Deletion of African swine fever virus interferon inhibitors from the genome of a virulent isolate reduces virulence in domestic pigs and induces a protective response

African swine fever virus (ASFV) encodes multiple copies of MGF360 and MGF530/505 gene families. These genes have been implicated in the modulation of the type I interferon (IFN) response. We investigated the effect of modulating the IFN response on virus attenuation and induction of protective immunity by deleting genes MGF360 (MGF360-10L, 11L, 12L, 13L, 14L) and MGF530/505 (MGF530/505-1R, 2R and 3R) and interrupting genes (MGF360-9L and MGF530/505-4R) in the genome of the virulent ASFV isolate Benin 97/1. Replication of this deletion mutant, BeninΔMGF, in porcine macrophages in vitro was similar to that of the parental virulent virus Benin 97/1 and the natural attenuated isolate OURT88/3, which has a similar deletion of MGF360 and 530/505 genes. Levels of IFN-β mRNA in macrophages infected with virulent Benin 97/1 isolate were barely detectable but high levels were detected in macrophages infected with OURT88/3 and intermediate levels in macrophages infected with BeninΔMGF. The data confirms that these MGF360 and MGF530/505 genes have roles in suppressing induction of type I IFN. Immunisation and boost of pigs with BeninΔMGF showed that the virus was attenuated and all pigs (5/5) were protected against challenge with a lethal dose of virulent Benin 97/1. A short transient fever was observed at day 5 or 6 post-immunisation but no other clinical signs. Following immunisation and boost with the OURT88/3 isolate 3 of 4 pigs were protected against challenge. Differences were observed in the cellular and antibody responses in pigs immunised with BeninΔMGF compared to OURT88/3. Deletion of IFN modulators is a promising route for construction of rationally attenuated ASFV candidate vaccine strains.     

Changes in the antibody status of a population following epidemic infection by influenza virus A2/Hong Kong/1/68

The haemagglutinin of influenza virus A2/Hong Kong/1/68 was shown to be markedly different from that of previously isolated A2 virus strains. No haemagglutination-inhibiting (HI) antibody to A2/Hong Kong/1/68 virus was detected in serum specimens collected in 1966 from persons aged 60 years or less. In contrast, HI antibody tests with 270 sera collected in 1968 indicated that 9·6% had demonstrable HI antibody at low titres, and 35·2% of 454 postepidemic (1969) sera had demonstrable HI antibody at relatively high titres. Most sera from persons aged 80 years and more collected in 1968 and 1969 had demonstrable HI antibody to influenza virus A2/Hong Kong/1/68. No HI antibody to the Hong Kong virus was detected in pre-epidemic sera from children aged 6 months to 3 years, whereas 32% of postepidemic sera had HI antibody. The acquisition of HI antibody to A2/Hong Kong/1/68 was not accompanied by an increase in the incidence or titres of HI antibody to heterotypic A2 influenza viruses. For sera from children aged 4-11 years, an increase of HI titre to heterotypic A2 influenza was found.     

