Respiratory explants as a model to investigate early events of contagious bovine pleuropneumonia infection

AbstractContagious bovine pleuropneumonia (CBPP) is a severe disease caused byMycoplasma mycoides subsp.mycoides (Mmm). Knowledge on CBPP pathogenesis is fragmented and hampered by the limited availability of laboratory animal and in vitro models of investigation. The purpose of the present study is to assess respiratory explants as useful tools to study the early stages of CBPP. Explants were obtained from trachea, bronchi and lungs of slaughtered cattle, tested negative forMycoplasma spp. and for the major bacterial and viral respiratory pathogens. The interaction ofMmm with explant cells was studied by immunohistochemistry (IHC), double-labelling indirect immunofluorescence (DLIIF) and laser scanning confocal microscopy (LSCM).Mmm capability to survive and proliferate within the explants was evaluated by standard microbiological procedures. Finally, the putative cellular internalization ofMmm was further investigated by the gentamicin invasion assay. IHC and DLIIF indicated thatMmm can colonize explants, showing a marked tropism for lower airways. Specifically,Mmm was detected on/inside the bronchiolar and alveolar epithelial cells, the alveolar macrophages and the endothelial cells. The interaction betweenMmm and explant cells was abolished by the pre-incubation of the pathogen with bovine anti-Mmm immune sera.Mmm was able to survive and proliferate in all tracheal, bronchial and lung explants, during the entire time course of the experiments. LSCM and gentamicin invasion...
Source: Veterinary Research - Category: Veterinary Research Source Type: research