Subgenotype diversity of hepatitis B virus American genotype F in Amerindians from Venezuela and the general population of Colombia

The objective of this study was the evaluation of the genetic diversity found in HBV circulating among Venezuelan Amerindians and the general population in Colombia. Phylogenetic analysis of the S region in 194 isolates showed that genotype F is highly predominant in Colombia and Venezuela. This might be related to the genetic background of the population. F3 is the main subgenotype which circulates in both countries. Phylogenetic analysis of 61 complete genome sequences of HBV American genotypes confirms the presence of two genotypes F and H, and 4 F subgenotypes. In Venezuela, subgenotypes F1, F2, and F3 circulate in East and West Amerindians, while only F3 was found among South Amerindians. Japreira community derived from Yucpa Amerindians around 150 years ago. However, several Japreira HBV sequences were forming a clade that can be classified as subgenotype 2b, differing from Yucpa sequences that belong mainly to subgenotype F3. The apparent absence of correlation between the phylogenetic groupings of HBV isolates with the ethnical origin in aboriginal populations might be suggesting a recent origin of HBV American subgenotypes, or a genetic drift effect.     

Evolutionary History of Hepatitis B Virus Genotype F: An In-depth Analysis of Argentine Isolates

A revised analysis on the evolutionary history of hepatitis B virus (HBV) genotype F is herein presented with the incorporation of two new complete genomes from Argentina. The study of the phylogenetic-tree topology, genetic distances, and amino acid mutations confirmed with high reliability the existence of four different genetic clusters of this genotype. Argentine isolates were located in two groups of viruses that showed a great inner homogeneity but, interestingly, divergence between them was in the order of that existing among groups from different locations. Although the origin of these two viral populations is not clear, they do not seem to derive from each other, therefore the existence of at least two founder viral populations in Argentina is a more acceptable explanation.     

四种方法检测乙型肝炎病毒基因型的比较

目的 比较四种方法检测乙型肝炎病毒基因型的差异性.方法 对36例乙型肝炎患者的血清分别采用测序技术,荧光定量PCR技术,恒温扩增技术,基因芯片技术进行乙肝病毒基因型的检测.结果 36份血清以测序技术为金标,观测荧光定量PCR技术特异性100%,敏感性83%,恒温扩增技术特异性100%,敏感性89%,基因芯片技术特异性100%,敏感度92%.结论 目前临床采用的四种方法检测乙型肝炎病毒基因型的特异性相同,敏感度以测序为金标准,基因芯片技术最灵敏,其次为恒温扩增技术,最后为荧光定量PCR技术.     

The Putative Recombination of Hepatitis B Virus Genotype B with Pre-C/C Region of Genotype C

Among hepatitis B virus (HBV) genotypes the B and C are most prevalent in China. To further study on the inside story of the intertypes, the genotype of 136 sequences from Chinese patients were analyzed either by restriction fragment length polymorphism on fragments or by phylogenetic analysis and bootscanning on full genome. The 22 complete sequences of genotype B clustered with different genotypes depending on gene fragments analyzed, which indicated that recombinant events occurred during HBV evolutionary history. To locate the recombinant regions, the sequences of HBV entire genome were analyzed by SimPlot program. The recombinant regions of B genotype with recombination were mapped in the pre-C/C region with relatively less varied size. Besides, three sequences of genotype C have recombination with genotype B or D in different regions. However, among all of the 136 sequences, none of authentic genotype B was identified. To investigate the possible mechanism responsible for intertype recombination, the selection pressure on the recombinant region was estimated by using CODEML program. All models allow for positively selected sites suggest existence of positive selection pressure. In conclusion, the genotype B with recombination was exclusive subgroup of genotype B in China. The mosaic genotype B might result from immune pressure on the pre-C/C gene.     

Sequence and Phylogenetic Analysis of Hepatitis B Virus Genotype G Isolated in Germany

Genotype G of hepatitis B virus (HBV) has only recently been discovered. This report describes the full-length sequence of genotype G HBV (designated 235/01) isolated in Germany from a chronic HBV carrier. The patient was hepatitis B e antigen-positive, had high HBV DNA levels of about 10¹⁰ copies/ml serum, lacked a measurable anti-HBc response, and was coinfected with human immunodeficiency virus type 1. Genome 235/01 showed characteristic genotype G-specific features: stop codons at codon 2 and 28 of the pre-C region and insertion of 36 nucleotides at the 5 end of the C gene. It was nearly identical (99.7% identity) to both genotype G genomes (B1-89 and FR1 from France) described so far, suggesting either close epidemiological link among European genotype G isolates or high genetic stability of genotype G.     

