RESUMEN
This study aimed at determining the clinical and pathological effects of the coinfection of young SPF chickens with chicken anemia virus (CAV) and Mycoplasma gallisepticum (MG) vaccine strains. The clinical signs, gross and microscopic lesions were determined after the experimental coinfection broilers with a CAV genotype 1 vaccine strain given intraperitoneally on the first day of age and a MG F-strain vaccine given intranasally on the 8th day of age. The experimental groups included the negative control (group 1), a group infected with the MG F-strain vaccine (group 2), and a group coinfected with CAV and MG vaccines (group 3). Chicks were examined clinically and post mortem at 23 days of age, and gross and microscopic lesions of the trachea, thymus, and air sacs were compared among treatments (Kruskal-Wallis test). Infections were confirmed by PCR for specific genetic fragments of each agent in the target tissues. Mortality was only observed in chicks on group 3, with two deaths and more severe lesions in the trachea, thymus and air sacs compared with groups 1 and 2 (p < 0.01). Dead chicks presented reduced thymus and spleen size, hemorrhagic trachea with catarrhal exudate and partial obstruction, pericarditis, catarrhal airsacculitis, lungs with liquid and ascites. The surviving chicks in group 3 showed more severe respiratory changes than those in group 2, in addition to thymus and spleen size reduction. Results indicate the adverse effects of the coinfection of young chickens with MG F-strain and CAV genotype 1 vaccines.
Asunto(s)
Animales , Coinfección/fisiopatología , Coinfección/veterinaria , Pollos/fisiología , Mycoplasma gallisepticum/patogenicidad , Virus de la Anemia del Pollo/fisiología , Administración Intranasal/veterinaria , Infecciones por Circoviridae/veterinaria , Infecciones por Mycoplasma/veterinaria , Inyecciones Intraperitoneales/veterinaria , Vacunas/uso terapéuticoRESUMEN
This study aimed at determining the clinical and pathological effects of the coinfection of young SPF chickens with chicken anemia virus (CAV) and Mycoplasma gallisepticum (MG) vaccine strains. The clinical signs, gross and microscopic lesions were determined after the experimental coinfection broilers with a CAV genotype 1 vaccine strain given intraperitoneally on the first day of age and a MG F-strain vaccine given intranasally on the 8th day of age. The experimental groups included the negative control (group 1), a group infected with the MG F-strain vaccine (group 2), and a group coinfected with CAV and MG vaccines (group 3). Chicks were examined clinically and post mortem at 23 days of age, and gross and microscopic lesions of the trachea, thymus, and air sacs were compared among treatments (Kruskal-Wallis test). Infections were confirmed by PCR for specific genetic fragments of each agent in the target tissues. Mortality was only observed in chicks on group 3, with two deaths and more severe lesions in the trachea, thymus and air sacs compared with groups 1 and 2 (p < 0.01). Dead chicks presented reduced thymus and spleen size, hemorrhagic trachea with catarrhal exudate and partial obstruction, pericarditis, catarrhal airsacculitis, lungs with liquid and ascites. The surviving chicks in group 3 showed more severe respiratory changes than those in group 2, in addition to thymus and spleen size reduction. Results indicate the adverse effects of the coinfection of young chickens with MG F-strain and CAV genotype 1 vaccines.(AU)
Asunto(s)
Animales , Coinfección/fisiopatología , Coinfección/veterinaria , Pollos/fisiología , Virus de la Anemia del Pollo/fisiología , Mycoplasma gallisepticum/patogenicidad , Vacunas/uso terapéutico , Inyecciones Intraperitoneales/veterinaria , Administración Intranasal/veterinaria , Infecciones por Circoviridae/veterinaria , Infecciones por Mycoplasma/veterinariaRESUMEN
A anemia infecciosa das galinhas(AIG) é uma das mais importantes doenças do sistema imune de galinhas domésticas.Por muito tempo, as doenças anêmico-hemorrágicas foram pouco entendidas,com confusões nas descrições das patogenias da anemia infecciosa,da doença infecciosa bursal e das adenoviroses,possivelmente em razão de as infecções naturais serem comumente combinadas [11]. Outras doenças hemorrágicas e que afetam o sistema imune e a medula óssea, como as micotoxicoses,muitas vezes associadas às infecções virais, agravam o quadro patológico.Em 1979, no Japão, entretanto,com a descrição do vírus da anemia infecciosa das galinhas (CAV), inicia-se o esclarecimento da importante doença[14]. O CAV pode ter estado envolvidona maioria dos episódios de doença anêmico-hemorrágica de etiologia infecciosa descrita antes de sua descoberta.
