Nova presloženica virusa A(H5N5) filogenetske grane 2.3.4.4. u divljih ptica i peradi, Hrvatska, 2016-2017

Highly pathogenic avian influenza (HPAI) causes flock mortality as high as 100% in susceptible poultry species but it also poses a threat for humans, particularly viruses of A/goose/Guangdong/96-like (GD/96) lineage. The emergence of novel HPAI viruses in migratory birds is of concern because of the potential for virus spread during migration. In late 2016, novel GD/96 reassortant clade 2.3.4.4 group B avian influenza H5N5 virus was detected in wild birds and domestic poultry in Croatia, concurrently with numerous detections of H5N8 virus of the same clade and group. Sequencing of the full genome of the H5N8 index case isolate (October 2016) and of all three H5N5 isolates (December 2016 -March 2017) has shown that the novel H5N5 reassortant virus most likely emerged as a result of complex reassortment process in Asia from HPAI H5N8 viruses after the later viruses have became established in wild bird population. Concurrent findings of both, H5N5 and H5N8 viruses, at the same locations in Croatia indicate that the H5N5 reassortant virus was introduced from Asia as a subpopulation of H5N8 viruses by the same wild bird flyways. Although the novel H5N5 reassortant virus possesses haemagglutinin of the GD/96 lineage, the virus genome has typical avian virus traits. Apart from mutations T215A in M1 protein and P42S in NS1 protein which are associated to increased virulence in mice, none of the mutations related to increased affinity to human-type (α-2,6) receptors and mammalian host adaptation were found. Nevertheless, the virus poses a serious threat to the poultry industry since high pathogenicity for gallinaceous birds was confirmed by high intravenous pathogenicity index (2.87).Visokopatogeni virusi influence ptica (VPVIP) uzrokuju i do 100% uginuća u osjetljivih vrsta peradi, ali predstavljaju i prijetnju ljudima, posebno virusi loze A/goose/Guangdong/96-like (GD/96). Pojava novih virusa VPVIP u ptica selica je od značaja zbog mogućeg širenja virusa tijekom migracija. Krajem 2016. godine u divljih ptica i domaće peradi u Hrvatskoj je otkrivena nova presloženica virusa influence ptica podtipa H5N5 loze GD/96, filogenetske grane 2.3.4.4, skupine B, istodobno s otkrivanjem brojnih virusa podtipa H5N8 iste filogenetske grane i skupine. Određivanje slijeda nukleotida cijelog genoma izolata iz prvog slučaja s virusom podtipa H5N8 (listopad 2016.) i svih triju izolata virusa podtipa H5N5 (prosinac 2016. - veljača 2017.) pokazalo je da je nova presloženica virusa podtipa H5N5 najvjerojatnije nastala u Aziji kao posljedica složenog procesa preslagivanja VPVIP podtipa H5N8 nakon što je potonji virus već bio nazočan u populaciji divljih ptica. Istodobni nalaz oba virusa podtipova H5N5 i H5N8 na istim mjestima u Hrvatskoj pokazuje da je nova presloženica virusa podtipa H5N5 unesena iz Azije kao potpopulacija virusa podtipa H5N8 istim selidbenim putovima divljih ptica. Iako nova presloženica virusa podtipa H5N5 posjeduje hemaglutinin loze GD/96, genom ovog virusa ima obilježja tipična za ptičje viruse influence. Osim mutacija T215A u M1 proteinu i P42S u NS1 proteinu koje su povezane s povećanom virulencijom za miševe, nije nađena niti jedna od mutacija povezanih s povećanim afinitetom prema receptorima humanog tipa (α-2,6) i prilagodbe prema sisavcima. Ipak, virus predstavlja ozbiljnu prijetnju peradarstvu, budući da je visoka patogenost za galiformne ptice potvrđena visokim intravenskim indeksom patogenosti (2,87)

Stereoselective cyclo-addition reactions of azomethine ylides catalysed by in situ generated Ag(I)/bisphosphine complexes

Stereoselective cyclo-addition reactions of azomethine ylides promoted by in situ generated Ag(I)/bisphosphine complexes were studied. Under the optimised conditions, the pyrrolidine products were isolated in up to 84 % yield and with up to 71 % e.e. The effects of various reaction variables on the stereoselectivity were also investigated

Molecular detection and phylogenetic analysis of adenovirus associated with fatal disease of juvenile bearded dragons(Pogona vitticeps) in Croatia

