Human bocavirus (HBoV)

The human bocavirus (HBoV) has been recently identified by means of molecular screening techniques in respiratory tract secretions from children with acute respiratory tract disease. This virus, which belongs to the Parvoviridae family, has been detected worldwide with a 5 to 10% prevalence among children with upper or lower respiratory tract infections, essentially during the winter period. A seroepidemiological study has shown that almost all the children have antibodies to HBoV by the age of five years, and HBoV infection seems to be rare in adults. HBoV is often detected in association with other respiratory viruses. This virus has also been detected in stools, but its role in gastroenteritis has not been yet established. Virological diagnostic of HBoV infection is based on the detection of viral DNA by PCR. Viral load determination by viral DNA quantitation in respiratory tract secretions could be a tool to differentiate between symptomatic HBoV infection and virus carriage.     

Prospective study of Human Bocavirus (HBoV) infection in a pediatric university hospital in Germany 2005/2006.

BACKGROUND: Human Bocavirus (HBoV), a new species of the genus parvovirus newly detected in 2005, seems to be a worldwide distributed pathogen among children with respiratory tract infection (prevalence 2%-18%). Recently published retrospective studies and one prospective birth cohort study suggest that HBoV-primary infection occurs in infants. METHODS: Prospective single center study over one winter season (November 2005-May 2006) with hospitalized children without age restriction using PCR-based diagnostic methods. RESULTS: HBoV DNA was detected in 11 (2.8%) of 389 nasopharyngeal aspirates from symptomatic hospitalized children (median age 9.0 months; range: 3-17 months). RSV, HMPV, HCoV, and Influenza B were detected in 13.9% (n=54), 5.1% (n=20), 2.6% (n=10), and 1.8% (n=7), respectively. There was no influenza A DNA detected in any of the specimens. The clinical diagnoses were acute wheezing (bronchitis) in four patients, radiologically confirmed pneumonia in six patients (55%) and croup syndrome in one patient. In five to six patients with pneumonia, HBoV was the only pathogen detected. While no patient had to be mechanically ventilated, 73% needed oxygen supplementation. In four (36.4%) patients at least one other viral pathogen was found (plus RSV n=3; 27.3%; Norovirus n=1; 9.1%). CONCLUSION: HBoV causes severe respiratory tract infections in infants and young children. Its role as a copathogen and many other open questions has to be defined in further prospective studies.     

Characterization of the cytopathic effect in human bronchial epithelial cell after Human Bocavirus Infection (HBoV)]

OBJECTIVE: In this study, human bronchial epithelial cells were inoculated with positive sputum specimens of HBoV. After four days' infection, cytopathic effects (CPE) were observed by inverted microscopy. These viruses all cause typical cell damages such as rounded and shrivelled, fusion and fallout. These damages got quick following increased future degenerations. The other assay result of CPE within the infected cells were observed by inverted microscopy, have typical "owl's eye" plaque and above 90 percent hemadsorption within the infected cells by erythrocytes for hemadsorption technique. The typical fluorescence lump of nucleus within the infected cells was found by indirect immunofluorescence technique. CONCLUSION: Isolation and identification of HBoV could be done in the human bronchial epithelial cell, and we found some characterizing CPE in the human bronchial epithelial cell after HBoV infection. The above studies pave a way for studying pathogenicity of human bocavirus.     

利用人支气管上皮细胞系分离和培养人博卡病毒

目的 研究人博卡病毒(HBoV)在呼吸道感染中致病性及机理.方法 利用人支气管上皮细胞系进行HBoV分离及培养,通过电镜对培养细胞中HBoV的形态及感染细胞进行研究,并采用逆转录PCR(RT-PCR)方法,检测HBoV在细胞中转录产物mRNA,同时对扩增产物进行测序及分析.结果 将含有HBoV阳性痰液标本无菌接种人支气管上皮细胞系,出现2例致使细胞发生明显的病变(CPE).电镜观察在细胞质中散在六角形或圆形的病毒粒子,大小18～26 nm之间,大部分是20nm.RT-PCR扩增产物经电泳检测与预期结果相符是295 bp,扩增产物测序结果与GenBank中HBoV序列比较,核苷酸同缘性99%,氨基酸同缘性100%.结论 HBoV感染人支气管上皮细胞后能够在该细胞内增殖,并产生特征性生物学改变.本研究为今后HBoV致病性及免疫应答谱研究奠定基础.     

