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Genotype B (genotype + b)
Kinds of Genotype B Selected AbstractsRibosomal DNA spacer genotypes of the Anopheles bancroftii group (Diptera: Culicidae) from Australia and Papua New GuineaINSECT MOLECULAR BIOLOGY, Issue 5 2001N. W. Beebe Abstract Mosquitoes of the Anopheles bancroftii group collected from Northern Australia and Papua New Guinea (PNG) were investigated for sequence variation within the ribosomal DNA ITS2. Wing fringe morphology originally used to identify members of this group was compared to genotypes identified by restriction fragment length polymorphism analysis (RFLP) and heteroduplex analysis (HDA) of the rDNA ITS2. Members of this group separated into four RFLP genotypes (A, B, C and D) with some genotypes displaying wing fringe polymorphisms. Heteroduplex analysis of the ITS2 within and between populations identified genotype A as containing two geographically separate ITS2 sequences: A1 from the Northern Territory of Australia and A2 from Queensland and the Western Province of PNG. Genotypes B and C and genotypes C and D were found sympatric and appeared to be evolving independently suggesting the possibility of cryptic species. Genotype C contained two ITS2 sequence types within the genome. [source] Clinical significance of a set of single nucleotide polymorphisms of hepatitis B virus core gene in Chinese Han patients with chronic hepatitis BJOURNAL OF MEDICAL VIROLOGY, Issue 11 2008Yirong Li Abstract To evaluate clinical significance of a set of SNPs of HBV core gene, a modified PCR-RFLP assay developed by Hannoun was adapted to determine HBV SNPs in 312 Chinese Han patients with chronic hepatitis B. Five typical RFLP patterns were found and named RFLP patterns C, D, E, G, and C/G mixture. The distribution of RFLP patterns was as follows: C, 61.5%; D, 2.6%; E, 9.6%; G, 16.7%; C/G mixture, 9.6%. The PCR amplicons of core gene were cloned into pGM-T, then colony PCR combined with RFLP and sequencing were used to confirm the presence of cleavage sites of Tsp509I and SNPs. 5 SNPs, A261T, A336C, A336T T337C and T385C, were found to be associated with RFLP patterns change and only SNP A336C or A336T caused the substitution of Glu-83 with Asp in HBcAg. The serum HBV DNA level in RFLP pattern C was higher than that in RFLP pattern G and C/G mixture, respectively, most possibly which associating with aminoacid change, Glu83Asp. The rate of elevated serum ALT levels in RFLP pattern C/G mixture was significantly lower than that in RFLP patterns C and G, respectively. The PCR amplicons of HBV S gene were sequenced and genotyped with HBV genotyping tools. It was found that RFLP patterns E and G were categorized into genotype B, RFLP pattern C showed two genotypes (B, C), and RFLP pattern D coincided with HBV genotype D, therefore, the modified PCR-RFLP can be adapted to determine HBV SNPs, not genotypes in Chinese Han patients with chronic hepatitis B. J. Med. Virol. 80:1885,1890, 2008. © 2008 Wiley-Liss, Inc. [source] Prevalence of HBV genotypes in Central and Eastern EuropeJOURNAL OF MEDICAL VIROLOGY, Issue 10 2008Katja Deterding Abstract The importance of hepatitis B virus (HBV) genotypes for disease progression and response to interferon-alpha-based treatment is well established. While almost all patients in the Mediterranean area are infected with HBV genotype D, HBV genotype A is dominant in Northern Europe. However, the distribution of HBV genotypes is unknown for several Central and Eastern European countries. Data are described of 1313 HBsAg-positive patients recruited at 14 referral centers in eight countries. There were only very few cases of HBV genotype B, C, E, F, and H infection while HBV genotypes A and D were found in 42% and 48% of patients, respectively. Eight percent of patients had positive bands for more than one genotype using the hybridization assay. The frequency of genotype A was higher in Poland (77%) and the Czech Republic (67%) as compared to Hungary (47%), Lithuania (41%), Croatia (8%), and Germany (32%). In contrast, HBV genotype D was most frequent in Croatian, Romanian, and Russian patients with 80%, 67%, and 93% of cases, respectively. In conclusion, HBV genotype A versus D showed significantly different distribution patterns in Central and Eastern Europe which deserves consideration for national guidelines and treatment decisions. J. Med. Virol. 