Frazão Miliane Rodrigues, Medeiros Marta Inês Cazentini, Duque Sheila da Silva, Falcão Juliana Pfrimer
Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
Instituto Adolfo Lutz de Ribeirão Preto, Ribeirão Preto, SP, Brazil.
J Med Microbiol. 2017 Mar;66(3):350-359. doi: 10.1099/jmm.0.000424. Epub 2017 Mar 20.
Purpose and methodology.Campylobacter jejuni is a major zoonotic pathogen that causes food-borne gastroenteritis worldwide. However, there are only a few studies available that have molecularly characterized C. jejuni strains isolated in Brazil. The aim of this study was to genotype 111 C. jejuni strains isolated from sick humans (43), monkey faeces (19), chicken faeces (14), chicken meat (33) and sewage (2) between 1996 and 2016 in Brazil using flaA-SVR (short variable region) sequencing and PFGE. Furthermore, the presence of 16 virulence genes was analysed by PCR.
Using PFGE and flaA-SVR sequencing, the 111 C. jejuni strains studied were grouped into three and two clusters, respectively, and some strains of different origin presented a similarity of ≥80 %. In total, 35 flaA-SVR alleles were detected. Alleles gt45, gt49 and gt57 were the most prevalent, in contrast with those frequently described in the PubMLST database. All 111 C. jejuni strains contained the genes flaA, flhA, cadF, docA, cdtA, cdtB, cdtC, iamA, ciaB, sodB, dnaJ, pldA, racR and csrA. The wlaN gene was detected in 11 strains (9.9 %), and the virB11 in just one strain (0.9 %).
In conclusion, the pathogenic potential of the C. jejuni strains studied was highlighted by the high frequency of the majority of the virulence genes searched. The flaA-SVR sequencing and PFGE results showed that some of the strains studied presented a high genotypic similarity, suggesting potential for transmission between animal sources and humans in this country. Altogether, the results characterize further C. jejuni isolates from Brazil, an important producer and exporter of chicken meat.
目的与方法。空肠弯曲菌是一种主要的人畜共患病原体，在全球范围内引起食源性肠胃炎。然而，仅有少数研究对巴西分离出的空肠弯曲菌菌株进行了分子特征分析。本研究的目的是使用flaA - SVR（短可变区）测序和脉冲场凝胶电泳（PFGE）对1996年至2016年间在巴西从患病人类（43株）、猴粪便（19株）、鸡粪便（14株）、鸡肉（33株）和污水（2株）中分离出的111株空肠弯曲菌菌株进行基因分型。此外，通过聚合酶链反应（PCR）分析16个毒力基因的存在情况。
使用PFGE和flaA - SVR测序，所研究的111株空肠弯曲菌菌株分别被分为三个和两个簇，并且一些不同来源的菌株呈现出≥80%的相似性。总共检测到35个flaA - SVR等位基因。与PubMLST数据库中经常描述的等位基因相比，gt45、gt49和gt57等位基因最为普遍。所有111株空肠弯曲菌菌株都含有flaA、flhA、cadF、docA、cdtA、cdtB、cdtC、iamA、ciaB、sodB、dnaJ、pldA、racR和csrA基因。在11株菌株（9.9%）中检测到wlaN基因，仅在1株菌株（0.9%）中检测到virB11基因。
总之，所研究的空肠弯曲菌菌株中大多数毒力基因的高频率突出了其致病潜力。flaA - SVR测序和PFGE结果表明，一些所研究的菌株呈现出高度的基因型相似性，表明该国动物源与人类之间存在传播的可能性。总体而言，这些结果进一步刻画了来自巴西（鸡肉的重要生产国和出口国）的空肠弯曲菌分离株的特征。
