National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, 080-8555, Hokkaido, Japan.
Philippine Carabao Center at Ubay Stock Farm, Ubay, 6315, Bohol, Philippines.
Ticks Tick Borne Dis. 2019 Jun;10(4):815-821. doi: 10.1016/j.ttbdis.2019.03.016. Epub 2019 Mar 23.
The water buffalo industry is a vital part of the Philippine livestock economy and is an essential contributor to the developing local dairy industry. Although relatively less susceptible to diseases, water buffaloes can still be infected and can act as reservoirs of tick-borne pathogens (TBPs). However, limited information is available regarding the prevalence of tick-borne infections in water buffaloes in the Philippines. This study was conducted to identify TBPs harbored by water buffaloes and to characterize these pathogens molecularly. One hundred water buffalo blood samples collected from three areas in Bohol, Visayas region, Philippines were screened for various TBPs using pathogen-specific PCR assays. TBPs were detected in 46% of the samples (39% singly infected, 7% coinfected). The pathogens detected were Anaplasma marginale (29%), Babesia bovis (21%), and B. bigemina (3%). None of the blood samples were positive for Theileria annulata, T. orientalis, and B. ovata. A. marginale infection rates were significantly higher (37.5%) among water buffaloes aged ≤6 years (P = 0.046) than those >6 years old (18.2%) and was detected only in Bulgarian Murrah (36.1%) and US Murrah (25.9%) breeds. Phylogenetic analyses revealed that groEL sequences of A. marginale were 100% identical with isolates from the Philippines (Batangas and Cebu) and China. Two B. bigemina RAP-1a gene sequences were identical to each other and were homologous with previous isolates from Thailand, Indonesia, Uruguay, and the Philippines. Moreover, four B. bovis SBP-2 partial sequences obtained in this study had 92.4-99.7% identities. This study is the first molecular detection and characterization of A. marginale, B. bigemina and B. bovis in water buffaloes in the Visayas region, and the first molecular confirmation of B. bovis infection in water buffaloes in the country. The findings presented in this study may serve as baseline data for crafting effective tick-borne disease surveillance and prevention programs in Bohol and in the Philippines.
水牛奶牛业是菲律宾家畜经济的重要组成部分，也是发展当地乳品业的重要贡献者。尽管水牛奶牛相对较少感染疾病，但仍可能感染并成为蜱传病原体（TBPs）的储主。然而，关于菲律宾水牛奶牛中蜱传感染的流行情况，信息有限。本研究旨在鉴定水牛奶牛携带的 TBPs，并对这些病原体进行分子特征分析。从菲律宾维萨亚斯地区 Bohol 的三个地区采集了 100 份水牛奶牛血液样本，使用病原体特异性 PCR 检测方法筛查各种 TBPs。在 46%的样本中检测到 TBPs（39%为单一感染，7%为混合感染）。检测到的病原体包括边缘无浆体（29%）、牛巴贝斯虫（21%）和双芽巴贝斯虫（3%）。没有血液样本对环形泰勒虫、东方泰勒虫和卵形巴贝斯虫呈阳性。年龄≤6 岁的水牛（37.5%）的边缘无浆体感染率明显高于>6 岁的水牛（18.2%）（P=0.046），并且仅在保加利亚摩拉水牛（36.1%）和美国摩拉水牛（25.9%）品种中检测到。系统进化分析显示，边缘无浆体 groEL 序列与来自菲律宾（巴丹加斯和宿务）和中国的分离株完全一致。两个双芽巴贝斯虫 RAP-1a 基因序列彼此相同，与来自泰国、印度尼西亚、乌拉圭和菲律宾的先前分离株同源。此外，本研究中获得的 4 个牛巴贝斯虫 SBP-2 部分序列具有 92.4-99.7%的同一性。本研究首次在维萨亚斯地区的水牛奶牛中分子检测和鉴定了边缘无浆体、双芽巴贝斯虫和牛巴贝斯虫，并首次在该国的水牛奶牛中分子确认了牛巴贝斯虫感染。本研究中的发现可为 Bohol 和菲律宾制定有效的蜱传疾病监测和预防计划提供基线数据。
