Incidence of human rabies and characterization of rabies virus nucleoprotein gene in dogs in Fujian Province, Southeast China, 2002-2012.

BACKGROUND: Rabies is a global fatal infectious viral disease that is characterized by a high mortality after onset of clinical symptoms. Recently, there has been an increase in the incidence of rabies in China. The aim of this study was to investigate the incidence of human rabies and characterize the rabies virus nucleoprotein gene in dogs sampled from Fujian Province, Southeast China from 2002 to 2012. METHODS: Data pertaining to human rabies cases in Fujian Province during the period from 2002 through 2012 were collected, and the epidemiological profiles were described. The saliva and brain specimens were collected from dogs in Quanzhou, Longyan and Sanming cities of the province, and the rabies virus antigen was determined in the canine saliva specimens using an ELISA assay. Rabies virus RNA was extracted from canine brain specimens, and rabies virus nucleoprotein gene was amplified using a nested RT-PCR assay, followed by sequencing and genotyping. RESULTS: A total of 226 human rabies cases were reported in Fujian Province from 2002 to 2012, in which 197 cases were detected in three cities of Quanzhou, Longyan and Sanming. ELISA assay revealed positive rabies virus antigen in six of eight rabid dogs and 165 of 3492 seemingly healthy dogs. The full-length gene fragment of the rabies virus nucleoprotein gene was amplified from the brain specimens of seven rabid dogs and 12 seemingly healthy dogs. Sequence alignment and phylogenetic analysis revealed that these 19 rabies virus nucleoprotein genes all belonged to genotype I, and were classified into three genetic groups. Sequencing analysis showed a 99.7% to 100% intra-group and an 86.4% to 89.3% inter-group homology. CONCLUSIONS: This study is the first description pertaining to the epidemiological characteristics of human rabies cases and characterization of the rabies virus nucleoprotein gene in dogs in Fujian Province, Southeast China. Our findings may provide valuable knowledge for the development of strategies targeting the prevention and control of rabies.

Molecular epidemiology of hepatitis C virus among different groups of people in the province of Fujian, China.

Genotyping of hepatitis C virus (HCV) can provide valuable information for prognosis and treatment duration prediction. To explore the genetic diversity of HCV in Fujian Province, China, 112, 104 and 48 anti-HCV-positive serum samples were collected from volunteer blood donors, IDUs and patients, respectively, from Jan 2008 to Dec 2008 and were genotyped through sequence analysis, followed by phylogenetic analysis in the C/E1 and NS5B regions. Genotypes could be determined for 85.61 and 84.85 % of samples in the C/E1 and NS5B region, respectively. 6a was the most prevalent subtype, which accounted for 42.04 and 43.75 % in the C/E1 and NS5B region, respectively. Mixed infection and potential recombination were detected in this study. Kappa tests indicated that similar results were obtained by two genotyping methods targeting the C/E1 and NS5B regions. The differences in the main prevalent subtype between the three target groups suggest diversity of HCV prevalence in different populations.

Construction and characterization of a full-length infectious clone from a fast-replicating, X4-tropic HIV-1 subtype B' isolate.

In HIV-1 epidemics in China, HIV-1 subtype B' is the most predominant subtype circulating in intravenous drug users. In this study, we constructed an HIV-1 full-length infectious molecular clone based on the primary virus LWJ, which was isolated from an HIV-infected patient in Fujian Province, China. Phylogenetic and bootscanning analysis of the viral sequence revealed that the isolate LWJ belonged to HIV-1 subtype B'. The infectious clone was designated as "pLWJ". The virus (LWJ-c) produced from this infectious clone by in vitro transfection of 293T cells could infect both human peripheral blood mononuclear cells (PBMCs) and human the T cell line MT4. Interestingly, the cloned LWJ-c virus utilized CXCR4 as its co-receptor and could replicate in vitro with similar efficiency and kinetics compared to its parental primary isolate LWJ as well as the clade B reference virus NL4-3. The LWJ-c virus could also cause cytopathic effects in both PBMCs and MT cells. Sequence analysis of the envelope glycoprotein of pLWJ showed that a conserved GPGR motif and an arginine at position 11 were present in the V3 loop, which was consistent with previous reports regarding CXCR4 co-receptor usage and syncytium-inducing (SI) phenotype. Thus, the infectious clone represents a fast-replicating, high-producing, CXCR4-tropic and syncytium-inducing isolate. Given the prevalence of HIV-1 subtype B' in China, this infectious clone can be a very useful tool to provide a versatile molecular model for research focusing on the biological properties of this subtype.

