Daniel J King

United States Department of Agriculture, Washington, D. C., DC, United States

Are you Daniel J King?

Claim your profile

Publications (27)68.73 Total impact

  • [show abstract] [hide abstract]
    ABSTRACT: Worldwide, Newcastle disease (ND) remains one of the most economically important diseases of poultry. Current vaccination strategies for commercial poultry include the use of inactivated and live ND vaccines that typically induce protection against virulent field viruses. Here, we tested the efficacy of an antigen-antibody complex (AAC) ND vaccine delivered in ovo. Commercial maternal antibody-positive broiler chickens (Gallus domesticus) were vaccinated in ovo with an AAC vaccine composed of live B1-LaSota Newcastle disease virus (NDV) complexed with NDV-specific antiserum, and then they were challenged at weekly intervals after hatch. Challenge viruses included three exotic ND disease (END) viruses: the neurotropic strain Texas GB NDV-92-01 (TxGB) and two viscerotropic isolates, one isolate from the 2002-2003 outbreak in California (California 2002 isolate S212676 [CA]) and the other isolate from a 1997 END outbreak in South Korea (South Korea 94-147 [SK]). Results demonstrate that maternal antibody was able to provide approximately 50% protection in either vaccinated or control chickens at 7 days of age after TxGB challenge. However, with challenge at > or = 14 days, most control birds died, whereas all AAC-vaccinated birds were protected. Challenge with the CA or SK viruses in chickens at 28 days of age resulted in 100% protection of vaccinated birds, whereas all control birds died. In addition, AAC-vaccinated birds displayed decreased incidence of viral shedding in oral and cloacal swabs than control birds. Antibody titers were significantly (P < 0.05) higher in vaccinated chickens, as determined by enzyme-linked immunosorbent assay and hemagglutinin-inhibition tests, than in nonvaccinated controls. Together, these results demonstrate the efficacy of AAC vaccines delivered in ovo to protect commercial poultry.
    Avian Diseases 09/2012; 56(3):555-60. · 1.73 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Attachment of Newcastle disease virus (NDV) to the host cell is mediated by the haemagglutinin-neuraminidase (HN), a multifunctional protein that has receptor recognition, neuraminidase (NA) and fusion promotion activities. The process that connects receptor binding and fusion triggering is poorly understood and amino acid residues important for the functions of the protein remain to be fully determined. During the process of generating an infectious clone of the Anhinga strain of NDV, we were able to rescue a NDV with highly increased fusogenic activity in vitro and decreased haemagglutinating activity, as compared with the wild-type parental strain. Sequencing of this recombinant virus showed a single mutation at amino acid position 192 of the HN protein (Ile→Met). In the present study, we characterized that single amino acid substitution (I192M) in three strains of NDV by assessing the NA activity and fusogenic potential of the mutated versus wild-type proteins in cell cultures. The original recombinant NDV harbouring the mutation in the HN gene was also used to characterize the phenotype of the virus in cell cultures, embryonated chicken eggs and day-old chickens. Mutation I192M results in low NA activity and highly increased cell fusion in vitro, without changes in the viral pathotype of recombinant viruses harbouring the mutation in vivo. The results obtained suggest that multiple regions of the HN-protein globular head are important for fusion promotion, and that wild-type levels of NA activity are not absolutely required for viral infection.
    Journal of General Virology 03/2011; 92(Pt 3):544-51. · 3.13 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: Newcastle disease virus (NDV) is an avian paramyxovirus that causes significant economic losses to the poultry industry worldwide. There is limited knowledge about the avian immune response to infection with virulent NDVs, and how this response may contribute to disease. In this study, pathogenesis and the transcriptional host response of chickens to a virulent NDV strain that rapidly causes 100% mortality was characterized. Using microarrays, a strong transcriptional host response was observed in spleens at early times after infection with the induction of groups of genes involved in innate antiviral and pro-inflammatory responses. There were multiple genes induced at 48 h post-infection including: type I and II interferons (IFNs), several cytokines and chemokines, IFN effectors and inducible nitric oxide synthase (iNOS). The increased transcription of nitric oxide synthase was confirmed by immunohistochemistry for iNOS in spleens and measured levels of nitric oxide in serum. In vitro experiments showed strong induction of the key host response genes, alpha IFN, beta interferon, and interleukin 1β and interleukin 6, in splenic leukocytes at 6 h post-infection in comparison to a non-virulent NDV. The robust host response to virulent NDV, in conjunction with severe pathological damage observed, is somewhat surprising considering that all NDV encode a gene, V, which functions as a suppressor of class I IFNs. Taken together, these results suggest that the host response itself may contribute to the pathogenesis of this highly virulent strain in chickens.