异氟醚预处理对大鼠肾缺血再灌注损伤的影响

目的观察异氟醚预处理对大鼠肾缺血再灌注（ischemia-reperfusion,I／R）损伤的影响,并探讨肿瘤坏死因子-α（TNF-α）在其中的作用。方法健康成年雄性SD大鼠36只,随机分成假手术组（s组）,缺血再灌注组（I／R组）和异氟醚预处理组（Iso＋I／R组）,每组各12只。S组进腹后仅分离韧带不阻断血流;I／R,组行肾脏缺血45rain,再灌注2h;Iso＋I／R组吸人1．5％（1MAC）异氟醚30min,停止吸入10rain后行I／R。在再灌注2h后测定血清尿素氮（BUN）和肌酐（cr）的含量,采用双抗体夹心酶联免疫吸附试验（ELISA法）测定。肾组织中TNF-α的浓度,同时取肾组织进行HE染色观察病理学改变。结果（1）与S组比较,I／R组和Iso＋I／R组血清BUN和cr表达水平、肾组织中TNF-α浓度均升高[BUN：（17．69±0．99）mmol／LV8（8．37±1．12）mmol／L,t=-23．55,P〈0．01;（12．26±1．11）mmol／Lvs（8．37±1．12）mmol／L,t=-19．09,P〈0．01;Cr：（103．22±13．42）μmol／Lvs（71．48±8．59）μmol／L,t=-21．45,P〈0．01;（86．51±11．49）μmol／Lvs（71．48±8．59）μmol／L,t=-9．87,P〈0．01;TNF-α：（0．51±0．07）rig／mlvs（0．43±0．00）ng／ml,t=-5．79,P〈0．01;（0．47±0．03）ng／Ⅱdvs（0．43±0．00）ng／ml,t=-8．86,P〈0．01]。（2）Iso＋I／R组血清BUN和Cr表达水平、肾组织中TNF-α浓度的升高幅度均小于I／R组[BUN：（12．26±1．11）mmol／LVS（17．69±0．99）retool／L,t=15．67,P〈0．01;Cr：（86．51±11．49）μmol／Lvs（103．22±13．42）μmol／L,t=6．68,P〈0．01;TNF-α：（0．47±0．03）ng／mlvs（0．51±0．07）ng／ml,t=2．61,P〈0．05]。（3）I／1t组、Iso＋I／R组。肾小管评分较S组升高[（17．26±1．45）VS（0．00±0．00）,t=-72．38,P〈0．01;（12．69±1．83）VS（0．00±0．00）,t=-39．53,P〈0．01]。Iso＋I／lt组肾小管评分较I／R组下降[（12．69±1．83）vs（17．26±1．45）,t=19．87,P〈0．01]。结论1．5％异氟醚预处理30min可减轻大鼠肾缺血再灌注损伤,其部分机制可能与下调肾组织中TNF-α水平有关。     

Field-based evidence for linkage of mutations associated with chloroquine (pfcrt/pfmdr1) and sulfadoxine-pyrimethamine (pfdhfr/pfdhps) resistance and for the fitness cost of multiple mutations in P. falciparum.

Mutations in the Plasmodium falciparum pfcrt gene on chromosome 7 and possibly mutations in pfmdr1 on chromosome 5 have a role in conferring resistance against chloroquine (CQ), as do mutations of pfdhfr on chromosome 4 and pfdhps on chromosome 8 in terms of resistance against sulfadoxine/pyrimethamine (SP). The additive role of multiple mutations in the development of resistance to each drug suggests a non-random occurrence. In this study, parasite isolates were obtained from 50 patients with uncomplicated P. falciparum malaria from rural Eastern Sudan, an endemic setting with minimal overlap of infection. The parasite isolates were genotyped for detection of 12 alleles in CQ and SP resistance genes. Our main findings were: (1) the frequency of mutant alleles, pfcrt K76T, pfmdr1 N86Y, pfdhfr N51I, pfdhfr S108N, pfdhps K540E and pfdhps A581G were; 0.90, 0.86, 0.84, 0.84, 0.80 and 0.20, respectively. (2) No mutations were detected for the pfdhfr loci A16V, C59R and I164L, and for pfdhps loci S436A, A437G and A613S. (3) There was a statistically significant association between the mutations in: (i) the CQ resistance (CQR) genes, pfcrt T76 and pfmdr1 Y86 (P< or =0.001), (ii) the SP resistance (SPR) genes, pfdhfr I51, pfdhfr N108 and pfdhps E540 (P< or =0.001-0.04) and (iii) the CQ "i" and SP "ii" resistance genes (P=0.001) 4. The fitness cost of multiple mutations was revealed by a significantly reduced parasite density of isolates bearing the mutant alleles (P=0.048). However, the significantly higher gametocyte carriage rate among isolates with resistance mutations (P=0.001) is possibly an evolutionary mechanism for survival of mutant parasites.     