Genetic characterization of three CRF01_AE full-length HIV type 1 sequences from Fujian Province, China.

BACKGROUND: One of the major characteristics of the human immunodeficiency virus type 1 (HIV-1) is its unusually high degree of genetic variability, which involves in genetic diagnosis, subtyping, vaccine design, and epidemiology. HIV-1 CRF01_AE is a main prevalent HIV-1 recombinant strain in China. In this study, three full-length CRF01_AE genomes from Fujian Province, China were cloned, sequenced, and analyzed; and the further genetic diversity defining and epidemiologic analysis were carried out. METHODS: Proviral DNA was extracted from non-cultured peripheral blood mononuclear cells, the near full-length HIV-1 genome was amplified and the PCR products were cloned into pCR-XL-TOPO vector and sequenced. 5'-long terminal repeat (LTR) and 3'-LTRs were amplified by additional independent PCR and cloned into pMD18T vector. Gene-based phylogenic tree was constructed and genetic distances were calculated by MEGA 3.1. Simplot was used for Bootscan analysis. RESULTS: The phylogeny and genetic distance analysis of the three near full-length sequences confirmed that these three samples clustered with CRF01_AE isolates, more close to Thailand CRF01_AE strain CM240, and were distantly related to African CRF01_AE strain 90CF402. Analysis of their genomic organization revealed the presence of nine potential open reading frames. There were no major deletions, rearrangements, or insertions in the three sequences, but an in-frame stop codon was found in tat gene of Fj051. LTRs of the three sequences contained a few nucleotides mutation. We did not find new mosaic recombinant in the three sequences. The V3 motif was GPGQ in all the three sequences, and there were only few amino acids differences in all three V3 loop sequences. CONCLUSION: This report reveals the background of the three full-length CRF01_AE genomes, the most dominantly circulating HIV-1 strain in Fujian Province, China. The work is essential for the design and development of an effective AIDS vaccine for the region.

[Sequence analysis of the full-length glycoprotein 120 gene of HIV-1 CRF01_AE in Fujian, China].

OBJECTIVE: To characterize full length glycoprotein 120 gene variations of 21 HIV-1 CRF01_AE isolated in Fujian, China, so as to help in the immunogenic research and vaccine design. METHODS: Twenty-one peripheral blood samples were randomly collected form 100 HIV-1CRF01_AE infected persons in Fujian 2004 approximately 2005. DNA was extracted, Nested-PCR was used to amplify the envelop protein full length gp120 gene. The PVR products underwent Sepharose electrophoresis. Genotype identification was done by BLAST program. Sequence analysis was conducted with Megalign and CLUSTAL1.83. Phylogenetic tree and genetic distance were analyzed by Neighbor-joining method and Distance program of MEGA software. The amino acid similarity analysis was done with DNASIS, and N-glycosylation site analysis was done with N-GLYCOSIDE program. RESULTS: Phylogenetic tree analysis showed that these 21 HIV-1 subtype CRF01_AE strains clustered with the AE reference strain, with an overall genetic distance of 9.5% +/- 2.5%. There were four types of V3 loop central motif: GPGQ (71.43%), GPGR (19.05%), GPGH (4.76%), and GQGQ (4.76%). Prediction of the potential use of co-receptors on the basis of the critical amino acids within V3 loop disclosed potential use of CCR4/CCR5 in 16 of the 21 sequences (76.19%), potential use of CCR4/CCR5 in 1 sequence (4.76%), and 4 samples (19.05%) failed to be predicted. Amino acid sequence analysis showed that V3 region was relatively conservative, whereas V1, V2, V4, and V5 wee more variable. N-linked glycosylation site analysis showed that most of the 21 sequences were relatively conservative. CONCLUSION: Sequences analysis show Most of the CRF01_AE virus strains in Fujian have a complicated source, and most of them are closely related to those of Southeast Asia and belong to the non-syncytium inducing (NSI) type.