ROLE OF ENVIRONMENTAL AMMONIA IN RESPIRATORY MYCOPLASMOSIS OF RATS

  • 1 January 1976
    • journal article
    • research article
    • Vol. 85  (1) , 115-+
Abstract
Young adult, Sherman and Fischer (F344) substrain, pathogen-free rats were inoculated intranasally with 108 colony-forming units (CFU) of Mycoplasma pulmonis and housed for 4-6 wk in environments with NH3 maintained at specific concentrations from 25-250 ppm. All levels of NH3 (whether produced naturally from soiled bedding or derived from a purified source) significantly increased the severity of the rhinitis, otitis media, tracheitis and pneumonia (including bronchiectasis) characteristic of murine respiratory mycoplasmosis (MRM). The prevalence of pneumonia, but not that of other respiratory lesions of MRM, showed a strong tendency to increase directly with environmental NH3 concentration. NH3 exposure of rats not infected with M. pulmonis caused anatomic lesions that were unlike those of MRM and were limited to the nasal passages. Environmental NH3, at concentrations commonly encountered in present day cage environments for rats, plays an important role in pathogenesis of MRM.