Spread of influenzaviruses A/ENGLAND/42/72 AND A/Hong Kong/1/68

Seroconversion for A/England/42/72 (H3N2) virus occurred in a child in Calcutta in August 1971, one month after the virus was first isolated in India. During the following 5 months a small increase was observed in the geometric mean titres (GMT). In mid-1972 the virus was in Kathmandu, Nepal, where the children had a higher GMT than the adults. The GMT increased sharply during 1972 and early 1973 and this increase was accompanied by an increased number of hospital admissions for respiratory diseases. Among the people in the isolated village of Lang Tang (3 500 m elevation), the GMT and prevalence for both A/England/42/72 and A/Hong Kong/1/68 (H3N2) were less than 50% of the Kathmandu values.     

一株人感染H9N2禽流感病毒高通量测序及序列分析

目的 对一株人感染H9N2禽流感病毒进行高通量测序（next-generation sequencing,NGS）分析,探讨其在人群流行的可能性。方法 应用高通量测序技术进行全基因组序列测定（whole genome sequencing,WGS）。对8个基因进行相似性检索,构建系统进化树并分析其关键位点的分子特征。结果 8个基因与GenBank基因库相似度最高序列的来源不完全一致,系统进化树显示HA基因属于欧亚系I群,M基因位于G1-like分支,PB2位于G9-like分支,NA位于一独立分支,PBl,PA,NP,NS均位于SH/F/98-like分支。HA基因裂解位点为PSRSSR/GLF,226位受体结合位点为L。除M2基因S31N突变之外,NA基因茎63~65位缺失,PA和PB2基因未发生L336M和Q591R,E627K等可以增强病毒对哺乳动物适应性的突变,但发现可以增强病毒毒力的突变如M1基因N30D和T215A,PB2基因L89V,NSl基因P42S。除M2基因S31N突变外,NA基因和M2基因的药物结合位点未发生E119G,R152K,H274Y,R292K和L26F,V27A,A30T,G34E等耐药性突变。HA和NA糖基化位点预测结果都有8个糖基化位点,其中分别有7个和5个可靠程度较高。结论 该H9N2禽流感病毒的大部分关键性位点较保守,只有少部分位点发生一定程度进化与变异,在人群引起流行的可能性不大,但需加强分子方面动态监测。     

大鼠肠道缺血/再灌注时肠淋巴干结扎对肠道屏障的影响

目的比较大鼠肠道缺血/再灌注时肠淋巴干结扎与不结扎对肠道屏障的影响,探讨肠道淋巴及肠道屏障功能在危重病发生中的作用。方法健康雄性SPF级SD大鼠随机分为4组:空白组、假手术组、肠道缺血/再灌注组、肠道缺血/再灌注 淋巴干结扎组。分别检测肠道损伤程度,细菌、内毒素的移位情况及循环中D-乳酸、二胺氧化酶(DAO)的水平。结果假手术组、肠道缺血/再灌注组、肠道缺血/再灌注 淋巴干结扎组的黏膜厚度及绒毛高度均较空白组显著降低(P<0.05),肠道缺血/再灌注组、肠道缺血/再灌注 淋巴干结扎组间差异无显著性;空白组、假手术组未检测到细菌移位,肠道缺血/再灌注组细菌移位率为40%,肠道缺血/再灌注 淋巴干结扎组细菌移位率为20%;内毒素水平肠道缺血/再灌注组最高,肠道缺血/再灌注 淋巴干结扎组较肠道缺血/再灌注组显著降低(P<0.05),但肠道缺血/再灌注组、肠道缺血/再灌注 淋巴干结扎组均较空白组、假手术组增高(P<0.05);肠道缺血/再灌注组、肠道缺血/再灌注 淋巴干结扎组D-乳酸与DAO水平较空白组、假手术组显著增加(P<0.05),且肠道缺血/再灌注组高于肠道缺血/再灌注 淋巴干结扎组(P<0.05)。结论肠道缺血/再灌注损伤可导致肠黏膜厚度和绒毛高度显著降低,肠淋巴干结扎对肠道形态虽无明显保护作用,但减少细菌在肠系膜淋巴结的定植并降低血循环中内毒素、D-乳酸与DAO的水平。     

