Molecular detection of Anaplasma spp., Babesia spp. and Theileria spp. in yaks (Bos grunniens) and Tibetan sheep (Ovis aries) on the Qinghai-Tibetan Plateau, China

Abstract

Background Anaplasma, Babesia and Theileria are tick-borne pathogens (TBPs) that affect livestock worldwide. However, information on these pathogens in yaks (Bos grunniens) and Tibetan sheep (Ovis aries) on the Qinghai-Tibet Plateau (QTP), China, is limited. In this study, Anaplasma spp., Babesia spp. and Theileria spp. infections were assessed in yaks and Tibetan sheep from Qinghai Province. Methods A total of 734 blood samples were collected from 425 yaks and 309 Tibetan sheep at nine sampling sites. Standard or nested polymerase chain reaction was employed to screen all the blood samples using species- or genus-specific primers. Results The results showed that 14.1% (60/425) of yaks and 79.9% (247/309) of Tibetan sheep were infected with at least one pathogen. Anaplasma ovis, Anaplasma bovis, Anaplasma capra, Anaplasma phagocytophilum, Babesia bovis and Theileria spp. were detected in this study, with total infection rates for all the assessed animals of 22.1% (162/734), 16.3% (120/734), 23.6% (173/734), 8.2% (60/734), 2.7% (20/734) and 19.3% (142/734), respectively. For yaks, the infection rate of A. bovis was 6.4% (27/425), that of B. bovis was 4.7% (20/425) and that of Theileria spp. was 3.3% (14/425). Moreover, 52.4% (162/309) of the Tibetan sheep samples were infected with A. ovis, 30.1% (93/309) with A. bovis, 56.0% (173/309) with A. capra, 19.4% (60/309) with A. phagocytophilum and 41.4% (128/309) with Theileria spp. Conclusions This study revealed the prevalence of Anaplasma spp., Babesia spp. and Theileria spp. in yaks and Tibetan sheep in Qinghai Province, China, and provides new data for a better understanding of the epidemiology of TBPs in these animals in this area of the QTP, China. Graphical Abstract

Serological Analysis of IgG and IgM Antibodies against Anaplasma spp. in Various Animal Species of the Qinghai-Tibetan Plateau

“…The recombinant Anaplasma MSP5 protein was used to perform indirect ELISAs for detecting IgG and IgM antibodies against Anaplasma spp. The MSP5 gene was amplified by PCR from cDNA of Tibetan sheep blood, which was confirmed from a sample that was positive for A. phagocytophilum [ 10 ]. Primers that included a BamH I site (underlined) in the forward primer (FAsMSP5BamH1) 5′-CGC GGATCC TTC AGC AAA ATC GGC GAG AGG-3′ and a Not I site (underlined) in the reverse primer (RAsMSP5Not1) 5′-ATAAGAAT GCGGCCGC CTA AGA ATT AAG CAT GTG ACC-3′ for MSP5 were used [ 29 ].…”

“…are obligate intracellular bacteria from the order Rickettsiales and the family Anaplasmataceae, and are serious TBPs that cause anaplasmosis in humans and animals by infecting red and white blood cells [ 4 , 5 , 6 , 7 , 8 ]. Anaplasmosis is characterized by hemolytic anemia in various animal species and is endemic in various tropical and subtropical regions worldwide [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ].…”

“…Although Anaplasma infections in animals have been characterized in some provinces in China [ 6 , 9 , 10 , 11 , 12 ], limited data are available on Anaplasma spp. antibodies in domestic and wild carrier animals in the Qinghai–Tibetan Plateau Area (QTPA).…”

Molecular Characterization, Expression Profiles of SMAD4, SMAD5 and SMAD7 Genes and Lack of Association with Litter Size in Tibetan Sheep

“…The Qinghai–Tibet Plateau (Tibetan Plateau) in China is the largest and highest plateau in the world [ 1 ]. It is located in northwest China and is characterized by extreme environmental conditions and a unique ecological environment involving high altitude, low oxygen levels, strong ultraviolet rays, low temperature, less rainfall and complex and variable terrain [ 2 , 3 , 4 , 5 ] inhabited by the numerous domestic animals. These animals play an essential role in the ecosystem and the livelihoods of the plateau residents.…”

“…These animals play an essential role in the ecosystem and the livelihoods of the plateau residents. Many domestic animals have lived for generations and have stable genetic adaptability to harsh living conditions [ 3 ]. Tibetan sheep ( Ovies aries ) is one of the domestic animal breeds distributed on the plateau.…”