Wen-Bin Zheng

Prevalence, Risk Factors and Multilocus Genotyping of Giardia intestinalis in Dairy Cattle, Northwest China

Giardia intestinalis is a cosmopolitan protozoan parasite that can infect a range of animals, including dairy cattle. As information regarding the prevalence and genotyping of G. intestinalis infection in dairy cattle in northwestern China is limited, 2,945 feces samples from 1,224 dairy cattle in Gansu Province and from 1,614 in Ningxia Hui Autonomous Region (NXHAR) were examined between December 2012 and March 2014. The overall prevalence of G. intestinalis was 3.63% (107/2,945), with 2.63% and 4.38% in Gansu and NXHAR, respectively. Logistic regression analysis showed region, age and season to be significant risk factors for G. intestinalis infection. Assemblage analysis identified 106 assemblage E and one assemblage A at the triose phosphate isomerase (tpi) locus in this study. Intravariations were also detected at tpi, glutamate dehydrogenase (gdh) and beta giardin (bg) loci within assemblage E, showing seven, three, and five new subtypes, respectively. Moreover, 13 new multilocus genotypes (E20‐E32) were observed in assemblage E. Effective strategies and measures should be taken to prevent and control giardiasis in Gansu and NXHAR.

Occurrence of Enterocytozoon bieneusi in Donkeys (Equus asinus) in China: A Public Health Concern

Enterocytozoon bieneusi is an important zoonotic parasite. It can infect virtually all animal species and has a global distribution. However, the prevalence of E. bieneusi in donkeys (Equus asinus) has only been reported in Algeria and Spain, and no information is available concerning genotypes of E. bieneusi in donkeys worldwide. In the present study, a total of 301 donkey fecal samples (48 from Jilin Province, 224 from Shandong Province and 29 from Liaoning Province) were collected and examined by PCR amplification of the internal transcribed spacer (ITS) region. The overall E. bieneusi prevalence was 5.3% (16/301), with 6.3% (3/48) in Jilin Province, 4.9% (11/224) in Shandong Province, and 6.9% (2/29) in Liaoning Province. Prevalence in different age groups ranged from 4.2 to 5.5%. E. bieneusi prevalence in donkeys sampled in different seasons varied from 4.2 to 6.5%. Altogether, four E. bieneusi genotypes were identified in this study, with two known genotypes (J and D) and two novel genotypes (NCD-1and NCD-2). Phylogenetic analysis revealed that genotypes D, NCD-1 and NCD-2 belonged to group 1, while the remaining genotype J was clustered into group 2. These findings revealed the occurrence of E. bieneusi in donkeys in China for the first time. Moreover, the present study also firstly genotyped the E. bieneusi in donkeys worldwide. These findings extend the distribution of E. bieneusi genotypes and provide baseline data for controlling E. bieneusi infection in donkeys, other animals and humans.

First Report of Bovine Leukemia Virus Infection in Yaks (Bos mutus) in China

Enzootic bovine leukosis (EBL) is a chronic lymphosarcoma disease of cattle caused by bovine leukemia virus (BLV). No information is available concerning the epidemiology of BLV infection in yaks (Bos mutus). One thousand five hundred and eighty-four serum samples from 610 black yaks and 974 white yaks from Gansu province, northwest China, were collected between April 2013 and March 2014 and tested for BLV antibodies using a commercially available ELISA kit. The overall BLV seroprevalence in yaks was 21.09% (334/1584), with 24.26% (148/610) black yaks and 19.10% (186/974) white yaks yielding positive results. Risk factor analysis indicated that with the exception of breed (OR = 1.36, 95% CI = 1.06–1.73, P < 0.05), the age, region, gender, farm, and the numbers of pregnancies were not considered as risk factors for the presence of BLV in yaks included in this study. This is the first report of BLV infection in yaks in China, which provides information for controlling BLV infection in yaks.

Prevalence and genotypes of Enterocytozoon bieneusi in sika deer in Jilin province, Northeastern China.

