Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
Infect Genet Evol. 2013 Oct;19:145-51. doi: 10.1016/j.meegid.2013.07.004. Epub 2013 Jul 13.
Infection of humans and animals caused by Salmonella is a major public health problem worldwide. Among the more than 2500 serovars, S. Infantis has been one of the 15 most isolated serovars in the world. Despite its clinical importance, little is known about the molecular characteristics of S. Infantis strains from Brazil. The aims of this study were to type S. Infantis isolates of this country and to assess their pathogenic potential. The molecular epidemiology of 35 S. Infantis strains, isolated from human sources (25) and food items (10) between 1984 and 2009 in São Paulo State, Brazil, were investigated using ERIC-PCR, PFGE and MLST. Furthermore, the presence of some virulence markers from Salmonella pathogenicity islands (SPIs) SPI-1 and SPI-2 and from the virulence plasmid was assessed by PCR. Using ERIC-PCR, 34 S. Infantis strains exhibited a high genetic similarity (≥ 93.7%) and using PFGE, 32 strains exhibited a similarity ≥ 80.6%. Additionally, MLST showed a high clonal similarity among strains that all presented the same ST32. Thirty-two isolates under investigation contained the virulence markers invA, sopB, sopD, sipA, sipD, ssaR, sifA, flgK, fljB and flgL. In conclusion, the S. Infantis strains studied were genetically similar, suggesting that a prevalent subtype has been causing disease and food contamination during a 25year period in São Paulo State, an important metropolitan region in Brazil. Furthermore, the contamination between strains from food items and sick humans indicates that better control measures for S. Infantis may be needed in this country.
人类和动物感染沙门氏菌是一个全球性的主要公共卫生问题。在超过 2500 个血清型中，婴儿沙门氏菌是世界上分离到的 15 个最常见血清型之一。尽管它具有重要的临床意义，但对于巴西婴儿沙门氏菌菌株的分子特征知之甚少。本研究的目的是对巴西的婴儿沙门氏菌分离株进行分型，并评估其致病潜力。使用 ERIC-PCR、PFGE 和 MLST 对 1984 年至 2009 年期间从巴西圣保罗州的人类来源（25 株）和食品（10 株）中分离的 35 株婴儿沙门氏菌进行了分子流行病学研究。此外，通过 PCR 评估了来自沙门氏菌致病性岛（SPI）SPI-1 和 SPI-2 以及毒力质粒的一些毒力标记物的存在情况。使用 ERIC-PCR，34 株婴儿沙门氏菌显示出高度的遗传相似性（≥93.7%），而使用 PFGE，32 株显示出≥80.6%的相似性。此外，MLST 显示出菌株之间存在高度的克隆相似性，所有菌株均呈现相同的 ST32。在所研究的 32 个分离株中，存在侵袭基因 invA、 SopB、 SopD、 SipA、 SipD、 ssaR、 SifA、 flgK、 fljB 和 flgL 等毒力标记物。综上所述，研究的婴儿沙门氏菌菌株具有遗传相似性，这表明在巴西圣保罗州 25 年期间，一种流行的亚型一直导致疾病和食品污染。此外，食品和患病人类之间的菌株污染表明，该国可能需要更好地控制婴儿沙门氏菌。
