ABSTRACT
Avipoxvirus affects chickens and wild birds, and it is characterized by lesions on the nonfeathered parts of the body (the cutaneous form), or necrotic lesions in the upper respiratory tract (the diphtheritic form). In poultry farming, avian pox is usually controlled by live attenuated vaccines. However, there have been many reports of outbreaks, even in flocks of vaccinated birds. In the present study, different outbreaks of the emerging clade E avipoxvirus were detected in commercial breeder flocks of chickens vaccinated against fowlpox virus in Southeast Brazil. Clinical manifestations of these outbreaks included a marked prevalence of moderate to severe progressive lesions in the beaks of affected birds, especially in roosters with increased mortality (up to 8.48%). Also, a reduced hatchability (up to 20.77% fewer hatching eggs) was observed in these flocks. Analysis of clinical samples through light and transmission electron microscopy revealed the presence of Bollinger bodies and poxvirus particles in epithelial cells and affecting chondrocytes. PCR, sequencing, and phylogenetic analysis of major core protein (P4b) and DNA polymerase (pol) genes identified this virus as clade E avipoxvirus. We also developed qPCR assays for open reading frames (ORFs) 49, 114, and 159 to detect and quantify this emergent virus. These results show the arrival and initial spread of this pathogen in the poultry industry, which was associated with harmful outbreaks and exacerbated clinical manifestations in vaccinated commercial breeder flocks. This study also highlights the relevance of permanent vigilance and the need to improve sanitary and vaccination programs.
Subject(s)
Avipoxvirus , Poultry Diseases , Animals , Avipoxvirus/genetics , Beak/pathology , Chickens , Disease Outbreaks/veterinary , Female , Male , Phylogeny , Poultry , Poultry Diseases/epidemiology , Poultry Diseases/prevention & control , Sex CharacteristicsABSTRACT
Chicken parvovirus (ChPV) is an agent frequently associated with runting stunting syndrome (RSS). This syndrome has been reported in association with ChPV in many countries, including Brazil; however, studies characterizing the virus on a molecular level are scarce, and ChPV pathogenicity in day-old chicks remains unclear. The aim of the present work was to establish the molecular characteristics of ChPV, determine the pathogenicity of ChPV in SPF chicks and detect and quantify ChPV by qPCR in several tissues and chicks of different ages. The experimental challenge was performed at one day of age, and daily and weekly observations were performed and five birds from each experimental group (mock and infected birds) were euthanized to perform the different analysis. ChPV genome copies were detected and quantified by qPCR in gut, spleen, thymus, kidney, pancreas, proventriculus and bursa. Clinically, the infected group presented with diarrhea 24 h post-infection, which persisted until 42 days of age. The small intestine was distended, and its contents were aqueous and foamy. Enteritis and dilated crypts with cyst shapes were observed in intestinal segments. Acute pancreatitis associated with lymphocytic nodules, infiltrating lymphocytes and plasma cells between the pancreatic acinus was observed. Koch's postulate was demonstrated and the genetic characterization of the VP1 gene showed that the Brazilian ChPV isolate belongs to the ChPV II group.
ABSTRACT
Marek's disease virus (MDV) and the reticuloendotheliosis virus (REV) are two of the primary oncogenic viruses that significantly affect chickens. In Brazil, there have been no previous published reports on the presence of field REV alone or in coinfection. This retrospective study analyzes samples from a case of lymphoproliferative lesions from a backyard chicken flock. MDV and REV were detected by PCR and classified as MDV1 and REV3, respectively, through sequencing and phylogenetic analysis based on the glycoprotein B (gB) genes for MDV and the polymerase (pol) and envelope (env) genes for REV. Real-time PCR reactions were performed for MDV to rule out the presence of the Rispens vaccine strain. This is the first report of the presence of REV in coinfection with a MDV clinical case in Brazil and the first molecular characterization of REV in South America. This study highlights the importance of molecular diagnosis for REV and MDV in poultry. In addition, this study highlights the distribution of these two viruses worldwide and the latent risk of them solely or in coinfection to this part of the world.
ABSTRACT
A infecção pelo vírus da imunodeficiência felina (FIV) em gatos domésticos é caracterizada por distúrbios imunológicos, que geralmente se manifestam tardiamente na doença. Semelhante à infecção pelo vírus da imunodeficiência humana (HIV) em humanos, a infecção pelo FIV geralmente está associada a infecções oportunistas e ao desenvolvimento progressivo de nefropatia. Portanto, o objetivo do presente estudo foi avaliar as alterações histopatológicas em rins de 10 gatos experimentalmente infectados pelo FIV submetidos a eutanásia 60 meses após a inoculação viral. Nos rins de 100% dos gatos infectados pelo FIV foram visualizadas lesões glomerulares e tubulointersticiais. As lesões glomerulares eram caracterizadas principalmente por espessamento global ou segmentar da membrana basal glomerular (glomerulonefrite membranosa). Glomeruloesclerose e, em dois casos, proliferação de células epiteliais intraglomerulares (crescente glomerular), também foram observados. Nefrite intersticial linfoplasmocítica foi a alteração tubulointersticial mais frequente, visualizada em diferentes intensidades nos rins de 100% dos gatos. Os resultados do presente estudo demonstram que o tempo prolongado entre a infecção e a avaliação histopatológica pode ter sido decisivo para o surgimento das lesões renais em todos os gatos infectados pelo FIV e para o agravamento dessas lesões em alguns gatos...
The feline immunodeficiency virus (FIV) infection in domestic cats is characterized by immunological disorders that commonly manifest in a later stage of the disease. Similarly to the human immunodeficiency virus (HIV) infection in humans, FIV infection is commonly associated with opportunistic infections and progressive development of nephropathies. Therefore, the aim of the present study was to perform histological evaluation of the kidneys of 10 cats experimentally infected with FIV and euthanized at 60 months after viral inoculation. In the kidneys of 100% of the cats infected with FIV, glomerular and tubulointerstitial lesions were seen. The glomerular lesions were mainly characterized by global or segmental thickening of the glomerular basement membrane (membranous glomerulonephritis). Glomerulosclerosis, and in two cases, proliferation of intraglomerular epithelial cells (glomerular crescent) were also observed. The intersticial lymphoplasmacytic nephritis was the tubulointerstitial alteration most frequent and was observed in different intensity levels in 100% of the cats. The results of the present study demonstrate that the prolonged time between infection and histopathological evaluation may have been decisive for the arising of renal lesions in all cats infected with FIV and for the increase of these lesions in some cats...