Complete genome sequences and phylogenetic analysis of hepatitis delta viruses isolated from nine Turkish patients

Hepatitis delta virus (HDV) is a subviral agent of hepatitis B virus (HBV), and its life cycle is dependent on HBV. It is commonly accepted that HDV has eight distinct genotypes. In this study, the complete nucleotide sequences of HDV genomes isolated from nine Turkish patients were obtained by RT-PCR using two pairs of primers that cover the entire HDV genome. PCR products were sequenced directly. The results showed that these 9 isolates were approximately 1680 base pairs in length and clustered in the genotype HDV-1 branch when phylogenetic analysis was done with the sequences together with the complete sequences of HDV genomes representing each genotype retrieved from GenBank. Analysis of a portion of the large hepatitis D antigen (L-HDAg) gene showed that sequence similarity among these Turkish isolates is between 87.4 and 97.1%, and the Turkish isolates have the most sequence similarity to HDV-1 (90.5%), while they have the least sequence similarity to HDV-3 (64.1%). Full-genome analysis indicates that the sequence similarity is between 80.7 and 95.4%, and the highest sequence similarity is 84.8% (between the Turkish isolates and HDV-1). The lowest sequence similarity is 56.4% (between the Turkish isolates and HDV-3). In conclusion, phylogenetic analysis shows that the Turkish HDV isolates belong to HDV-1.     

Plasmodium (Haemamoeba) cathemerium gene sequences for phylogenetic analysis of malaria parasites

The DNA sequence information on avian malaria parasites of the genus Plasmodium is quite limited. At present, sequences of only 6 out of 34 valid species are available. However, sequence data of avian malaria parasites are particularly important with regard to the resolution of the phylogenetic relationships of the most virulent human malaria agent, Plasmodium falciparum. The question as to whether P. falciparum originates from avian or from mammalian parasites would contribute to our understanding of its biology and would probably facilitate the interpretation of experimental results. To add to the body of molecular data, we sequenced three genes (cytochrome b, 18 SSU rRNA, caseinolytic protease C) of different organellar origin of one of the most widespread avian malaria parasites, Plasmodium (Haemamoeba) cathemerium, which once used to be an important laboratory in vivo model in human malaria research. The analysis of the new P. cathemerium sequences in direct comparison with the rodent parasite P. berghei and the four human malaria parasites by pairwise distance calculation do not suggest a closer relationship of P. cathemerium to P. falciparum than to the other species involved.     

Complete coding sequences of European brown hare syndrome virus (EBHSV) strains isolated in 1982 in Sweden

European brown hare syndrome (EBHS) is characterised by high mortality of European brown hares (Lepus europaeus) and mountain hares (Lepus timidus). European brown hare syndrome virus (EBHSV) and the closely related rabbit haemorrhagic disease virus (RHDV) comprise the genus Lagovirus, family Caliciviridae. In contrast to RHDV, which is well studied, with more than 30 complete genome sequences available, the only complete genome sequence available for EBHSV was obtained from a strain isolated in 1989 in France. EBHS was originally diagnosed in Sweden in 1980. Here, we report the complete coding sequences of two EBHSV strains isolated from European brown hares that died with liver lesions characteristic of EBHS in Sweden in 1982. These sequences represent the oldest complete coding sequences of EBHSV isolated from the original area of virus diagnosis. The genomic organisation is similar to that of the published French sequence. Comparison with this sequence revealed several nucleotide substitutions, corresponding to 6 % divergence. At the amino acid level, the Swedish strains are 2 % different from the French strain. Most amino acid substitutions were located within the major capsid protein VP60, but when considering the amino acid sequence length of each protein, VP10 is the protein with the highest percentage of amino acid differences. The same result was obtained when Swedish strains were compared. This evolutionary pattern has not been described previously for members of the genus Lagovirus.     

