ABSTRACT
Gill disorders have become more prevalent and widespread in finfish aquaculture in recent years. Their aetiology is often considered to be multifactorial. Effective diagnosis, control and prevention are hindered by the lack of standardised methodologies to characterise the aetiological agents, which produce an array of clinical and pathological presentations. The aim of this study was to define a novel gross pathological scoring system suitable for field-based macroscopic assessment of complex or multifactorial gill disease in farmed Atlantic salmon, using samples derived from a gill disease outbreak in Chile. Clinical assessment of gross gill morphology was performed, and gill samples were collected for qPCR and histology. A novel total gill scoring system was developed, which assesses gross pathological changes combining both the presumptive or healed amoebic gill disease (AGD) and the presence of other types of gill lesions. This scoring system offers a standardised approach to characterise the severe proliferative pathologies in affected gills. This total gill scoring system can substantially contribute to the development of robust mitigation strategies and could be used as an indicator trait for incorporating resistance to multifactorial gill disease into breeding goals.
ABSTRACT
Bacterial kidney disease (BKD) is widespread in many areas of the world and can cause substantial economic losses for the salmon aquaculture industry. The objective of this study was to investigate the pathophysiological response and gene expression profiles related to the immune response at different water temperatures and to identify the best immunopathological biomarkers to define a phenotype of resistance to BKD. The abundance of msa transcripts of R. salmoninarum in the head kidney was significantly higher in infected fish at 11°C. R. salmoninarum induced significantly more severe kidney lesions, anemia and impaired renal function at 11°C. In addition, the expression pattern of the genes related to humoral and cell-mediated immune responses in infected fish at 11 and 15°C was very similar, although R. salmoninarum induced a significantly greater downregulation of the adaptive immune response genes at the lower water temperature. These results could be due to a suppressed host response directly related to the lowest water temperature and/or associated with a delayed host response related to the lowest water temperature. Although no significant differences in survival rate were observed, fish infected at the lowest temperature showed a higher probability of death and delayed the mortality curve during the late stage of infection (35 days after infection). Thirty-three immunopathological biomarkers were identified for potential use in the search for a resistance phenotype for BKD, and eight were genes related specifically to the adaptive cell-mediated immune response.
Subject(s)
Fish Diseases/immunology , Fish Diseases/microbiology , Gram-Positive Bacterial Infections/veterinary , Salmo salar/immunology , Salmo salar/microbiology , Animals , Cold Temperature , Disease Resistance/genetics , Environment , Gram-Positive Bacterial Infections/immunology , Immunity, Cellular/genetics , Immunity, Cellular/immunology , Renibacterium , Salmo salar/genetics , Transcriptome , WaterABSTRACT
Se seleccionaron 56 pacientes embarazadas controladas en el Programa Maternidad de el Consultorio General Urbano (C.G.U.) Dr. Mateo Bencur de Punta Arenas, para participar en una experiencia orientada a deterninar los efectos de la clorhexidina gel al 1 por cento usada como dentífrici, en el desarrollo de la placa microbiana y gingivitis. Todas las pacientes usaron clorhexidina gel al 1 por cento durante ocho semanas sin modificar los hábitos de higiene bucal, solamente reemplazaron su dentífrico por el gel. Los índice de placa y gingival fueron determinados al inicio y al final de la exoeriencia observándose una reducción estadísticamente significativa de ellos. El diseño experimental aplicado fue Antes-Después. Los resultados mostraron una reducción estadísticamente significativa en los índices de placa y gingival
