Hematological values associated to the serological and molecular diagnostic in cats suspected of Ehrlichia canis infection

The literature contains several studies on feline ehrlichiosis. However, information about the characteristics of Ehrlichia infection in cats is still scanty. This study evaluated the association between Ehrlichia spp. infection and the hematologic data of 93 cats treated at the Federal University of Mato Grosso Veterinary Hospital in Cuiabá, state of Mato Grosso, Brazil. The presence of or exposure to Ehrlichia spp. infection was evaluated by Polymerase Chain Reaction (PCR) targeting the dsb and 16S rRNA gene of Ehrlichia, and by detection of anti-Ehrlichia canis IgG antibodies in Indirect Fluorescence Assay (IFA), respectively. Eight (8.6%) cats tested positive by PCR and the partial DNA sequence obtained from PCR products was a 100% match to E. canis. Forty-two (45.1%) cats showed antibody reactivity against Ehrlichia spp. Hematological alterations such as low erythrocyte count, thrombocytopenia, lymphopenia and monocytosis were observed in PCR positive cats. Among them, low erythrocyte counts were associated with IgG antibody titers of 40 to 640 and five cats also tested positive by PCR. Furthermore, PCR-positive cats showed a tendency to be lymphopenic. No correlation was found between age and sex, and no ticks were observed in any of the examined cats.现有文献已刊载数项关于猫埃立克体病的研究，但有关猫埃立克体（Ehrlichia）感染特征的相关信息仍较为匮乏。本研究针对巴西马托格罗索州库亚巴市马托格罗索联邦大学兽医院收治的93只家猫，评估了埃立克体属（Ehrlichia spp.）感染与其血液学指标之间的关联。本研究分别采用靶向埃立克体属dsb基因与16S rRNA基因的聚合酶链式反应（Polymerase Chain Reaction，PCR），以及间接荧光抗体试验（Indirect Fluorescence Assay，IFA）检测抗犬埃立克体（Ehrlichia canis）IgG抗体，以判定受试猫是否存在埃立克体属感染或既往暴露情况。经PCR检测，8只（占比8.6%）猫呈阳性，且从PCR产物中获得的部分DNA序列与犬埃立克体（E. canis）的同源性达100%。共有42只（占比45.1%）猫呈现埃立克体属抗体反应阳性。PCR检测阳性的猫可见红细胞计数降低、血小板减少症、淋巴细胞减少症以及单核细胞增多症等血液学异常。其中，红细胞计数降低与IgG抗体滴度介于40至640之间相关，且其中5只猫的PCR检测结果同样呈阳性。此外，PCR阳性猫存在淋巴细胞减少的趋势。未发现年龄与性别之间存在相关性，且所有受检猫均未发现蜱虫。