Lutheran University of Brazil, 8001, Canoas, Rio Grande Do Sul, 92425-020, Brazil.
Simbios Biotechnology, Cachoeirinha, Rio Grande do Sul, Brazil.
Braz J Microbiol. 2021 Sep;52(3):1523-1533. doi: 10.1007/s42770-021-00508-0. Epub 2021 May 14.
Salmonella enterica serovar Enteritidis is frequently isolated from animal-source foods associated with human salmonellosis outbreaks. This serovar was spread to animal (mainly poultry) farms worldwide in the 1980s, and it is still detected in foods produced in many countries, including Brazil. The present study reports a retrospective genome-wide comparison of S. Enteritidis from foodborne outbreaks in Southern Brazil in the last two decades. Fifty-two S. Enteritidis isolates were obtained from foodborne outbreaks occurring in different cities of the Brazilian southernmost State, Rio Grande do Sul (RS), from 2003 to 2015. Whole-genome sequences (WGS) from these isolates were obtained and comparatively analyzed with 65 additional genomes from NCBI. Phylogenetic and Bayesian analyses were performed to study temporal evolution. Genes related to antibiotic resistance and virulence were also evaluated. The results demonstrated that all S. Enteritidis isolates from Southern Brazil clustered in the global epidemic clade disseminated worldwide originally in the 1980s. Temporal analysis demonstrated that all Brazilian isolates had a tMRCA (time to most recent common ancestor) in 1986 with an effective population size (N) increase soon after until 1992, then becoming constant up to now. In Southern Brazil, there was a significant decrease in the spreading of S. Enteritidis in the last decade. In addition, three antibiotic resistance genes were detected in all isolates: aac(6')-Iaa, mdfA, and tet(34). These results demonstrate the high frequency of one only specific S. Enteritidis lineage (global epidemic clade) in foodborne outbreaks from Southern Brazil in the last two decades.
肠炎沙门氏菌血清型肠炎亚种经常从与人类沙门氏菌病暴发有关的动物源食品中分离出来。该血清型于 20 世纪 80 年代传播到世界各地的动物（主要是家禽）养殖场，目前仍在包括巴西在内的许多国家生产的食品中检测到。本研究报告了过去 20 年巴西南部食源性疾病暴发中肠炎沙门氏菌的全基因组回顾性比较。从 2003 年至 2015 年，从巴西南部南里奥格兰德州不同城市发生的食源性疾病暴发中获得了 52 株肠炎沙门氏菌分离株。从这些分离株中获得了全基因组序列（WGS），并与来自 NCBI 的 65 个额外基因组进行了比较分析。进行了系统发育和贝叶斯分析以研究时间进化。还评估了与抗生素耐药性和毒力相关的基因。结果表明，巴西南部所有肠炎沙门氏菌分离株均聚集在全球流行的分支中，该分支最初于 20 世纪 80 年代在全球传播。时间分析表明，所有巴西分离株的 tMRCA（最近共同祖先的时间）为 1986 年，随后在 1992 年之前有效种群数量（N）增加，然后一直保持到现在。在巴西南部，过去十年中肠炎沙门氏菌的传播明显减少。此外，所有分离株均检测到三种抗生素耐药基因：aac(6')-Iaa、mdfA 和 tet(34)。这些结果表明，在过去 20 年中，巴西南部食源性疾病暴发中肠炎沙门氏菌的流行谱系（全球流行分支）非常普遍。