Complete sequences and phylogenetic analyses of a Singapore isolate of broad bean wilt fabavirus

Summary.  The complete nucleotide (nt) sequence of a Singapore isolate of broad bean wilt fabavirus from Megakepasma erythrochlamys L., designated BBWV-ME, was determined. Its bipartite genome consisted of two positive-sense single-stranded ribonucleic acids (RNA). RNA1 (5951 nt in length) encoded a putative protease cofactor, nucleotide triphosphate (NTP)-binding domain (helicase), viral genome-linked protein (VPg), protease and RNA-dependent RNA polymerase (RdRp). RNA2 (3607 nt in length) encoded a putative movement protein (MP) and coat proteins (CP). Genome organization of BBWV-ME was similar to other viruses in the Comoviridae family. Phylogenetic analyses showed that fabaviruses were more closely related to the comoviruses than the nepoviruses. Received February 23, 2000 Accepted July 18, 2000     

重症急性呼吸道感染儿童中人博卡病毒的分型检测与基因进化分析

目的 了解重症急性呼吸道感染住院儿童中人博卡病毒（HBoV）的感染状况,流行病学特征及其进化特征.方法 采用巢式PCR的方法,对来自北京儿童医院重症急性呼吸道感染住院儿童的259份鼻咽抽吸物,进行人博卡病毒（HBoV）分型检测与测序,同时进行了合并感染检测、流行病学、临床特点及基因多态性分析.结果 共检出56份人博卡病毒感染阳性标本,阳性率为21.6％,[95％ CI（16.0％～27.3％）,P＜0.0001],其中2岁以下儿童感染率较高.与其他呼吸道常见病毒的合并感染率为94.6％.HBoV阳性产物测序分析发现,人博卡病毒1型占96.4％ （54/56）,2、3型各1份.HBoV阳性株分型区（VP1/VP2）序列变异不明显.结论 人博卡病毒是儿童急性呼吸道感染常见的病原体,以I型最为常见,分型区（VP1/VP2）序列较保守.HBoV在重症急性呼吸道感染儿童中是否起到真正的致病作用还需进一步的研究.     

人博卡病毒1型的近似全基因组扩增及HBoV1-4重组分析

目的 扩增人博卡病毒1型的近似全基因组序列,分析HBoV1-4之间的基因重组关系.方法 以检出HBoV1单阳性的鼻咽抽吸物为原始标本,采用PCR的方法扩增HBoV1的5个片段并测序,Blast比对确定是HBoV1片段后用DNAMAN进行序列拼接,拼接序列与已提交的近似全基因组的HBoV1在不同编码区进行同源性分析,并构建进化树;对HBoV1-4的不同编码区进行序列比对和进化分析,揭示HBoV1-4间的基因重组.结果 得到近似全长为5287 bp的HBoV1-NC序列,同源性分析发现HBoV1-NC与重庆株进化关系最近,与广州株进化距离最远;HBoV3可能由HBoV1和HBoV4重组进化而来,HBoV4可能由HBoV2与HBoV3重组进化而来.结论 本研究成功获得近似全基因组的HBoV-NC,HBoV1-4间存在着基因重组关系.     

Complete coding sequences of cDNAs of four variants of rabbit skeletal muscle troponin T

Summary Four variants of troponin T (TnT) cDNAs have been isolated and sequenced. These cDNAs have been derived from rabbit skeletal muscle, the most widely studied source of troponin, of a 11-day-old animal. One variant (TnT-1) contains the complete coding sequence, while in three variants the coding sequences are truncated at the 5 termini. The previously published amino acid sequence differs from the present cDNA-derived sequences at three locations. At least two, possibly all, of them are probably accounted for by errors in peptide sequencing. The present results are consistent with the two types of alternative splicing of TnT genes, both being first reported on the rat gene. (1) Highly variable sequences in the amino-terminal region are accounted for by the alternative splicing of exons 4–8 in an interchangeable but not mutually exclusive manner. (2) In the carboxyl-terminal region, the alternative splicing of two exons 17 (-type) or 16 (-type) in mutually exclusive manner is consistent with the difference between all the four cDNAs, which express exon 17, and the previously published peptide sequence (derived from the adult muscle) in which exon 16 is present. This variation also corresponds to the finding in chicken skeletal muscle that the choice of exon 16 or 17 may be dependent on developmental stages. Finally, a sequence is observed corresponding to an extra exon or exons between exons 5 and 6. This sequence is shorter than that of the chicken skeletal muscle gene and is not detected in the rat skeletal muscle gene.     

