This Article Full Text Full Text (PDF) A correction has been published Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Lee, C.-W. Articles by Suarez, D. L. Search for Related Content PubMed PubMed Citation Articles by Lee, C.-W. Articles by Suarez, D. L.

 Previous Article  |  Next Article 

Journal of Virology, September 2005, p. 11412-11421, Vol. 79, No. 17
0022-538X/05/$08.00+0     doi:10.1128/JVI.79.17.11412-11421.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

H5N2 Avian Influenza Outbreak in Texas in 2004: the First Highly Pathogenic Strain in the United States in 20 Years?

Southeast Poultry Research Laboratory, USDA Agricultural Research Service, Athens, Georgia 30605,¹ Texas Veterinary Medical Diagnostic Laboratory, Poultry Diagnostic Laboratory, Gonzales, Texas 78629,² National Veterinary Services Laboratories, USDA Animal and Plant Health Inspection Service, Ames, Iowa 50010³

Received 9 February 2005/ Accepted 27 May 2005

In early 2004, an H5N2 avian influenza virus (AIV) that met the molecular criteria for classification as a highly pathogenic AIV was isolated from chickens in the state of Texas in the United States. However, clinical manifestations in the affected flock were consistent with avian influenza caused by a low-pathogenicity AIV and the representative virus (A/chicken/Texas/298313/04 [TX/04]) was not virulent for experimentally inoculated chickens. The hemagglutinin (HA) gene of the TX/04 isolate was similar in sequence to A/chicken/Texas/167280-4/02 (TX/02), a low-pathogenicity AIV isolate recovered from chickens in Texas in 2002. However, the TX/04 isolate had one additional basic amino acid at the HA cleavage site, which could be attributed to a single point mutation. The TX/04 isolate was similar in sequence to TX/02 isolate in several internal genes (NP, M, and NS), but some genes (PA, PB1, and PB2) had sequence of a clearly different origin. The TX/04 isolate also had a stalk deletion in the NA gene, characteristic of a chicken-adapted AIV. By analyzing viruses constructed by in vitro mutagenesis followed by reverse genetics, we found that the pathogenicity of the TX/04 virus could be increased in vitro and in vivo by the insertion of an additional basic amino acid at the HA cleavage site and not by the loss of a glycosylation site near the cleavage site. Our study provides the genetic and biologic characteristics of the TX/04 isolate, which highlight the complexity of the polygenic nature of the virulence of influenza viruses.

This article has been cited by other articles:

• Das, A., Suarez, D. L. (2007). Development and bench validation of real-time reverse transcription polymerase chain reaction protocols for rapid detection of the subtypes H6, H9, and H11 of avian influenza viruses in experimental samples. jvdi 19: 625-634 [Abstract] [Full Text]  
• Pappas, C., Matsuoka, Y., Swayne, D. E., Donis, R. O. (2007). Development and Evaluation of an Influenza Virus Subtype H7N2 Vaccine Candidate for Pandemic Preparedness. CVI 14: 1425-1432 [Abstract] [Full Text]  
• Cauthen, A. N., Swayne, D. E., Sekellick, M. J., Marcus, P. I., Suarez, D. L. (2007). Amelioration of Influenza Virus Pathogenesis in Chickens Attributed to the Enhanced Interferon-Inducing Capacity of a Virus with a Truncated NS1 Gene. J. Virol. 81: 1838-1847 [Abstract] [Full Text]  
• Das, A., Spackman, E., Senne, D., Pedersen, J., Suarez, D. L. (2006). Development of an Internal Positive Control for Rapid Diagnosis of Avian Influenza Virus Infections by Real-Time Reverse Transcription-PCR with Lyophilized Reagents.. J. Clin. Microbiol. 44: 3065-3073 [Abstract] [Full Text]