    Journal of General Virology 01/2011; 92(Pt 4):931-9. · 3.13 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: Virulent Newcastle disease virus isolates from the 1971 and 2002 U.S. outbreaks are of the same serotype but a different genotype than current vaccine strains. Prior experiments with inactivated vaccines in chickens show significantly less virus shed in birds vaccinated with a homologous vaccine (same genotype as challenge) compared to chickens vaccinated with genotypically heterologous vaccines. Subsequent experiments have compared the protection induced in chickens by live vaccines of B1 and LaSota (genotype II), Ulster (genotype I), and recombinant viruses that express the hemagglutinin neuraminidase gene (HN) or the HN and fusion gene (F) of CA 2002 (genotype V). Vaccinates were challenged with virulent viruses CA 2002 (genotype V) or Texas GB (TXGB, genotype II). After challenge with CA 2002 the birds vaccinated with a live recombinant genotype V virus containing the HN of CA 2002 shed significantly less virus in oropharyngeal swabs compared to B1 and had fewer birds shedding virus compared to B1, LaSota, and Ulster vaccinates. After challenge with CA 2002 birds vaccinated with the recombinant containing both the HN and F of CA 2002 (rA-CAFHN) shed less virus, and fewer birds shed virus compared to LaSota-vaccinated birds. TXGB-challenged LaSota-vaccinated birds shed less virus, and fewer birds shed virus compared to TXGB-challenged rA-CAFHN-vaccinated birds. Genotypic differences between vaccine and challenge did not diminish ability of vaccines to protect against disease, but genotypic similarity did reduce virus shed and may reduce transmission. The development and use of vaccines of the same genotype as the expected field challenge may provide an additional tool for control of this important poultry pathogen.
    Avian Diseases 04/2009; 53(1):39-49. · 1.73 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: House flies (Musca domestica) and little house flies (Fannia canicularis) were examined for their ability to take up and harbor a velogenic strain of exotic Newcastle disease virus (ENDV) (family Paramyxoviridae, genus Avulavirus). Laboratory-reared flies were allowed to feed on evaporated milk containing ENDV at a virus concentration of 10(8.3) egg infectious dose (EID)50/0.1 ml or on poultry feces containing an ENDV titer of 10(5.8) EID50/0.1 g. Flies exposed to either infectious food source for 24 hr became transiently infected with virus. Virus persisted predominantly in the mid- and hindgut, with relatively little virus isolated from the remainder of the fly body. Virus persisted similarly in both fly species that were fed evaporated milk containing ENDV, with a maximum ENDV titer of 10(5.98) EID50/fly for the house fly and 10(4.78) EID50/fly for the little house fly at 1 day postexposure; titers decreased on subsequent days to 10(2.38) EID50/fly for house fly and > or = 1 EID50/fly for little house fly at 5 days postexposure. Both fly species acquired viral titers greater than the infective dose for a susceptible chicken (10(3.0) EID50-10(4.0) EID50). In addition, flies fed evaporated milk containing a high titer of ENDV maintained viral titers above the infective dose for up to 4 days postexposure to the infectious food source. Flies fed on infective feces retained a chicken infective dose for only one day. The decrease in viral titer over time was significantly explained by logistic regression for both fly species (P < 0.05). The slope of the regression line was not different for the two fly species (P < 0.05), indicating a similar rate of virus loss.
    Avian Diseases 09/2008; 52(3):375-9. · 1.73 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: As part of West Nile virus surveillance programs in Rhode Island and eastern Texas between 2000 and 2007, brain tissue was collected from 5,608 dead birds representing 21 avian orders found in public places or reported by homeowners. Fifteen Newcastle disease virus isolates were recovered only from birds of the order Columbiformes and were positively identified by the USDA-validated real-time reverse transcription-PCR assay targeting the matrix gene and more specifically as pigeon paramyxovirus serotype 1 (PPMV-1) by hemagglutinin inhibition with monoclonal antibodies. Based upon partial genomic sequencing and phylogenetic analysis, the newly isolated viruses represent a distinct sublineage within class II genotype VIb. All of the viruses (15/15) were classified as virulent based upon their fusion cleavage site motif ((112)RRKKRF(117)) and intracerebral pathogenicity indices of >0.7 (ranging from 0.98 to 1.35); however, these viruses escaped detection by the fusion gene-based real-time PCR test for virulence. Modifications introduced to the probe site of the fusion gene-based assay allowed rapid virulence detection within this distinct sublineage.
