Aim: Aspergillus fumigatus remains a major respiratory pathogen in both ornamental birds and poultry. Aspergillosis can be responsible for high mortality rates and induces significant economic losses, particularly in turkey production. Treatment options are limited. The aim of the present study was to evaluate the efficacy of oral itraconazole in experimentally infected turkeys. For that purpose, we used a nebulised intratracheal model of aspergillosis previously developed by our research group (Melloul et al. 2014). Material and Methods: Few-day old turkeys (n=28) were challenged with 107 conidia of A. fumigatus (CBS 144.89) by intratracheal nebulisation using a MicroSprayer device (day 0). A first group of birds (n = 21) was further treated by itraconazole per os at 10 mg/kg for 7 days (from day 1 to 7). Seven challenged but untreated birds were used as controls. Birds were monitored at least twice daily and every signs of morbidity or mortalities were recorded. Targeted organs of the respiratory tract from all dead and euthanized animals were removed aseptically and the fungal burden was assessed and compared by real-time PCR, galactomannan (GM) dosage and fungal colony (CFU) counting from lungs. Results and discussion: Almost all birds treated with itraconazole presented transient clinical signs but no mortality was observed in this group, unlike in the control group (45% mortality). A significant decrease in fungal burden in lungs was recorded in turkeys treated with itraconazole at the end of the experiment after measuring by culture (CFU/g of lung), GM dosage (GM index) and qPCR (conidial equivalent/g of lung) on RNA 28S target. All these results are consistant with a protective effect of itraconazole administered per os in young turkeys with acute aspergillosis after experimental inoculation.
Full conference title:
- ISHAM 19th (2015)