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| Villar,L.M.; Amado,L.A.; Gaspar,A.M.C.. |
| Hepatitis A virus (HAV) replicates relatively slowly in cell culture without a cytopathic effect, a fact that limits the use of tissue culture assays. The radioimmunofocus assay is the standard method for HAV titration, although it is labor intensive and requires the use of radioisotopes. A simple, rapid and objective infectivity assay based on an in situ enzyme immunoassay (EIA) is described here for a Brazilian cell culture-adapted HAV strain (HAF-203). The assay uses a peroxidase-labeled polyclonal antibody to fixed monolayers as an indicator of infection. EIA may be completed within 7 days using serial 5-fold dilutions of the virus, yielding a titer of 5.024 log 50% tissue culture infective dose (TCID50)/ml for HAF-203. This technique had a detection... |
| Tipo: Info:eu-repo/semantics/other |
Palavras-chave: Hepatitis A virus; Virus titration; Enzyme immunoassay. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004000700011 |
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| Villar,L.M.; Morais,L.M.; Aloise,R.; Melo,M.M.M.; Calado,I.A.; Lampe,E.; Gaspar,A.M.C.. |
| The Northeast region is the location of most cases of acute hepatitis A virus (HAV) in Brazil. In the present study, the genotypes of HAV strains from Pernambuco State, one of most populous states in the Northeast region, were characterized. Blood samples positive for anti-HAV IgM from 145 individuals (mean age = 29.1 years), collected during 2002 and 2003, were submitted to nested RT-PCR for amplification of the 5'non-translated region (5'NTR) and VP1/2A regions of the HAV genome. The VP1/2A and 5'NTR regions were amplified in 39 and 21% of the samples, respectively. Nucleotide sequencing was carried out in 46% of VP1/2A and in 53% of 5'NTR isolates. The identity in nucleotide sequence of the VP1/2A region ranged from 93.6 to 100.0%. Phylogenetic analysis... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Hepatitis A virus; Molecular epidemiology; Sub-genotype IA; Sub-genotype IB. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2006000700004 |
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