Resumo

Chlamydiosis is a worldwide infectious disease of birds caused by Chlamydophila psittaci. Natural infections occur in many avian species, however, in Brazil, this bacterium has been mainly detected in psittacine birds. In general, infected hosts, even without showing clinical signs of chlamydiosis, shedding the microorganism in the excreta for long periods. The purpose of this study was to identify and characterize samples of C. psittaci from monk parakeets (Myiopsitta monachus) linked to cases of diseases in humans. Samples were submitted to DNA extraction and molecular analyses were performed using polymerase chain reaction (PCR) for amplification of fragments of the ompA gene encoding the major outer membrane protein that is present in all chlamydial species. Amplification of the ompA-genes produced fragments of 1050 bp, which were further sequenced and analyzed using the GenBank database. It was observed a high homology with the strains 6BC and 08DC60 related with the C. psittaci genotype A. Additionally, the amplified ompA-products were genotyped by PCR-restriction fragment length polymorphism (PCR-RFLP) using the restriction endonuclease enzyme AluI, which revealed pattern of genotype A. These results are in accordance with previous studies showing that this genotype predominates among psittacine birds. Unfortunately, nowadays the C. psittaci can be considered endemic in psittacine birds in Brazil. This fact is a concern since C. psittaci is the etiologic agent of a zoonosis and infections in humans (psittacosis) frequently result from exposure to psittacine birds. Genotype A poses a major implications for public health since several outbreaks of psittacosis are often related to it. Infection usually occurs when a person inhales organisms that have been aerosolized from dried feces or respiratory tract secretions from infected birds. To the best of our knowledge, this is the first report on the molecular characterization by sequencing and PCR-RFLP for identification of genotypes of C. psittaci in Brazilian birds. Further studies on genetic relatedness of C. psittaci from different host species are needed to better understand the epidemiology of chlamydiosis and provide means of prevention and control of the disease in humans and animals. Support: Fapesp, CNPq.