Search

The exploration of novel biomarkers to assess poultry health is of paramount importance, not only to enhance our understanding of the pathogenicity of zoonotic agents but also to evaluate the efficacy of novel treatments as alternatives to antibiotics. The present study aimed to investigate potential gut health biomarkers in broiler chicks challenged by Campylobacter jejuni and subjected to a continuous water disinfection program. A total of 144 one-day-old hatched broiler chicks were randomly allocated to four treatment groups with four replicates each, according to the following experimental design: Group A received untreated drinking water; Group B received drinking water treated with 0.01-0.05% v / v Cid 2000™ (hydrogen peroxide, acetic acid and paracetic acid); Group C was challenged by C. jejuni and received untreated drinking water; and Group D was challenged by C. jejuni and received drinking water treated with 0.01-0.05% v / v Cid 2000™. The use of Cid 2000™ started on day 1 and was applied in intervals until the end of the experiment at 36 days, while the C. jejuni challenge was applied on day 18. Potential biomarkers were investigated in serum, feces, intestinal tissue, intestinal content, and liver samples of broilers. Statistical analysis revealed significant increases ( p < 0.001) in serum cortisol levels in C. jejuni -challenged broilers. Serum fluorescein isothiocyanate dextran (FITC-d) increased significantly ( p = 0.004) in broilers challenged by C. jejuni and treated with drinking water disinfectant, while fecal ovotransferrin concentration also increased significantly ( p < 0.001) in broilers that received the drinking water disinfectant alone. The gene expression levels of occludin ( p = 0.003) and mucin-2 ( p < 0.001) were significantly upregulated in broilers challenged by C. jejuni , while mucin-2 significantly increased in birds that were challenged and received the drinking water disinfectant ( p < 0.001). TLR-4 expression levels were significantly ( p = 0.013) decreased in both groups that received the drinking water disinfectant, compared to the negative control group. Finally, the C. jejuni challenge significantly increased ( p = 0.032) the crypt depth and decreased ( p = 0.021) the villus height-to-crypt-depth ratio in the ileum of birds, while the tested disinfectant product increased ( p = 0.033) the villus height in the jejunum of birds. Furthermore, the counts of C. jejuni in the ceca of birds ( p = 0.01), as well as its translocation rate to the liver of broilers ( p = 0.001), were significantly reduced by the addition of the water disinfectant. This research contributes to novel insights into the intricate interplay of water disinfection and/or C. jejuni challenge with potential intestinal biomarkers. In addition, it emphasizes the need for continued research to unveil the underlying mechanisms, expands our understanding of broiler responses to these challenges and identifies breakpoints for further investigations.

Clinical manifestations from the lower respiratory tract are rare in canine leishmaniosis (CanL), making bronchoscopy and lung fine-needle aspiration (FNA) seldomly justified. The aim of this prospective study was to investigate the involvement of Leishmania infantum in the lungs of dogs with naturally occurring CanL by bronchoscopy and examination of bronchoalveolar lavage fluid (BALF), bronchial mucosa biopsies, and FNA, using immunodiagnostics. Dogs with relevant concurrent diseases and azotemia were excluded. Cough was detected in 5/31 (16.1%) dogs. Lesions (hyperemia, edema, mucosal granularity, secretions) were identified upon bronchoscopy in 19/31 (61.3%) dogs. The cytology of BALF revealed histiocytic inflammation in 14/31 (45.2%) dogs; the parasite was identified in one dog (3.2%). The immunofluorescence antibody test in BALF was positive in 15/31 (48.4%) dogs. Histopathology of bronchial mucosa and/or adjacent alveoli revealed lesions (mononuclear cell infiltration, fibrosis, edema, thickening of the inter-alveolar septa) in 24/31 (77.4%) dogs, with no Leishmania amastigotes. Positive antigen staining was observed within the cytoplasm of mononuclear cells in immunocytochemistry and immunohistochemistry. Μononuclear cells showed antigenic positivity in bronchial mucosa (27/31; 87.1%), BALF (30/31; 96.8%), and lung FNA (27/31; 87.1%). In conclusion, lungs seem to be affected from CanL more commonly than previously believed, and bronchoscopy allows obtaining valuable samples for antemortem diagnosis.