Studies on relationships between human and porcine influenza. 1. Serological evidence of infection in swine in Great Britain with an influenza A virus antigenically like human Hong Kong-68 virus

Serological evidence of infection of swine in Great Britain with an influenza A virus closely related to the human A/Hong Kong/68 (H3N2) variant was detected by a variety of serological tests. The Hong Kong/68 virus was first detected in man in Great Britain in August 1968 and was prevalent in the winters of 1968-69 and 1969-70. There was no evidence that swine had been infected with a Hong Kong/68-like virus before the appearance of the virus in man. The detection of virus-neutralizing antibody and high titres of neuraminidase-inhibiting antibody for Hong Kong/68 virus, and the production of precipitin lines corresponding to influenza A ribonucleoprotein and haemagglutinin and neuraminidase antigens of Hong Kong virus in immunodiffusion tests indicated that the swine sera contained antibody specific for the Hong Kong/68 virus. Evidence suggested that the infection of swine occurred in the early months of 1970. Clinical influenza among swine in Great Britain was not reported during the study period and there was no serological evidence of infection with “classical” swine influenzavirus strains.     

Experimental infection of human volunteers with a swine influenzavirus antigenically related to the human A-Hong Kong-68 virus

An influenzavirus of swine origin (swine/Taiwan/7310/70) antigenically closely related to the human A/Hong Kong/68 virus readily infected human volunteers. Those infected developed antihaemagglutinin and antineuraminidase antibodies to the human A/Hong Kong/68 virus as well as to the swine/Taiwan virus. The clinical reactions produced by the swine/Taiwan virus were, however, milder than those produced in volunteers infected with A/Hong Kong/68. In contrast, two other “classical” swine viruses (strains antigenically related to the prototype swine/Iowa/15/30 strain), immunologically distinct from the Hong Kong/68 virus, possessed low infectivity for man.     

Studies on relationships between human and porcine influenza. 2. Immunological comparisons of human A-Hong Kong-68 virus with influenza A viruses of porcine origin

Antigenic comparisons were made between the human A/Hong Kong/68 (H3N2) virus and a collection of influenza A viruses of swine origin. Haemagglutination-inhibition and neuraminidase-inhibition tests were used in addition to immunoprecipitin tests with monospecific antisera prepared against purified haemagglutinin and neuraminidase preparations. The antigenic relationships revealed by the studies are summarized as follows: (1) swine/Taiwan/7310/70 virus contained envelope antigens that were antigenically indistinguishable from those of A/Hong Kong/68 virus, (2) “classical” strains of swine influenzavirus related to A/swine/Iowa/15/30 (Hsw1N1) isolated between 1930 and 1967 contained neuraminidase that was antigenically distinct from that of A/Hong Kong/68 virus but related to that of human A0 and A1 viruses, and (3) the haemagglutinins of certain strains of “classical” influenza A virus appeared to show a minor antigenic relationship with the haemagglutinin of A/Hong Kong/68 virus. Immunoprecipitin tests suggested that this relationship was confined to only one of the two antigenic components of the haemagglutinin subunit. The antigenic relationships are discussed in respect of possible epidemiological relationships between human and swine influenza A viruses. It is proposed that the swine/Taiwan isolates be designated A/swine/Taiwan/70 (H3N2), indicating their antigenic identity with the human A/Hong Kong/1/68 virus.     

