Estudo comparativo da virulência de amostras de vacina do vírus da doença de Newcastle em galinhas SPF por meio da análise morfométrica da espessura traqueal

Nunes, J.; Vasconcelos, A.C.; Jorge,; Guimarães, Euripedes Batista; Martins, N. R. S.; Resende, J.S.

doi:10.1590/s0102-09352002000400001

Cited by 6 publications

(3 citation statements)

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“…To assess the post-vaccination reaction in the trachea of birds subjected to ND vaccination, we compared the groups to each other. The results seen at four and seven days post vaccination were similar to results described by Nunes et al (2002), in which the pneumotropic La Sota samples had greater thickness of the tracheal mucosa, coherent to it is ICPI. The superior quality of the ST3 was evident at 14 and 21 days, as demonstrated by the lesser thickness of the mucosa in comparison to the results of the other strains.…”

Section: Discussionsupporting

confidence: 87%

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Tracheal post-vaccinal reaction to different strains of Newcastle disease vírus

et al. 2022

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The aim of the present study was to evaluate the post-vaccinal reaction to two lentogenic vaccine strains of Newcatle disease virus (NDV) and a recombinant turkey herpesvirus (rHVT) vaccine expressing the fusion glycoprotein of NDV in broiler chickens through histomorphometric and histopathologic analyses of the trachea. The experiment involved 245 chicks housed in randomized blocks with three different enclosures under controlled conditions of temperature, light and ventilation. Each enclosure represented a vaccine strain and was divided into groups according to the administration route. Each block also had its own control group composed of unvaccinated birds. The vaccine strains PHY.LMV.42 (PL42) and La Sota (LS) were selected according to the Intracerebral Pathogenicity Index (ICPI) and the rHVT-NDV Serotype 3 strain (ST3) was selected for representing non-NDV infection. At two, four, seven, 14 and 21 days post vaccination, fragments from the middle third of the trachea were collected and submitted to routine histological processing. For the histomorphometric analysis, the slides were photographed, and the thickness of the tracheal mucosa was measured. Statistical analysis involved two-way ANOVA and Tukey’s post-hoc test with a 5% significance level. For the histopathological evaluation, lesions were described as to the degree of intensity and distribution. At four and 14 days post vaccination with the LS strain administered by the ocular route, the means of thickening of the tracheal mucosa (20.85±7.31μm and 26.97±5.50μm, respectively) were significantly higher (p<0.05) than for all other strains, which was related to the severe histopathological lesions found in this group, characterized by hyperemia, hyperplasia of the mucous glands, moderate deciliation and multifocal lymphohistiocytic inflammatory infiltrate. At 21 days, broiler chickens vaccinated with the ST3 strain showed more discrete lesions and less thickening of the tracheal mucosa (23.23±7.62μm; p<0.05) in comparison with other studied strains. The lesions found in this group were only hemorrhage, deciliation and mild focal lymphocytic inflammatory infiltrate. The results of the histomorphometry and histopathology of the trachea indicated that vaccination with rHVT-NDV Serotype 3 strain induced lower degree post-vaccine tracheal lesions compared to other vaccine strains analyzed in this study.

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Section: Discussionsupporting

confidence: 87%

“…Histomorphometric and histopathologic analyses. The protocol described by Nunes et al (2002) was used for the histomorphometric analysis of the tracheal mucosa. The slides were examined and photographed (magnification: 40X) with a DM500 Leica ® trinocular optical microscope.…”

Section: Methodsmentioning

confidence: 99%

Tracheal post-vaccinal reaction to different strains of Newcastle disease vírus

et al. 2022

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“…After vaccination with the VG/ GA strain, solid immunity to virulent NDV is conferred to inoculated chickens with or without the presence of maternal antibodies as evidenced by resistance to virulent NDV challenge [15,17]. Additionally, the vaccine-induced respiratory reactions are decreased or avoided when using the VG/GA strain, probably by diminishing the level of replication in the respiratory epithelia of young chickens [18].…”

Section: Introductionmentioning

confidence: 99%

Genomic comparison of the complete coding and intergenic regions of the VG/GA Newcastle disease virus and its respirotropic clone 5

2008

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The complete genome of the Villegas-Glisson/University of Georgia (VG/GA) strain of Newcastle disease virus (NDV) and that of a plaque purified clone (clone 5) exhibiting a respiratory phenotype were sequenced and analyzed. The VG/GA strain, isolated from the intestine of healthy turkeys, replicates in the respiratory and intestinal tract of chickens. It is used worldwide as a vaccine strain and its tissue tropism is extremely important for protection against velogenic viscerotropic NDV which targets both intestinal and respiratory epithelia, inducing severe gross and microscopic damage. The clone 5, a plaque purified clone from the VG/GA strain, cannot be recovered from the intestine of infected birds, suggesting a respirotropic nature. A modified primer sequence-independent amplification method was used to sequence the complete coding regions of both viruses and to assess phylogenetic relationships and genomic basis for phenotype differences. The phylogenetic analysis grouped the VG/GA strain and the clone 5 within class II, genotype II viruses and showed that they are greater than 99.9% identical with only 5 nucleotides differences. Both are closely related to classic vaccine strains, such as LaSota and B1. Only 3 amino acid differences at the fusion protein differentiated the VG/GA strain from the clone 5. These differences may explain the differential phenotype observed in the VG/GA strain and are discussed.

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The VG/GA strain of Newcastle disease virus: mucosal immunity, protection against lethal challenge and molecular analysis

et al. 2008

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The VillegasÁGlisson/University of Georgia (VG/GA) strain of Newcastle disease virus (NDV) isolated from the intestine of healthy turkeys has been proposed to replicate in the respiratory and intestinal tract of chickens. In the present study, the virus distribution, the mucosal and systemic immune response, the efficacy against lethal challenge and the full genome sequence of the VG/GA strain were compared with the La Sota strain of NDV. The VG/GA strain was detected at different time points in the respiratory and intestinal tract of chickens with a preferential tropism for the latter. Both the VG/GA and La Sota strains induced NDVspecific immunoglobulin A (IgA) at the upper respiratory tract. IgA levels were higher in the trachea for the La Sota strain, while they were higher in the bile and intestine for the VG/GA strain. Positive correlation between virus distribution of the viruses and IgA production was observed. Despite the presence of the maternal antibodies in broilers, early vaccination with the VG/GA strain afforded 95% to 100% protection against lethal challenge, equivalent to the protection conferred by the La Sota strain. Full genome sequence analysis classified the VG/GA strain within class II, genotype II viruses, which also include most of the respirotropic vaccine strains. Differences with the La Sota strain at the nucleotide and amino acid levels that may explain the differential phenotype of the VG/GA were observed; however, verification of the significance of those changes is required. Taken together, these results validate field observations on the efficacy of VG/ GA vaccination and demonstrated the unique characteristics of the strain.

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Estudo comparativo da virulência de amostras de vacina do vírus da doença de Newcastle em galinhas SPF por meio da análise morfométrica da espessura traqueal

Cited by 6 publications

References 4 publications

Tracheal post-vaccinal reaction to different strains of Newcastle disease vírus

Tracheal post-vaccinal reaction to different strains of Newcastle disease vírus

Genomic comparison of the complete coding and intergenic regions of the VG/GA Newcastle disease virus and its respirotropic clone 5

The VG/GA strain of Newcastle disease virus: mucosal immunity, protection against lethal challenge and molecular analysis

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