DNA amplification methods for diagnosis and epidemiological investigations of avian mycoplasmosis

This review describes some applications of DNA amplification methods for diagnosis or epidemiological investigations of avian mycoplasmosis. Tests for direct detection of pathogenic mycoplasmas have been developed. Moreover, most avian mycoplasma species can be differentiated, according to their unique restriction fragment length polymorphism (RFLP) patterns generated after digestion of PCR products with different restriction enzymes. In order to characterize isolates below the species level, PCR-based subtyping methods have been introduced. One of them, arbitrarily primed-PCR, results in strain-specific arrays of DNA fragments that can distinguish even closely related strains of a given species. This method was successfully used to investigate the molecular epidemiology of vaccine strains and of Mycoplasma gallisepticum conjunctivitis in songbirds. Major issues in the development of DNA-amplification tests concern the selection of the appropriate target, specimen collection, DNA preparation and detection of amplification reaction inhibitors. Careful consideration to the design and work flow of the facility are necessary to avoid false-positive results.