Mycoplasma sturni from a California House Finch with Conjunctivitis Did Not Cause Disease in Experimentally Infected House Finches

Abstract

Mycoplasma gallisepticum conjunctivitis emerged in 1994 as a disease of free-ranging House Finches (Carpodacus mexicanus) in North America and has also been isolated from other songbirds with conjunctivitis. A key feature for the successful study of natural and experimental disease has been the apparent, very-high correlation between characteristic eye lesions and M. gallisepticum. Mycoplasma sturni was originally isolated from an adult European Starling (Sturnus vulgaris) with bilateral conjunctivitis and has since been reported in a relatively small number of other avian species, but not in House Finches. We identified as M. sturni a mycoplasma isolate from a California House Finch with conjunctivitis. However, experimental infection of House Finches with the M. sturni isolate failed to reproduce the disease. Therefore, M. gallisepticum remains the primary known cause of conjunctivitis in House Finches.

Occurrence of Mycoplasma spp. in wild birds: phylogenetic analysis and potential factors affecting distribution

“…All these species of birds showed clinical signs comparable to those present in the European starling. However, the presence of M. sturni was also confirmed in birds that did not show any clinical signs 23 and in those birds whose symptoms were due to MG infection 21 . Other mycoplasmas which can present respiratory signs in wild birds are M. buteonis , M. corogypsi , M. falconis , and M. gypis , that were found in raptors from the Falconiformes and Accipitriformes orders 24 .…”

“…Another Mycoplasma species that can cause conjunctivitis is Mycoplasma sturni , but its host range is limited to only wild birds. Mycoplasma sturni was identified for the first time in a European starling ( Sturnus vulgaris ) with severe bilateral conjunctivitis 19 and also isolated from other passerine species such as the northern mockingbird ( Mimus polyglottos ), blue jay ( Cyanocitta cristata ) 20 , house finch ( Haemorhous mexicanus ) 21 , cliff swallow ( Petrochelidon pyrrhonota ) 22 , American crow ( Corvus brachyrhynchos ), and American robin ( Turdus migratorius ) 23 . All these species of birds showed clinical signs comparable to those present in the European starling.…”

The detection of Mycoplasma sturni and Mycoplasma moatsii from the choana of a barn swallow (Hirundo rustica): a case report

“…Moreover M. sturni failed to reproduce disease by experimental infection in a study using wild- caught House Finches. The conjunctival inoculation of a M. sturni isolate originating from a wildlife case with conjunctivitis resulted in transient infection in one of nine House finches, but no disease [ 22 ].…”

House Finch (Haemorhous mexicanus) Conjunctivitis, and Mycoplasma spp. Isolated from North American Wild Birds, 1994–2015

“…from House Finches. In 2006, we identified a House Finch isolate made in California as M. sturni that was not pathogenic by experimental infection (Ley et al 2010) and remains a unique finding. In a 2015 California submission from three House Finches and one Red-tailed Hawk ( Buteo jamaicensis ), M. gallisepticum was isolated from a House Finch and M. gypis was isolated from the Red-tailed Hawk and the other two House Finches, a novel finding in this host.…”