差异。此外，我们将巴西分离株的数据与来自其他南美国家的公共领域中可用的菌株数据进行了比较。我们使用 Illumina 技术对巴西 256 株肠炎沙门氏菌进行了基因组测序，这些菌株是在巴西 48 年的时间内分离的，包括流行前和流行后时期。系统发育分析显示，1994 年前和后分离的菌株存在明显的谱系。此外，可能与肠炎沙门氏菌在全球范围内出现有关的噬菌体区域 SE20 仅存在于流行后聚类的菌株中。总之，我们的结果表明，巴西分离的肠炎沙门氏菌菌株的基因组特征在 1994 年后发生了变化，被全球流行的菌株群所取代。可以假设，前噬菌体 SE20 的存在可能赋予了这些菌株更好的在鸡中定植的能力，从而更好地解释了巴西和其他南美国家肠炎沙门氏菌病例数量的增加。然而，要验证这一假设，还需要进一步的研究。
