[Show abstract][Hide abstract] ABSTRACT: We conducted detailed genetic analyses of the hemagglutinin-neuraminidase (HN) gene in 272 human parainfluenza virus type 3 (HPIV3) isolates from children with acute respiratory illness during the period 2002-2009 in Yamagata prefecture, Japan. A phylogenetic tree constructed by the Bayesian Markov Chain Monte Carlo (MCMC) method showed that the strains diversified at around 1946 and the rate of molecular evolution was 1.10x10-3 substitutions/site/year. Identity was high among the present strains (<90%) and the p-distances were short. Furthermore, we found four positive selection sites and some key amino acid substitutions in active/catalytic sites of the HN protein. The results suggest that the HN gene of HPIV3 in the present strains rapidly evolved, similarly to other virus genes such as the G gene of respiratory syncytial virus. However, the biological functions and detailed structures of the HN glycoprotein in some of these strains may have been altered.
Full-text · Article · Jan 2014 · Journal of Medical Microbiology
[Show abstract][Hide abstract] ABSTRACT: We developed a new quantification method for the measles virus (MeV) nucleoprotein (N) gene using real-time reverse transcriptase PCR. This method allowed us to quantify 10(1)-10(7) copies per reaction (corresponding to 5x10(-1)-5x10(5) copies microl(-1)) of the MeV N gene. We also quantified the MeV N gene from the throat swabs of 22 patients with measles as well as the MeV genotypes A, D3, D5, D9 and H1 in viral suspensions derived from MeV-infected cells. As a result, 3.9x10(3)-5.2x10(6) copies ml(-1) and 7.4x10(7)-2.0x10(8) copies ml(-1) of the MeV genomes (N gene) were detected in the throat swabs and viral suspensions, respectively. No other viruses (enteroviruses, respiratory syncytial virus, human metapneumovirus or mumps virus) were detected in the assay. The results suggest that this method is applicable to the detection and quantification of some genotypes of MeV.
Full-text · Article · Jun 2009 · Journal of Medical Microbiology