80:1707,1711, 2008. © 2008 Wiley-Liss, Inc. [source] Role of hepatitis B virus genotypes and quantitative HBV DNA in metastasis and recurrence of hepatocellular carcinomaJOURNAL OF MEDICAL VIROLOGY, Issue 4 2008Yuehua Huang Abstract Identification of risk factors for recurrence and metastasis of HCC is important for the prognosis of HCC surveillance in chronic HBV infection. In this article, 125 HCC patients recruited were followed up prospectively for tumor metastasis and recurrence for a median of 104 (10,130) weeks. HBV DNA level was detected by LightCycler-based real-time fluorescence quantitative polymerase chain reaction-restriction system. HBV genotypes were determined by using PCR restriction-fragment length polymorphism. BCP and PC mutations were performed by PCR and direct sequencing of amplified products. Among 125 HCC patients, 19 patients were excluded because of the lack of follow-up data and the remaining 106 patients were followed up of 2 years and entered into analysis. Sixty-nine patients had tumor metastasis or recurrence during the follow-up and the cumulative probability of HCC metastasis or recurrence was 65.1%. On multivariate analysis, genotype C and HBV DNA level were the risk factors for HCC recurrence or metastasis. The incidence of recurrence or metastasis increased with baseline HBV DNA level in a dose-response relationship ranging from 22% for HBV DNA level of less than 3 log10 copies/ml to 80% for HBV DNA level of 5 log10 copies/ml or greater (P,=,0.012). Fifty-seven (74.0%) and 12 (41.4%) patients had metastasis or recurrence in patients with genotype C and B, respectively. The adjusted OR of recurrence or metastasis for genotype C compared with genotype B was 9.755 (P,=,0.009). In conclusion, elevated HBV DNA level and genotype C are strong risk predictors of HCC metastasis or recurrence. J. Med. Virol. 80:591,597, 2008. © 2008 Wiley-Liss, Inc. [source] Hepatitis B virus genotypes in children and adolescents in Japan: Before and after immunization for the prevention of mother to infant transmission of hepatitis B virusJOURNAL OF MEDICAL VIROLOGY, Issue 6 2007Ayano Inui Abstract The genotype distribution of hepatitis B virus (HBV) was investigated in 118 children in Japan. One hundred and sixteen children (98%) had chronic HBV infection, and the remainder had acute hepatitis. Genotyping of HBV was determined by PCR and sequencing analysis in the S gene. Genotype C (86%) was the most frequent, followed by genotype B (9%), D (2.5%), and A (1.0%). Transmission routes of HBV to children were from mothers in 91 patients (77%), fathers in 8 (6.5%), mother or father in 1 (1%), family members other than the parents in 5 (4%), and unknown in 13 (11.5%). The relationship between routes of HBV transmission and HBV genotypes was studied. Eighty-eight (97%) of 91 children of mother-to-infant transmission were genotype C, while 13 (49%) of 27 children of the routes other than the mother to infant transmission were genotype C. The number of children with genotype C who were infected from their mothers was significantly higher than those with genotype B, D, or A (P,<,0.01). In conclusion, HBV genotypes influence not only clinical characteristics but also the mechanisms of inter-personal HBV transmission. J. Med. Virol. 79: 670,675, 2007. © 2007 Wiley-Liss, Inc. [source] Clinical and virological characteristics of lamivudine resistance in chronic hepatitis B patients: A single center experienceJOURNAL OF MEDICAL VIROLOGY, Issue 3 2005Jian Sun Abstract We have investigated the characteristics of lamivudine-resistant strains in patients with chronic hepatitis B in Guangdong, China, where the predominant genotypes are B and C. Two hundred forty-seven patients treated with lamivudine in Nanfang Hospital were followed-up. Patients with hepatitis B e antigen (HBeAg) positive and hepatitis B virus (HBV)-DNA levels over 7.5,×,106 copies/ml at baseline had a shorter time to the selection of YMDD mutant (P,=,0.02 and 0.00, respectively). The detection of YMDD mutant precedes HBV-DNA breakthrough and alanine transaminase (ALT) flare in about 2 and 3 months, respectively. The ALT flare after the appearance of YMDD mutants was more evident in HBeAg positive patients than HBeAg negative patients (P,=,0.02). After emergence of YMDD mutant, the HBV-DNA level was significantly higher in genotype C patients compared with genotype B patients (P,=,0.02). No significant difference of YMDD mutant pattern was found between patients with genotype B and C. Four kinds of new mutants were found in over two patients including rtL80I, rtG172E, rtG174C, and rtG172E/rtG174C. In vitro transfection and real-time analysis showed that rtG172E, rtG174C, and rtG172E/rtG174C mutants had a decreased replication competence compared with wild type (33%, 27%, and 15% of the wild type HBV, respectively). Our result suggest that genotypic monitoring of YMDD mutant is important for the management of patients treated with lamivudine. J. Med. Virol. 