[Show abstract][Hide abstract] ABSTRACT: To give a new perspective on the codon usage of the hepatitis C virus (HCV) and the factors accounting for shaping the codon usage pattern of the virus, the relative synonymous codon usage (RSCU) values, aromaticity and hydrophobicity of each polyprotein of the virus, effective number of codons (ENC) values and nucleotide contents were calculated to implement a comparative analysis to evaluate the dynamics of the virus evolution. The RSCU values of each codon of 144 HCV ORFs indicated that all abundant codons were C/G-ended codons. The plots of principal component analysis based on sub-genotype of HCV indicated that sub-genotype 1a and 1b separated clearly on the axis of f2 suggesting that the codon usage bias between sub-genotype 1a and 1b strains was different. By comparing the codon usage between HCV and human cells, we found that the synonymous codon usage pattern of HCV was a mixture of coincidence and antagonism to that of host cells. The characteristics of the synonymous codon usage patterns and nucleotide contents of HCV, and the correlation analysis between GC(3s), GC(1,2s), GC% (ORF), GC% (5'-UTR), GC% (3'-UTR), aromaticity, hydrophobicity and ENC value, respectively, indicated that mutational pressure was the dominant factor accounting for the codon usage variation and selection pressure also accounted for HCV codon usage pattern.
Infection, genetics and evolution: journal of molecular epidemiology and evolutionary genetics in infectious diseases 09/2011; 11(8):2098-102. DOI:10.1016/j.meegid.2011.08.025 · 3.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The usefulness of reverse transcription loop-mediated isothermal amplification (RT-LAMP) for the rapid diagnosis of hepatitis C virus (HCV) RNA was evaluated. This assay showed higher sensitivities than that of nested RT-PCR, with a detection limit of 600 IU mL(-1) , and no cross-reactivity was observed with hepatitis A virus, hepatitis B virus and hepatitis E virus. Furthermore, 106 stored sera from recently diagnosed cases were retrospectively investigated with real-time RT-PCR, the nested RT-PCR, in parallel with this new assay. The general detection rates of HCV RT-LAMP, real-time PCR and the nested RT-PCR for 106 stored sera samples were 95%, 96% and 88%, respectively. This study provides the first data on the usefulness of HCV RT-LAMP in the diagnosis of HCV RNA, especially in the early clinical diagnosis of acute HCV infection.