Newly recognized bocaviruses (HBoV,HBoV2) in children and adults with gastrointestinal illness in the United States

BackgroundThe human bocavirus (HBoV) is a newly recognized parvovirus associated with respiratory and gastrointestinal disease. Recently, two new members of the parvovirus family have been recognized, HBoV2 and HBoV3.ObjectivesHere we investigate stool and respiratory samples for the presence of HBoV, HBoV2 and HBoV3.Study designStool samples collected from 12/1/2007 to 3/31/2008 were screened by PCR for the presence of HBoV, HBoV2, and HBoV3. Extracted DNA from respiratory specimens archived between 10/17/2005 and 3/29/2006 were screened by PCR for HBoV2 and HBoV3. Medical records for all bocavirus positive patients were reviewed.ResultsOf 479 stool samples screened, 328 (68.5%) were from adults, and 151 (31.5%) were from children. Sixteen (3.4%) patients were positive for the presence of a bocavirus, including 10 (2.1%) HBoV and 6 (1.3%) HBoV2. No HBoV3 was detected in stool samples. Frequency of HBoV and HBoV2 in stool samples from children was 3.3% and 0.7%, and from adults was 1.5% and 1.5% respectively. Clinical findings in patients with HBoV and HBoV2 in stool include diarrhea (50% and 83.3%), abdominal pain (40%, 33.3%), and cough (10%, 50%). Of 868 respiratory samples screened, none were positive for either HBoV2 or HBoV3.ConclusionsThe newly recognized parvovirus HBoV2 circulates in the United States. Patients with bocaviruses in stool have evidence of gastrointestinal illness. HBoV2 was not detected in respiratory samples. HBoV3 was not detected in either stool or respiratory samples.     

Antibodies against Structural and Nonstructural Proteins of Human Bocavirus in Human Sera

