Secato Caroline Tostes, Gonçalves Luiz Ricardo, Ramos Inalda Angélica de Souza, Calchi Ana Cláudia, Mongruel Anna Claudia Baumel, da Silva Thiago Merighi, Machado Rosangela Zacarias, André Marcos Rogério
Graduate Program in Agricultural Microbiology, School of Agricultural and Veterinary Sciences (FCAV), São Paulo State University (UNESP), Jaboticabal, SP, 14884-900, Brazil.
Vector-Borne Bioagents Laboratory (VBBL), Department of Pathology, Reproduction and One Health, School of Agricultural and Veterinary Sciences (FCAV), São Paulo State University (UNESP), Jaboticabal, SP, 14884-900, Brazil.
Trop Anim Health Prod. 2025 Jun 14;57(5):267. doi: 10.1007/s11250-025-04499-0.
Brazil has the largest buffalo herd outside the Asian continent, with more than 1.5 million head. As buffalo farming has become an economically important activity, studies on the occurrence of pathogens shared between cattle and buffalo are necessary. The aim of this study was to investigate the molecular occurrence of piroplasmids and bacterial agents (Anaplasmataceae and Coxiellaceae) potentially transmitted by vectors in buffaloes in southeastern Brazil using molecular methods. DNA was extracted from blood samples of 81 buffaloes, 165 Rhipicephalus microplus ticks, and 92 Haematopinus tuberculatus lice collected from buffaloes in the municipality of Passos, state of Minas Gerais, Brazil. These samples were subjected to conventional PCR (cPCR) assays based on three endogenous genes, namely gapdh from mammals, 16S rRNA from ticks, and cox-1 from lice. Positive samples from these PCR assays were then submitted to a real-time PCR (qPCR) assay targeting IS1111 of Coxiella burnetii, cPCR for Ehrlichia spp. (dsb gene), and nested-PCR assays targeting the 18S rRNA gene of Piroplasmida, sbp-2 of Babesia bovis, and rap-1α of Babesia bigemina. All buffalo and ectoparasite DNA samples tested positive in the PCR assays for the endogenous genes. All samples were negative in the qPCR for C. burnetii and nested PCR for B. bigemina (rap-1α). For Ehrlichia spp., 6/257 (2.3%) ectoparasites (five ticks and one louse) tested positive, with BLASTn analysis showing 88.04% to 100% identity with Ehrlichia minasensis. In the nPCR for piroplasmids (18S rRNA), 8/81 (9.9%) buffaloes and one tick (0.7%) tested positive, with BLASTn analysis showing > 99.9% identity with B. bovis and B. bigemina. In the nPCR for B. bovis (sbp-2), 1/81 buffalo (1.2%) was positive. This study demonstrated, for the first time, the occurrence and co-infection of tick-borne hemoparasites in buffaloes and associated ectoparasites in southeastern Brazil. The lack of positivity for E. minasensis and low molecular occurrence for B. bovis and B. bigemina among buffaloes sampled may be associated with the higher resistance of this ruminant species to R. microplus ticks and vectored pathogens.
巴西拥有亚洲大陆以外最大的水牛群，数量超过150万头。随着水牛养殖已成为一项具有重要经济意义的活动，对牛和水牛之间共患病原体的发生情况进行研究很有必要。本研究的目的是使用分子方法调查巴西东南部水牛中可能通过媒介传播的梨形虫和细菌病原体（无形体科和柯克斯体科）的分子发生情况。从巴西米纳斯吉拉斯州帕苏斯市的水牛身上采集了81份水牛血液样本、165只微小扇头蜱和92只水牛结节血虱，提取了其中的DNA。这些样本基于三个内源性基因进行常规PCR（cPCR）检测，即哺乳动物的甘油醛-3-磷酸脱氢酶（gapdh）、蜱的16S rRNA和虱子的细胞色素氧化酶亚基1（cox-1）。然后，将这些PCR检测的阳性样本进行针对伯氏柯克斯体IS1111的实时PCR（qPCR）检测、针对埃立克体属（dsb基因）的cPCR检测，以及针对梨形虫18S rRNA基因、牛巴贝斯虫sbp-2和双芽巴贝斯虫rap-1α的巢式PCR检测。所有水牛和外寄生虫的DNA样本在内源性基因的PCR检测中均呈阳性。所有样本在伯氏柯克斯体的qPCR检测和双芽巴贝斯虫（rap-1α）的巢式PCR检测中均为阴性。对于埃立克体属，6/257（2.3%）的外寄生虫（五只蜱和一只虱子）检测呈阳性，BLASTn分析显示与米纳斯埃立克体的同一性为88.04%至100%。在梨形虫（18S rRNA）的巢式PCR检测中，8/81（9.9%）的水牛和一只蜱（0.7%）检测呈阳性，BLASTn分析显示与牛巴贝斯虫和双芽巴贝斯虫的同一性>99.9%。在牛巴贝斯虫（sbp-2）的巢式PCR检测中，1/81（1.2%）的水牛呈阳性。本研究首次证明了巴西东南部水牛及其相关外寄生虫中蜱传血液寄生虫的发生和共感染情况。在所采样的水牛中，米纳斯埃立克体缺乏阳性结果以及牛巴贝斯虫和双芽巴贝斯虫的低分子发生率可能与该反刍动物物种对微小扇头蜱和媒介传播病原体的较高抗性有关。
