Leukocytes respiratory burst activity as indicator of innate immunity of pacu Piaractus mesopotamicus

Abstract

The present study evaluated the assay to quantify the respiratory burst activity of blood leukocytes of pacu as an indicator of the innate immune system, using the reduction of nitroblue tetrazolium (NBT) to formazan as a measure of the production of reactive oxygen species (ROS). In order to assess the accuracy of the assay, fish were challenged by Aeromonas hydrophila and sampled one week after challenge. The A. hydrophila infection increased the leukocyte respiratory burst activity. The protocol showed a reliable and easy assay, appropriate to determine the respiratory burst activity of blood leukocytes of pacu, a neotropical fish, in the present experimental conditions. Keywords: immune methodology, fish immunology, cellular immunity. Atividade respiratória de leucócitos como indicador de imunidade inata de pacu (Piaractus mesopotamicus)Resumo O presente estudo avaliou o ensaio para quantificar a atividade respiratória dos leucócitos do sangue de pacu como um indicador do sistema imune inato, usando a redução do nitroazul tetrazólio (NBT) a formazan como medida da produção de espécies reativas de oxigênio (EROs). Para avaliar a precisão do ensaio, peixes foram desafiados por Aeromonas hydrophila e amostrados uma semana após o desafio. A infecção com A. hydrophila aumentou a atividade respiratória dos leucócitos. O protocolo se mostrou confiável e de fácil aplicação, apropriado para determinar a atividade respiratória de leucócitos do sangue do pacu, peixe neotropical, nas condições experimentais apresentadas.Palavras-chave: metodologia, imunidade de peixe, imunidade mediada por células.

Energy deficit does not affect immune responses of experimentally infected pacu (Piaractus mesopotamicus)

“…In this study, we investigated the effects of energetic deficit following starvation on innate immune and metabolic responses of pacu, an important farmed fish in South America, after experimental pathogen exposure. Published studies have concerned pacu response to starvation [17,18], stress [19], metabolism [20] and immune responses [21] but none associated metabolic mobilization to an experimental bacterial infection.…”

Na2EDTA anticoagulant impaired blood samples from the teleost Piaractus mesopotamicus

“…The reactive oxygen species (ROS) production of the blood leukocytes was evaluated using nitroblue tetrazolium (NBT) reduction following the method of Biller--Takahashi et al (2013). Briefly, 100 µL of blood mixed with the anticoagulant was added to 100 µL of phosphate-buffered-saline (pH 8.4) containing NBT (Sigma, USA).…”

Disease resistance of pacu Piaractus mesopotamicus (Holmberg, 1887) fed with β-glucan

“…There are a few studies that report on immune manipulation of Brazilian species such as in pacu (Piaractus mesopotamicus) (Teleostei: Characidae) which is one of the most important freshwater fish farmed in Brazil (Jatobá et al, 2008;Biller-Takahashi et al, 2012;Mouriño et al, 2012;Biller-Takahashi et al, 2013). However, its farming has been facing disease threats and little information is available on the use of immunostimulants or the effects of bacterial infection in general Brazilian aquaculture (Garcia et al, 2007;Martins et al, 2009a;Biller-Takahashi et al, 2014).…”