Immunofluorescence assays (IFAs) for detection of human bocavirus (HBoV) proteins (VP1, VP2, NP-1, and NS1) were developed. The VP1 IFA was the most sensitive for detection of IgG antibody and suitable for screening. IgG antibodies in convalescent-phase sera from HBoV-positive patients were detected by VP1 and VP2 IFAs. Sensitivities of NP-1 and NS1 IFAs were low.Human bocavirus (HBoV), belonging to the family Parvoviridae, subfamily Parvovirinae, and genus Bocavirus, was cloned by molecular screening of pooled human respiratory tract samples in 2005 (2). Until the identification of HBoV, human parvovirus B19 (subfamily Parvovirinae, genus Erythrovirus) had been the only known human pathogen in the family Parvoviridae (42). HBoV has been detected in patients with respiratory tract infections in many countries by PCR or real-time PCR, the rate of HBoV detection ranging from 1.5 to 19% (1, 3-5, 8, 9, 13, 14, 24, 26-28, 30, 31, 33, 35-39, 41). However, the causative role of HBoV in respiratory tract infection remains unclear. In fact, HBoV is codetected with other respiratory viruses in many cases of lower respiratory tract infection (1, 3, 8, 9, 13, 14, 20, 30, 34, 39, 41).Real-time PCR for HBoV has been used to analyze the pathophysiology of HBoV infections. High loads of HBoV in nasopharyngeal samples, mainly in the absence of other viral agents, have been found in some studies, suggesting a causative role in acute respiratory tract infections (1, 17). Another study showed that the load of HBoV in nasopharyngeal samples from patients with bronchiolitis was significantly higher than that in patients with the diagnosis of febrile seizures (34).Seroepidemiological study is also an important tool for diagnosis of and research on HBoV infection. Antibodies against HBoV in serum are raised after HBoV infection, suggesting that HBoV infection evokes a systemic immune response (11, 18, 19, 23). Recently, we developed an immunofluorescence assay (IFA) to measure titers of specific antibodies against HBoV VP1, which is one of the structural proteins of HBoV (11). HBoV encodes two structural proteins (VP1 and VP2) and two nonstructural proteins (NP-1 and NS1) (2). The recombinant structural proteins (VP1 and VP2) of B19 have been used for the detection of IgG and IgM antibodies against B19 (6, 22). More recently, the nonstructural protein (NS1) of B19 was shown to play a significant role in serodiagnosis of acute infection, thereby supplementing the role played by B19 structural proteins as diagnostic antigens (10, 12, 15). The purpose of this study was to compare the efficiencies of IFAs using individual proteins of HBoV.A baculovirus expression kit (Bac-to-Bac system) was used to prepare histidine (His)-tagged VP1, VP2, NP-1, and NS1 proteins for expression in a baculovirus-insect cell system in accordance with the instructions of the manufacturer (Invitrogen, Carlsbad, CA). The genomic DNA corresponding to VP1, VP2, NP-1, and NS1 proteins of HBoV from strain JPBS05-52 (GenBank accession numbers {"type":"entrez-nucleotide","attrs":{"text":"EF035488","term_id":"117156186","term_text":"EF035488"}}EF035488, {"type":"entrez-nucleotide","attrs":{"text":"EU984096","term_id":"199582973","term_text":"EU984096"}}EU984096, and {"type":"entrez-nucleotide","attrs":{"text":"EU984097","term_id":"199582975","term_text":"EU984097"}}EU984097) was amplified by PCR with the following primers: HBoV VP1 start (5′-ATC GTC TCG CAT GAG TAA AGA AAG TGG CAA-3′), HBoV VP2 start (5′-ATC GTC TCG CAT GTC TGA CA CTG ACA TTC A-3′), HBoV VP1 and VP2 end (5′-GCC TCG AGT TAC AAT GGG TGC ACA CGG C-3′), HBoV NP-1 start (5′-ATC GTC TCG CAT GAG CTC AGG GAA TAT GAA-3′), HBoV NP-1 end (5′-GCC TCG AGT TAA TTG GAG GCA TCT GCT T-3′), HBoV NS1 start (5′-ATC CAT GGC TTT CAA TCC TCC T-3′), and HBoV NS1 end (5′-CGC TCG AGT TAC TTA CTT GGT G-3′) (the restriction sites in the primers used for cloning are underlined). The following procedures for making baculoviruses were described previously (11). Trichoplusia ni (Tn5) cells in T25 flasks were infected with recombinant baculoviruses expressing His-tagged VP1, VP2, NP-1, and NS1 proteins of HBoV and with mock baculovirus at a multiplicity of infection of 10 virus particles per cell and were resuspended in 250 μl of phosphate-buffered saline (PBS). The procedures for Western blot analysis were described previously (11). The results of Western blot analysis are shown in Fig. ​Fig.1A.1A. The predicted molecular sizes of His-VP1, His-VP2, His-NP-1, and His-NS1 fusion proteins of HBoV were 78.1, 63.4, 29.0, and 75.0 kDa, respectively, which were consistent with the molecular sizes of these proteins determined by Western blotting using anti-six-histidine tag monoclonal antibody.Open in a separate windowFIG. 1.