Australski su gušteri, bradate agame (Pogona vitticeps), vrlo popularni kućni ljubimci koji se uzgajaju u zatočeništvu u brojnim zemljama, a međunarodna trgovina ove vrste guštera nije zanemariva. Bradate agame su osjetljive na infekciju adenovirusom agamida tipa 1 (BDAdv-1) čiji je uzročnik usko povezan s raznim kliničkim znacima poput: iznenadne smrti, letargije, slabosti, proljeva, dehidracije, anoreksije, zaostajanja u rastu i neuroloških simptoma koji nastaju zbog oštećenja jetara. Opisana je fatalna bolest dviju juvenilnih bradatih agama u Hrvatskoj tijekom koje je detektirana infekcija adenovirusom. Osim slabosti, anoreksije, kaheksije i dehidracije, u jedne agame je bio naglašen opistotonus. U fecesu agama je postupkom lančane reakcije polimerazom dokazan adenovirus, dok je nukleotidnim sekvenciranjem i filogenijskom analizom nađena visoka podudarnost s BDAdv-1 izolatima iz bradatih agama u SAD-u, Austriji i Njemačkoj (>99,6 %-100 %), ali i s BDAdv-1 iz slobodnoživućih bradatih agama u Australiji (>99,2 %). Pokušaj izdvajanja virusa kroz dvije pasaže u pačjim embrijima ili deset pasaža u kokošjim embrijima nije dao pozitivan rezultat.Bearded dragons (Pogona vitticeps) are popular pets bred in captivity in numerous countries, with considerable international trade of this species. Bearded dragons are sensitive to bearded dragon adenovirus 1 (BDAdv-1) which causes or is closely associated with various clinical symptoms including sudden death, lethargy, weakness, diarrhoea, dehydration, anorexia, retarded growth, and neurological symptoms resulting from liver damage. A fatal disease of two juvenile bearded dragons in Croatia during which adenovirus was detected is described. Weakness, anorexia, cachexia and dehydration were present in the male and the female bearded dragon, in addition to marked opistothonus in the female. The adenovirus was detected by PCR while nucleotide sequencing and phylogenetic analysis revealed high homology with BDAdv-1 strains from bearded dragons in the United States, Austria and Germany (>99.6–100%), but also with BDAdv-1 from free-ranging Australian bearded dragons (>99.2%). An attempt to isolate the virus through two passages in duck embryos or ten passages in chicken embryos did not yield a positive result

Pojavnost influence u životinja u Hrvatskoj: kratak pregled povodom 100 godina od pojave pandemije 1918.

