The influence of host tissue on M. gallisepticum vlhA gene expression.

Mycoplasma gallisepticum, a significant poultry pathogen, has evolved rapidly in its new passerine host since its first reported isolation from house finches in the US in 1994. In poultry, M. gallisepticum infects the upper respiratory tract, causing tracheal mucosal thickening and inflammation, in addition to inflammation of the reproductive tract.

Immunologic Pathways in Protective versus Maladaptive Host Responses to Attenuated and Pathogenic Strains of Mycoplasma gallisepticum.

Mycoplasmas are small bacterial commensals or pathogens that commonly colonize host mucosal tissues and avoid rapid clearance, in part by stimulating inflammatory, immunopathogenic responses. We previously characterized a wide array of transcriptomic perturbations in avian host tracheal mucosae infected with virulent, immunopathologic ; however, mechanisms delineating these from protective responses, such as those induced upon vaccination, have not been thoroughly explored. In this study, host transcriptomic responses to two experimental vaccines were assessed during the first 2 days of infection.

Variable Lipoprotein Hemagglutinin A Gene () Expression in Variant Mycoplasma gallisepticum Strains .

, the primary etiologic agent of chronic respiratory disease, is a significant poultry pathogen, causing severe inflammation and leading to economic losses worldwide. Immunodominant proteins encoded by the variable lipoprotein and hemagglutinin () gene family are thought to be important for -host interaction, pathogenesis, and immune evasion, but their exact role remains unknown. Previous work has demonstrated that phase variation is dynamic throughout the earliest stages of infection, with 3.

Transcriptional Profiling of the Chicken Tracheal Response to Virulent Mycoplasma gallisepticum Strain R.

, the primary etiologic agent of chronic respiratory disease (CRD) in poultry, leads to prolonged recruitment and activation of inflammatory cells in the respiratory mucosa. This is consistent with the current model of immune dysregulation that ostensibly allows the organism to evade clearance mechanisms and establish chronic infection. To date, studies using quantitative reverse transcription-PCR (qRT-PCR) and microarrays have shown a significant transient upregulation of cytokines and chemokines from tracheal epithelial cells (TECs) and tracheal tissue in response to virulent strain R that contributes to the infiltration of inflammatory cells into the tracheal mucosa.

Attenuated Phenotype of a Recent House Finch-Associated Mycoplasma gallisepticum Isolate in Domestic Poultry.

, known primarily as a respiratory pathogen of domestic poultry, has emerged since 1994 as a significant pathogen of the house finch () causing severe conjunctivitis and mortality. House finch-associated (HFMG) spread rapidly and increased in virulence for the finch host in the eastern United States. In the current study, we assessed virulence in domestic poultry with two temporally distant, and yet geographically consistent, HFMG isolates which differ in virulence for house finches-Virginia 1994 (VA1994), the index isolate of the epidemic, and Virginia 2013 (VA2013), a recent isolate of increased house finch virulence.