Detection and identification of Chlamydophila psittaci in asymptomatic parrots in Poland

An overall prevalence of 10.3% was observed using two different PCR assays, both providing similar results. Thirteen of the PCR-positive samples were genotype A, two were genotype B, and one could not be classified.These results indicate widespread dissemination of C. psittaci in Polish psittacine populations, without any clinical signs of chlamydiosis, and hence could pose a zoonotic hazard. PCR screening provided a definitive diagnosis of psittacosis, and subsequent ompA gene analysis could be helpful for better understanding the epidemiology of the C. psittaci genotypes. To the best of our knowledge, this is the first report of the incidence of C. psittaci in parrots in Poland.The order Chlamydiales contains at least four distinct family groups: Chlamydiaceae, Simkaniaceae, Waddliaceae and Parachlamydiaceae. Within the family Chlamydiaceae there are two distinct genera: Chlamydia and Chlamydophila. The Chlamydophila genus has seven recognised species, namely Chlamydophila pecorum, Chlamydophila pneumoniae, Chlamydophila psittaci, Chlamydophila abortus, Chlamydophila caviae (formerly Chlamydophila psittaci guinea pig conjunctivitis strain) and Chlamydophila felis[1,2].A unique developmental cycle distinguishes Chlamydophila from other intracellular bacteria [3]. The infectious elementary body (EB) and the vegetative reticulate body (RB) are two major developmental forms involved in the cycle. One of the predominant proteins found on the surface of both the EB and RB forms is the major outer membrane protein (MOMP, OmpA). MOMP makes up 60% of the total outer membrane protein [4], and published data have indicated that it is critical for chlamydial infection [5-7].C. psittaci has been isolated and described from various birds and mammals [8-10], and has variously been subdivided into the strains/serovars/genotypes A–F, M56 and WC (referred to hereafter as genotypes). Each genotype is assumed to exhibit stringent host specificity: A in psittacine birds, B in pigeons,