Low Occurrence of Acinetobacter baumannii in Gulls and Songbirds

Acinetobacter baumannii is a worldwide occurring nosocomial pathogen, the natural habitats of which remain to be defined. Recently, white stork nestlings have been described as a recurring source of A. baumannii. Here, we challenged the hypothesis of a general preference of A. baumannii for avian hosts. Taking advantage of campaigns to ring free-living birds, we collected cloacal swab samples from 741 black-headed gulls (Chroicocephalus ridibundus) in Poland, tracheal and cloacal swabs from 285 songbirds in Poland as well as tracheal swabs from 25 songbirds in Slovenia and screened those for the growth of A. baumannii on CHROMagar (TM) Acinetobacter. Of the 1,051 samples collected only two yielded A. baumannii isolates. Each carried one variant of the bla(OXA-51-like) gene, i.e. OXA-71 and OXA-208, which have been described previously in clinical isolates of A. baumannii. In conclusion, our data do not support a general preference of A. baumannii for avian hosts.