    Journal of clinical microbiology 09/2008; 46(10):3303-10. · 4.16 Impact Factor
  • Colleen Thomas, Daniel J King, David E Swayne
    [show abstract] [hide abstract]
    ABSTRACT: Avian influenza viruses (AIV) and Newcastle disease viruses (NDV) of high pathogenicity cause severe systemic disease with high mortality in chickens and can be isolated from the meat of infected chickens. Although AIV and NDV strains of low pathogenicity are typically not present in chicken meat, virus particles in respiratory secretions or feces are possible sources of carcass contamination. Because spread of AIV and NDV is associated with movement of infected birds or their products, the presence of these viruses in chicken meat is cause for concern. This study presents thermal inactivation data for two viruses of high pathogenicity in chickens (AIV strain A/chicken/Pennsylvania/1370/1983 and NDV strain APMV-1/ chicken/California/S0212676/2002) and two viruses of low pathogenicity in chickens (AIV strain A/chicken/Texas/298313/ 2004 and NDV strain APMV-1/chicken/Northern Ireland/Ulster/1967). Under the conditions of the assay, high-pathogenicity AIV was inactivated more slowly in meat from naturally infected chickens than in artificially infected chicken meat with a similar virus titer. In contrast, high-pathogenicity NDV was inactivated similarly in naturally and artificially infected meat. Linear regression models predicted that the current U.S. Department of Agriculture-Food Safety and Inspection Service time-temperature guidelines for cooking chicken meat to achieve a 7-log reduction of Salmonella also would effectively inactivate the AIV and NDV strains tested. Experimentally, the AIV and NDV strains used in this study (and the previously studied H5N1 high-pathogenicity AIV strain A/chicken/Korea/ES/2003) were effectively inactivated in chicken meat held at 70 or 73.9 degrees C for less than 1 s.
    Journal of food protection 07/2008; 71(6):1214-22. · 1.83 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Low-virulence Newcastle disease viruses (loNDV) are frequently recovered from wild bird species, but little is known about their distribution, genetic diversity, or potential to cause disease in poultry. NDV isolates recovered from cloacal samples of apparently healthy waterfowl and shorebirds (WS) in the United States during 1986 to 2005 were examined for genomic diversity and their potential for virulence (n = 249). In addition 19 loNDV isolates from U.S. live bird markets (LBMs) were analyzed and found to be genetically distinct from NDV used in live vaccines but related to WS-origin NDV. Phylogenetic analysis of the fusion protein identified nine novel genotypes among the class I NDV, and new genomic subgroups were identified among genotypes I and II of the class II viruses. The WS-origin viruses exhibited broad genetic and antigenic diversity, and some WS genotypes displayed a closer phylogenetic relationship to LBM-origin NDV. All NDV were predicted to be lentogenic based upon sequencing of the fusion cleavage site, intracerebral pathogenicity index, or mean death time in embryo assays. The USDA real-time reverse transcription-PCR assay, which targets the matrix gene, identified nearly all of the class II NDV tested but failed to detect class I viruses from both LBM and WS. The close phylogenetic proximity of some WS and LBM loNDV suggests that viral transmission may occur among wild birds and poultry; however, these events may occur unnoticed due to the broad genetic diversity of loNDV, the lentogenic presentation in birds, and the limitations of current rapid diagnostic tools.
    Journal of Virology 12/2007; 81(22):12641-53. · 5.08 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Strains of Newcastle disease virus (NDV) can be separated into genotypes based on genome differences even though they are antigenically considered to be of a single serotype. It is widely recognized that an efficacious Newcastle disease (ND) vaccine made with any NDV does induce protection against morbidity and mortality from a virulent NDV challenge. However, those ND vaccines do not protect vaccinates from infection and viral shed from such a challenge. Vaccines prepared from ND viruses corresponding to five different genotypes were compared to determine if the phylogenetic distance between vaccine and challenge strain influences the protection induced and the amount of challenge virus shed. Six groups of 4-week-old specific pathogen-free Leghorn chickens were given oil-adjuvanted vaccines prepared from one of five different inactivated ND viruses including strains B1, Ulster, CA02, Pigeon84, Alaska 196, or an allantoic fluid control. Three weeks post-vaccination, serum was analyzed for antibody content using a hemagglutination inhibition assay against each of the vaccine antigens and a commercial NDV ELISA. After challenge with virulent CA02, the birds were examined daily for morbidity and mortality and were monitored at selected intervals for virus shedding. All vaccines except for the control induced greater than 90% protection to clinical disease and mortality. The vaccine homologous with the challenge virus reduced oral shedding significantly more than the heterologous vaccines. NDV vaccines formulated to be phylogenetically closer to potential outbreak viruses may provide better ND control by reducing virus transmission from infected birds.