Synthesis, characterisation, activities, cell uptake and DNA binding of [[trans-PtCl(NH3)2] [mu-(H2N(CH2)6NH2)] [trans-PdCl(NH3)2](NO3)Cl

The dinuclear complex: [[trans-PtCl(NH(3))(2)] [mu-(H(2)N(CH(2))(6)NH(2))] [trans-PdCl(NH(3))(2)](NO(3))Cl (code named DHD) has been synthesized and characterized. The activity against human cancer cell lines including ovarian: A2780, A2780(cisR), cell up take, level of binding with DNA and nature of interaction of the compound with pBR322 plasmid and salmon sperm DNAs have been determined. The compound is found to exhibit significant anticancer activity against ovarian cancer cell lines: A2780, A2780(cisR) and A2780(ZD0473R)--about two times as active as cisplatin against A2780 cell line, about five times as active as cisplatin against A2780(cisR) and A2780(ZD0473R) cell lines. The higher activity of DHD suggests that the compound is able to overcome multiple mechanisms of resistance operating in A2780(cisR) and A2780(ZD0473R) cell lines. DHD is believed to form a range of interstrand GG adducts with duplex DNA that induces global changes in the DNA conformation, unlike cisplatin and ZD0473 that form mainly intrastrand adducts that induces a local kink in a DNA strand. Increasing prevention of BamH1 digestion of form I and form II pBR322 plasmid DNA with the increase in concentration of DHD provides support to the idea that the interstrand binding of DHD with pBR322 plasmid DNA brings about global changes in DNA conformation.     

Human parainfluenza virus type I (HPIV1) vaccine candidates designed by reverse genetics are attenuated and efficacious in African green monkeys

A set of recombinant, live attenuated human parainfluenza virus type 1 (rHPIV1) vaccine candidates was evaluated for attenuation, immunogenicity, and protective efficacy in African green monkeys (AGMs). Temperature sensitive (ts) and non-ts attenuating (att) mutations in the P/C and L genes were introduced individually or in various combinations into rHPIV1, including the C(R84G) and HN(T553A) mutations identified in the present work and the C(F170S), L(Y942A), and L(L992C) mutations identified previously. The rHPIV1 vaccine candidates exhibited a spectrum of attenuation in AGMs. One genetically and phenotypically stable vaccine candidate, rC(R84G/F170S)L(Y942A/L992C), was attenuated and efficacious in AGMs and is a promising live attenuated intranasal HPIV1 vaccine candidate suitable for clinical evaluation.     

Genetic Variation among African Swine Fever Genotype II Viruses,Eastern and Central Europe

African swine fever virus (ASFV) was first reported in eastern Europe/Eurasia in 2007. Continued spread of ASFV has placed central European countries at risk, and in 2014, ASFV was detected in Lithuania and Poland. Sequencing showed the isolates are identical to a 2013 ASFV from Belarus but differ from ASFV isolated in Georgia in 2007.     

Comparative Analysis of African Swine Fever Virus Genotypes and Serogroups

African swine fever virus (ASFV) causes highly lethal hemorrhagic disease among pigs, and ASFV’s extreme antigenic diversity hinders vaccine development. We show that p72 ASFV phylogenetic analysis does not accurately define ASFV hemadsorption inhibition assay serogroups. Thus, conventional ASFV genotyping cannot discriminate between viruses of different virulence or predict efficacy of a specific ASFV vaccine.     

Recombinant murine gammaherpesvirus 68 (MHV-68) as challenge virus to test efficacy of vaccination against chronic virus infections in the mouse model

