Characteristics of amino acid sequences of envelop protein V3 loop of human immunodeficiency virus type 1 quasi-species in long-term non-progressors infected with human immunodeficiency virus type 1 / 中华传染病杂志

Objective To investigate the characteristics of V3 loop amino acid sequences of human immunodeficiency virus type 1 (HIV-1) quasi-species in long-term non-progressors (LTNP)infected with HIV. Methods End-point limiting dilution polymerase chain reaction (EPLD PCR) was used to amplify the env gene c2-v3-c3 region of single HIV-1 provirus from five LTNPs at sequential time points. The PCR products were then sequenced and the amino acid sequences of V3 loop were analyzed by sequence confirm analysis technology. Results The results showed that there were one to ten kinds of polymorphisms in the V3 region of HIV-1 quasi-species which were found from the serial samples of the five LTNP. However, the sequences of the predominant strains were either completely consistent or at most changed at one or two residues in the serial samples of individual patient. The tetramer compositions of the tip of V3 loop were consistent in each patient. It was GPGR in four patients and GPGK in one patient. It was speculated the co-receptor of HIV-1 was CC chemokine receptor (CCR)-5 based on the amino acids at the residue 11 and residue 25 of V3 loop and the net charge of V3 loop. Conclusions There are various polymorphisms at the HIV V3 loop in LTNP. However, the tetramer composition of the tip part of V3 loop is stable. The LTNP are very likely infected with non-syncytium inducing (NSI) strain.

Analysis of haemagglutinin gene of the first influenza A-H1N1 viral strain isolated in Guangdong Province during an influenza A pandemic in 2009 / 中华传染病杂志

Objective To detect and analyze the haemagglutinin (HA) gene of the first influenza A-H1N1 viral strain isolated in Guangdong Province during an influenza A pandemic in 2009.Methods A-H1N1 virus strain was isolated from the throat swab of the first patient diagnosed with A-H1N1 virus infection in Guangdong Province in 2009. Viral nucleonic acid was extracted from supernatant of cell culture and amplified using reverse transcriptase-polymerase chain reaction (RT-PCR) with HA gene-specific primers. The product was cloned, sequenced, and the homology was analyzed. Results A 1710 bp HA gene of the first influenza A-H1N1 viral strain in Guangdong Province in 2009 was acquired, which was named as A/GuangzhouSB/01/2009 (H1N1) HA with GenBank access No. GQ268003. The homology of the studied HA gene and the 277 influenza A (H1N1) isolates reported in the epidemic areas was 99.0%-99.8%, and as high as 99.8% when compared with the isolates reported in the United States where the patient had traveled. When the studied HA gene was compared with 25 isolates of Chinese seasonal A-H1N1 virus, the homology was 72.3%-85.6%. Conclusions The homology of the first isolated A-H1N1 viral strain in Guangdong Province in 2009 and epidemic influenza A-H1N1 virus is high, while it is low compared with Chinese seasonal A-H1N1 virus.

Establishment of an end-point limiting-dilution PCR assay for detection of human immunodeficiency virus type 1 quasispecies / 中华检验医学杂志

detection of HIV-1 quasispecies in HIV-1 infected populations with low level viral load.

Detection and analysis of nucleotide sequence of enteroviros 71 from four adults with hand, foot and mouth disease / 中华传染病杂志

Objective To identify the pathogens that cause hand, foot and mouth disease (HFMD) in adults and analyze the nucleotide sequences characteristics of enterovirus 71 (EV71). Methods The reverse transcription-polymerase chain reaction (RT-PCR) method was used to detect the enterovirus from the samples of four adult HFMD patients. The 227 bp amplified segments of EVT1 were then sequenced and compared with the sequences of previously isolated EVT1 strains available from GenBank by homogeneity and phylogenetic tree analyses. Results All the results of RT-PCR with enterovirus universal primers and EVT1 specific primers were positive. The EV71 sequences analysis showed that the four new sequences (named as GZ19610, GZ99310, GZ99355 and GZ46477) shared 96.0% to 99.1% nucleotide identify themselves and shared 96.9% to 100.0% homology with the strain Fuyang/17.08/3 isolated in 2008 from Fuyang, Anhui Province. Phylogenetic tree analysis showed that the genotype of the four new sequences was all subtype C4, they were the same sub-genotype as those strains isolated from Chinese mainland and Chinese Taiwan in 2004, and the genetic distance between them was most closely. Conclusions EV71 can cause adult HFMD. Compared with the nucleotide sequences of EV71 strains that isolated now and formerly in China, there is no large variation of the EV71 sequences isolated from four adult HFMD patients in Guangzhou this time. The adult HFMD patients should be isolated for treatment to avoid them transmitting the virus and causing disease spreading.

Sequence analysis of hepatitis B virus S gene "a" determinant in patients with positive HBsAg and anti-HBs / 中华临床感染病杂志

Objective To identify the sequence of hepatitis B virus S gene"a"determinant in patients with positive HBsAg and anti-HBs.Methods Nested-PCR Was used to amplify the HBV S gene in 4 patients with positive HBsAg and anti-HBs,and the PCR products were sequenced directly or after cloning.The sequences of"a" determinants were then analyzed by sequence alignment.Results Direct sequencing of PCR products showed that there was one amino acid (aa)residue in"a"determinant less conserved region emerging polymorphism in all 4 patients.Clone sequencing showed that aa residue at 126 of "a"determinant in patient 1 miSht be Thr,Ile and Set,at 134 might be Phe and Set;the aa at 126 in patient 2 misht be Ala and Thr.and in patient 3 might be Ile and Asn;aa polymorphism was not found in patient 4.Conclusion The polymorphism of"a"determinant in HBV S gene might be associated with positivity of both HBsAg and anti-HBs in hepatitis B patients.

Clinicial analysis of the first imported ease of Chikungunya fever in China / 中华传染病杂志

Objective To investigate the epidemiological, clinical and pathogenic characteristics and prognosis of the first imported case of Chikungunya fever in China in 2008. Methods Epidemiological and clinical data of this mate adult patient were analyzed retrospectively. Chikungunya virus (CHIKV)-IgM was detected using enzyme linked immunosorbent assay (ELISA) and colloidal gold immunoassay. CHIKV-RNA was detected using real-time fluorescent polymerase chain reaction (RT-PCR). Results This patient had onset of fever on March 2 in 2008 and lasted for 5 days. In addition, he felt joint and muscle pains, headache and found generalized engorged maculopapule. The laboratory tests showed leukopenia and thrombocytopenia. CHIKV-IgM was detected positive at day 9 after the onset and CHIKV-RNA was all positive at day 3, 5, 7, 9 after the onset. A 575 bp fragment of RT-PCR product was sequenced and detected the nucleotide homology was 99% compared with CHIKV sequences in GenBank. The patient recovered with symptomatic supportive treatment.Conclusion This imported case of Chikungunya virus infection is reported for the first time in China.It shows similar clinical manifestations with dengue fever.