Vieira Maria Isabel Botelho, Costa Márcio Machado, de Oliveira Mateus Tonial, Gonçalves Luiz Ricardo, André Marcos Rogério, Machado Rosangela Zacarias
Professor do Programa de Pós-Graduação em Bioexperimentação, UPF, Passo Fundo, RS, Brazil.
Professor do curso de Medicina Veterinária, UPF, Passo Fundo, RS, Brazil.
Acta Trop. 2018 Mar;179:81-87. doi: 10.1016/j.actatropica.2017.12.028. Epub 2017 Dec 29.
Equine piroplasmosis is a disease caused by the hemoparasites Babesia caballi and Theileria equi and is considered to be the most important parasitic infection affecting Equidae. The objective of the present study was to carry out an epidemiological molecular and serological survey for the presence of these two protozoal organisms in equids from the northwestern region of the State of Rio Grande do Sul (RS), south Brazil. For this purpose, blood samples were collected from 90 equids in the city of Passo Fundo, RS, Brazil. Those were animals used for sport activities, outdoor recreational riding, and work including cattle herding and mounted patrol. Anti-T. equi and anti-B. caballi IgG antibodies were detected in the sera of those animals by commercial ELISA kits. The molecular diagnosis of equine piroplasmosis due to T. equi or B. caballi (or both) consisted in the amplification of the 18S rRNA gene by nested PCR followed by sequencing of the amplified PCR product and sequence comparison and phylogenetic analysis of the isolates; 17 (18.9%) and 5 (5.55%) out of the 90 serum samples tested in this study were positive for T. equi and B. caballi, respectively. Piroplasmid 18S rRNA gene fragments were detected by PCR in 24.4% (22/90) of the samples analysed and shared 99-100% identity with sequences of T. equi by BLASTn. Samples for the phylogenetic analysis were divided into 2 groups. In group A, there was close phylogenetic relationship between 4 sequences and sequences previously reported along the US-Mexico border, in South Africa, and in Brazil. There was a phylogenetic proximity between 5 samples from group B and samples tested by other authors in the US and Spain. Variation of the 18S rRNA gene allowed the identification of 9 new T. equi genotypes in the geographical region studied.
马焦虫病是一种由血液寄生虫马巴贝斯虫和驽巴贝斯虫引起的疾病，被认为是影响马科动物的最重要的寄生虫感染。本研究的目的是对巴西南部南里奥格兰德州（RS）西北部地区的马科动物中这两种原生动物的存在情况进行流行病学分子和血清学调查。为此，从巴西RS州帕索丰杜市的90匹马科动物身上采集了血样。这些动物用于体育活动、户外休闲骑行以及包括放牛和骑马巡逻在内的工作。通过商业ELISA试剂盒在这些动物的血清中检测抗驽巴贝斯虫和抗马巴贝斯虫IgG抗体。由驽巴贝斯虫或马巴贝斯虫（或两者）引起的马焦虫病的分子诊断包括通过巢式PCR扩增18S rRNA基因，随后对扩增的PCR产物进行测序，并对分离株进行序列比较和系统发育分析；在本研究检测的90份血清样本中，分别有17份（18.9%）和5份（5.55%）对驽巴贝斯虫和马巴贝斯虫呈阳性。通过PCR在24.4%（22/90）的分析样本中检测到梨形虫18S rRNA基因片段，经BLASTn分析，这些片段与驽巴贝斯虫序列的同源性为99 - 100%。用于系统发育分析的样本分为两组。在A组中，4个序列与之前在美国 - 墨西哥边境、南非和巴西报道的序列有密切的系统发育关系。B组的5个样本与美国和西班牙其他作者检测的样本有系统发育上的相似性。18S rRNA基因的变异使得在研究的地理区域中鉴定出9种新的驽巴贝斯虫基因型。
