Vectors and Vector-borne Diseases Research Programme, Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, South Africa.
Centre for Wildlife Studies, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110, South Africa.
Parasit Vectors. 2019 Mar 26;12(1):138. doi: 10.1186/s13071-019-3395-x.
Feline babesiosis, sporadically reported from various countries, is of major clinical significance in South Africa, particularly in certain coastal areas. Babesia felis, B. leo, B. lengau and B. microti have been reported from domestic cats in South Africa. Blood specimens from domestic cats (n = 18) showing clinical signs consistent with feline babesiosis and confirmed to harbour Babesia spp. piroplasms by microscopy of blood smears and/or reverse line blot (RLB) hybridization were further investigated. Twelve of the RLB-positive specimens had reacted with the Babesia genus-specific probe only, which would suggest the presence of a novel or previously undescribed Babesia species. The aim of this study was to characterise these organisms using 18S rRNA gene sequence analysis.
The parasite 18S rRNA gene was cloned and sequenced from genomic DNA from blood samples. Assembled sequences were used to construct similarity matrices and phylogenetic relationships with known Babesia spp. Fifty-five 18S rRNA gene sequences were obtained. Sequences from 6 cats were most closely related to published B. felis sequences (99-100% sequence identity), while sequences from 5 cats were most closely related to B. leo sequences (99-100% sequence identity). One of these was the first record of B. leo in Mozambique. One sequence had 100% sequence identity with the published B. microti Otsu strain. The most significant finding was that sequences from 7 cats constituted a novel Babesia group with 96% identity to Babesia spp. previously recorded from a maned wolf (Chrysocyon brachyurus), a raccoon (Procyon lotor) from the USA and feral raccoons from Japan, as well as from ticks collected from dogs in Japan.
Babesia leo was unambiguously linked to babesiosis in cats. Our results indicate the presence of a novel potentially pathogenic Babesia sp. in felids in South Africa, which is not closely related to B. felis, B. lengau and B. leo, the species known to be pathogenic to cats in South Africa. Due to the lack of an appropriate type-specimen, we refrain from describing a new species but refer to the novel organism as Babesia sp. cat Western Cape.
猫巴贝斯虫病，偶尔在不同国家报道，在南非具有重要的临床意义，特别是在某些沿海地区。在南非的家猫中已经报道了巴贝斯虫、狮子巴贝斯虫、伦加巴贝斯虫和微小巴贝斯虫。对表现出与猫巴贝斯虫病一致的临床症状并通过血涂片显微镜检查和/或反向线印迹杂交（RLB）杂交确认存在巴贝斯属锥虫的家猫血液标本（n=18）进行了进一步调查。12 份 RLB 阳性标本仅与巴贝斯属特异性探针反应，这表明存在新的或以前未描述的巴贝斯虫种。本研究的目的是使用 18S rRNA 基因序列分析来描述这些生物体。
从血液样本的基因组 DNA 中克隆并测序了寄生虫 18S rRNA 基因。使用组装序列构建了相似性矩阵，并与已知的巴贝斯属种建立了系统发育关系。获得了 55 个 18S rRNA 基因序列。6 只猫的序列与已发表的巴贝斯虫序列最密切相关（99-100%序列同一性），而 5 只猫的序列与狮子巴贝斯虫序列最密切相关（99-100%序列同一性）。其中一个是莫桑比克狮子巴贝斯虫的首次记录。一个序列与已发表的奥氏微小巴贝斯虫 Otsu 株具有 100%的序列同一性。最显著的发现是，来自 7 只猫的序列构成了一个新的巴贝斯虫群，与以前从鬃狼（鬃狼）、美国浣熊（浣熊）和日本野狸身上记录的巴贝斯属种以及从日本狗身上采集的蜱中记录的巴贝斯属种具有 96%的同一性。
狮子巴贝斯虫与猫的巴贝斯虫病明确相关。我们的结果表明，南非猫中存在一种新的潜在致病性巴贝斯虫，与南非已知对猫致病的巴贝斯虫、伦加巴贝斯虫和狮子巴贝斯虫关系不密切。由于缺乏适当的模式标本，我们避免描述一个新物种，但将新的生物体称为西开普猫巴贝斯虫。