乙型肝炎病毒临床感染形式与乙型肝炎病毒基因型之间的关系

目的 分析浙江省乙型肝炎病毒(HBV)的基因型分布,并了解基因型与临床表现形式之间的关系.方法 采用实时荧光定量PCR技术分别检测HBV基因型和HBV-DNA含量,采用化学发光技术检测乙肝免疫标志物,并对三种检测结果进行分析.结果 425份标本检出基因B型138例(32.47％),基因C型272例(64.00％),B\C混合型15例(3.50％),未发现其他基因型;发现C型基因HBV-DNA含量与HBeAg阳性率均高于B型基因,具有统计学差异P＜0.05;以临床诊断分析无症状的病毒携带者(ASC)以B型基因为主,而慢性乙型肝炎(CHB)、肝硬化(LC)以C型感染为主.结论 浙江地区HBV感染者基因型以B、C为主,未检出其他基因型,不同基因型中基因C型较基因B型更易转为慢性化,基因C型HBV感染者所致病更为严重.     

Epidemiology and Genetic Characterization of Hepatitis A Virus Genotype IIA

Three hepatitis A virus (HAV) genotypes, I, II, and III, divided into subtypes A and B, infect humans. Genotype I is the most frequently reported, while genotype II is hardly ever isolated, and its genetic diversity is unknown. From 2002 to 2007, a French epidemiological survey of HAV identified 6 IIA isolates, mostly from patients who did not travel abroad. The possible African origin of IIA strains was investigated by screening the 2008 mandatory notification records of HAV infection: 171 HAV strains from travelers to West Africa and Morocco were identified. Genotyping was performed by sequencing of the VP1/2A junction in 68 available sera. Entire P1 and 5′ untranslated regions of IIA strains were compared to reference sequences of other genotypes. The screening retrieved 5 imported IIA isolates. An additional autochthonous case and 2 more African cases were identified in 2008 and 2009, respectively. A total of 14 IIA isolates (8 African and 6 autochthonous) were analyzed. IIA sequences presented lower nucleotide and amino acid variability than other genotypes. The highest variability was observed in the N-terminal region of VP1, while for other genotypes the highest variability was observed at the VP1/2A junction. Phylogenetic analysis identified 2 clusters, one gathering all African and two autochthonous cases and a second including only autochthonous isolates. In conclusion, most IIA strains isolated in France are imported by travelers returning from West Africa. However, the unexplained contamination mode of autochthonous cases suggests another, still to be discovered geographical origin or a French reservoir to be explored.Hepatitis A virus (HAV) is a small, nonenveloped hepatotropic virus classified in the genus Hepatovirus within the family Picornaviridae. Its genome consists of a 7,500-nucleotide linear, positive-stranded RNA with a single open reading frame (ORF) flanked by 5′ and 3′ untranslated regions (UTR) (3). The 5′ UTR is the most conserved region of the genome and contains an internal ribosome entry site (IRES). The ORF encodes a polyprotein organized into three functional regions: P1, P2, and P3. P1 is secondarily cleaved into four capsid proteins, VP1 to VP4, whereas P2 and P3 encode nonstructural proteins.Despite significant genetic variability, a single serotype has been described (13). Sequence variation of a 168-nucleotide fragment encompassing the VP1/2A junction has initially defined seven genotypes that differ by at least 15% and subtypes that differ by 7.0 to 7.5% (19). Six HAV genotypes (genotypes I to VI) are now defined based on analysis of the 900 nucleotides of the complete VP1 protein (6). Genotypes I, II, and III, divided into subtypes A and B, infect humans. The former genotype VII has been reclassified within the genotype II clade as subgenotype IIB (6, 14). Data on genotype distribution showed that genotype I was the most prevalent worldwide, with IA being reported more frequently than IB, and that subgenotype IIIA was prevalent in Central Asia (6, 16, 19). In areas of low endemicity, such as the United States and Western Europe, subgenotype IA dominates, but all genotypes and subtypes have been reported (6, 16, 23). Most HAV strains in these countries can be identified as imported strains by phylogenetic analysis thanks to growing sequence databases, which allow for the tracing of the geographic origin of a given subgenotype (16).Among HAV genotypes, subgenotypes IIA (former genotype II) and IIB (former genotype VII) were defined based on a single isolate of each: CF-53/Berne, isolated in France in 1979, and SLF88, isolated in Sierra Leone in 1988 (19). Their complete sequences are now available (4, 14). These two subgenotypes are rarely reported. Recently, sequence analysis of the P1 region allowed the identification of a recombinant IB-IIA virus in a patient returning from Morocco (7), and a second IIA strain, identified by VP1-2A analysis, was reported in a Dutch patient returning from Spain (23).From 2002 to 2007, six subgenotype IIA strains were isolated at the National Reference Centre for HAV in France (6/693 available strains [<1%]). Of these, only one was isolated from a patient reporting travel in an area of endemicity, in Benin, West Africa. Acute HAV infection has been a mandatory reportable disease in France since 2006. The mandatory notification records allowed us, first, to investigate the possible sub-Saharan origin of IIA strains by determining their prevalence among French travelers returning from Africa in 2008. Second, the genetic variability of all IIA isolates identified was characterized in order to gain insight into the molecular epidemiology of the IIA subgenotype and to elucidate the origin of autochthonous IIA cases.     

