Ovine babesioses, an important tick-borne disease of sheep and goats in China, is
caused by the reproduction of intraerythrocytic protozoa of the Babesia genus. Babesia
motasi-like is a Babesia parasite that infects small ruminant in China, and two sub-groups
of B. motasi-like can be subdivided based on differences in the rhoptry-associated-protein-1
gene. This study aimed to characterize the distribution, epidemiology and genetics
of B. motasi-like in animals and ticks. A molecular investigation was carried out
from 2009 to 2015 in 16 provinces in China. In total, 1081 blood samples were collected
from sheep and goats originating from 27 different regions, and 778 ixodid tick samples
were collected from 8 regions; the samples were tested for the presence of B. motasi-like
using a specific nested PCR assay based on the rap-1b gene. The results indicated
that 139 (12.9%), 91 (8.4%), 48 (4.4%) and 6 (0.7%) of the blood samples were positive
for general B. motasi-like, Babesia sp. BQ1 (Lintan and Ningxian), Babesia sp. Tianzhu
and Babesia sp. Hebei sub-groups, mixed infections, respectively. Among the collected
778 ixodid ticks (including Haemaphysalis longicornis, Haemaphysalis qinghaiensis,
Dermacentor silvarum, Ixodes persulcatus, Rhipicephalus sanguineus and Rhipicephalus
(Boophilus) microplus), the most frequently infected with Babesia were D. silvarum
and I. persulcatus (35.7%), followed by H. longicornis (26.8%), H. qinghaiensis (24.8%)
and R. sanguineus (9.3%). The PCR results were confirmed by DNA sequencing. The positive
rates of B. motasi-like infection in ticks were found to be higher in China, compared
with previous studies in other countries. B. motasi-like infections have not previously
been reported in D. silvarum, I. persulcatus or R. sanguineus. The findings obtained
in this study could be used for planning effective control strategies against babesiosis
in China.