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Genotype C (genotype + c)
Kinds of Genotype C Selected AbstractsImpact of the hepatitis B virus genotype and genotype mixtures on the course of liver disease in Vietnam,HEPATOLOGY, Issue 6 2006Nguyen L. Toan Eight genotypes (A-H) of hepatitis B virus (HBV) have been identified. However, the impact of different genotypes on the clinical course of hepatitis B infection remains controversial. We investigated the frequency and clinical outcome of HBV genotypes and genotype mixtures in HBV-infected patients from Vietnam, Europe, and Africa. In addition, we analyzed the effects of genotype mixtures on alterations in in vitro viral replication. In Asian patients, seven genotypes (A-G) were detected, with A, C, and D predominating. In European and African patients, only genotypes A, C, D, and G were identified. Genotype mixtures were more frequently encountered in African than in Asian (P = .01) and European patients (P = .06). In Asian patients, the predominant genotype mixtures included A/C and C/D, compared to C/D in European and A/D in African patients. Genotype A was more frequent in asymptomatic compared with symptomatic patients (P < .0001). Genotype C was more frequent in patients with hepatocellular carcinoma (HCC; P = .02). Genotype mixtures were more frequently encountered in patients with chronic hepatitis in comparison to patients with acute hepatitis B (P = .015), liver cirrhosis (P = .013), and HCC (P = .002). Viral loads in patients infected with genotype mixtures were significantly higher in comparison to patients with a single genotype (P = .019). Genotype mixtures were also associated with increased in vitro HBV replication. In conclusion, infection with mixtures of HBV genotypes is frequent in Asia, Africa, and Europe. Differences in the replication-phenotype of single genotypes compared to genotype-mixtures suggest that co-infection with different HBV-genotypes is associated with altered pathogenesis and clinical outcome. (HEPATOLOGY 2006;43:1375,1384.) [source] Ribosomal 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] 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] Replication efficiency and sequence analysis of full-length hepatitis B virus isolates from hepatocellular carcinoma tissuesINTERNATIONAL JOURNAL OF CANCER, Issue 5 2002Xu Lin Abstract Prolonged replication of hepatitis B virus (HBV) in liver tissues of hepatitis B patients has been considered as an important risk factor for the development of malignancy. Few studies on full-length HBV sequencing in association with the replication efficiency of isolates from HCC tissues have been reported. To study the structural and functional genomics of HBV isolates from Chinese hepatocellular carcinoma (HCC) patients, full-length HBV genomes were amplified from 6 HBV-marker positive HCC tissues and used to transfect HepG2 cells. Five of 6 isolates showed high replicative efficiency. All isolates were of genotype C and "hot-spots" mutations were detected in the B cell and T helper (Th) cell epitopes of the envelope and the core region. In addition, the X region of 2 isolates contained a stop-codon mutation that was predicted to result in a truncated X protein. High replicative HBV immune escape mutants that persist in infected hepatocytes could be 1 of the important factors to initiate pathological processes for the development of HCC in Chinese patients. © 2002 Wiley-Liss, Inc. [source] Characterization of hepatitis B virus reverse transcriptase sequences in Chinese treatment naive patientsJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 8 2009Yue Han Abstract Background and Aims:, The hepatitis B virus (HBV) reverse transcriptase (RT) plays an important role in viral replication. The aim of the present study was to characterize profiles of the RT region and to construct a database for further studies. Methods:, Serum samples were obtained from 328 treatment naive patients chronically infected with HBV in five Chinese cities. Mutation status, genotypes and deep sequence analysis were carried out by amplifying and sequencing the RT region. Results:, The base usage in the RT region differed at the mono- and dinucleotide level and thymidine dominated. The higher the variability of the strain was, the more it replicated. No significant clustering was found between our HBV RT sequences and those isolated 10 years ago (achieved from genebank). Nucleotide analogue resistance related mutants exist. The M204V/I mutation was found in 1.8% of the strains, 1.2% had L180M+ M204V/I, 0.6% had A181T/V, and only one had all three mutations. Minor strain mutants were found in 9.3% of the samples studied. The genotype B patients made up 36.6% (88.7% B2) and were mostly found in southern China, 63.4% (92.2% C2) were genotype C, and only one was genotype D. The average age of HBeAg positive genotype B patients was 29.5 ± 10.4 years, for genotype C it was 36.1 ± 10.9 (P < 0.001). Conclusion:, Primarily antiviral resistance related mutant strains do exist in treatment naïve patients. Without antiviral pressure, HBV strains evolved at a normal speed. In depth sequence analysis implied that viral replication might be correlated with its variability, which needs to be further investigated. [source] A serological and molecular survey of hepatitis B in children 15 years after inception of the national hepatitis B vaccination program in eastern China,JOURNAL OF MEDICAL VIROLOGY, Issue 9 2009Ying Dong Abstract The emergence of mutations in the hepatitis B virus (HBV) S gene has threatened the long-term success of vaccination programs since the worldwide introduction of effective vaccines against hepatitis B. This study was conducted on 5,407 