MAPK involvement in cytokine production in response to Corynebacterium pseudotuberculosis infection.

BACKGROUND: Caseous lymphadenitis (CL) is a contagious infectious disease of small ruminants caused by Corynebacterium pseudotuberculosis. Is characterized by the formation of abscesses in the lymph nodes and intestines of infected animals, induced by inflammatory cytokines. The production of cytokines, such as IL-10, TNF-α, IL-4 and IFN-γ, is regulated by mitogen-activated protein kinase (MAPK) pathway activation. The present study investigated the involvement of MAPK pathways (MAPK p38, ERK 1 and ERK 2) with respect to the production of cytokines induced by antigens secreted by C. pseudotuberculosis over a 60-day course of infection. CBA mice (n = 25) were divided into three groups and infected with 102 colony forming units (CFU) of attenuated strain T1, 102 CFU of virulent strain VD57 or sterile saline solution and euthanized after 30 or 60 days. Murine splenocytes were treated with specific inhibitors (MAPK p38 inhibitor, ERK 1/2 inhibitor or ERK 2 inhibitor) and cultured with secreted antigens obtained from pathogenic bacteria (SeT1 or SeVD57). RESULTS: The MAPK pathways evaluated were observed to be involved in the production of IL-10, under stimulation by secreted antigens, while the MAPK p38 and ERK 1 pathways were shown to be primarily involved in TNF-α production. By contrast, no involvement of the MAPK p38 and ERK 1 and 2 pathways was observed in IFN-γ production, while the ERK 2 pathway demonstrated involvement in IL-4 production only in the mouse splenocytes infected with VD57 under stimulation by SeT1. CONCLUSION: The authors hypothesize that MAPK p38 and ERK 1 pathways with respect to TNF-α production, as well as the MAPK p38 and ERK 1 and 2 pathways in relation to IL-10 production under infection by C. pseudotuberculosis are important regulators of cellular response. Additionally, the lack of the MAPK p38 and ERK 1/2 pathways in IFN-γ production in infected CBA murine cells stimulated with the two secreted/excreted antigens, in IL-4 production showing involvement only via the ERK 2 pathway under stimulation by SeT1 antigen during 60-day infection period with the virulent strain, suggests that these pathways regulated the production of pro-inflammatory and regulatory cytokines in the splenic cells of CBA mice.

Anticorpos contra o vírus da Doença Infecciosa Bursal e detecção do genoma viral em criações de frango de corte e galinhas de quintal no polo avícola da Bahia / Antibodies anti-Infectious Bursal Disease virus and viral genome detection in broilers and chickens backyard at Bahia's poultry production area

Este estudo teve como objetivo determinar a frequência de anticorpos e detectar o genoma viral do vírus da Doença Infecciosa Bursal em criações de frangos de corte e em criações de subsistência localizadas em duas regiões do polo avícola da Bahia. Foram coletadas 758 amostras de soro de frangos de corte e 320 amostras de galinhas de quintal para avaliação da frequência de anticorpos utilizando ELISA indireto. Para a detecção e caracterização do vírus foram coletados 6 pools de bursas de Fabrícius em frangos de corte e 3 pools em criações de subsistência, analisados posteriormente com PCR/RFLP. Os resultados revelaram que não há proteção uniforme na criação comercial nas duas regiões estudadas, sugerindo falha na vacinação e desafio com vírus no ambiente. Também observaram-se altos títulos em galinhas de quintal não vacinadas, com variação nos títulos relacionada com desafios de campo. Nos testes moleculares, verificaram-se que três pools de frangos de corte eram positivos, sendo dois para cepa vacinal (G3) e um para cepa variante (G15). Nas criações de subsistência, houve uma amostra positiva para cepa variante (G15). Os resultados demonstram a necessidade de monitoramento em ambas as criações.

The aim of this study was to determine the frequency of antibodies anti-Infectious Bursal Disease Virus as well as to detect the virus in broilers and chicken backyard, raised in two different regions at Bahia's poultry production area. A total of 758 serum samples were collected from broilers and 320 from chicken backyard, in order to assess the frequency of antibodies using an indirect ELISA. For virus detection and characterization it was collected 6 bursal pools from broilers and 3 from chicken backyard, which were further analyzed with PCR/RFLP. The results showed that there is no uniform protection in commercial flocks of the two different regions, suggesting that it may be occurring vaccination errors and that it may be occurring challenge from viruses at the environment. High titers were observed in no vaccinated chicken backyard. Molecular tests revealed that 3 broilers pools were positive in which 2 matched the vaccine strain (G3) and 1 a variant strain (G15). One sample from free-ranging chickens was positive for the variant strain (G15). These results demonstrate the need for monitoring both types of exploration.

Soroepidemiologia da doença de Newcastle em plantéis de avestruzes dos Estados da Bahia e de São Paulo / Serologic occurrence of Newcastle disease in ostriches raised in Bahia and São Paulo

Estudos sorológicos em Avestruzes (Struthio camelus) são ferramentas úteis para analisar os riscos relacionados à Doença de Newcastle nesses plantéis e à avicultura nacional. No presente estudo, amostras de sangue foram obtidas de avestruzes de ambos os sexos, de diferentes faixas etárias e sem apresentação de sintomatologia clínica, criadas nos Estados da Bahia e de São Paulo com o objetivo de avaliar a presença de anticorpos contra o vírus da Doença de Newcastle por meio de ELISA indireto. Foram testadas 339 amostras provenientes do Estado da Bahia e 105 amostras do Estado de São Paulo. Apesar de os proprietários afirmarem que não foi utilizada vacina em seus animais, foi verificada positividade na Bahia de 17,9 por cento e de 4,7 por cento em São Paulo, em avestruzes, sugerindo contato com vírus vacinal ou de campo.

Serological studies in ostriches (Struthio camelus) are important tools to assess the risk of Newcastle disease in these herds and to the national poultry industry. In the present study blood samples were obtained from male and female ostriches without symptoms of the disease, raised in Bahia and São Paulo in order to evaluate the presence of antibodies against Newcastle disease virus using an indirect ELISA. There were collected 339 samples in Bahia and 105 samples in São Paulo. Although the owners guarantee that animals were not vaccinated, it was verified the presence 17,9 percent positives in Bahia and 4,7 percent in São Paulo, suggesting contact with vaccinal or field strain.