    Vaccine 11/2007; 25(41):7238-46. · 3.49 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Flies were collected by sweep net from the vicinity of two small groups of "backyard" poultry (10-20 chickens per group) that had been identified as infected with exotic Newcastle disease virus (family Paramyxoviridae, genus avulavirus, ENDV) in Los Angeles County, CA, during the 2002-2003 END outbreak. Collected flies were subdivided into pools and homogenized in brain-heart infusion broth with antibiotics. The separated supernatant was tested for the presence of ENDV by inoculation into embryonated chicken eggs. Exotic Newcastle disease virus was isolated from pools of Phaenicia cuprina (Wiedemann), Fannia canicularis (L.), and Musca domestica L., and it was identified by hemagglutination inhibition with Newcastle disease virus antiserum. Viral concentration in positive pools was low (<1 egg infectious dose50 per fly). Isolated virus demonstrated identical monoclonal antibody binding profiles as well as 99% sequence homology in the 635-bp fusion gene sequence compared with ENDV recovered from infected commercial egg layer poultry during the 2002 outbreak.
    Journal of Medical Entomology 09/2007; 44(5):840-4. · 1.86 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: The usefulness of reverse transcription-polymerase chain reaction (RT-PCR) from formalin-fixed, paraffin-embedded (FFPE) tissues was examined and compared to the immunohistochemistry (IHC) and in situ hybridization (ISH) assays for detection of Newcastle disease virus (NDV). Spleen and lung tissues were collected from chickens experimentally infected with either of 2 NDV isolates: a low virulent virus (LaSota) and a virulent virus (from the 2002-2003 California outbreak). The tissues were harvested immediately postmortem and fixed in 10% neutral buffered formalin for approximately 52 hours. Also, just before euthanasia, oral and cloacal swabs were collected for virus isolation. RNA was obtained from the FFPE tissues by digestion with proteinase K and subsequent extraction with phenol, chloroform, and isoamyl alcohol. By seminested RT-PCR with primers for the NDV matrix gene, a 232-base pair (bp) product was generated and visualized by electrophoresis. The results of PCR were compared to those of IHC for viral nucleoprotein and ISH for matrix gene (850 bp) on 3-microm sections and to those of virus isolation from swabs. All samples from infected chickens were positive by RT-PCR, including samples that were negative by both IHC and ISH. The RT-PCR positives included tissue from chickens that were no longer shedding virus detectable by virus isolation. The RT-PCR was an effective and sensitive method to detect NDV in FFPE tissues. To the authors' knowledge, this is the first report of NDV detection in FFPE tissues as a diagnostic approach possibly suitable for archival materials.
    Journal of veterinary diagnostic investigation: official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc 08/2007; 19(4):396-400. · 1.18 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Newcastle disease viruses isolated from Hong Kong live bird markets (LBMs) were not detected by a USDA-validated matrix gene real-time reverse transcription-PCR (RT-PCR) assay. Based upon phylogenetic analysis of the fusion gene, these viruses were related to lentogenic class I viruses found in U.S. LBMs and wild waterfowl. An alternative real-time RT-PCR assay which complements the matrix gene assay was developed to efficiently detect class I viruses.
