Molecular Detection and Characterization of Babesia and Theileria in Cattle and Water Buffaloes from Southern Luzon, Philippines

Abstract

Babesia and Theileria are tick-borne protozoan parasites that can cause significant economic losses in the cattle industry. This study aimed to contribute to the limited epidemiological data on Theileria orientalis as well as Babesia bigemina and B. bovis in large ruminants in the Philippines. Blood samples of 412 cattle and 108 water buffalo collected from four provinces in Southern Luzon, Philippines, were initially tested for the 18S rRNA gene of piroplasms through nested PCR. Positive samples were further subjected to species-specific PCR. The 18s rRNA of piroplasms was detected in 123 (29.9%) cattle and three (2.8%) water buffaloes. Theileria orientalis was found to be the most common piroplasm in cattle with a detection rate of 17.5%, followed by Babesia bovis and B. bigemina. Co-infections were also observed. Two water buffaloes were found infected with B. bovis, while one was positive for B. bigemina. The phylogenetic tree for B. bovis showed clustering of the isolates in two clades together with isolates from other countries, and a third separate clade. Meanwhile, the T. orientalis isolates in this study were distributed in three clades together with reported isolates from other countries. This study confirms the presence of T. orientalis in the Philippines and reports the genetic diversity of B. bovis and T. orientalis.

Bovine Piroplasma Populations in the Philippines Characterized Using Targeted Amplicon Deep Sequencing

“…More than half of the cattle samples examined (58.64%) were positive when tested using RLB primers, which is higher than a previous survey in four Philippine provinces that noted a 29.9% detection rate [24]. In contrast, using a similar assay, the rates reported in cattle from Zambia (63.4%) [17] and Pakistan (85.8%) [15] were higher than the rate of detection presented here.…”

“…The major causative agents of bovine babesiosis in the Philippines, B. bovis and B. bigemina, were the most commonly identified species in the cattle samples in the current survey. Using PCR tests, bovine Babesia species have been molecularly detected in at least 10 provinces nationwide [18,19,21,22,24,35]. T. orientalis was also present, which was similarly detected in previous surveys of bovines in the Philippines [20,21,24].…”

“…Using PCR tests, bovine Babesia species have been molecularly detected in at least 10 provinces nationwide [18,19,21,22,24,35]. T. orientalis was also present, which was similarly detected in previous surveys of bovines in the Philippines [20,21,24]. The species that causes oriental theileriosis, T. orientalis, which was previously believed to only…”

“…Bovine babesiosis and theileriosis are long believed to be endemic diseases in the Philippines due to the rarity of clinical cases despite the widespread presence of TBD agents. In the Philippines, previous molecular reports and species characterization have depended on the application of qualitative molecular techniques, i.e., the use of PCR assays and Sanger sequencing [18][19][20][21]24,34]. In the present study, we characterized the piroplasma populations circulating in field cattle raised in three provinces of the Philippines through the high-throughput NGS platform via the Ampliseq technique.…”

“…So far, piroplasmas that have been molecularly detected from cattle in the Philippines include Babesia bovis, B. bigemina, B. naoakii, Theileria orientalis, and Theileria sp. [18][19][20][21][22][23][24], most of which have been reported in the Luzon and Visayas regions. Of these, B. bovis, B. bigemina, and T. orientalis are among the most important piroplasma parasites in cattle in the Philippines, as they contribute to economic losses.…”