Influenza is an important respiratory disease of human beings and different animal species caused by influenza viruses belonging to the family Orthomyxoviridae, which comprises four genera (Influenzavirus A, B, C and D). In an introductory overview a brief historical review of the main pandemics of influenza A in humans worldwide is given. Spanish, Asian, Hong Kong, Russian influenza and North American swine influenza, as well as infections caused by the recently occurring influenza D virus, are briefly described. Aquatic birds are the natural reservoirs of influenza A viruses worldwide, and harbour viruses with all possible combinations of 16 haemagglutinin (HA) and 9 neuraminidase (NA) subtypes. The crossing of the species barrier by avian influenza viruses is presented. A previous review on the zoonotic nature of influenza viruses was published in Croatia in 1982. Outbreaks of equine, swine and avian influenza have been described in Croatia. HI antibodies to A/swine/Texas/4199/1998 (H3N2) were detected in dog sera. Epizootics of equine influenza caused by H7N7 and H3N8 subtypes have been known in Croatia for 80 years. Recent outbreaks showed an antigenic drift of the viruses involved. American lineage H3N8 was detected. The last serological evidence worldwide of A/equine H7N7 was reported from Croatia. New outbreaks of H3N8 were likely the result of vaccine failure. Serological examination of domestic pigs has revealed the prevalence of the H1N1 and H3N2 subtypes. Tested feral pigs were serologically positive to H1N1 and H3N2 subtypes. Recent clinical outbreaks of swine influenza caused by the H1N1 subtype were documented by immunohistochemistry, nucleic acid detection and virus isolation. Avian influenza had no impact on poultry production in Croatia until late 2005 when a highly pathogenic zoonotic avian influenza (HPAI) virus of the H5N1 subtype was detected in wild birds in eastern Croatia. The multiple introduction of the Asian HPAI H5N1 virus into Croatia by wild birds was documented. From October 2016 until March 2017, 19 outbreaks of HPAI H5N8 were detected in Croatia, 16 in wild birds and three in poultry. The new H5N5 reassortant virus was introduced from Asia. Avian influenza virus of H16 subtype was isolated from black-headed gulls.Influenca je zarazna bolest ljudi i različitih životinjskih vrsta prouzročena virusima influence porodice Orthomyxoviridae, koji su svrstani u 4 roda: Influenzavirus A, B, C i D. Uvodno je iznesen kratak povijesni prikaz najvažnijih pandemija influence A u ljudi u 20. stoljeću: španjolske, azijske, hongkongške, ruske i sjeverno-američke (svinjske) gripe te infekcije prouzročene novim influenca D virusom. Vodene ptice prirodni su rezervoar virusa influence A diljem svijeta. U njih su dokazane sve antigenske kombinacije od mogućih 16 podtipova hemaglutinina i 9 podtipova neuraminidaze. Opisan je međuvrsni prijenos ptičjih virusa influence o čemu se u nas može naći podosta rasprava u znanstvenoj i stručnoj literaturi. U Hrvatskoj su u prošlosti opisane epizootije influence konja, svinja i ptica, a protutijela inhibicije hemaglutinacije za A/swine/Texas/4199/1998 (H3N2) dokazana su u serumu pasa. Nakon prvog opisa prije 80 godina, česta su izvješća o pojavi epizootija influence konja prouzročene podtipovima H7N7 i H3N8. U novijim epizootijama dokazano je antigensko skretanje uzročnika s naglaskom da izdvojeni podtip H3N8 pripada američkoj liniji. Već duže vrijeme nema dokaza o aktivnosti podtipa H7N7 u svijetu. Nalaz specifičnih protutijela za taj podtip posljednji put je dokazan upravo u Hrvatskoj. Smatra se da se pojava novih epizootija influence konja uzrokovanih podtipom H3N8 može pripisati neodgovarajućem antigenskom sastavu rabljenih cjepiva. Na osnovi seroloških istraživanja influence u domaćih svinja pokazalo se da u njihovoj populaciji kolaju podtipovi H1N1 i H3N2. Serološki je utvrđeno da ti podtipovi kolaju i u populaciji divljih svinja u Hrvatskoj. U najnovije doba opisana je klinička slika influence svinja uzrokovane podtipom H1N1 u nekim mnoštvenim uzgojima u Hrvatskoj. Osebujan klinički nalaz potkrijepljen je pozitivnim nalazom pretragom RT-PCR-om, pozitivnim imunohistokemijskim nalazom u tkivu plućiju zahvaćenih svinja te izdvajanjem virusa na staničnoj kulturi MDCK. Influenca ptica nije imala nekog utjecaja na peradarsku proizvodnju u Hrvatskoj sve do 2005. godine, kada je zoonotski visoko patogeni virus ptičje gripe podtip H5N1 bio utvrđen u divljih ptica na području Istočne Hrvatske. Nakon toga ustanovljena je višestruka pojava azijskog visokopatogenog podtipa H5N1 u divljih ptica u Hrvatskoj. Od listopada 2016. do ožujka 2017. godine zabilježeno je 19 pojava visokopatogenog podtipa H5N8, od čega 16 u divljih ptica, a tri u domaće peradi. Nova presloženica H5N5 u Hrvatsku je bila prenesena iz Azije. U riječnog galeba u okolici Zagreba dokazan je podtip H16

Local Intrinsic Dimensionality Measures for Graphs, with Applications to Graph Embeddings

The notion of local intrinsic dimensionality (LID) is an important advancement in data dimensionality analysis, with applications in data mining, machine learning and similarity search problems. Existing distance-based LID estimators were designed for tabular datasets encompassing data points represented as vectors in a Euclidean space. After discussing their limitations for graph-structured data considering graph embeddings and graph distances, we propose NC-LID, a novel LID-related measure for quantifying the discriminatory power of the shortest-path distance with respect to natural communities of nodes as their intrinsic localities. It is shown how this measure can be used to design LID-aware graph embedding algorithms by formulating two LID-elastic variants of node2vec with personalized hyperparameters that are adjusted according to NC-LID values. Our empirical analysis of NC-LID on a large number of real-world graphs shows that this measure is able to point to nodes with high link reconstruction errors in node2vec embeddings better than node centrality metrics. The experimental evaluation also shows that the proposed LID-elastic node2vec extensions improve node2vec by better preserving graph structure in generated embeddings