    Journal of Clinical Microbiology 05/2007; 45(4):1310-4. · 4.07 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: The principal molecular determinant of virulence of Newcastle disease virus (NDV) is the amino acid sequence at the fusion cleavage activation site. To extend the understanding of the role of the fusion cleavage activation site in NDV virulence, the pathogenesis in chickens of a lentogenic LaSota isolate and two infectious clones, NDFL and NDFLtag, were compared. NDFL is an infectious clone of a lentogenic NDV strain (LaSota E13-1), and NDFLtag is the infectious clone with the fusion cleavage site sequence mutated to the virulent motif. NDFL and NDFLtag were described by Peeters et al. The viruses were inoculated intraconjunctivally into groups of 4-wk-old white leghorn chickens and compared in a pathogenesis study for determination of disease causation (clinical signs of disease, gross lesions, histology, virus isolation, and serology) and viral distribution (presence of viral nucleoprotein and mRNA was detected by immunohistochemistry and in situ hybridization, respectively). The modification of the fusion cleavage activation site to the virulent motif in the infectious clone only slightly increased disease severity and viral distribution in the pathogenesis assessment, even though dramatically increased pathogenicity of NDFLtag was confirmed by standard pathogenicity index tests. The result, that the mutated fusion cleavage site of NDV-NDFLtag had only a small influence on pathogenesis in chickens compared to either E13-1 or NDFL, suggests that the pathogenic effects of NDV are not dependent on the fusion cleavage site alone.
    Avian Diseases 01/2007; 50(4):483-8. · 1.73 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: The effect of mutations of Newcastle disease virus (NDV) fusion (F) gene, hemagglutinin-neuraminidase (HN) gene, and phosphoprotein (P) gene and HN chimeras between the virulent Beaudette C and low virulence LaSota strains on pathogenesis and pathogenicity was examined in fully susceptible chickens. A virulent F cleavage site motif within a LaSota backbone increased pathogenicity and severity of clinical disease. A LaSota HN within a Beaudette C backbone decreased pathogenicity indices and disease severity. A Beaudette C HN within a LaSota backbone did not change either pathogenicity indices or severity of disease in chickens. Loss of glycosylation at site 4 of the HN or modified P gene of Beaudette C decreased pathogenicity indices and caused no overt clinicopathologic disease in chickens. Both pathogenicity indices and clinicopathologic examination demonstrated that the F, HN, and P genes of NDV collectively or individually can contribute to viral virulence.
    Virology 10/2006; 353(2):333-43. · 3.37 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: The susceptibility, immune response, and protection to challenge after vaccination in racing pigeons (Columbia livia) was assessed with the 2002-2003 exotic Newcastle disease (END) virus responsible for the most recent major outbreak in Southern California. Immunologically naïve pigeons appeared resistant to disease, regardless of dose, after a natural route of exposure. Twenty percent morbidity was observed in each group of birds receiving between 10(2.1) and 10(8.1) 50% embryo infectious dose (EID50) per bird, with one bird succumbing to challenge in the 10(8.1) EID50/bird group at day 12 postinoculation. Although resistant to disease, birds in all groups continued to shed virus from either oral or cloacal route at the end of the 14-day sampling period, and seroconversion was only observed in birds receiving > or =10(6.1) EID50. Single or double vaccination of juvenile and adult birds with pigeon paramyxovirus virus type 1 (PPMV-1) vaccine followed by END challenge with 10(6.1) EID50/bird decreased the duration, incidence, and viral load. A positive correlation was observed between the presence of hemagglutination-inhibiting antibody titers at challenge and decreased viral shedding. Overt clinical signs of disease were not observed in any PPMV-1-vaccinated birds after challenge.
    Avian Diseases 10/2006; 50(3):336-41. · 1.73 Impact Factor
  • Bruce S Seal, Daniel J King
    04/2006; , ISBN: 9780470015902
  • Avian Diseases - AVIAN DIS. 01/2006; 50(3):336-341.
  • [show abstract] [hide abstract]
    ABSTRACT: Avian paramyxovirus type 1, commonly referred to as Newcastle disease virus (NDV), is a serious pathogen of significant economic importance to the industry. To investigate the role of the fusion (F), hemagglutinin-neuraminidase (HN), and (P) phosphoprotein gene sequences in virulence, six strains of Newcastle disease virus (NDV) representing all pathotypes and seven recombinant strains created by reverse genetics were inoculated into 9-day-old chicken embryos. Tissues and chorioallantoic membranes (CAM) were harvested at 24-hour intervals post-inoculation. Riboprobe in situ hybridization and immunohistochemistry highlighted distinct tissue tropisms among the viruses. Presence of F and/or HN from virulent viruses inserted into lentogenic backbones caused dissemination of virus in a manner similar to wild type virulent viruses. Disruption of P gene decreased dissemination of velogeinic infectious clones. It is concluded that each of these genes contributes to pathogenicity.