Treatment of Genotype 2 and Genotype 3 Hepatitis C Virus (HCV) Infection in Human Immunodeficiency Virus Positive Patients

Approximately 25 % of persons living with the human immunodeficiency virus (HIV) are coinfected with the hepatitis C virus (HCV). In cohort studies of HIV-HCV coinfection, HCV genotypes 2 and 3 account for 15 %–64 % of disease. Compared with HCV monoinfection, liver disease is accelerated in coinfected patients, and anti-HCV treatment is less successful. This article reviews the current knowledge and recommendations for management of HCV genotype 2 and 3 infection in patients living with HIV. While pegylated interferon (PEG-IFN)/ ribavirin (RBV) remains the standard treatment for HCV genotype 2/3 infection, ongoing clinical trials with more effective therapies will soon be available. In particular, an IFN sparing regimen of sofosbuvir/RBV may become available in 2014. It is also evident that HCV genotypes 2 and 3 respond differently to therapy and should be approached differently both in practice and in clinical trials. Issues including drug-drug interactions between anti-HCV and anti-HIV therapies are addressed.     

Antigenic Relationships Among Newcastle Disease Virus Mutants Obtained from Laboratory Strains and from Recent California Isolates

The antigenic relationship between pairs of plaque mutants of Newcastle disease virus (NDV) derived from laboratory strains and from isolates from the 1971-72 California epizootic were examined by kinetic neutralization test. Comparing four sets of mutants from laboratory strains by both kinetic neutralization and hemagglutination inhibition tests, a similarity was found in the antigenic relationship expressed as an r value with both tests. However, kinetic neutralization was the more precise as well as sensitive assay. Antigenic diversity was greatest between pairs of mutants from different strains, but distinctions could also be made between mutants from the same strains such as Herts-L and Herts-S with an r value of 36%. Examination of mutants from the California epizootic isolated from separate locations and at different times showed antigenic divergence which was greatest between two red-plaque mutants with an r value of 39%. Antigenic distinctions were found between a red- and clear-plaque mutant obtained from isolates taken from brain and tracheal swabs of one infected chicken. In addition to antigenic divergence found between pairs of some mutants, two of the clear-plaque mutants reacted more avidly with antibody than did the corresponding red-plaque partner. Thus, both differences in antigenicity and avidity can be found among these NDV mutants. The antigenic variation found among these mutants is similar to that found within a serotype. This would imply that at the present NDV is a single serological type.     

乙型和丙型肝炎病毒感染的免疫学研究进展

世界范围内持续感染乙型肝炎病者（HBV）、丙型肝炎病毒（HCV）的患者已超过5亿。这两种病毒在病原学上有许多共同特点，但在病毒学特点上以及在慢性肝炎的免疫逃逸机制上均有着显著的差别。在早期天然免疫应答方面，HBV感染最初几周并不引起肝脏基因表达的改变，而HCV则会引起许多肝内基因表达改变。在特异性免疫应答方面，HBV和HCV感染后机体清除病毒的途径主要有特异性CTL细胞的杀伤作用、CD4^＋细胞的辅助作用、抗体的中和作用或杀伤作用。相对于HBV来说，HCV在成人更多引起慢性肝炎。     

当前流行的乙型流感病毒血凝素蛋白的抗原性及其基因特性

通过抗原性分析弄清了近年来连续２次乙型流感病毒在我国人群中造成流感流行，是由于乙型流感病毒株发生抗原性变异所造成。通过毒粒基因分析发现，我国人群中流行的Ｂ／Ｐａｎａｍａ／４５／９０类毒株，其ＨＡＩ区氨基酸序列比国际代表性毒株Ｂ／Ｐａｎａｍａ／４５／９０病毒在１６５位点上多一个氨基酸（天冬酰胺），乙型流感病毒流行株可能具有地区性差异。     

The Leu477 and Leu613 of ORF2-Encoded Protein Are Critical in Forming Neutralization Antigenic Epitope of Hepatitis E Virus Genotype 4