75:391,398, 2005. © 2005 Wiley-Liss, Inc. [source] Hepatitis B virus genotypes and spontaneous hepatitis B e antigen seroconversion in Taiwanese hepatitis B carriersJOURNAL OF MEDICAL VIROLOGY, Issue 3 2004Jia-Horng Kao MD Abstract Hepatitis B virus (HBV) is classified into eight genotypes (A,H), and genotype C is associated with more aggressive liver disease compared to genotype B. However, the mechanisms responsible for the clinical differences remain unclear. To test whether genotype C patients had with lower rates of spontaneous hepatitis B ge antigen (HBeAg) seroconversion than genotype B patients, stored serum samples from 146 Taiwanese adult HBeAg-positive hepatitis B carriers followed-up for a mean of 52 months (range, 12,120 months) were tested for HBV genotype by a molecular method. Genotype C patients were significantly older than genotype B patients (mean age, 37,±,12 vs. 29,±,10 years, P,<,0.001). During the follow-up period, genotype C patients had a significantly lower rate of spontaneous HBeAg seroconversion than genotype B patients (27 vs. 47%, P,<,0.025). Spontaneous HBeAg seroconversion occurred one decade later in genotype C patients compared with genotype B patients. Multivariate analyses identified age ,35 years (odds ratio: 2.08; 95% confidence interval [CI], 1.07,4.0; P,<,0.05), high baseline serum alanine aminotransferase level (odds ratio: 2.34; 95%CI, 1.39,4.09; P,<,0.005), and HBV genotype B (odds ratio: 1.94; 95%CI, 1.03,3.63; P,<,0.05) as independent factors associated with spontaneous HBeAg seroconversion. In conclusion, genotype C patients, compared to genotype B patients, have a delayed HBeAg seroconversion in the immune clearance phase of chronic HBV infection, which may contribute to a more progressive liver disease and more refractory to antiviral therapy. J. Med. Virol. 72:363,369, 2004. © 2004 Wiley-Liss, Inc. [source] Difference in prognosis between patients infected with hepatitis B virus with genotype B and those with genotype C in the Okinawa Islands: A prospective studyJOURNAL OF MEDICAL VIROLOGY, Issue 3 2003Tomokuni Nakayoshi Abstract The factors contributing to the prognosis of hepatitis B virus (HBV)- related chronic liver disease were assessed prospectively in 72 patients with chronic hepatitis B confirmed clinically and pathologically. A comparative study was undertaken between patients infected with genotype B and those with genotype C. During the follow-up period, 13 (81.3%) of 16 patients with genotype B who were initially hepatitis B e antigen (HBeAg) positive became HBeAg negative and 14 (51.9%) of 27 with genotype C became HBeAg negative. HBeAg had been cleared in 8 (61.5%) of 13 patients with genotype B within the first 2 years of the follow-up, but in only one (7.1%) of 14 with genotype C (P,<,0.05). Four (11.4%) of 35 patients with genotype B had progressed to cirrhosis, whereas, 12 (32.4%) of 37 patients with genotype C progressed to cirrhosis, including two patients with hepatocellular carcinoma. Multivariate analysis showed that difference in HBV genotype influenced significantly either the clearance of HBeAg or the development of cirrhosis. In conclusion, HBeAg was cleared from sera more frequently and earlier in patients with genotype B compared with those with genotype C, and development of cirrhosis occurred less frequently in patients with genotype B compared with those with genotype C. Thus, HBV genotypes may influence the prognosis of HBV-related chronic liver disease. J. Med. Virol. 70:350,354, 2003. © 2003 Wiley-Liss, Inc. [source] Prevalence of hepatitis B virus DNA polymerase mutations in treatment-naïve patients with chronic hepatitis BALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 11-12 2009M. H. NGUYEN Summary Background, One of the most important factors in treatment failure using nucleos(t)ide analogues in chronic hepatitis B is anti-viral resistance. Primary drug resistance refers to amino acid changes in the hepatitis B virus polymerase/reverse transcriptase (rt) that result in reduced susceptibility to anti-viral agents. Pre-existing drug resistance mutations may occur in untreated patients and may affect their treatment outcomes. Aim, To determine the prevalence of hepatitis B DNA polymerase mutations in treatment-naïve patients. Methods, We used a direct PCR sequencing test to detect DNA polymerase mutations in 472 consecutive treatment-naïve patients at two community gastroenterology clinics in Northern California. Results, A majority of patients were Asians (>95%), had either genotype B or C (95%) and had no evidence of cirrhosis or liver cancer (94%). Mean age was 45 ± 13 and mean hepatitis B virus DNA was 5.3 ± 1.8 log10 IU/mL. Most patients did not have any detectable mutations (82.4%). Some (16.7%) had mutations of unknown clinical significance (rtV207M/L/I) and only 4 patients had rtA181A/S, rtA194S or M250I. Conclusions, No rtM204V/I