Efficient vaccines against AIDS, Hepatitis C and other persistent virus infections are urgently needed. Vaccine development has been especially hampered by the lack of suitable small animal models to reliably test the protective capacity of candidate vaccines against such chronic viral infections. A natural mouse pathogen such as MHV-68 that persists lifelong after infection, appears to be a particularly promising candidate for a more relevant model system. Here, we investigated infections with recombinant MHV-68 as novel mouse challenge model to test the efficacy of heterologous vaccines based on recombinant modified vaccinia virus Ankara (MVA). To apply ovalbumin (OVA) as a model antigen, we constructed the recombinant virus MHV-68-OVA by BAC technology and characterized genetic stability and replicative capacity of the virus in vitro and in vivo. We demonstrated the ability of MHV-68-OVA to produce ovalbumin upon tissue culture infection. Moreover, the use of MHV-68-OVA-infected target cells allowed for efficient ex vivo amplification of OVA-specific, MHC class I-restricted CD8 T cells derived from MVA-OVA-vaccinated C57BL/6 mice. Finally, we immunized C57BL/6 mice with MVA-OVA and challenged the animals with MHV-68-OVA testing different time points and routes of infection. Vaccinated mice were infected with MHV-68-OVA but showed reduced viral loads in the acute and latent phase of challenge infection. These data strongly suggest the usefulness of the MHV-68 challenge model for further evaluation of recombinant vaccines against persisting virus infections.     

Synthesis, characterization, activities, cell uptake and DNA binding of trinuclear complex: [{trans-PtCl(NH(3))}(2)mu-{trans-Pt(NH(3))(2-hydroxypyridine)-(H(2)N(CH(2))(6)NH(2))(2)]Cl(4)

The trinuclear complex: [{trans-PtCl(NH(3))}(2)mu-{trans-Pt(NH(3))(2-hydroxypyridine)-(H(2)N(CH(2))(6)NH(2))(2)]Cl(4) (code named CH9) has been synthesized and characterized. The activity of the compound against human ovarian cancer cell lines: A2780, A2780(cisR) and A2780(ZD0473R), cell up take, level of binding with DNA and nature of its interaction with pBR322 plasmid DNA have been determined. Although the compound is found to be less active (about a half time as active as cisplatin) against the parent ovary cell line A2780, it is found to be more active than cisplatin against resistant cell lines: A2780(cisR) (3.6 times more) and A2780(ZD0473R) (3.4 times more). The higher activity of CH9 against the resistant cell lines suggests that the compound has been able to overcome multiple mechanisms of resistance operating in A2780(cisR) and A2780(ZD0473R) cell lines. Like other multicentered complexes, the compound is believed to form a range of interstrand GG adducts with duplex DNA that induces permanent global changes in the DNA conformation. This binding is different from that of cisplatin and ZD0473 that form mainly intrastrand adducts, inducing a local kink in a DNA strand. Increasing prevention of BamH1 digestion of form I and form II pBR322 plasmid DNA with the increase in concentration of CH9 provides support to the idea that global changes in DNA conformation are induced as a result of its interaction with the compound.     

Immunity to influenza in ferrets: XI. Cross-immunity between A/Hong Kong/68 and A/England/72 viruses: serum antibodies produced by infection or immunization

The degree of immunity due to cross-reactions between antibody to influenza virus A/Hong Kong/1/68 and A/England/42/72 was studied in ferrets. Ferrets were immunized with the viruses by either live infection or by inoculation with inactivated virus vaccines. The vaccines were given with Freund''s incomplete adjuvant or were given to ferrets previously infected with influenza virus A/PR/8/34. As a result of these immunizations the animals all produced similar titres of serum HI antibody to the immunizing virus, although the degree of cross-reaction with the other virus strain was variable. After immunization the animals were challenged by infection with an A/Eng/42/72-like virus and their degree of immunity was measured. It was found that the greatest immunity was in ferrets previously infected with the homologous A/Eng/42/72 virus. Animals previously infected with A/HK/68 virus also showed a measurable degree of immunity to A/Eng/42/72 infection, and this was greater than that found in animals given inactivated virus vaccines. The immunity produced by the vaccines was approximately equal, regardless of which vaccine or method of immunization was used. Thus, live infection produced a more effective, broader immunity than did the use of inactivated virus vaccines.     