Asunto(s)
Animales , Virus de la Anemia del Pollo/fisiología , Virus de la Anemia del Pollo/patogenicidad , Anemia/veterinaria , Aves de Corral/virología , Pollos/fisiología , Pollos/virología , Crianza de Animales Domésticos , Vacunas/uso terapéutico , Inmunoterapia Activa/veterinaria , Transmisión de Enfermedad Infecciosa/veterinariaRESUMEN
Infection of poultry with chicken anemia virus (CAV) is implicated in several field problems in broiler flocks due to the immunosuppression generated and, consequently, the increased susceptibility to secondary infections. Recently, we have reported an increased occurrence of clinical cases caused by CAV strains distantly related to those commonly used for vaccination. In order to understand the behavior of two Argentinean CAV strains (CAV-10 and CAV-18) in two-week-old chickens, an immune and histopathological study was performed. Neither mortality nor clinical signs were observed in the infected or control groups. Thymus lobes from chickens infected with both CAV viruses were smaller compared to the negative control group. At 14 days post-infection (dpi), only chickens inoculated with CAV-10 show a severe depletion of lymphocytes in the thymus cortex and in follicles from the bursa of Fabricius. Also thymopoiesis disorders, such as reduction in the percentage of total DP (CD4 + CD8α+) thymocytes and alteration in the percentages of DP subpopulations, were more important in animals inoculated with the CAV-10 than the CAV-18 strain. In addition, only animals infected with CAV-10 show a decrease in CD8αß splenocytes. Altogether our results show that, although both Argentinean CAV strains produce subclinical infections in chickens causing immunosuppression at 14 dpi, they might differ in their in vivo pathogenicity.
Asunto(s)
Virus de la Anemia del Pollo/fisiología , Pollos , Infecciones por Circoviridae/veterinaria , Genoma Viral , Enfermedades de las Aves de Corral/virología , Subgrupos de Linfocitos T/metabolismo , Animales , Argentina , Infecciones Asintomáticas , Bolsa de Fabricio/inmunología , Bolsa de Fabricio/virología , Virus de la Anemia del Pollo/genética , Virus de la Anemia del Pollo/inmunología , Infecciones por Circoviridae/inmunología , Infecciones por Circoviridae/patología , Tolerancia Inmunológica , Datos de Secuencia Molecular , Enfermedades de las Aves de Corral/inmunología , Enfermedades de las Aves de Corral/patología , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria , Bazo/inmunología , Bazo/virología , Timo/inmunología , Timo/virologíaRESUMEN
The pathogens Plasmodium juxtanucleare and chicken anaemia virus (CAV) are easily transmitted and potentially harmful to chickens. In this study, we established an experimental model to investigate the effects of avian malaria caused by P. juxtanucleare in white leghorn specific-pathogen-free (SPF) chicks previously immunosuppressed with CAV. Parasitaemia, haematological variables and clinical and pathological parameters were determined in four different experimental groups: chicks coinfected by CAV and P. juxtanucleare strain (Coinfected group), chicks exclusively infected by CAV (CAV group) or P. juxtanucleare (Malaria group) and uninfected chicks (Control group). Our data demonstrated that P. juxtanucleare parasitaemia was significantly higher in the Coinfected group. Furthermore, haematological parameters, including the RBC, haematocrit and haemoglobin concentration were significantly reduced in coinfected chicks. In agreement with the changes observed in haematological features, the mortality among coinfected chicks was higher compared with animals with single infections. Clinical analysis indicated moderate changes related to different organs size (bursa of Fabricius, heart and liver) in coinfected birds. The experimental coinfection of SPF chickens with P. juxtanucleare and CAV may represent a research tool for the study of avian malaria after CAV immunosuppression, enabling measurement of the impacts caused by different pathogens during malarial infection.
Asunto(s)
Virus de la Anemia del Pollo/fisiología , Infecciones por Circoviridae/veterinaria , Malaria Aviar/parasitología , Plasmodium/clasificación , Plasmodium/fisiología , Enfermedades de las Aves de Corral/parasitología , Animales , Pollos , Infecciones por Circoviridae/complicaciones , Coinfección , Huésped Inmunocomprometido , Malaria Aviar/complicaciones , Filogenia , Plasmodium/genética , Enfermedades de las Aves de Corral/etiología , Enfermedades de las Aves de Corral/virología , Organismos Libres de Patógenos EspecíficosRESUMEN
Specific amino acid (aa) substitutions in VP1, VP2 and VP3 genes were reported as a distinctive feature of the American CIA-1 strain, characterized as having a variable rate of growth and tropism for different MSB-1 cell sublines [Renshaw RW, Soiné C, Weinkle T, O'Connell PH, Ohashi K, Watson S, et al. A hypervariable region in VP1 of chicken anemia virus mediates rate of spread and cell tropism in tissue culture. J Virol 1996;70(12):8872-8]. DNA sequencing of 878 nucleotides from twelve Brazilian CAV, eight of which tested for in vitro isolation in three different sources of MDCC-MSB1 cell line and identified as lacking capacity to propagate in any of these cells, were compared to sequence data available for CAV strains propagated or not in cell culture. Alignment of the deduced aa resulted in a lack of singled out amino acid substitutions in the partial genomic sequences of Brazilian isolates that would entirely contrast them to viruses propagated in MSB-1 cells, indicating that the combined VP1, VP2 and VP3 substitutions observed may not entirely account as sole determinants of CAV isolation and propagation in MDCC-MSB-1 cells.