Teknősökben előforduló adenovírusok diverzitása (Autoreferátum és bővített irodalmi összefoglaló)

Abstract

SUMMARY Background: Adenoviruses (AdVs) are common infectious agents of different vertebrates worldwide. The members of the family Adenoviridae are currently classified into five genera, of which Mastadenovirus and Aviadenovirus contain the usually stenoxen pathogens of mammals and birds, respectively. Members of the other two genera, Atadenovirus and Siadenovirus, seem to be euryxen and capable of infecting representatives of several distant taxa of vertebrates, both of them including birds. The genus Ichtadenovirus encompasses the single known fish AdV originating from the white sturgeon (Acipenser transmontanus).Objectives: By reviewing their own results and the international literature, the authors summarize the current knowledge about the AdV infections of turtles.Materials and Methods: Organ samples and cloacal swabs, collected from dead or live fresh water turtles, were processed for DNA extraction and screened by broad-spectrum nested PCRs. The sequences of the PCR products were used in phylogeny reconstructions.Results and Discussion: DNA fragments (of approx. 320 bp and 470 bp) were amplified and sequenced from the DNA-dependent DNA polymerase and the hexon genes, respectively. The presence of a novel type AdV was demonstrated in 14 (29%) of the 48 samples examined. In some cases, the PCR products, obtained from the DNA polymerase gene, proved to be polymorphic. By molecular cloning, several different AdV genotypes were revealed in certain animals. The hexon PCR was positive in 2 samples only, yielding identical sequences. The phylogeny reconstructions, based on the deduced amino acid sequences, showed that the novel turtle adenoviruses form a separate cluster that merits the establishment of a new genus within the family Adenoviridae. The authors proposed to name this genus Testadenovirus. Similar viruses, also belonging to the new AdV lineage, have been detected in four additional turtle species from the superfamily Testudinoidea. The genetic relationships of the AdVs seemed to be congruent with those assumed for the respective turtle species.