Cloning and sequencing analyses of the complete genome of the provirus of the Inner-Mongolia pandemic strain of the Jaagsiekte sheep retrovirus / 病毒学报

To investigate the kinship between the Inner Mongolia pandemic strain and representative strains of the Jaagsiekte sheep retrovirus (JSRV), total DNA from the lung tissue of a JSRV-infected sheep in Inner Mongolia was used to clone fragments of gag, pro and pol genes. The recombinant plasmid pMD-JSRV (including complete genomic sequence of the JSRV strain isolated from Inner Mongolia) was constructed by linking all the cloned fragments with long terminal repeat (LTR) and env gene fragments (cloned previous and reserved by our research team). Sequence analyses revealed that the genome was 7690 bp in length and contained several typical molecular markers for exogenous form of JSRV. These included the Sca I restriction site in the gag gene, two predicted "CCHC" motifs of zinc finger in the encoded nucleocapsid protein and the predicted "YXXM" motif in the TM region of Env. Homology analyses showed that the virus strain belonged to the JSRV type II. pMD-JSRV and AF105220 strains shared a nucleotide identification of 95%. The full length genomic clone of JSRV could provide a molecular basis for an infectious JSRV molecular clone as well as an experimental platform to study the detection and pathogenesis of JSRV.

The pathogenic spectrum of hand, foot and mouth disease and molecular characterizations of human enterovirus 71 in Inner Mongolia autonomous region in 2010 / 病毒学报

To study the pathogenic spectrum of hand, foot and mouth disease (HFMD) and the molecular characterizations of human enteroviruses 71 (HEV71) isolated from the clinical specimens of HFMD patients in Inner Mongolia in 2010. A total of 921 clinical specimens including stools and throat swabs were collected from HFMD patients in outpatient service in Inner Mongolia and then viral isolation was performed, the positive viral isolates were identified by using the real-time PCR method (detecting EV, HEV71 and CVA16 in a single tube), and VP4 and VP1 coding region amplification and sequencing was performed with the viral isolates that were identified as non-HEV71, non-CVA16 HEVs. A total of 153 viruses were isolated form 921 clinical specimens, the positive rate was 16.61%, of which 61 (39.87%) were HEV71, 82 (53.59%) were CVA16, 7 (6.53%) were other HEVs(6 were CVB4 and 1 was polio vaccine virus type II) and 3 (1.96%) were adenoviruses. Nine viruses were isolated from severe cases, of which 6 were HEV71 and 3 were CVA16. Thirty two HEV71 isolates were selected from the patients presenting mild symptoms and the patients presenting severe symptoms randomly, and the VP1 coding regions of represented HEV71 isolates were amplified and sequenced. Finally the phylogenetic tree was constructed among the VP1 coding regions of the different genotypes and subgenotypes of HEV71 strains. The nucleotide acid and amino acid of 32 represented HEV71 strains in Inner Mongolia were closed to HEV71 strains isolated from mainland China since 2007, especially from Beijing in 2008, and it showed that all HEV71 strains clustered within the C4a evolution branch of C4 subgenotype. There was slight difference in the nucleotide and the amino acid sequence in VP1 region among the 32 Inner Mongolia HEV71 strains, the identity were 96.4%-100% and 98.14%-100%, respectively, and there was a little difference in the nucleotide acid sequence between the HEV71 strains from Inner Mongolia in 2010 and in 2007, the identity was from 96.95% to 97.87%. Thirty two HEV71 strains were in different lineages in the phylogenetic tree, and it indicated that these strains belonged to many different viral transmission chains. HEV71 and CVA16 were the main pathogens of HFMD in Inner Mongolia in 2010 and most severe cases were caused by HEV71. All the HEV71 strains circulated in Inner Mongolia belonged to C4a evolution branch within C4 subgenotype. Phylogenetic analysis revealed that 2010 Inner Mongolia HEV71 strains were located in different lineages, and had more nucleotide identity with 2008 Beijing HEV71 strains than with 2007 Inner Mongolia HEV71 strains. This indicated that Inner Mongolia HEV71 strains had not evolved independently, but co-evolved with the HEV71 strains in other provinces in mainland China.

B1a and b1b evolutionary branch of coxsackie virus A16 co-prevailed in Inner Mongolia Autonomous Region / 病毒学报

To study on the molecular evolution of Coxsackie virus A16 (CVA16)isolated from clinical speci-mens of Hand, foot and mouth Disease( HFMD) patients in Inner Mongolia in 2010. A total of 921 clinical specimens including stools, throat swabs and vesicle fluids were collected from 888 HFMD patients in out-patient service in Inner Mongolia and viral isolation was then performed, the positive viral isolates were identified by using the real-time PCR method detecting CVA16. A total of 50 CVA16 isolates were selected from the patients presenting mild symptoms, severe symptoms and the death patients randomly, and the VP1 coding regions of representative CVA16 isolates were amplified and sequenced. Finally the phylogenetic tree was constructed among the VP1 coding regions of the different genotypes and subgenotypes of CVA16 strains. Eighty two viruses were isolated form 921 clinical specimens, the positive rate was 8. 90%, of which 3 viruses were isolated from severe cases and 1 viruses was from death cases. The nucleotide acid of 50 representative CVA16 strains in Inner Mongolia were closed to CVA16 strains isolated from mainland China since 1998, especially from Beijing in 2009 and from Henan in 2010, the identity were 96. 18% approximately 98. 88% and 94. 94a approximately 98. 76%, respectively. There was a little difference in the nucleotide acid between the CVA16 strains from Inner Mongolia in 2010 and in 2007, the identity were 91. 68% approximately 96. 52% The phylogenetic tree showed that all CVA16 strains clustered within Bla and B1b evolution branch of B1 genotype. There was slight difference in the nucleotide and the amino acid in VP1 region among the 50 Inner Mongolia CVA16 strains, the identity were 89. 99% approximately 100% and 98. 31% approximately 100%, respectively, indicating that these strains belonged to many different viral transmission chains. The CVA16 strains circulated in Inner Mongolia in 2010 were all belong to B1a and B1b evolution branch of B1 genotype, and the two evolutionary branchs of Coxsackie virus A16 were co-evolved and co-prevailed in Inner Mongolia Autonomous Region.

A specific PCR assay and a nested PCR assay for the screening of ovine pulmonary adenomatosis / 病毒学报

Ovine pulmonary adenomatosis (OPA) is a naturally occurring contagious lung tumor of sheep which was caused by an exogenous retrovirus of sheep, jaagsiekte retrovirus (JSRV). Although no specific circulating antibodies against the virus coud be detected in infected sheep, exogenous JSRV proviral DNA sequences (exJSRV) and JSRV RNA transcripts could be detected in lung tumors, lymphoreticular system and peripheral blood mononuclear cells (PBMC) from sheep affected by OPA. The sheep genome carried 15 to 20 copies of endogenous retrovirus loci (enJSRV) that were similar to JSRV in structural genes but the divergene in U3. Therefore, primers specific for the U3 sequences of exJSRV were designed for the specific PCR and nested PCR (n-PCR). Sensitivity between specific PCR assay and n-PCR assay was compared by using serial dilutions of positive plasmid pJSRV-LTR in a background of 700ng sheep genome DNA. Sensitivity of n-PCR was ten-fold higher than specific PCR. The n-PCR was only available in blood test for detection of JSRV infected sheep and might be useful in epidemiological studies and disease control of OPA.