UNLABELLED Mutations in the polymerase genes are known to play a major role in avian influenza virus adaptation to mammalian hosts. Despite having avian origin PA and PB2, the 2009 pandemic H1N1 virus (pH1N1) can replicate well in mammalian respiratory tracts, suggesting that these proteins have acquired mutations for efficient growth in humans. We have previously shown that PA from the pH1N1 v...

BACKGROUND & OBJECTIVES Since not much information on Chandipura virus is available, an attempt was made to study the growth kinetics of the virus in certain vertebrate, invertebrate cell lines and embryonated chicken eggs. METHODS Comparative study of Chandipura virus (CHPV) growth kinetics in three vertebrate cell lines [Vero E6, Rhabdo myosarcoma (RD), Porcine stable kidney (PS) cell lines...

Hepatitis A virus (HAV), an atypical member of the Picornaviridae, grows poorly in cell culture. To define determinants of HAV growth, we introduced a blasticidin (Bsd) resistance gene into the virus genome and selected variants that grew at high concentrations of Bsd. The mutants grew fast and had increased rates of RNA replication and translation but did not produce significantly higher virus...

An interference between a thermosensitive (ts) mutant and the wild-type (wt) of tick-borne encephalitis (TBE) virus in Ixodes ricinus L. and Rhipicephalus appendiculatus (Neumann) ticks is reported. I. ricinus females were dually infected by a parenteral inoculation of ts and wt strains at 10-day interval. Interference was demonstrated by the lowered ability of wt virus to replicate in ticks pr...

Virus replication efficiency is influenced by two conflicting factors, kinetics of the cellular interferon (IFN) response and induction of an antiviral state versus speed of virus replication and virus-induced inhibition of the IFN response. Disablement of a virus's capacity to circumvent the IFN response enables both basic research and various practical applications. However, such IFN-sensitiv...

The pattern of development of meningopneumonitis virus in the allantois of the chick embryo was described in a recently published report from this laboratory (1). The growth cycle of this virus was determined by titrating allantoic fluids and membrane suspensions, obtained at various intervals after the inoculation of virus, for infectivity in mice and chick embryos. The development of virus in...

Inoculation of newborn mice with lymphocytic chloriomeningitis (LCM) virus resulted in decreased weight gain, liver cell necrosis, and death. Injection of potent sheep immunoglobulin against mouse interferon markedly inhibited these manifestations of LCM virus disease despite the fact that these treated mice had 100-fold more LCM virus in their serum. We conclude that interferon induced by LCM ...

Respiratory syncytial virus (RSV) is the only infectious disease for which a monoclonal antibody (MAb) is used in humans. Palivizumab (PZ) is a humanized murine MAb to the F protein of RSV. PZ-resistant viruses appear after in vitro and in vivo growth of RSV in the presence of PZ. Fitness for replication could be a determinant of the likelihood of dissemination of resistant viruses. We assessed...