(A) Western blot analysis of His-VP1 (VP1), His-VP2 (VP2), His-NP-1 (NP-1), and His-NS1 (NS1) proteins of HBoV expressed by a baculovirus system, compared with negative-control protein (NC). Anti-six-histidine tag monoclonal antibody was incubated on nitrocellulose membranes. (B) Age distribution of seropositive rates for HBoV VP1 IgG (black columns), VP2 IgG (white columns), NP-1 IgG (striped columns), and NS1 IgG (gray columns). m, months; y, years. (C and D) Detection of the IgG and IgM antibodies against VP1, VP2, NP-1, and NS1 proteins of HBoV in acute-phase (A) and convalescent-phase (C) serum samples from four patients with acute HBoV infection by IFAs. White circles, black circles, white triangles, and black triangles correspond to patient numbers 1, 2, 3, and 4, respectively, in reference 11.IFAs using Tn5 cells infected with recombinant baculoviruses expressing VP1, VP2, NP-1, and NS1 proteins of HBoV were developed as described previously (11, 16). A total of 205 serum samples were randomly obtained from outpatients or inpatients (aged 0 months to 41 years) at six hospitals (see Acknowledgments) in Hokkaido Prefecture of Japan from 1998 to 2005. All samples were collected after obtaining informed consent from the patients or the parents of child patients. Titers of specific antibodies against VP1, VP2, NP-1, and NS1 proteins of HBoV in the 204 human serum samples were measured by IFAs. The serum samples were diluted 1:40 with PBS and applied individually onto slides carrying Tn5 cells infected with recombinant baculoviruses expressing VP1, VP2, NP-1, and NS1 proteins of HBoV and mock baculovirus. Serum samples that had clear fluorescence signals on slides carrying Tn5 cells infected with recombinant baculoviruses and had no fluorescence signals on slides carrying cells infected with mock baculovirus were judged to be IFA positive. The IFA-positive serum samples were then serially diluted twofold in PBS from 1:40 to 1:10,240, and titers were determined by IFAs in the same manner. The results of IFAs were checked by two reviewers (R.S. and R.E.) who were not blinded to the results from the other reviewer. If a serum sample was considered to be positive by both reviewers, the serum sample was judged to be IFA positive, and if a serum sample was considered to be negative by one or both reviewers, the serum sample was judged to be IFA negative. One serum sample that had fluorescence signals on the slide with Tn5 cells infected with mock baculovirus at a 1:40 dilution was excluded from this study. The results for the remaining 204 serum samples are summarized in Table ​Table1.1. The highest seroprevalence was observed in the IFA for HBoV VP1-specific IgG (146 of 204 samples [71.6%] were positive), with the next highest levels obtained by the IFAs for HBoV VP2-specific IgG (51 of 204 samples [25.0%] were positive), HBoV NP-1-specific IgG (46 of 204 [22.5%] were positive), and HBoV NS1-specific IgG (20 of 204 [9.8%] were positive). IgG antibodies against VP2, NP-1, and NS1 proteins of HBoV were not detected in serum samples negative for HBoV VP1-specific IgG (data not shown). When the HBoV VP1-specific IgG IFA was used as a standard, the sensitivities of HBoV VP2-specific IgG, HBoV NP-1-specific IgG, and HBoV NS1-specific IgG IFAs were 35, 32, and 14%, respectively (data not shown). The IFA titers of HBoV VP1-specific IgG ranged between 40 and 5,120, with a median titer of 160 and a geometric mean titer of 374 (Table ​(Table1).1). The differences between IFA titers of IgG antibodies against HBoV VP1 and those of IgG antibodies against the other three proteins tested (HBoV VP2, NP-1, and NS1) were statistically significant (P < 0.01 by the Kruskal-Wallis test) (Table ​(Table1).1). The age-related seropositivity rate for IgG antibodies against HBoV VP1 was higher than those for IgG antibodies against the other three proteins (HBoV VP2, NP-1, and NS1), except in the 6- to 8-month-old group (Fig. ​(Fig.1B).1B). It has been shown previously that both HBoV capsid (VP1 and VP2) proteins are derived from overlapping reading frames and that VP1 and VP2 proteins are identical except for an additional 129 amino acids on the amino terminus of the VP1 protein (2). These findings suggest that the unique portion of VP1 containing 129 amino acids may be immunodominant. Further studies are necessary to determine the epitopes recognized by human sera. Recently, it has been reported that the unique region of VP1 from B19 is immunodominant in comparison with the VP2 protein from B19 and elicits a long-lasting immune response because specific IgG antibodies were present in blood donors of all age groups (32, 43). The HBoV VP1-specific IgG IFA showed the highest seroprevalence, and HBoV VP1 protein is therefore the most suitable antigen for IFAs to study the seroepidemiology of HBoV infection. Four groups have previously described an enzyme-linked immunosorbent assay (ELISA) system using recombinant VP2-based virus-like particles (VLP) (7, 18, 23, 25). Further studies are necessary to determine which assay (IFA versus VLP-based ELISA) and which antigen (recombinant VP1 versus recombinant VP2-based VLP) are most sensitive for the detection of HBoV-specific antibodies.