or rtN236T mutations were observed in our study. Less than 1% of our patients had mutations that can be associated with primary resistance to existing anti-viral therapies for hepatitis B virus. [source] Differences of YMDD mutational patterns, precore/core promoter mutations, serum HBV DNA levels in lamivudine-resistant hepatitis B genotypes B and CJOURNAL OF VIRAL HEPATITIS, Issue 11 2007X. P. Pan Summary., The aims of this study were to investigate the viral differences among lamivudine-resistant hepatitis B virus (HBV) genotypes B and C in vivo. Fifty-three patients carrying lamivudine-resistant HBV were enrolled in this study. HBV genotypes, Levels of alanine aminotransferase (ALT), HBV DNA levels were monitored during therapy. The polymerase and precore/core promoter genes were amplified by polymerase chain reaction and their products were sequenced directly. Among 53 patients resistant HBV genotypes B and C accounted for 41.50% and 58.50%, respectively. The occurrence of reverse transcriptase rt204I mutants was lower in genotype B (36.36%) than that in genotype C (87.10%), whereas rt204V mutants was higher in genotype B (63.64%) than that in genotype C (12.90%). The occurrence of precore mutation (nt1896A) was higher in genotype B (77.27%) than that in genotype C (32.26%). Serum HBV DNA levels after emergence of lamivudine resistance were higher in genotype C (7.71 ± 0.80 Log copies/mL) compared with genotype B (6.97 ± 0.77 Log copies/mL). Multivariate analysis identified pretreatment HBV DNA levels, HBeAg status and HBV genotype as independent factors associated with a shorter time to lamivudine resistance(P = 0.035, P = 0.006 and P = 0.001, respectively). Multivariate analysis showed that HBV genotype (P = 0.004) and pretreatment ALT levels (P = 0.01) was independently associated with YMDD mutational patterns. The results showed that the YMDD mutational patterns, precore mutation and serum HBV DNA levels differ between lamivudine-resistant HBV genotypes B and C in vivo. It is valuable for treatment of lamivudine-resistant HBV in clinic. [source] Clinical significance and evolution of core promoter and precore mutations in HBeAg-positive patients with HBV genotype B and C: a longitudinal studyLIVER INTERNATIONAL, Issue 6 2007Chien-Hung Chen Abstract Background/Aims: The aims of this longitudinal study were to investigate whether the clinical outcome and evolution of core promoter and precore mutations were different during hepatitis B e antigen (HBeAg) seroconversion between hepatitis B virus (HBV) genotypes B and C in HBeAg-positive patients with chronic hepatitis B. Patients and Methods: The core promoter and precore sequences were determined from serial sera of 156 HBeAg-positive patients with chronic HBV infection. Results: In HBV genotype C, the T1762/A1764 mutant was detected earlier than the A1896 mutant, and the frequency was significantly higher than in HBV genotype Ba over the entire follow-up period. In HBV genotype Ba, A1896 was found earlier than the T1762/A1764 mutant, and the frequency was significantly higher than in genotype C only before HBeAg seroconversion, and the A1896 mutant played an important role in HBeAg seroconversion in HBV genotype Ba. In addition, the T1846 variant was an independent factor associated with HBeAg seroconversion. Furthermore, HBV genotype C was associated with the development of G or C1753 and T1766/A1768 mutations, and the reactivation of hepatitis after HBeAg seroconversion. Based on Cox's regression analysis, the significant risk factors of liver cirrhosis were older age at entry [hazard ratio (HR)=1.085, 95% confidence interval (CI)=1.036,1.136, P=0.001], alanine transaminase (ALT) >80 U/l (HR=3.48, 95% CI=1.37,8.86, P=0.009), and the T1762/A1764 mutant (HR=5.54, 95% CI=2.18,14.08, P<0.001). Conclusions: Our study showed that different HBV genotypes were associated with various mutations in the core promoter and precore regions during HBeAg seroconversion. T1762/A1764 mutation could be useful in predicting clinical outcomes in HBeAg-positive patients with HBV infection. [source] Isolation of Exophiala dermatitidis from endotracheal aspirate of a cancer patientMYCOSES, Issue 6 2006S. J. Taj-Aldeen Summary Exophiala (Wangiella) dermatitidis is a melanised (darkly pigmented) yeast-like organism that has been reported from the environment and wild animals. The organism is a frequent coloniser of lungs of patients with cystic fibrosis and causes occasional disseminated phaeohyphomycosis and fungaemia. Exophiala dermatitidis is distributed worldwide, but cerebral cases are restricted to East Asia. We report a case of 54-year-old Qatari female patient with a known history of cancer, suffering from pulmonary disorder. Culture of endotracheal aspirate