"Actinobacillus " ( " Pasteurella " ) " ureae " and " A . hominis " occur in the respiratory tracts of healthy humans and may be involved in the pathogenesis of sinusitis, bronchopneumonia, and meningitis . " A . actinomycetemcomitans " occurs in the human oral microflora, and together with anaerobic or capnophilic organisms ( HACEK group organisms ) may cause endocarditis.
