Mycoplasma spp. in Passeriformes in Germany

Little is known about the significance of mycoplasmas in different free-ranging bird species. One hypothesis is that the prevalence of mycoplasmas and the influence of vocalization on reproduction are evolutionarily linked. To add another piece of information toward proving or disproving this hypothesis and obtain more information about the clinical relevance of mycoplasmas, choanal swabs from different passerine species presented to a veterinary clinic were examined for mycoplasmas using culture and Mycoplasma genus-specific PCR. When mycoplasmas were detected, the species was identified by sequencing the partial 16S rRNA and 16S-23S rRNA intergenic spacer region. In total, 221 passerines from 34 species and 17 families were sampled. Mycoplasmas were detected in 12% of the Passeriformes and mostly in four families: Sturnidae, Muscicapidae, Turdidae, and Hirundinidae. The most commonly detected Mycoplasma sp. was Mycoplasma sturni; this did not seem to be an obligate pathogen. Additionally, Mycoplasma columborale, Mycoplasma moatsii, and two unidentified Mycoplasma spp. were detected. The results indicate that in some passerine families, mycoplasmas occur with an intermediate prevalence. The rare occurrence of mycoplasmas in many passerine bird species seems to be in accordance with the hypothesis of an evolutionary link between mycoplasma prevalence and the influence of vocalization on reproduction, but the findings of our study could not prove or disprove this hypothesis. Further studies of mycoplasma prevalence in free-ranging passerine populations are needed.