Pathogenicity and cytadherence of Mycoplasma imitans in chick and duck embryo tracheal organ cultures. Infect. Immun

Two strains of the avian organismMycoplasma imitans were examined for pathogenicity and cytadherence in chicken and duck embryo tracheal organ cultures, and a virulent strain of the related pathogen Mycoplasma gallisepticum was included for comparison. All consistently caused ciliostasis in tracheal explants from both hosts, and examination of infected tissues by immunofluorescence and transmission electron microscopy demonstrated that M. imitans proliferated on the epithelial surface and adhered to the respiratory epithelium by means of its terminal tip structure in the same manner as M. gallisepticum. These observations endorse the striking phenotypic similarities between M. imitans and M. gallisepticum and suggest that M. imitans may have pathogenic potential in vivo. Tracheal organ cultures (TOCs) derived from various ani-mal hosts have proved very useful for studying the pathogen-esis of respiratory mycoplasma infections in vitro. Ciliary ac-tivity, which has been shown to correlate with tissue viability, is used as a measure of injury (18), and TOCs prepared from chicks or chicken embryos have been used by a number of workers to assess pathogenicity of avian and mammalian my