Jian-Gang Ma

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.

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 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.

First detection and genetic characterization of Toxoplasma gondii in market-sold oysters in China

Toxoplasma gondii oocysts in the water might be filtered through the gills of shellfish in the process of feeding, and can be concentrated in the digestive glands. Consumers might become infected through ingestion of the shellfish unless they are discharged or inactivated by the shellfish. Thus, the purpose of this study was to evaluate the presence of T. gondii in market-sold oysters in China under natural conditions using a molecular approach. A total of 998 oysters were collected from markets in four cities (Weihai, Qingdao, Yantai and Rizhao) of Shandong province, eastern China. Of these, 26 samples (2.61%) were tested positive by nested PCR amplification of T. gondii B1 gene. Only one of the 26 positive samples was typed completely, and was identified as ToxoDB Genotype #9. This is first report of T. gondii in market-sold oysters in China, suggesting that oysters have the ability to filter and retain T. gondii oocysts in their tissues, which represents a risk to public health because oysters are frequently ingested in nature.

De novo transcriptome sequencing and analysis of the juvenile and adult stages of Fasciola gigantica

Fasciola gigantica is regarded as the major liver fluke causing fasciolosis in livestock in tropical countries. Despite the significant economic and public health impacts of F. gigantica there are few studies on the pathogenesis of this parasite and our understanding is further limited by the lack of genome and transcriptome information. In this study, de novo Illumina RNA sequencing (RNA-seq) was performed to obtain a comprehensive transcriptome profile of the juvenile (42days post infection) and adult stages of F. gigantica. A total of 49,720 unigenes were produced from juvenile and adult stages of F. gigantica, with an average length of 1286 nucleotides (nt) and N50 of 2076nt. A total of 27,862 (56.03%) unigenes were annotated by BLAST similarity searches against the NCBI non-redundant protein database. Because F. gigantica needs to feed and/or digest host tissues, some proteases (including cysteine proteases and aspartic proteases), which play a role in the degradation of host tissues (protein), have been paid more attention in the present study. A total of 6511 distinct genes were found differentially expressed between juveniles and adults, of which 3993 genes were up-regulated and 2518 genes were down-regulated in adults versus juveniles, respectively. Moreover, stage-specific differentially expressed genes were identified in juvenile (17,009) and adult (6517) F. gigantica. The significantly divergent pathways of differentially expressed genes included cAMP signaling pathway (226; 4.12%), proteoglycans in cancer (256; 4.67%) and focal adhesion (199; 3.63%). The transcription pattern also revealed two egg-laying-associated pathways: cGMP-PKG signaling pathway and TGF-β signaling pathway. This study provides the first comparative transcriptomic data concerning juvenile and adult stages of F. gigantica that will be of great value for future research efforts into understanding parasite pathogenesis and developing vaccines against this important parasite.

Prevalence and risk factors of Giardia duodenalis in domestic rabbbits (Oryctolagus cuniculus) in Jilin and Liaoning province, northeastern China

BACKGROUND Giardia duodenalis is one of the most important intestinal parasites that can infect virtually all animals, including rabbits and humans. However, there is little information regarding the prevalence and genotypes of G. duodenalis in domestic rabbits in China. METHODS A total of 426 rabbit fecal samples (136 from Shenyang City, 174 from Changchun City, and 116 from Jilin City) were examined by Lugols iodine staining with microscopy analysis, and the positive samples were genotyped at the triosephosphate isomerase (tpi) and the beta giardin (bg) gene loci using nested PCR. RESULTS Forty-two (9.86%) out of 426 rabbit fecal samples were G. duodenalis-positive under microscopy analysis, and the highest G. duodenalis infection rate was 23.08% on farm 6. The prevalence of G. duodenalis in rabbits from different cities ranged from 1.47% to 14.37%. Among different age groups, G. duodenalis prevalence in rabbits ranged from 5.41% to 12.58%. The prevalence of G. duodenalis in outdoor rabbits and indoor rabbits was 14.29% and 6.77%, respectively. In the present study, region and farming mode were highly correlated with G. duodenalis infection in rabbits. All 42 G. duodenalis isolates were successfully amplified and sequenced at the tpi and bg loci, and only G. duodenalis assemblage B were identified. CONCLUSION This study not only further confirmed the dominance of G. duodenalis assemblage B in rabbits, but also further improved the foundation data concerning the distribution of G. duodenalis assemblages in China.

Prevalence and genotypes of Enterocytozoon bieneusi in pigs in southern China

Enterocytozoon bieneusi is one of the most important causative agents of microsporidiosis, causing diarrhoea the symptoms of enteric disease in humans and animals. Although there is some information on the prevalence and genotypes of E. bieneusi in China, there is still a lack of data in pigs in southern China. In the present study, a total of 396 faecal specimens were collected from pigs in Zhejiang, Guangdong and Yunnan provinces in southern China, and were examined by nested PCR amplification of the ribosomal internal transcribed spacer (ITS) for the prevalence and genotypes of E. bieneusi. The overall prevalence of E. bieneusi in pigs was 31.57% (125/396), forming 15 genotypes, including 9 known genotypes (EbpC, EbpA, D, G, H, PigEBITS5, Henan-IV, KIN-1, CHS5) and 6 novel genotypes (GD1, ZJ1, ZJ2, YN1, YN2 and YN3), which were all clustered into Group 1. Moreover, multilocus sequence typing (MLST) showed that 6, 3, 4 and 5 types were identified in MS1, MS3, MS7 and MS4 loci, respectively, representing four multilocus genotypes (MLGs), designated as MLGs novel-1 to novel-4 in the present study. This is the first detailed study of E. bieneusi using MLST in pigs in southern China, which extended information about the distribution of E. bieneusi genotypes in China.

Enterocytozoon bieneusi in Minks (Neovison vison) in Northern China: A Public Health Concern

Enterocytozoon bieneusi is the most important causative agent of microsporidiosis and can infect almost all vertebrate and invertebrate hosts, including minks (Neovison vison). In the present study, a total of 298 feces samples (including 79 from Heilongjiang province, 31 from Hebei province, 67 from Jilin province, 90 from Liaoning province, and 31 from Shandong province, Northern China) were examined by nested PCR amplification of the internal transcribed spacer (ITS) region of the rRNA gene. The overall prevalence of E. bieneusi in minks was 10.1%, with 10.5% in Jilin province, 32.3% in Hebei province, 8.9% in Liaoning province, 0% in Shandong province, and 6.3% in Heilongjiang province. Furthermore, multiple logistic regression analysis revealed that region was only risk factors associated with E. bieneusi infection in the investigated minks. Five E. bieneusi ITS genotypes (three known genotypes, namely D, Peru11, and EbpC; two novel genotypes, namely, NCM-1 and NCM-2) were found in the current study. Importantly, genotypes D, Peru11 and EbpC, previously identified in humans, were also found in minks, which suggested that minks are the potential sources of human microsporidiosis. To the best of our knowledge, this is the first report of E. bieneusi infection in minks worldwide. The results of the present survey have implications for the controlling E. bieneusi infection in minks, other animals and humans.