children (0,8 years old) in eastern China in 2007. We analyzed the prevalence of HBsAg, anti-HBs, and "a"-determinant mutations in the HBV S gene by microparticle enzyme immunoassays, PCR, and DNASTAR software. The total HBsAg prevalence was 1.52% (82/5,407) in the children and increased with age. In contrast, the positive rate (65.42%, 2,374/3,629) and the titers of anti-HBs decreased with age. The predominant infection was HBV of genotype C and serotype adr (45/51; 88% of cases). Mutations of I126T, amino acid 137 (nt553T deletion mutation), G145A, G145R, and F158S were found in the children; the mutations of amino acid 137 and F158S have not been reported previously. The total prevalence of mutant strains was 14% (7/51). To investigate whether the infection resulted from maternal transmission, we compared the S gene sequences in 16 mother,child pairs. Fourteen mother,child pairs exhibited the same HBV genotype, with 99.5,100% sequence homology in the S gene, while two pairs exhibited different genotypes. This study suggested that the hepatitis B vaccination strategies in eastern China have been successful. Although the emergence of "a"-determinant mutations in the HBV S gene have resulted in HBV infection in immunized children, this does not pose a threat to the vaccination strategies. The HBV-infected children had contracted the infection via vertical transmission. J. Med. Virol. 81:1517,1524, 2009. © 2009 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] Analysis of hepatitis B virus quasispecies distribution in a Korean chronic patient based on the full genome sequences,JOURNAL OF MEDICAL VIROLOGY, Issue 3 2007Hong Kim Abstract Although Korea is a hepatitis B virus (HBV) endemic area, relatively few full-length genome sequences are available. In particular, no comparative analysis has been performed on the full-genome sequences of different HBV quasispecies from a single Korean patient. This report describes the full-length sequences of five HBV clones (two clones with shorter PCR amplicons and three clones with longer amplicons). Large deletions, that is, 685-bp, 487-bp, and 144-bp, that might interfere with the production of normal proteins were observed in four of five clones. Double mutations in the basal core promoter (BCP) region (T1762/A1764) were detected in two clones but no precore mutations (A1896) were detected in any of the five clones. These data support previous results that genotype C, in particular Korean clones of this genotype, is prone to mutations. Two independent mechanisms, namely, the deletions of long lengths and amino acid substitutions followed by BCP double mutations might contribute to the diversity of HBV quasispecies. Considering the importance of HBV quasispecies as HBV variant sources, the distribution of HBV quasispecies in mutation prone genotype C prevalent areas like Korea, should be monitored to improve the management of chronic HBV infections and to control HBV variants that arise due to the administration of vaccine or antiviral therapy. J. Med. Virol. 79:212,219, 2007. © 2007 Wiley-Liss, Inc. [source] Favorable efficacy of long-term lamivudine therapy in patients with chronic hepatitis B: An 8-year follow-up studyJOURNAL OF MEDICAL VIROLOGY, Issue 4 2005Norio Akuta Abstract The long-term efficacy of lamivudine therapy in patients with hepatitis B virus (HBV) infection is still not clear. In this study, 20 non-cirrhotic Japanese patients infected with HBV received lamivudine therapy for more than 1 year and were followed for a median period of 8.5 years (range, 6.7,8.7 years). The rates of HBe antigen (HbeAg) negative, HBV-DNA undetectable, and alanine aminotransferase (ALT) normal level at the start of lamivudine were 55%, 25%, and 20% and 85%, 80%, and were 80%, respectively, at the last visit, including patients who received additional treatment. The values at the last visit tended to and were significantly higher than those at the start. The values improved at the last visit regardless of the emergence of YMDD motif mutant and continuation of lamivudine. YMDD mutant and biochemical relapse with mutant virus (breakthrough hepatitis) appeared in 65% and 45% during follow-up, respectively, but severe breakthrough hepatitis occurred in only 5%. Furthermore, 80% of patients who received additional treatment for breakthrough hepatitis, regardless of continuation of lamivudine, were ALT normal level at the last visit, in contrast to 25% untreated. HBsAg clearance occurred in two patients of the discontinuous lamivudine group with non-vertical transmission, who were relatively young. One was infected with HBV genotype C with breakthrough hepatitis and the other had no YMDD mutant and was infected with genotype D, a rare type in Japan. None developed cirrhosis or hepatocellular carcinoma (HCC) during follow-up. Our results suggest that long-term lamivudine therapy improves long-term prognosis, especially when additional treatment for breakthrough hepatitis is used. J. Med. Virol. 