Hepatitis E virus （HEV） genotype 4 was originally identified in China. Its neutralization antigenic epitopes have not been characterized. Recently, we identified a neutralizing monoclonal antibody （mAb） IG10, which was generated following immunization of mice with p166Chn, a recombinant protein comprising 464-629 amino acids （aa） of the HEV genotype 4 capsid protein. In this study, a panel of 22 N- and/or C-terminal truncated and 6 site-directed mutated p166Chn proteins were prepared. Only those N- or C-terminal truncated proteins containing the region 477-613 aa could react with the mAb 1G10, suggesting the neutralization epitope of HEV genotype 4 is located between aa477 and aa613. However, a both N- and C-terminal truncated protein, pN477-C613, neither reacted to 1G10 nor elicited neutralizing antibodies in mice, while another both terminal truncated protein, pN472-C617, did, suggesting the flanking regions of the pN477-C613 could help to stabilize and allow presentation of the neutralization epitope to the immune system. Substituting Leu477 and/or Leu613 with the polar, uncharged threonine （Thr） caused 〉 50% reduction of the mutants＇ immunoreactivity to IG10, whereas replacement by hydrophobic phenylalanine （Phe） made little impact on the immunoreactivity, revealing functional associations between hydrophobicity of aa at positions 477 and 613 and the antigenicity of p166Chn. These data suggested Leu477 and Leu613 are critical in forming the neutralization epitope of HEV genotype 4. Cellular ＆ Molecular Immunology. 2008;5（6）：447-456.     

慢性肝炎交叉感染的临床对比分析

目的研究慢性乙型肝炎重叠甲型肝炎与乙型肝炎重叠戊型肝炎患者在临床表现、预后及病毒之间相互干扰方面的异同。方法慢性乙型肝炎重叠甲型肝炎组50例,慢性乙型肝炎重叠戊型肝炎组50例和单纯乙型肝炎组50例,其中每组各含4例肝硬化患者;对3组患者的临床表现实验室检查等进行对比分析。结果在症状、转氨酶及胆红素方面,重叠感染组均重于单纯慢性乙型肝炎组（P〈0.05或P〈0.01）。但与预后有关的一些指标,如白蛋白、凝血酶原活动度及病死率,两种重叠感染对慢性乙型肝炎的影响有所不同：甲型肝炎重叠感染似对慢性乙型肝炎影响不大,但戊型肝炎重叠感染似对慢性乙型肝炎有比较严重的不良影响。在病毒干扰方面,两种重叠感染似对乙型肝炎病毒复制均有一定抑制作用,戊型肝炎重叠感染更明显。结论甲型肝炎重叠感染对慢性乙型肝炎的症状、转氨酶、胆红素虽有一定影响,但对其预后无太大影响,对乙型肝炎病毒复制似有一定的抑制,但不如戊型肝炎明显;戊型肝炎重叠感染对慢性乙型肝炎的临床表现及其预后均有明显的影响,对乙型肝炎病毒的抑制也较强。     

Hepatitis delta virus genotypes I and III circulate associated with hepatitis B virus genotype F In Venezuela.

The genotypes of hepatitis B (HBV) and delta (HDV) viruses circulating among Venezuelan Amerindian populations, where these viruses are endemic, were determined by sequencing of PCR amplified products from HBsAg positive sera. HDV genotype I (n = 7, 6 from West Amerindians), and III (n = 5, 4 from South Amerindians), were found. Only one HDV genotype I isolate was associated with HBV genotype D, 4 HDV genotype I and 2 HDV genotype III infected individuals were co-infected with HBV genotype F. The failure to detect the South American HDV genotype III in West Amerindians might be related to the outbreak of fulminant hepatitis with high mortality rate occurred between 1979 and 1982, probably affecting more the Amerindians infected with HDV genotype III. These results suggest the circulation of HDV genotype I among Amerindians, probably introduced through European immigrations, and that this HDV genotype is able to replicate in association with HBV genotype F.     

丁型肝炎病毒在乙肝病毒感染者中分布状况及其分子生物学研究

通过对丁型肝炎病毒（ＨＤＶ）的放免法检测和巢式ＰＣＲ技术检测，在１２０例乙肝病毒感染者中，检测到１３例ＨＤＶ标记阳性（阳性率为１０．８％），５０例乙肝病毒携带者，３例抗ＨＤＶ－ＩｇＭ阳性。经对照所得乙肝患者同乙肝病毒携带者的ＨＤＶ阳性差异结果支持ＨＤＶ的存在常伴随着谷丙转氨酶（ＡＬＴ）活性上升的观点。实验结果还提示了ＨＤＶ和乙型肝炎病毒（ＨＢＶ）重叠感染易发生重症或慢性肝炎。地ＨＤＶ的检测方法进行