Purpose

This study aimed to analyze the frequency of piroplasmids in the blood of dogs in Rio de Janeiro, compare the performance of microscopic techniques, assess the risk factors associated with infections and also molecularly and morphologically characterize the piroplasmids identified.

Methods

In all, 407 blood samples were collected from dogs between 2018 and 2019. These were subjected to microscopic parasitological techniques for thin and thick smears, stained with Giemsa and using a rapid staining kit. The slides were read under an optical microscope and the protozoa were characterized morphometrically. In addition, the blood samples were subjected to molecular characterization for diagnosing piroplasmid species using primers that amplified the gene 18S rRNA.

Results

Piroplasmids were detected in 38 (9.3%) samples. Of these, 33 samples presented nucleotide sequences compatible with Babesia vogeli. Most of the positive samples were young, male, defined breeds dogs that had been attended in clinics in São Gonçalo city. Thrombocytopenia and leukopenia were the hematological alterations more observed in positive samples, but positive samples without alterations were also detected. The sex was the only variable that showed statistical differences. Males dogs being more often infected than females (p < 0.05). The microscope slides mostly showed piriform and oval merozoites measuring greater than 2.5 µm in length, which were compatible with B. vogeli. However, smaller forms were also identified, thus demonstrating the polymorphic nature of this parasite.

Conclusion

Babesia vogeli was detected in blood samples from dogs in the metropolitan cities of Rio de Janeiro by molecular techniques in different parasite morphotypes.

中文翻译：

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巴西里约热内卢自然感染犬 Piroplasms 的显微检测、血液学评价和分子表征

目的

本研究旨在分析里约热内卢狗血液中 piroplasmids 的频率，比较显微技术的性能，评估与感染相关的风险因素，并在分子和形态学上表征所鉴定的 piroplasmids。

方法

在 2018 年至 2019 年期间，总共从狗身上收集了 407 份血液样本。 这些样本经过显微镜寄生虫学技术，用于薄涂片和厚涂片，用吉姆萨染色并使用快速染色试剂盒。在光学显微镜下读取载玻片并从形态计量学上表征原生动物。此外，使用扩增基因 18S rRNA 的引物对血样进行分子表征以诊断梨质粒种类。

结果

在 38 个 (9.3%) 样品中检测到 Piroplasmids。其中，33 个样本呈现出与Babesia vogeli相容的核苷酸序列。大多数阳性样本是在圣贡萨洛市诊所就诊的年轻、雄性、特定品种的狗。血小板减少和白细胞减少是阳性样品中观察到较多的血液学改变，但也检测到没有改变的阳性样品。性别是唯一显示出统计学差异的变量。雄性犬比雌性犬更常被感染（p  < 0.05）。显微镜载玻片大多显示长度大于 2.5 µm 的梨状和椭圆形裂殖子，与B. vogeli相容. 然而，也发现了更小的形式，从而证明了这种寄生虫的多态性。

结论

通过不同寄生虫形态类型的分子技术，在里约热内卢大城市的狗的血液样本中检测到巴贝斯虫。