Summary Chlamydia psittaci is a zoonotic pathogen associated primarily with avian chlamydiosis. New chlamydial agents with suspected zoonotic potential were recently detected from domestic poultry in Germany and France indicating that the spectrum of Chlamydiaceae encountered in birds is not confined to a single chlamydial species. For further characterization, a specific real‐time PCR targeting the conserved 16S rRNA gene was developed and validated for a specific detection of these atypical Chlamydiaceae. In order to address the epidemiological importance of the new chlamydial agents and their distribution, Chlamydiaceae‐positive chicken samples collected from flocks from five different countries were examined. The results confirmed that C. psittaci is not the predominant chlamydial species among chickens examined and suggested that the new chlamydial agents could putatively be widespread in poultry flocks (France, Greece, Croatia, Slovenia and China at least) justifying their systematic investigation when poultry samples are submitted to laboratories for avian chlamydiosis diagnosis. Besides, 16S rRNA‐based dendrogram, including sequences from both isolates of the new chlamydial agents or positive samples as well as representative sequences from species belonging to the order Chlamydiales, showed the new chlamydial agents to form a distinct line of descent separated from those of other chlamydial species, but clearly grouped within the family Chlamydiaceae. Finally, the phylogenetic tree inferred from the multi‐locus sequence typing based on four housekeeping fragments (gatA, gidA, enoA and hflX) and the ompA‐based dendrogram showed an almost identical topology of the new chlamydial agents with that recovered by 16S rRNA‐based dendrogram. Interestingly, partial ompA gene sequences displayed considerable diversity among isolates.

During 2003, 278 adult pigeons (Columba livia) and 54 birds of 11 other free-living species were caught in the various locations in the City of Zagreb, Croatia. Sera from 182 pigeons were tested for the presence of antibodies against Chlamydophila (C.) psittaci by ELISA test and 174 of them (95.6%) were found positive. Because of the high positivity rate in sera, cloacal swabs of 278 pigeons as well as 54 other species of free-living birds were tested for the presence of C. psittaci antigen. Fourty-four of the 278 pigeons (15.83%) were antigen positive, whereas all 54 of the wild birds were negative. Antigen-positive pigeons were euthanised and examined pathomorphologically and cytologically. Findings of specific antibodies and antigen of C. psittaci confirmed the high rate of infection among urban pigeons in the City of Zagreb, fortunately not among other free-living birds. Although the pigeon serovars of C. psittaci are considered to be of moderate pathogenicity for humans, the identification of 15.8% antigen-positive birds represents a potential source of infection to humans, especially for elderly people and immunodeficient patients, as well as for poultry in the Zagreb city area.

Barić-Rafaj (2007) The effects of castration on the growth parameters, carcass yield and meat chemical composition of intensively reared Common Pheasant (PhasianuscolchicuscolchicusL.

A total of 411 samples from birds of different species originating from all counties of the Republic of Croatia have been tested for the presence of Chlamydophila psittaci. The sampling was conducted in pet stores, breeders' aviaries, in a specialized bird clinic and in zoos. The testing included 177 parrots, 169 pigeons, 58 canaries and 7 finches. For the detection of specific C. psittaci antigen a commercial ELISA kit was used- IDEIATM PCE Chlamydia (DAKO Cytomation Ltd., United Kingdom). The samples that were non-specifically positive or doubtful in the ELISA test (a total of 26 samples) were analyzed also by means of polymerase chain reaction (PCR). Diagnostic ELISA method found a total of 17.03% birds positive for chlamydiosis, and after additional testing by PCR a total of 12.65% positive ones were found. According to bird species, the most frequently positive ones were canaries and pigeons (15.52% and 13.02%), and according to the sampling location most of the positive birds were found in pet stores (16.52%), but a high percentage of positive samples were also found in breeders’ aviaries (11.76%). The average positive result for chlamydiosis in 12.65% of tested birds is alarming and it confirms the importance of monitoring bird health and of prescribed legal regulations when it comes to chlamydial diseases, as well as education of persons involved in breeding, keeping or selling birds