Baggio-Souza Vinícius, Berger Laura, Mallmann-Bohn Rafaela, Reis Adeyldes Oliveira, Basilio Lay Greco, Pereira Yasmin Santanna, Tirelli Luiza, Fagundes-Moreira Renata, da Silva João Vitor Dos Santos Alves, das Neves Lorena Freitas, Moroz Ludmila Rodrigues, Santos Huarrisson Azevedo, Espinoza Maria E Marecos, Daudt Cíntia, Gregori Fabio, Giroto-Soares Aline, da Silva Flávio Roberto Chaves, Garcia João Luis, de Aguiar Daniel Moura, Peixoto Maristela Peckle, Venzal José Manuel, Dantas-Torres Filipe, André Marcos Rogério, Soares João Fabio
Laboratory of Protozoology and Vector-Borne Rickettsioses - ProtozooVet, Faculty of Veterinary - FAVET, Federal University of Rio Grande do Sul - UFRGS, Porto Alegre, Rio Grande do Sul, Brazil.
Department of Public Health, Experimental and Forensic Medicine, University of Pavia, Pavia, Italy.
Parasit Vectors. 2025 Jul 13;18(1):282. doi: 10.1186/s13071-025-06923-8.
In South America, Babesia vogeli is the primary causative agent of canine babesiosis, and brown dog ticks (Rhipicephalus sanguineus sensu lato) are the vectors. The recent separation of brown dog ticks into Rhipicephalus sanguineus sensu stricto ("temperate lineage") and Rhipicephalus linnaei ("tropical lineage") raised suspicions of the possibility of two distinct Babesia genotypes or even species being transmitted by these tick species.
To investigate this hypothesis, dog blood samples from Brazil (eight states), Paraguay, and Uruguay were collected to determine the genetic diversity of B. vogeli in South America. The samples were collected from temperate regions (southern Brazil and Uruguay), where the putative vector is R. sanguineus, and from the tropical areas (southeastern, midwestern, northeastern, and northern Brazil and Paraguay), where R. linnaei is the vector. DNA samples from B. vogeli-positive dogs were extracted to amplify the 18S ribosomal RNA, internal transcribed spacers 1 and 2, heat shock protein 70, cytochrome c oxidase subunit 1, cytochrome oxidase c subunit 3, and cytochrome b genes. The sequences obtained were aligned with available B. vogeli sequences in GenBank and other homologous sequences to construct phylogenetic trees, haplotype networks, and matrices.
Our haplotypic and phylogenetic analyses congruently indicated the existence of one genotype in temperate areas and another in tropical areas, where R. sanguineus and R. linnaei act as vectors, respectively. While the percentage of similarity varied among the evaluated genetic markers, the results indicated a clear differentiation between the B. vogeli genotypes associated with temperate and tropical regions.
Our data indicate the existence of two B. vogeli genotypes in South America, associated with temperate and tropical areas. This contributes to a better understanding of B. vogeli's genetic diversity and opens new avenues for researching the ecology and coevolution of B. vogeli genotypes and their tick vectors. Owing to their correlation with the climatic region and the historical nomenclature of their vectors, we suggest the nomenclature of "temperate" and "tropical" B. vogeli genotypes.
在南美洲，伯氏巴贝斯虫是犬巴贝斯虫病的主要病原体，棕色犬蜱（血红扇头蜱复合种）是传播媒介。最近，棕色犬蜱被分为狭义血红扇头蜱（“温带谱系”）和林氏扇头蜱（“热带谱系”），这引发了人们对这两种蜱虫可能传播两种不同巴贝斯虫基因型甚至物种的怀疑。
为了验证这一假设，收集了来自巴西（八个州）、巴拉圭和乌拉圭的犬血样本，以确定南美洲伯氏巴贝斯虫的遗传多样性。样本采集自温带地区（巴西南部和乌拉圭），该地区假定的传播媒介是狭义血红扇头蜱，以及热带地区（巴西东南部、中西部、东北部和北部以及巴拉圭），该地区的传播媒介是林氏扇头蜱。提取伯氏巴贝斯虫阳性犬的DNA样本，以扩增18S核糖体RNA、内转录间隔区1和2、热休克蛋白70、细胞色素c氧化酶亚基1、细胞色素氧化酶c亚基3和细胞色素b基因。将获得的序列与GenBank中可用的伯氏巴贝斯虫序列和其他同源序列进行比对，以构建系统发育树、单倍型网络和矩阵。
我们的单倍型和系统发育分析一致表明，在温带地区存在一种基因型，在热带地区存在另一种基因型，狭义血红扇头蜱和林氏扇头蜱分别是这两个地区的传播媒介。虽然评估的遗传标记之间的相似性百分比有所不同，但结果表明与温带和热带地区相关的伯氏巴贝斯虫基因型之间存在明显差异。
我们的数据表明，在南美洲存在两种与温带和热带地区相关的伯氏巴贝斯虫基因型。这有助于更好地理解伯氏巴贝斯虫的遗传多样性，并为研究伯氏巴贝斯虫基因型及其蜱传播媒介的生态学和协同进化开辟了新途径。由于它们与气候区域及其传播媒介的历史命名法相关，我们建议将伯氏巴贝斯虫基因型命名为“温带”和“热带”。