revealed the growth of E. dermatitidis concomitant with Candida krusei. The final diagnosis of E. dermatitidis and attribution to genotype B was achieved by sequencing the rDNA internal transcribed spacer (ITS) region. The present case concerns a pulmonary colonisation by E. dermatitidis, similar to that commonly seen in cystic fibrosis patients. For the detection of E. dermatitidis in clinical specimens culturing techniques are required. The patient finally expired with persistent cancer and C. krusei fungaemia. Review of literature and listing of E. dermatitidis cases published after 1992 show a sharp increase in clinical cases during the 1990s. [source] Genotype distribution of Candida albicans isolates by 25S intron analysis with regard to invasivenessMYCOSES, Issue 11-12 2004Z. C. Karahan Candida albicans; Genotyp; Invasivität Summary The aim of this study was to genotype Candida albicans strains isolated from patients with invasive and non-invasive deep-seated infections. For this purpose, 301 C. albicans isolates (81 invasive and 220 non-invasive) were genotyped by using specific PCR primers designed to span the transposable group I intron of the 25S rDNA gene. Fifty-three of the 81 invasive isolates were genotype A (65.4%), eight were genotype B (9.9%) and 20 were genotype C (24.7%), while 98 of the 220 non-invasive isolates were genotype A (44.6%), 46 were genotype B (20.9%) and 76 were genotype C (34.5%). Genotype A was more prevalent among invasive isolates and genotypes B and C were more prevalent among non-invasive isolates (P = 0.0046). Genotypes D and E which represent C. dubliniensis were not found. These results indicate that there may be a relationship between C. albicans genotypes and invasiveness; genotype A being more invasive than others. The presence or absence of the transposable group I intron in the 25S rDNA gene may be important in determining the invasiveness of C. albicans. Zusammenfassung Ziel dieser Arbeit war, Candida albicans -Isolate von Patienten mit invasiven und nicht-invasiven Läsionen zu genotypisieren. Es wurden 301 Isolate (81 invasive und 220 nicht-invasive) untersucht. Die Genotypisierung wurde mittels eines spezifischen PCR Primers, der das Group I-Intron des 25S rDNA Gens umfasst, durchgeführt. 53 der invasiven Isolate waren Genotyp A (65,4%), 8 Genotyp B (9,9%), und 20 Genotyp C (24,7%); anderseits waren 98 der nicht-invasiven Isolate Genotyp A (44,6%), 46 Genotyp B (20,9%), und 76 Genotyp C (34,5%). Genotyp A überwog unter invasiven Isolaten, während die Genotypen B und C unter nicht-invasiven Isolaten vorherrschten (P = 0.0046). Die Genotypen D und E, die Candida dubliniensis umfassen, wurden nicht gefunden. Diese Ergebnisse zeigen, dass es eine Beziehung zwischen C. albicans -Genotypen und Invasivität gibt und dass Genotyp A invasiver ist als andere. Das Group I-Intron des 25S rDNA Gens scheint für die Invasivitätsabschätzung bei C. albicans brauchbar zu sein. [source] Characterization of Genotypes of Enterocytozoon bieneusi in Immunosuppressed and Immunocompetent Patient GroupsTHE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 4 2009ROBERT J. TEN HOVE ABSTRACT. A retrospective phylogenetic analysis was performed on isolates of Enterocytozoon bieneusi to characterize the genotypes in different patient cohorts. Fifty-seven isolates, collected from patients living in Malawi and the Netherlands, were classified by age and immune status of the hosts. Sequence analysis of the internal transcribed spacer (ITS) region identified 16 genotypes; nine have not previously been described. Genotypes K and D were most prevalent among patient groups, whereas genotype C was restricted to transplantation patients receiving immunosupressives and genotype B showed a predisposition toward patients living with HIV/AIDS. Different genotypes showed more dispersion among isolates from Malawi compared with those from the Netherlands. A constructed map estimating the genealogy of the ITS region reveals a dynamic evolutionary process between the genotypes. [source] Hepatitis B virus genotypes and HBsAg subtypes in refugees and injection drug users in the United States determined by LiPA and monoclonal EIAJOURNAL OF MEDICAL VIROLOGY, Issue 3 2001Paul D. Swenson Abstract Hepatitis B virus (HBV) genotyping and hepatitis B surface antigen (HBsAg) subtyping were carried out on sera from 196 HBsAg-positive patients, including 151 refugees entering the United States and 45 injection drug users in Seattle. HBsAg subtyping was performed by enzyme immunoassay (EIA) using a panel of monoclonal antibodies and the HBV genotype was determined by polymerase chain reaction (PCR) followed by detection of amplified HBV DNA by a reverse-phase hybridization line probe assay (LiPA) using