Establishment of persistent enteric mycobacterial infection following streptomycin pre-treatment

AbstractMycobacterium avium subsp.paratuberculosis (MAP) is the causative agent of paratuberculosis, a chronic gastrointestinal disease affecting ruminants. This disease remains widespread in part due to the limitations of available diagnostics and vaccines. A representative small animal model of disease could act as a valuable tool for studying its pathogenesis and to develop new methods for paratuberculosis control, but current models are lacking. Streptomycin pre-treatment can reduce colonization resistance and has previously been shown to improve enteric infection in aSalmonella model. Here, we investigated whether streptomycin pre-treatment of mice followed byMAP gavage could act as a model of paratuberculosis which mimics the natural route of infection and disease development in ruminants. The infection outcomes ofMAP were compared toM. avium subsp.hominissuis (MAH), an environmental mycobacterium, andM. bovis andM. orygis, two tuberculous mycobacteria. Streptomycin pre-treatment was shown to consistently improve bacterial infection post-oral inoculation. This model led to chronicMAP infection of the intestines and mesenteric lymph nodes (MLNs) up to 24-weeks post-gavage, however there was no evidence of inflammation or disease. These infection outcomes were found to be specific toMAP. When the model was applied to a bacterium of lesser virulenceMAH, the infection was comparatively transient. Mice infected with bacteria of greater virulence,M. bovis orM. orygis, develop...
Source: Gut Pathogens - Category: Microbiology Source Type: research