    Microbial Pathogenesis 10/2005; 39(3):69-75. · 1.97 Impact Factor
  • Source
    Darrell R Kapczynski, Daniel J King
    [show abstract] [hide abstract]
    ABSTRACT: During 2002-2003, exotic Newcastle disease (END) virus caused a major outbreak among commercial and backyard poultry in southern California and adjacent states. The outbreak raised concerns regarding the protective immunity of commercially available vaccines for prevention and control of this virus in poultry. We sought to determine if existing commercial live and inactivated Newcastle disease virus (NDV) vaccines could provide protection against the 2002-2003 END virus, and whether current commercial NDV-vaccination programs for broiler-breeders (BB) and broilers (Br) would protect against END-challenge. In the first experiment, birds received a single dose of either inactivated or live B1-type vaccine at 2 weeks-of-age and were challenged 2 weeks post-vaccination with a lethal dose of END. In the second experiment, a high (10(6.9)EID50/bird) or low (10(3.9)EID50/bird) dose of live B1 was applied to 8-week-old chickens, followed by lethal END challenge. In the third experiment, NDV field-vaccinated commercial BB (65 weeks-of-age) and Br (36 days-of-age) were challenged against END virus. Results indicated that both the live and inactivated vaccines protected against morbidity and mortality and significantly reduced the incidence and viral titers shed from chickens in comparison with sham controls, but did not prevent infection and virus shedding. In addition, both doses of live vaccine protected birds and significantly decreased the number of birds shedding virus. All unvaccinated control chickens challenged with END died within 6 days post-challenge (pc). Protection from disease correlated with the presence of antibody titers (determined by enzyme-linked immunosorbent assay (ELISA) or hemagglutination inhibition (HI)) at day of challenge. Commercial BB were protected from disease and exhibited low incidence and titer of challenge virus shed. In contrast, commercial Br exhibited 66% mortality and shed significantly more virus than the BB birds. These results underscore the need to develop new NDV vaccines and vaccine strategies for use during outbreak situations to protect birds from both disease and infection to reduce virus shedding.
    Vaccine 06/2005; 23(26):3424-33. · 3.49 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Avian paramyxovirus 1 (APMV-1), also referred to as Newcastle disease virus (NDV), variants of low virulence were isolated from chickens, ducks and other unidentified species found in live-bird markets of the northeastern United States. These isolates were characterized as APMV-1 by the hemagglutination-inhibition (HI) assay utilizing NDV-specific polyclonal antisera. However, the isolates failed to react with a monoclonal antibody that has specificity for a wide variety of APMV-1 isolates. Although only highly virulent isolates require reporting to international regulatory agencies, the ability to correctly identify APMV-1 types is important for control and regulatory purposes. Protein gel patterns of the purified isolates resembled previously reported APMV-1 and anti-NDV polyclonal sera recognized the viral proteins. For three isolates oligonucleotide primers specific for the nucleoprotein, fusion protein and polymerase genes of NDV were utilized to synthesize cDNA using viral RNA as a template. Approximately 12kb of the genome was subsequently sequenced for the three isolates that included the nucleoprotein, phosphoprotein, matrix protein, fusion (F) protein, hemagglutinin-neuraminidase protein genes and a 5' portion of the polymerase gene. The isolates had an F protein cleavage site sequence of ERQER/LVG indicating low-virulence viruses that phylogenetically separated with other unique NDV isolates designated as a lineage 6 genotype. Additionally, a four amino acid insert was detected in the predicted phosphoprotein which complies with the "rule of six" among paramyxoviruses. These APMV-1 genotypes have not been previously reported in North America and further substantiate the heterogeneous genetic nature of these commercially important pathogens found worldwide.
    Veterinary Microbiology 04/2005; 106(1-2):7-16. · 3.13 Impact Factor

Publication Stats

540 Citations
68.73 Total Impact Points


  • 2002–2012
    • United States Department of Agriculture
      • Agricultural Research Service (ARS)
      Washington, D. C., DC, United States
  • 2003–2007
    • University of Georgia
      • • Department of Veterinary Pathology
      • • Department of Pathology
      Athens, GA, United States
  • 2004
    • Animal and Plant Health Inspection Service
      Buzzards Bay, Massachusetts, United States
  • 2001
    • Instituto Nacional de Tecnología Agropecuaria
      • Instituto de Biotecnología
      Buenos Aires, Buenos Aires F.D., Argentina