Mycoplasma sturni is a recently described organism previously associated with conjunctivitis in European starlings (Sturnus vulgaris), northern mockingbirds (Mimus polyglottos) and blue jays (Cyanocitta cristata). Herein we describe the isolation of M. sturni from an American crow (Corvus brachyrhynchos) presenting with conjunctivitis. A nested-PCR was designed for identification of M. sturni in clinical specimens and the sensitivity of the reaction was found to be 10 colony-changing units. The organism was found in asymptomatic American crows caged with a nestmate of the crow with conjunctivitis. Mycoplasma sturni also was found in asymptomatic American robins (Turdus migratorius) and in a European starling (Sturnus vulgaris) housed at the same facility as the crows. Heterogenity of M. sturni isolates from different host species was found by random amplified polymorphic DNA (RAPD) analyses. Heterogeneity also was found among M. sturni isolates recovered from American crows.

We suggest that M. sturni can successfully infect American crows and American robins with or without the presence of clinical disease. Furthermore, we demonstrate that nested-PCR is an effective method for the detection of M. sturni and that substantial genetic heterogeneity exists among natural isolates of this bacterial pathogen.