1. Istituto Zooprofilattico Sperimentale of Sicily, Via Gino Marinuzzi 3, Palermo 90129, Italy
2. Lega Italiana Protezione Uccelli (LIPU), Ficuzza, Palermo, Italy
3. Mycoplasma Group, Veterinary Laboratories Agency (Weybridge), Addlestone, Surrey KT15 3NB, UK