Enterocytozoon bieneusi is one of the most important zoonotic pathogen that can infect almost all animals, including humans. However, little information is available regarding prevalence and genotypes of E. bieneusi in sika deer. In the present study, the prevalence of E. bieneusi infection in sika deer in Jilin province, Northeastern China was examined using PCR amplification of the internal transcribed spacer (ITS) region of the ribosomal RNA (rRNA) gene. 23 (7.06%) of 326 samples were tested E. bieneusi-positive, and the risk factor significantly associated with E. bieneusi prevalence was the age of sika deer. Sequence analysis of the ITS rRNA gene suggested that 8 genotypes of E. bieneusi were found in this study, with five known genotypes, namely J (n = 11), BEB6 (n = 4), EbpC (n = 1), CHN-DC1 (n = 1), KIN-1 (n = 1) and three novel genotypes, namely JLD-1 (n = 2), JLD-2 (n = 2) and JLD-3 (n = 1). Phylogenetic analysis indicated that genotypes CHN-DC-1, KIN-1, EbpC, JLD-2 and JLD-3 fell into group 1, while other three genotypes (genotypes J, BEB6 and JLD-1) were clustered into group 2 (so-called bovine-specific groups). These findings indicated the presence of zoonotic E. bieneusi in Jilin province, Northeastern China. Effective strategies should be performed to control E. bieneusi infection in sika deer, other animals and humans.

Seroprevalence and Risk Factors of Bluetongue Virus Infection in Tibetan Sheep and Yaks in Tibetan Plateau, China

Bluetongue (BT), caused by bluetongue virus (BTV), is an arthropod-borne viral disease in ruminants. However, information about BTV infection in yaks in China is limited. Moreover, no such data concerning BTV in Tibetan sheep is available. Therefore, 3771 serum samples were collected from 2187 Tibetan sheep and 1584 yaks between April 2013 and March 2014 from Tibetan Plateau, western China, and tested for BTV antibodies using a commercially available ELISA kit. The overall seroprevalence of BTV was 17.34% (654/3771), with 20.3% (443/2187) in Tibetan sheep and 13.3% (211/1584) in yaks. In the Tibetan sheep group, the seroprevalence of BTV in Luqu, Maqu, Tianzhu, and Nyingchi Prefecture was 20.3%, 20.8%, 20.5%, and 19.1%, respectively. The seroprevalence of BTV in different season groups varied from 16.5% to 23.4%. In the yak group, BTV seroprevalence was 12.6%, 15.5%, and 11.0% in Tianzhu, Maqu, and Luqu counties, respectively. The seroprevalence in different seasons was 12.6%, 15.5%, 15.4%, and 9.0% in spring, summer, autumn, and winter, respectively. The season was the major risk factor concerning BTV infection in yaks (P < 0.05). The date of the BTV seroprevalence in Tibetan sheep and yaks provides baseline information for controlling BT in ruminants in western China.

The presence of Giardia intestinalis in donkeys, Equus asinus , in China

BackgroundGiardia intestinalis is one of the most important zoonotic enteric parasites. As no information regarding prevalence and genotype of G. intestinalis in donkeys (Equus asinus) in China is available, 181 faecal samples from 48 donkeys from Jilin Province, from 104 from Shandong Province and from 29 from Liaoning Province were examined between May and December 2015.FindingsTwenty-eight (15.47%) out of 181 donkey samples were tested G. intestinalis-positive by nested amplification of the triosephosphate isomerase (tpi) gene. The prevalence in different regional groups varied from 10.42 to 18.27%. The prevalence in adult and young donkeys was 14.29 and 22.92%, respectively. Otherwise, the prevalence was 11.69% in summer and 18.27% in winter. However, no statistically significant differences were found in relation to region or age group. Sequence analysis of the tpi, glutamate dehydrogenase (gdh) and beta giardin (bg) loci identified 4, 1 and 3 subtypes of assemblage B, respectively. Moreover, four novel multilocus genotypes (MLGs novel-1 to novel-4) were identified in assemblage B.ConclusionsThis first report of G. intestinalis in donkeys in China indicates that further studies of nation-wide molecular epidemiology and geographical distribution of Giardia in donkeys are warranted. Effective strategies should be implemented to control G. intestinalis infection in donkeys, other animals and humans.