genotype-specific probes. HBV DNA was detected by PCR in 155 (79%) of the 196 sera and all 155 were genotyped by LiPA. Samples from Southeast Asia were predominantly genotype B/subtype ayw1 and genotype C/adr; samples from the former Soviet Union and eastern Europe were mostly genotype D/ayw2 and genotype D/ayw3; samples from east Africa were mainly genotype A/adw2 and genotype D/ayw2; and samples from injection drug users were mostly genotype D/ayw3 and genotype A/adw2. Some strains of ayw3 gave atypical monoclonal antibody reactivity patterns in the subtyping assay due to a Val/Ala instead of a Thr at amino acid residue 118 and a Thr instead of a Met at residue 125. A strain of ayw2 also gave an atypical monoclonal antibody reactivity pattern due to an Ala instead of a Thr at amino acid residue 123. LiPA genotyping and monoclonal EIA subtyping can provide useful information for epidemiological studies. J. Med. Virol. 64:305,311, 2001. © 2001 Wiley-Liss, Inc. [source] Molecular evolutionary analysis and mutational pattern of full-length genomes of hepatitis B virus isolated from Belgian patients with different clinical manifestationsJOURNAL OF MEDICAL VIROLOGY, Issue 3 2010Mahmoud Reza Pourkarim Abstract Molecular evolutionary patterns of 62 HBV full-length genomes obtained from Belgian patients were characterized. Phylogenetic analysis revealed diverse HBV subgenotypes including A2 and A6 (46.8%), D1,D4 (38.8%), E (9.7%), C1 (1.6%), and B2 (1.6%). The study population consisted of patients with different ethnic origin (Caucasian, Turkish, Asian, Arab, and African). One HBV D/C recombinant isolate was identified, which encoded subtype adw2. An HBV subgenotype D4 with an aberrant subtype ayw4 was detected. Although none of the genotypes was associated with a specific disease outcome, several nucleotide substitutions, deletions and insertions were observed within the HBV preS1/S and X genes, particularly among patients with active chronic hepatitis B infection and patients with cirrhosis. Within the immunological domain of the HBsAg gene, the most frequent substitutions were sT125M and sT118A. High rates of precore and basal core promoter mutations were detected in patients infected with genotype D of HBV. Almost half of the patients who received lamivudine therapy for at least 1 year had HBV variants associated with lamivudine drug resistance. In conclusion, the most common HBV genotypes in West Europe (A and D) also prevail in Belgium. The highest degree of genetic diversity was detected in HBV genotype D. In addition, this study reveals the circulation of exotic HBV genotypes B, C, and E in Belgium. J. Med. Virol. 82:379,389, 2010. © 2010 Wiley-Liss, Inc. [source] Prediction of response to treatment of chronic hepatitis B with pegylated interferon in the PhilippinesJOURNAL OF MEDICAL VIROLOGY, Issue 2 2010Dorothy M. Agdamag Abstract The response marker for interferon has not been investigated fully for hepatitis B viruses (HBVs) in the Philippines where novel subtypes B5 and C5 were recognized recently. The prediction parameters for interferon treatment were assessed, with emphasis on the mutation patterns in the basal core promoter and precore regions in patients with chronic hepatitis B. Seventeen HBeAg-positive patients were stratified according to response to treatment with pegylated interferon based on HBe seroconversion and HBV load. Intra-patient distributions of wild-type strains (A1762, G1764) and variants (T1762, A1764) were analyzed using HBV-DNA amplification and subsequent molecular cloning. The rate of variants (T1762, A1764) harbored by a patient was higher among responders (41.2% and 31% per person on average) than among non-responders (2.4% and 2.4%) to treatment with pegylated interferon at the baseline, respectively (P,<,0.05). The rate of variants (T1762, A1764) harbored by responders (41.2% and 31%) decreased to 1.7% and 1.7%, and wild-type strains (A1762, G1764) conversely became majority (98.3% and 98.3%) after treatment with pegylated interferon, respectively. HBV strains harbored by two of six responders and a patient with lower baseline load (1.0,×,104,copies/ml) showed genotype shift from A to other genotypes, where genotype A disappeared preferentially after the loss of HBeAg and genotypes B and C formed a major population. These results suggest that the HBV variants (T1762, A1764) and HBV genotype A in the Philippines have an advantage in the response to pegylated interferon. These results warrant a large-scale examination for further precise prediction of the response to treatment with interferon. J. Med. Virol. 