75:491,498, 2005. © 2005 Wiley-Liss, Inc. [source] Comparison of full length sequences of hepatitis B virus isolates in hepatocellular carcinoma patients and asymptomatic carriers of Korea,JOURNAL OF MEDICAL VIROLOGY, Issue 1 2005Byung-Cheol Song Abstract Relatively few genomic sequences of Korean hepatitis B virus (HBV) isolates are available. Moreover, no comparative study has been made between the full-length genomes of Korean HBV isolates and clinical status. To evaluate mutations in HBV isolates obtained from chronically infected HBV patients in terms of clinical significance, we determined the genomic sequences of HBV isolates obtained from three hepatocellular carcinoma (HCC) patients (He52, He53, and He82) and from three asymptomatic carriers (He74, He100, and He127). A comparison of sequence variations showed that the HBV isolates from the three HCC patients showed higher frequencies of mutation than the isolates from the three asymptomatic carriers. Three characteristic mutation patterns were identified in the HBV isolates from the HCC patients, which distinguished the HBV isolates from the asymptomatic carriers. First, HBV isolates from the three HCC patients both had double mutations in a core promoter (T1762/A1764) and a precore mutation (A1896). Second, although these isolates belonged to genotype C, 11 amino acids deletions in the preS1 region, specific for HBV genotype D, were detected in the isolates of two HCC patients (He52 and He82). Third, mutations (I127T/N, K130M, and V131I) at three codons in the carboxy functional region of X protein were observed in isolates from all three HCC patients. Additionally, phylogenetic analysis based on the entire HBV sequences showed that all six isolates belonged to genotype C2, as do other Korean strains. J. Med. Virol. 75:13,19, 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] Molecular and serological aspects of HBsAg-negative hepatitis B virus infections in North AmericaJOURNAL OF MEDICAL VIROLOGY, Issue 1 2003C.C. Hsia Abstract A few hepatitis B virus (HBV) infections are characterized by the presence of HBV DNA in serum or liver tissue, or both, in the absence of detectable hepatitis B surface antigen (HBsAg) in serum. However, such infections have rarely been described previously in North American patients. In the present study, 31 hepatocellular carcinoma (HCC) patients from the United States and Canada who had no detectable HBsAg in their serum were studied. In these 31 HBsAg-negative HCC patients, HBV DNA was detected in HCC and/or in adjacent nontumorous liver tissue using nested polymerase chain reaction (PCR) in 5/9 (56%) patients from the United States and in 12/22 (55%) from Canada. The 17 HBV DNA-positive/HBsAg-negative patients from the United States and Canada included 9 without any serological markers for HBV and 8 with detectable antibodies to hepatitis B core antigen. In these patients, HBV genotype C was the most prevalent genotype (11/17; 64%). HBV genotypes have not been previously reported in HCC patients from North America. Replicative intermediate forms of HBV (covalently closed circular HBV DNA) were detected in 2/17 (12%) HBV DNA-positive/HBsAg-negative patients, indicating that at least two of these patients had actively replicating HBV infections. The use of tests to detect HBV DNA permitted the identification of HBV infections in HBsAg-negative HCC patients from North America. Among these patients, those with antibody to hepatitis C virus (HCV) would otherwise have been designated "HCV-associated HCCs" based on serological tests alone. These findings provide a new perspective on determining the possible viral etiologies of HCCs in North America. J. Med. Virol. 70: 20,26, 2003. © 2003 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] Characterization of hepatitis B surface antigen strains circulating in the Kingdom of CambodiaJOURNAL OF VIRAL HEPATITIS, Issue 1 2006C. T. Srey Summary., A collection of hepatitis B surface antigen (HBsAg)-reactive serum specimens from the Pasteur Institute of Cambodia was investigated for the genotype, predicted serotype and the presence of diagnostically significant mutations in the surface protein. From a set of 794 samples, 15 were identified serologically to harbour possible HBsAg mutants and were investigated further. An additional 20 samples were included into the study for PCR and sequence analysis. Of the 22 samples which were HBV-DNA-positive, 16 were of genotype C with the remaining six being genotype B. Point mutations resulting in amino acid substitutions were noted in 10 samples. The majority of these mutations occurred outside the a determinant. [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] 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] Characterization of Hepatitis B Virus Surface Antigen and Polymerase Mutations in Liver Transplant Recipients Pre- and Post-TransplantAMERICAN JOURNAL OF TRANSPLANTATION, Issue 6 2003Jeffrey J. Germer We evaluated serum samples from 18 chronic hepatitis B virus (HBV) patients who underwent liver transplantation for the presence of HBV polymerase and S gene mutations and HBV genotype using a new commercially available sequencing assay. All three patients with hepatitis B immune globulin (HBIG) treatment failure followed by nucleoside analogue treatment failure were infected with HBV genotype C; a pre-existing HBV S antigen (HBsAg) mutation (sD144A) was identified in one patient pretransplant, while sG145R mutations emerged in the other two patients post-transplant. These HBsAg mutations persisted for the duration of the study (5,6 years), despite the absence of HBIG administration for a 4,5-year period. Significant viral polymerase mutations (rtL180M and rtM204I/V) also emerged in all of these patients following treatment with lamivudine and/or famciclovir. Four of six patients with HBIG breakthrough without nucleoside analogue treatment failure yielded potentially significant HBsAg mutations post transplant. These data do not support previous reports highlighting the disappearance of HBsAg mutants in liver transplant recipients after discontinuation of HBIG. Determination of HBV genotype, as well as identification of HBV polymerase and S gene mutations in liver transplant candidates may be warranted to optimize HBV management strategies post transplant. [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] Ribosomal 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] | |||||||||||||