TABLE 1.

Seroprevalence of IgG antibodies against HBoV proteins detected by IFAs using a baculovirus expression system

Mitochondrial DNA sequences of triatomines (Hemiptera: Reduviidae): phylogenetic relationships

The phylogenetic relationships among 18 species of Triatominae were inferred based on mitochondrial DNA (mtDNA) sequences. The species of Triatoma included 11 belonging to the infestans complex [T. infestans (Klug), T. guasayana Wygodzinsky & Abalos, T. sordida (St?l), T. platensis Neiva, T. brasiliensis Neiva, T. rubrovaria (Blanchard), T. vitticeps (St?l), T. delpontei Roma?a & Abalos, T. maculata (Erichson), T. patagonica Del Ponte, and T. matogrossensis Leite & Barbosa] and four others of the same genus but of different complexes [T. circummaculata (St?l), T. protracta (Uhler), T. dimidiata (Latreille), and T. mazzottii Usinger]. As possible outgroups we used Mepraia spinolai Mazza, Panstrongylus megistus (Burmeister), and Rhodnius prolixus St?l. We analyzed mtDNA fragments of the 12S and 16S ribosomal RNA genes from each of the 18 species, as well as of the cytochrome oxidase I (COI) gene from nine. The 12S, 16S, and COI gene sequences were analyzed individually and combined. All of the phylogenetic analyses unambiguously supported two clusters: one including T. infestans, T. platensis, and T. delpontei, and the other T. sordida and T. mutagrossensis. Inclusion of T. circummaculata into the infestans complex was confirmed, although this is in disagreement with the morphological classification. On the other hand, our analyses showed that T. dimidiata is closely related to a phylosoma complex species, T. mazzottii. This is consistent with the tentative classification previously made based on morphological characters. The issue of the monophyly of the genus Triatoma remains unresolved.     

Complete genome sequences and phylogenetic analysis of West Nile virus strains isolated from the United States,Europe, and the Middle East

The complete nucleotide sequences of eight West Nile (WN) virus strains (Egypt 1951, Romania 1996-MQ, Italy 1998-equine, New York 1999-equine, MD 2000-crow265, NJ 2000MQ5488, NY 2000-grouse3282, and NY 2000-crow3356) were determined. Phylogenetic trees were constructed from the aligned nucleotide sequences of these eight viruses along with all other previously published complete WN virus genome sequences. The phylogenetic trees revealed the presence of two genetic lineages of WN viruses. Lineage 1 WN viruses have been isolated from the northeastern United States, Europe, Israel, Africa, India, Russia, and Australia. Lineage 2 WN viruses have been isolated only in sub-Saharan Africa and Madagascar. Lineage 1 viruses can be further subdivided into three monophyletic clades.     

Complete genome sequence and phylogenetic analysis of hepatitis B virus (HBV) isolated from Mongolian patients with chronic HBV infection

Although there is a report of a high rate of hepatitis B virus (HBV) infection in Mongolia, the entire nucleotide sequence of HBV circulating among Mongolian patients has not been reported. To obtain the complete nucleotide sequence of the Mongolian HBV, viral DNA was extracted from sera of patients with HBV infection. Six Mongolian HBV strains were amplified by PCR. Complete genomic sequences were determined for two Mongolian HBV isolates, MBT181 and MMU36. The entire genome of Mongolian HBV isolates was 3,182 bp long and genetic distance between Mongolian HBV isolates was 3.2%. Precore stop codon resulting from a guanine to adenine mutation at nucleotide 1,896 was detected in MBT181 strain. Based on phylogenetic analysis, the six Mongolian isolates were classified as genotype D.     

Complete sequence and phylogenetic analysis of a porcine bocavirus strain swBoV CH437

Porcine bocavirus (PBoV), a member of genus Bocavirus, family Parvoviridae, was first identified in 2009 in Swedish swine herds suffering from postweaning multisystemic wasting syndrome. Up to date, the different species of PBoVs have been reported in different countries. Especially, the virus isolated in China was complicated. In this study, we detected a novel PBoV strain swBoV CH437 from clinical samples collected in Gansu Province, Northwest China. The complete genome of swBoV CH437 was 5,275 nucleotides (nt) in length and contains three ORFs: ORF1 encodes NS1 (2,004 nt, 667 aa), ORF3 encodes NP1 (681 nt, 226 aa), and ORF2 encodes VP1 (2,049 nt, 682 aa) and VP2 (1,641 nt, 546 aa). Sequence analysis demonstrated that the NS1 gene shared 24.2–88.6 % nucleotide sequence identity, the NP1 shared 21.3–89.9 %, less than 95 % nucleotide sequence identity with other PBoV strains. Therefore, we propose that swBoV CH437 should be classified as a novel PBoV species.