82:213,219, 2010. © 2009 Wiley-Liss, Inc. [source] Genetic characteristics of hepatitis B virus genotypes as a factor for interferon-induced HBeAg clearanceJOURNAL OF MEDICAL VIROLOGY, Issue 8 2007Jinlin Hou Abstract The factors determining the responsiveness of different hepatitis B virus (HBV) genotypes to interferon treatment are not fully understood. We investigated the relationship between HBV genetic characteristics and the outcome of short (16 weeks) or prolonged (32 weeks) treatment with standard interferon-alpha in a prospectively followed cohort of 103 patients across Europe with HBeAg positive chronic hepatitis B. INNO-LiPA assays and HBV DNA sequencing were used to determine HBV genotypes, mutations in the core promoter and precore/core regions. After 16-weeks interferon-alpha treatment, the rate of HBeAg clearance was higher in genotype A versus all other genotypes (P,=,0.014), or genotype D alone (P,=,0.05). The HBV genome analysis revealed that: (i) after 16-weeks treatment, an HBV subpopulation with core promoter mutations emerged or increased (P,<,0.001) only in genotype A; (ii) the core gene of genotype A has the lowest number of amino acid variations in comparison with genotypes B, C, or D. Logistic regression analysis identified genotype A as a positive predictor of short (16 weeks) treatment response (P,=,0.001; odds ratio 6.19, 95 confidence interval 1.94,19.8), having a greater impact than baseline HBV DNA or alanine aminotransferase (ALT) levels. In contrast, the response to prolonged interferon-alpha treatment was not different between HBV genotypes. These results suggest that HBV genotype A responds earlier to interferon treatment than other genotypes, which is associated with its molecular characteristics. The optimal duration of interferon-based therapies in chronic hepatitis B may vary between different HBV genotypes. J. Med. Virol. 79: 1055,1063, 2007. © 2007 Wiley-Liss, Inc. [source] Differences of YMDD mutational patterns, precore/core promoter mutations, serum HBV DNA levels in lamivudine-resistant hepatitis B genotypes B and CJOURNAL OF VIRAL HEPATITIS, Issue 11 2007X. P. Pan Summary., The aims of this study were to investigate the viral differences among lamivudine-resistant hepatitis B virus (HBV) genotypes B and C in vivo. Fifty-three patients carrying lamivudine-resistant HBV were enrolled in this study. HBV genotypes, Levels of alanine aminotransferase (ALT), HBV DNA levels were monitored during therapy. The polymerase and precore/core promoter genes were amplified by polymerase chain reaction and their products were sequenced directly. Among 53 patients resistant HBV genotypes B and C accounted for 41.50% and 58.50%, respectively. The occurrence of reverse transcriptase rt204I mutants was lower in genotype B (36.36%) than that in genotype C (87.10%), whereas rt204V mutants was higher in genotype B (63.64%) than that in genotype C (12.90%). The occurrence of precore mutation (nt1896A) was higher in genotype B (77.27%) than that in genotype C (32.26%). Serum HBV DNA levels after emergence of lamivudine resistance were higher in genotype C (7.71 ± 0.80 Log copies/mL) compared with genotype B (6.97 ± 0.77 Log copies/mL). Multivariate analysis identified pretreatment HBV DNA levels, HBeAg status and HBV genotype as independent factors associated with a shorter time to lamivudine resistance(P = 0.035, P = 0.006 and P = 0.001, respectively). Multivariate analysis showed that HBV genotype (P = 0.004) and pretreatment ALT levels (P = 0.01) was independently associated with YMDD mutational patterns. The results showed that the YMDD mutational patterns, precore mutation and serum HBV DNA levels differ between lamivudine-resistant HBV genotypes B and C in vivo. It is valuable for treatment of lamivudine-resistant HBV in clinic. [source] Molecular and serological characterization of hepatitis B virus in deferred Ghanaian blood donors with and without elevated alanine aminotransferaseJOURNAL OF VIRAL HEPATITIS, Issue 11 2006D. Candotti Summary., Candidate blood donors in Ghana are frequent carriers of hepatitis B virus (HBV). A comparative study of 117 donor samples including 46 with alanine aminotransferase (ALT) , 60 IU/L and 71 with ,40 IU/L level was undertaken. S and the basic core promoter-precore regions (BCP/PC) sequencing was used to identify genotypes and variants relevant to HBV natural history, respectively. Age, viral load, HBe status were correlated with molecular data. HBV genotype E (87%) was dominant with little genotypes A (10%) and D (3%). Comparing individuals with or without liver disease, an association between liver disease and older age (P = 0.004) and higher viral load (P = 0.002) whether as a whole population or only genotype E was found. Compared with a commercial assay, BCP/PC sequencing had lower sensitivity to detect mixtures of wild-type and variant viruses but detected BCP deletions. BCP 1762/1764 