PELISTEGA EUROPAEA GEN. NOV., SP. NOV., A BACTERIUM ASSOCIATED WITH RESPIRATORY-DISEASE IN PIGEONS - TAXONOMIC STRUCTURE AND PHYLOGENETIC ALLOCATION

Twenty-four strains isolated mainly from infected respiratory tracts o f pigeons were characterized by an integrated genotypic and phenotypic approach. An extensive biochemical examination using conventional tes ts and several API microtest systems indicated that all isolates forme d a phenotypically homogeneous taxon with a DNA G+C content between 42 and 43 mol%. Whole-cell protein and fatty acid analysis revealed an u nexpected heterogeneity which was confirmed by DNA-DNA hybridizations. Four main genotypic sub-groups (genomovars) were delineated. 16S rDNA sequence analysis of a representative strain indicated that this taxo n belongs to the beta-subclass of the Proteobacteria with Taylorella e quigenitalis as its closest neighbour (about 94.8 % similarity). A com parison of phenotypic and genotypic characteristics of both taxa sugge sted that the pigeon isolates represented a novel genus for which the name Pelistega is proposed. In the absence of differential phenotypic characteristics between the genomovars, it was preferred to include al l of the isolates into a single species, Pelistega europaea, and strai n LMG 10982 was selected as the type strain. The latter strain belongs to fatty acid cluster I and protein electrophoretic sub-group 1, whic h comprise 13 and 5 isolates, respectively. It is not unlikely that th e name P. europaea will be restricted in the future to organisms belon ging to fatty acid cluster I, or even to protein electrophoretic sub-g roup 1, upon discovery of differential diagnostic features.