Molecular characterization of atypical Chlamydia and evidence of their dissemination in different European and Asian chicken flocks by specific real-time PCR.

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.

Surveillance of influenza A viruses in wild birds in Slovenia from 2006 to 2010.

Within the framework of the surveillance program for the early detection of H5 and H7 subtypes of avian influenza (AI) viruses, samples from 2547 wild birds of different species that were collected between 2006 and 2010 were examined by PCR-based methods. AI viruses of various subtypes were detected in 4.4% of birds from four different orders: Anseriformes, Ciconiiformes, Charadriiformes, and Pelecaniformes. Highly pathogenic avian influenza (HPAI) H5N1 viruses were detected only in 2006. HPAI H5N1 virus was confirmed in 1.9% of birds from four different species. Comparison of nucleotide sequences of the H5N1 hemagglutinin gene indicated that two different HPAI H5N1 viruses from the European-Middle Eastern-African clade 1 had been introduced into Slovenia, despite the relatively short duration of the HPAI outbreak. Low pathogenic avian influenza (LPAI) viruses were detected in 2.5% of birds during a 5-yr period. The subtypes H1, H2, H3, H4, H5, H7N7, H8, H10, H11, and H13N6 were determined in 18 out of 64 cases. The highest prevalence (81%) of LPAI viruses, including the H5 subtype, were found in birds sampled as a part of the "active" surveillance system.

Novel adenoviruses from captive psittacine birds in Slovenia.

To assess the prevalence of adenoviruses in psittacine birds kept in Slovenia, 258 cloacal swabs were collected from different psittacine species and screened by a nested PCR with degenerate, consensus primers targeting the adenoviral DNA polymerase gene. Forty-two samples were found to be positive. By sequencing, 28 samples from 10 different parrot species were identified as the formerly described siadenovirus, psittacine adenovirus 2 (PsAdV-2). A second siadenovirus, a variant of PsAdV-5 (described earlier from Pacific parrotlet, sun parakeet, cockatiel and budgerigar) was found in seven budgerigars, two cockatiels and an amazon parrot species. A variant of Meyer's parrot adenovirus (aviadenovirus, proposed PsAdV-8) was identified in an African grey parrot and a cockatiel. Two novel atadenoviruses were revealed in cockatiel (PsAdV-9) and rose-ringed parakeet (PsAdV-10). These results support the earlier finding that many PsAdVs can cross the species barrier among psittacines, especially effectively in the case of PsAdV-2.