The objective of this study was to compare the effect of two conventional H9N2 avian influenza (AI) vaccines on replication and shedding of the H9N2 AI virus in broiler chickens. These inactivated oil emulsion vaccines contain either a UAE or an Iranian H9N2 AI isolate. One hundred and fifty one-day-old commercial broiler chickens were randomly divided into six groups. The birds, except for the...

The Beaudette strain of avian infectious bronchitis virus propagated in chicken embryo kidney cells is stabilized by exposure to 1 M MgSO(4) at 50 C for 80 min, at pH values ranging from 4 to 10.

Chicken anaemia agent (CAA) was purified using differential centrifugation and successive cycles of equilibrium density gradient centrifugation using sucrose and CsCl. The purification method was dependent on the use of an antigen-detecting ELISA based on a CAA-specific monoclonal antibody. Virus particles banded at a density of 1.33 to 1.34 g/ml in CsCl and measured 23.5 +/- 0.8 nm in diameter...

BACKGROUND As a typical retrovirus, the evolution of Avian leukosis virus subgroup J (ALV-J) in different infectious ecosystems is not characterized, what we know is there are a cloud of diverse variants, namely quasispecies with considerable genetic diversity. This study is to explore the selection of infectious ecosystems on dominant variants and their evolutionary dynamics of ALV-J between D...

Infectious clones of West Nile virus (WNV) have previously been generated and used to decipher the role of viral proteins in WNV virulence. The majority of molecular clones obtained to date have been derived from North American, Australian, or African isolates. Here, we describe the construction of an infectious cDNA clone of a Mediterranean WNV strain, IS-98-ST1. We characterized the biologica...

The term “slow infection” was introduced for the first time by the Icelandic researcher B. Sigurdsson in 1954 (Sigurdsson, 1954). With this term, he designated the interaction of the virus with the host, characterized by a prolonged (many months and even years) incubation period, at what time several organs or systems become affected and thereafter, results in slow, but progressive development ...