Synthesis, characterisation, activities, cell uptake and DNA binding of a trinuclear complex: [[trans-PtCl(NH3)]2mu-[trans-Pd(NH3)(2-hydroxypyridine)-(H2)N(CH2)6NH2)2]Cl4

The trinuclear complex: [[trans-PtCl(NH3)](2)mu-[trans-Pd(NH(3))(2-hydroxypyridine)-(H(2)N(CH(2))(6)NH(2))(2)]Cl(4) (code named CH25) has been synthesized and characterized. The activity of the compound against human ovarian cancer cell lines: A2780, A2780 cisR and A2780 ZD0473R, cell up take, level of binding with DNA and nature of its interaction with pBR322 plasmid DNA have been determined. The compound is found to exhibit significant anticancer activity against the cell lines-about 45 times as active as cisplatin against A2780 cell line, about 76 times as active as cisplatin against A2780(cisR) cell line and about seven times as active as cisplatin against A2780cell line. The higher activity of CH25 suggests that the compound is able to overcome multiple mechanisms of resistance operating in A2780(cisR) and A2780(ZD0473R) cell lines. The compound is believed to form a range of interstrand GG adducts with duplex DNA that induces global changes in the DNA conformation, unlike cisplatin and ZD0473 [also known as AMD473 and JM473: cis-(2-methylpyridine)(ammine)dichloroplatinum(II)] that form mainly intrastrand adducts that induces a local kink in a DNA strand. The increasing prevention of BamH1 digestion of form I and form II pBR322 plasmid DNA with the increase in concentration of the compound is believed to be due to interstrand binding that brings about global changes in DNA conformation.     

湖南省2007-2008年A/H3N2亚型流感病毒血凝素基因特性研究

目的了解2007-2008年湖南省流感病毒优势流行毒株A(H3N2)亚型的基因变异特征。方法取病原学监测中分离到的29株A(H3N2)亚型流感病毒毒株,对其血凝素基因进行逆转录-聚合酶链反应(RT-PCR),扩增产物纯化后测序;测序结果与WHO全球流感疫苗株序列进行同源比对,绘制种系发生树。结果2007年的分离株与2007-2008年北半球疫苗株A/Wisconsin/67/05比较,变异位点主要为G50E,S138A,K140I,R142G以及N144D。2008年分离株与北半球疫苗株A/Wisconsin/67/05比较,变异位点主要为G50E,S138A,K140I,L157S;而与2008-2009年北半球疫苗株A/Brisbane/10/07比较显示,变异位点主要为K140I,L157S。结论湖南省2007-2008年A(H3N2)亚型流感流行毒株的HA1基因发生了变异,可能是导致其流行的重要原因。     

50例HBV基因分型及P区耐药突变分析

目的:调查温州乙型肝炎患者血清HBV基因分型和P区基因逆转录酶区(RT区)序列的突变情况。方法:选取50例接受核苷类似物治疗后的乙型肝炎患者作为研究对象,采用PCR产物直接测序法,并对扩增产物进行测序,将测序结果与GenBank中的标准序列进行比对分析,同时确定基因型。结果:在50例中C型44例,占88%,B型6例,占12%。存在位点突变者25例(50%)。其中检出以单位点rtM204I/V/S突变为主,9例,占36%,rtA181V/T突变4例,占16%,rtM204I/V/S+rtL180M突变5例,占20%,rtV214A,rtA181V/T+rtV173L,rtM204I/V/S+rtQ215H,rtM204I/V/S+rtL180M+rtV173L,rtM204I/V/S+rtL180M+rtV207I,rtM204I/V/S+rtL180M+rtT184A/G/I/S,rtM204I/V/S+rtL180M+rtT184A/G/I/S+rtA181V/T突变各占1例,占4%。结论:多数乙型肝炎患者在HBV P区可检出突变,突变形式多样,其中以rtM204I/V/S突变为主,应用DNA序列测定法分析HBV P区基因突变,获得的信息全面,对临床评估病情进展和实施抗病毒治疗有参考价值。