Criado-Fornelio A, Rey-Valeiron C, Buling A, Barba-Carretero J C, Jefferies R, Irwin P
Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad de Alcalá, 28871-Alcalá de Henares, Spain.
Vet Parasitol. 2007 Mar 31;144(3-4):261-9. doi: 10.1016/j.vetpar.2006.09.042. Epub 2006 Nov 7.
The prevalence of hematozoan infections (Hepatozoon canis and Babesia sp., particularly Babesia canis vogeli) in canids from Venezuela, Thailand and Spain was studied by amplification and sequencing of the 18S rRNA gene. H. canis infections caused simultaneously by two different isolates were confirmed by RFLP analysis in samples from all the geographic regions studied. In Venezuela, blood samples from 134 dogs were surveyed. Babesia infections were found in 2.24% of the dogs. Comparison of sequences of the 18S rRNA gene indicated that protozoan isolates were genetically identical to B. canis vogeli from Japan and Brazil. H. canis infected 44.77 per cent of the dogs. A representative sample of Venezuelan H. canis isolates (21.6% of PCR-positives) was sequenced. Many of them showed 18S rRNA gene sequences identical to H. canis Spain 2, albeit two less frequent genotypes were found in the sample studied. In Thailand, 20 dogs were analyzed. No infections caused by Babesia were diagnosed, whereas 30 per cent of the dogs were positive to hematozoan infection. Two protozoa isolates showing 99.7-100% identity to H. canis Spain 2 were found. In Spain, 250 dogs were studied. B. canis vogeli infected 0.01% of the animals. The sequence of the 18S rRNA gene in Spanish isolates of this protozoa was closely related to those previously deposited in GenBank (> 99% identity). Finally, 20 red foxes were screened for hematozoans employing semi-nested PCR and primers designed to detect Babesia/Theileria. Fifty percent of the foxes were positive to Theileria annae. In addition, it was found that the PCR assay was able as well to detect Hepatozoon infections. Thirty five percent of the foxes were infected with two different H. canis isolates showing 99.8-100% identity to Curupira 1 from Brazil.
通过对18S rRNA基因进行扩增和测序，研究了委内瑞拉、泰国和西班牙犬科动物中血孢子虫感染（犬肝簇虫和巴贝斯虫属，特别是犬巴贝斯虫沃氏亚种）的流行情况。通过RFLP分析，在所有研究地理区域的样本中均证实了由两种不同分离株同时引起的犬肝簇虫感染。在委内瑞拉，对134只犬的血样进行了检测。发现2.24%的犬感染了巴贝斯虫。18S rRNA基因序列比较表明，原生动物分离株在基因上与来自日本和巴西的犬巴贝斯虫沃氏亚种相同。犬肝簇虫感染了44.77%的犬。对委内瑞拉犬肝簇虫分离株的一个代表性样本（PCR阳性的21.6%）进行了测序。其中许多分离株的18S rRNA基因序列与西班牙2型犬肝簇虫相同，尽管在所研究的样本中发现了两种频率较低的基因型。在泰国，对20只犬进行了分析。未诊断出由巴贝斯虫引起的感染，而30%的犬血孢子虫感染呈阳性。发现了两种与西班牙2型犬肝簇虫同一性为99.7 - 100%的原生动物分离株。在西班牙，对250只犬进行了研究。犬巴贝斯虫沃氏亚种感染了0.01%的动物。该原生动物西班牙分离株的18S rRNA基因序列与先前存入GenBank的序列密切相关（同一性> 99%）。最后，采用半巢式PCR和设计用于检测巴贝斯虫/泰勒虫的引物，对20只赤狐进行了血孢子虫筛查。50%的狐狸泰勒虫安娜亚种呈阳性。此外，还发现PCR检测方法也能够检测肝簇虫感染。35%的狐狸感染了两种不同的犬肝簇虫分离株，它们与来自巴西的库鲁皮拉1型同一性为99.8 - 100%。
