This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Afonso, C. L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Afonso, C. L.

 Previous Article  |  Next Article 

Journal of Virology, September 2008, p. 9303, Vol. 82, No. 18
0022-538X/08/$08.00+0     doi:10.1128/JVI.01231-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.

LETTER TO THE EDITOR

Not So Fast on Recombination Analysis of Newcastle Disease Virus


arrow
LETTER
 
Regarding the letter of Han et al. published earlier in the Journal of Virology (3) indicating that "powerful evidence" of recombination is a call for caution in the use of Newcastle disease virus (NDV)-based vaccines, I would like to suggest that the evidence for recombination is still weak. The authors cite three reports that suggest the existence of recombination, but a closer look reveals the possibility of oversight in the interpretation of the data (1, 2, 5). There is evidence of recombination in the existing GenBank NDV sequences, but unfortunately, the vast majority of these available NDV sequences have been obtained by PCR amplification of RNAs from crude field samples grown in eggs. The possibility of reporting artificial recombination caused by polymerase template switching in these samples or by laboratory-generated recombinants needs to be considered. The widespread use of live vaccines in poultry and the extensive presence of nonvirulent endemic NDVs in live bird markets and in wildlife (4) make the existence of unnoticed mixed infections in field samples likely. In the particular case of the three publications cited, the Chare et al. and Han et al. results are based on the analysis of GenBank sequences that were obtained without any purification. In the Qin et al. paper, three plaque purification steps were performed, but no attempts were made to confirm the absence of contaminant viruses in the original samples or to investigate the possibility of contamination with PCR products, which normally abound in NDV sequencing laboratories. In fact, despite the availability of a large number of NDV sequences in GenBank databases, no NDV report exists that describes the generation of a natural progeny of viruses derived from a recombination event. Although I agree with the authors in the need for caution in the use of live NDV vectored vaccines, caution in the interpretation of the data is also needed.


arrow
FOOTNOTES
 
Ed. note: There is no reply to this letter.


arrow
REFERENCES
 
    1
  1. Chare, E. R., E. A. Gould, and E. C. Holmes. 2003. Phylogenetic analysis reveals a low rate of homologous recombination in negative-sense RNA viruses. J. Gen. Virol. 84:2691-2703.[Abstract/Free Full Text]
    2. 2
  2. Han, G. Z., C. Q. He, N. Z. Ding, and L. Y. Ma. 2008. Identification of a natural multi-recombinant of Newcastle disease virus. Virology 371:54-60.[CrossRef][Medline]
    3. 3
  3. Han, G. Z., X. P. Liu, and S. S. Li. 2008. Caution about Newcastle disease virus-based live attenuated vaccine. J. Virol. 82:6782.[Free Full Text]
    4. 4
  4. Kim, L. M., D. J. King, P. E. Curry, D. L. Suarez, D. E. Swayne, D. E. Stallknecht, R. D. Slemons, J. C. Pedersen, D. A. Senne, K. Winker, and C. L. Afonso. 2007. Phylogenetic diversity among low-virulence Newcastle disease viruses from waterfowl and shorebirds and comparison of genotype distributions to those of poultry-origin isolates. J. Virol. 81:12641-12653.[Abstract/Free Full Text]
    5. 5
  5. Qin, Z., L. Sun, B. Ma, Z. Cui, Y. Zhu, Y. Kitamura, and W. Liu. 2008. F gene recombination between genotype II and VII Newcastle disease virus. Virus Res. 131:299-303.[CrossRef][Medline]
Claudio L. Afonso*
SEPRL
ARS-USDA, SAA
934 College Station Road
Athens, Georgia 30605

* Phone: (706) 546-3642
Fax: (706) 546-3161
E-mail: claudio.afonso{at}ars.usda.gov

Journal of Virology, September 2008, p. 9303, Vol. 82, No. 18
0022-538X/08/$08.00+0     doi:10.1128/JVI.01231-08
Copyright © 2008, American Society for Microbiology. All Rights Reserved.




This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Afonso, C. L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Afonso, C. L.

Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»