variants were positively correlated with older age (P < 0.0001) and elevated ALT levels (P = 0.01). PC 1896 stop codon was marginally correlated with viral load (P = 0.09). HBV genotype E infection natural history appears different from genotypes B and C prevalent in Asia. Donors with liver disease being older, with higher viral load and higher BCP variant proportion may be at higher risk of cirrhosis and hepatocellular carcinoma [source] Clinical significance and evolution of core promoter and precore mutations in HBeAg-positive patients with HBV genotype B and C: a longitudinal studyLIVER INTERNATIONAL, Issue 6 2007Chien-Hung Chen Abstract Background/Aims: The aims of this longitudinal study were to investigate whether the clinical outcome and evolution of core promoter and precore mutations were different during hepatitis B e antigen (HBeAg) seroconversion between hepatitis B virus (HBV) genotypes B and C in HBeAg-positive patients with chronic hepatitis B. Patients and Methods: The core promoter and precore sequences were determined from serial sera of 156 HBeAg-positive patients with chronic HBV infection. Results: In HBV genotype C, the T1762/A1764 mutant was detected earlier than the A1896 mutant, and the frequency was significantly higher than in HBV genotype Ba over the entire follow-up period. In HBV genotype Ba, A1896 was found earlier than the T1762/A1764 mutant, and the frequency was significantly higher than in genotype C only before HBeAg seroconversion, and the A1896 mutant played an important role in HBeAg seroconversion in HBV genotype Ba. In addition, the T1846 variant was an independent factor associated with HBeAg seroconversion. Furthermore, HBV genotype C was associated with the development of G or C1753 and T1766/A1768 mutations, and the reactivation of hepatitis after HBeAg seroconversion. Based on Cox's regression analysis, the significant risk factors of liver cirrhosis were older age at entry [hazard ratio (HR)=1.085, 95% confidence interval (CI)=1.036,1.136, P=0.001], alanine transaminase (ALT) >80 U/l (HR=3.48, 95% CI=1.37,8.86, P=0.009), and the T1762/A1764 mutant (HR=5.54, 95% CI=2.18,14.08, P<0.001). Conclusions: Our study showed that different HBV genotypes were associated with various mutations in the core promoter and precore regions during HBeAg seroconversion. T1762/A1764 mutation could be useful in predicting clinical outcomes in HBeAg-positive patients with HBV infection. [source] Genotype distribution of Candida albicans isolates by 25S intron analysis with regard to invasivenessMYCOSES, Issue 11-12 2004Z. C. Karahan Candida albicans; Genotyp; Invasivität Summary The aim of this study was to genotype Candida albicans strains isolated from patients with invasive and non-invasive deep-seated infections. For this purpose, 301 C. albicans isolates (81 invasive and 220 non-invasive) were genotyped by using specific PCR primers designed to span the transposable group I intron of the 25S rDNA gene. Fifty-three of the 81 invasive isolates were genotype A (65.4%), eight were genotype B (9.9%) and 20 were genotype C (24.7%), while 98 of the 220 non-invasive isolates were genotype A (44.6%), 46 were genotype B (20.9%) and 76 were genotype C (34.5%). Genotype A was more prevalent among invasive isolates and genotypes B and C were more prevalent among non-invasive isolates (P = 0.0046). Genotypes D and E which represent C. dubliniensis were not found. These results indicate that there may be a relationship between C. albicans genotypes and invasiveness; genotype A being more invasive than others. The presence or absence of the transposable group I intron in the 25S rDNA gene may be important in determining the invasiveness of C. albicans. Zusammenfassung Ziel dieser Arbeit war, Candida albicans -Isolate von Patienten mit invasiven und nicht-invasiven Läsionen zu genotypisieren. Es wurden 301 Isolate (81 invasive und 220 nicht-invasive) untersucht. Die Genotypisierung wurde mittels eines spezifischen PCR Primers, der das Group I-Intron des 25S rDNA Gens umfasst, durchgeführt. 53 der invasiven Isolate waren Genotyp A (65,4%), 8 Genotyp B (9,9%), und 20 Genotyp C (24,7%); anderseits waren 98 der nicht-invasiven Isolate Genotyp A (44,6%), 46 Genotyp B (20,9%), und 76 Genotyp C (34,5%). Genotyp A überwog unter invasiven Isolaten, während die Genotypen B und C unter nicht-invasiven Isolaten vorherrschten (P = 0.0046). Die Genotypen D und E, die Candida dubliniensis umfassen, wurden nicht gefunden. Diese Ergebnisse zeigen, dass es eine Beziehung zwischen C. albicans -Genotypen und Invasivität gibt und dass Genotyp A invasiver ist als andere. Das Group I-Intron des 25S rDNA Gens scheint für die Invasivitätsabschätzung bei C. albicans brauchbar zu sein. [source] | |||||||||||||