RESUMO

Avian poxvirus (APV) is an enveloped double-stranded DNA virus that affects many domestic and wild birds worldwide. APVs are classified into three clades (A to C), represented by fowlpox (FP) virus (clade A), canarypox virus (clade B), and psittacinepox virus (clade C), although two additional clades (D and E) have been proposed. In this study, a tumorlike skin lesion found in a domestic fowl was submitted for molecular diagnosis of Avipoxvirus by PCR and sequencing. The phylogenetic analysis revealed that the amplified segment of the corelike 4b protein and polymerase genes clustered in clade E. The APVs in clade E were previously reported from outbreaks in Hungary (flock of turkeys) and in Mozambique (layer chickens), associated with a possible vaccine failure to protect against clade E viruses. To our knowledge, this report is the first identification of clade E in this country, providing new information about host range and genetic diversity of APVs in Brazil, and may represent a potential risk of FP disease outbreaks in commercial poultry.

Reporte de caso- Identificación del Avipoxvirus clado E en Brasil. El poxvirus aviar (APV) es un virus de ADN bicatenario envuelto que afecta a muchas aves domésticas y silvestres en todo el mundo. Los poxvirus aviares se clasifican en tres clados (A, B y C), representados por el virus de la viruela aviar (FP) (clado A), el virus de la viruela del canario (clado B) y el virus de la viruela de los psitácidos (clado C), aunque dos clados adicionales (D y E) han sido propuestos. En este estudio, una lesión cutánea similar a un tumor encontrada en una gallina doméstica fue sometida a diagnóstico molecular de Avipoxvirus por PCR y secuenciación. El análisis filogenético reveló que el segmento amplificado de los genes de la proteína del centro 4b y de la polimerasa se agruparon en el clado E. Los poxvirus aviares en el clado E se reportaron previamente de brotes en Hungría (parvada de pavos) y en Mozambique (gallinas de postura), asociados con una posible falla de la vacuna para proteger contra los virus del clado E. De acuerdo con el conocimiento de los autores, este informe es la primera identificación del clado E en este país, brindando nueva información sobre el rango de hospedadores y la diversidad genética de poxvirus aviares en Brasil, y puede representar un riesgo potencial de brotes de viruela aviar en aves comerciales.

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Salmonella enterica subsp. enterica serovar Gallinarum biovar Gallinarum (SG) causes fowl typhoid (FT), a septicaemic disease which can result in high mortality in poultry flocks. The absence of flagella in SG is thought to favour systemic invasion, since bacterial recognition via Toll-like receptor (TLR)-5 does not take place during the early stages of FT. In the present study, chicks susceptible to FT were inoculated with a wild type SG (SG) or its flagellated motile derivative (SG Fla(+)). In experiment 1, mortality and clinical signs were assessed, whereas in experiment 2, gross pathology, histopathology, systemic invasion and immune responses were evaluated. SG Fla(+) infection resulted in later development of clinical signs, lower mortality, lower bacterial numbers in the liver and spleen, and less severe pathological changes compared to SG. The CD8(+) T lymphocyte population was higher in the livers of chicks infected with SG at 4 days post-inoculation (dpi). Chicks infected with SG had increased expression of interleukin (IL)-6 mRNA in the caecal tonsil at 1 dpi and increased expression of IL-18 mRNA in the spleen at 4 dpi. In contrast, the CD4(+) T lymphocyte population was higher at 6 dpi in the livers of birds infected with SG Fla(+). Therefore, flagella appeared to modulate the chicken immune response towards a CD4(+) T profile, resulting in more efficient bacterial clearance from systemic sites and milder infection.

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Ad libitum feeding causes excessive follicular development and is associated with extensive metabolic changes in broiler - breeder hens. Restricting feed intake reduces excessive follicular development, but the mechanisms mediating this response are unknown. In the present study, the effects of feeding on follicular development in immature broil er - breeder hens were examined. There was an increase in the proportion of follicles 100 - 300, 300 - 500 and >500 μ m in diameter and a decrease in follicles <100 μ m in full - fed (FF) compared to restricted - fed (RF) hens. Increased follicular development in FF hens was associated with a greater expression of steroidogenic transcripts ( STAR, CYP11A1, HSD3B , and CYP19 ) within the ovarian cortex of FF hens. These transcripts represent markers of more advanced follicular development. However, increased follicular development in FF hens was not associated with changes in the expression of other factors previously implicated in follicular development, including those encoding TGF - beta ligands ( AMH, BMP6, BMP15 , or GDF9 ) or their signaling proteins (SMAD2/3 or SMAD1/5/9). Changes in histone modifications associated with proliferation, including trimethylated histone H3K4, trimethylated histone H3K27 , and acetylated histone H3K9 , we re also not different between treatment groups. However, feed restriction caused serine phosphorylation to localize strongly to the ovarian stroma of FF hens compared to RF hens. In contrast, phosphorylation of tyrosine residues localized more prominently to the surface of granulosa cells from RF hens. Thus, restricted feeding may enhance the efficiency of reproduction by suppressing early follicular development which is associated with changes in granulosa cell protein phosphorylation status.

Assuntos

RESUMO

Ad libitum feeding causes excessive follicular development and is associated with extensive metabolic changes in broiler - breeder hens. Restricting feed intake reduces excessive follicular development, but the mechanisms mediating this response are unknown. In the present study, the effects of feeding on follicular development in immature broil er - breeder hens were examined. There was an increase in the proportion of follicles 100 - 300, 300 - 500 and >500 μ m in diameter and a decrease in follicles <100 μ m in full - fed (FF) compared to restricted - fed (RF) hens. Increased follicular development in FF hens was associated with a greater expression of steroidogenic transcripts ( STAR, CYP11A1, HSD3B , and CYP19 ) within the ovarian cortex of FF hens. These transcripts represent markers of more advanced follicular development. However, increased follicular development in FF hens was not associated with changes in the expression of other factors previously implicated in follicular development, including those encoding TGF - beta ligands ( AMH, BMP6, BMP15 , or GDF9 ) or their signaling proteins (SMAD2/3 or SMAD1/5/9). Changes in histone modifications associated with proliferation, including trimethylated histone H3K4, trimethylated histone H3K27 , and acetylated histone H3K9 , we re also not different between treatment groups. However, feed restriction caused serine phosphorylation to localize strongly to the ovarian stroma of FF hens compared to RF hens. In contrast, phosphorylation of tyrosine residues localized more prominently to the surface of granulosa cells from RF hens. Thus, restricted feeding may enhance the efficiency of reproduction by suppressing early follicular development which is associated with changes in granulosa cell protein phosphorylation status.(AU)

Assuntos