Seroprevalence and Risk Factors of Toxoplasma gondii Infection in Farmed Minks (Neovison vison) in Northeastern and Eastern China

Toxoplasma gondii is an important intracellular parasite, which can infect endothermic vertebrate animals, including minks (Neovison vison). However, information on T. gondii infection in minks in China is limited. Therefore, we investigated the seroprevalence and risk factors of T. gondii infection in minks in northeastern and eastern China. A total of 1499 mink blood samples were randomly collected from eight cities between March 2014 and January 2015 in northeastern and eastern China, and antibodies to T. gondii were examined using the modified agglutination test. Overall, the seroprevalence of T. gondii infection was 8.14% in the examined minks. The T. gondii seroprevalence was different among cities (ranging from 1.85% in Changchun to 15.75% in Dalian), genders (4.31% in male and 6.22% in female), seasons (spring: 11.64%; summer: 7.34%; autumn: 7.37%; and winter: 7.32%), and ages (young: 5.79%; subadult: 5.03%; and adult: 11.08%). Region and age were considered as risk factors for T. gondii infection. These results provided baseline data for the prevention and control of T. gondii infection in minks in China.

Prevalence and risk factors of Cryptosporidium infection in farmed pigs in Zhejiang, Guangdong, and Yunnan provinces, China

Cryptosporidiosis is caused by species of Cryptosporidium protozoa that can infect a wide range of host animals worldwide. However, data regarding Cryptosporidium infection in farmed pigs in subtropical areas in China is limited. Therefore, a total of 396 fecal samples were obtained from farmed pigs from Zhejiang (n = 124), Guangdong (n = 72), and Yunnan (n = 200) provinces, China, and were tested by PCR amplification of the small subunit (SSU) rRNA gene. The overall prevalence of Cryptosporidium in pigs was 17.68% (70/396), with 20.11% (36/179) in male pigs and 15.67% (34/217) in female pigs. Additionally, Cryptosporidium prevalence was 8.33% (6/72) in Guangdong province, 14.52% (18/124) in Zhejiang province, and 23.00% (46/200) in Yunnan province. A DNA sequence analysis of the SSU rRNA gene revealed that all of the isolates represented C. scrofarum. This is the first report of C. scrofarum infection in pigs in Guangdong and Yunnan provinces in subtropical areas of China. The results of the present study provide foundation data for control and prevention of Cryptosporidium infection in pigs in the study areas in China.

Seroprevalence and Risk Factors of Fascioliasis in Yaks, Bos grunniens , from Three Counties of Gansu Province, China

The aim of this study was to determine the seroprevalence and risk factors of fascioliasis in yaks, Bos grunniens, from 3 counties of Gansu Province in China. A total of 1,584 serum samples, including 974 samples from white yaks from Tianzhu, 464 from black yaks from Maqu, and 146 from black yaks from Luqu County, were collected and analyzed using ELISA to detect IgG antibodies against Fasciola hepatica. The overall F. hepatica seroprevalence was 28.7% (454/1,584), with 29.2% in white yaks (284/974) and 27.9% in black yaks (170/610). The seroprevalence of F. hepatica in yaks from Tianzhu, Luqu, and Maqu was 29.2%, 22.6%, and 29.5%, respectively. Female yaks (30.9%) had higher F. hepatica seroprevalence than male yaks (23.4%). Also, F. hepatica seroprevalence varied by different age group from 24.1% to 33.8%. Further, the seroprevalence ranged from 21.8% to 39.1% over different seasons. Interestingly, the season and age of yaks were associated with F. hepatica infection in yaks in the investigated areas. These findings provided a basis for further studies on this disease in yaks from 3 counties of Gansu Province in northwestern China, which may ultimately support the development of effective control strategies of fascioliasis in these areas.

First report of bovine viral diarrhea virus and Mycobacterium avium subspecies paratuberculosis infection in Tibetan sheep (Ovis aries) in Tibetan Plateau, China

Bovine viral diarrhea virus (BVDV) and Mycobacterium avium subspecies paratuberculosis (MAP) are important pathogens, which cause serious disease in animals. However, information about BVDV and MAP infection in Tibetan sheep in China is limited. Two thousand one hundred and eighty-seven blood samples were collected from Tibetan sheep between April 2013 and March 2014 from the Tibetan Plateau and tested for BVDV and MAP antibodies using commercial ELISA kits. The overall seroprevalence of BVDV and MAP in Tibetan sheep was 36.7 and 11.29%, respectively. Furthermore, risk factor analysis indicated that the age of sheep was statistically significant associated with BVDV infection and the region was considered as the risk factor of MAP infection in sheep (P < 0.05), gender and season were not considered as risk factors. This is the first report of seroprevalence and risk factors associated with BVDV and MAP infection in Tibetan Sheep in China, which will provide baseline information for controlling BVDV and MAP infection in ruminants in the Tibetan Plateau, western China.