Coincident with human activity in recent decades, human-associated microorganisms have arrived to the Antarctic region, possibly linked to increasing presence of scientific bases and ship-borne tourists. In the Arctic, humans have been present for a very long time, and the few parts of the Arctic without human activities is decreasing with time. The studies in this thesis investigate the occurrence of different pathogens in Antarctic and Arctic wildlife, especially in birds. The first study shows the existence of Enteropatogenic Escherichia coli (EPEC) in Antarctic fur seals. The EPEC isolates were so called atypical EPECs, carrying the eae gene but lacking the bfp gene. This is the first record of a diarrheogenic E. coli in wild animals in the Antarctic. The second study displays that spreading of antibiotic resistance mechanisms appears to be much more efficient than previously was known. Enterococcus faecium isolated from Alaskan birds showed high resistance to vancomycin and teicoplanin, but also to ampicillin and ciprofloxacin. These isolates also carried vanA genes and the virulent esp gene, which places the isolates in the clinical clone CC17 and indicates the isolates had a human origin. Bacteria from birds that reside in the Bering Strait region in the third study, demonstrates that only six of 145 E. coli from 532 birds had reduced antibiotic susceptibility. Despite this, selective screen on E. coli showed only four ESBL-producing isolates. The four E. coli isolates carried CTX-M genes. One isolate belonged to the E. coli O25b - ST131 genotype, which is a successful clone with a global spread. In the fourth study, 123 seawater samples and 400 fresh penguin feces were analyzed. From these, 71 E. coli strains were isolated and only one E. coli from penguins was resistant to one antibiotic (cloramfenicol), whereas in E. coli from seawater, resistance against ampicillin, tetracycline, streptomycin and trim-sulfa were detected. E. coli carrying ESBL type CTX -M genes were also detected and Multilocus Sequencing Typing (MLST) showed six different sequence types (ST) previously reported in humans: ST131, ST227, ST401, ST410, ST685 and ST937. In the short time interval between the second study (2005) and the third study (2010) in relation to the fifth study (2012) we found a dramatic increase in antibiotic-resistant genes in the Arctic region. Enterococci, E. coli, and Kl. pneumoniae carried antibiotic resistance genes to an extent and variety not previously reported. E. coli from Arctic birds showed resistant to 1, 2, 3, 4, and 5 different antibiotics. Resistant gene type vanA was confirmed in enterococci and ESBL genes type TEM, SHV and CTX-M in E. coli and Kl. pneumoniae was detected. Multilocus Sequencing typing (MLST), indicating that both E. coli and Kl. pneumoniae carrying ESBL markers that connects them to the humans. In summary, the combined studies strengthen that bacteria that cause infections in humans could spread to relatively pristine environments. We concluded that human and associated antibiotic-resistant bacteria has reached a global level, then we showed that ESBL- carrying bacteria circulating nowadays also in the last ESBL-free continent, Antarctica.

As aves silvestres são consideradas importantes reservatórios de diversos vírus aviários que podem afetar aves comerciais. Dessa forma, o monitoramento das aves silvestres é fundamental para garantir a sanidade dos plantéis avícolas brasileiros. Nos últimos anos, o número de espécies de aves nas quais os coronavírus aviários foram encontrados aumentou vertiginosamente em diversos países. Contudo, poucos estudos envolvendo a detecção de coronavírus aviários em aves de cativeiro e aves silvestres ou sinantrópicas foram realizados no Brasil. Assim, o presente estudo teve como objetivo identificar a presença dos coronavírus aviários em aves silvestres no Brasil e caracterizá-los molecularmente. As amostras foram testadas através do teste de RRT-PCR para detecção do gene UTR do IBV, bem como uma nested-PCR para detecção do gene S1 dos coronavírus aviários. O sequenciamento de alto desempenho foi utilizado para caracterizar os vírus detectados. No total, foram testadas 300 amostras de aves silvestres (147 suabes orofaringeanos e 153 suabes cloacais). No total, 27 amostras foram positivas pelo teste RRT-PCR. Duas amostras de Anseriformes das amostras positivas no teste de RRT-PCR foram selecionadas para sequenciamento de alto desempenho. Em ambas as amostras sequenciadas foi constatada a co-infecção pelos vírus da bronquite infecciosa e vírus da doença de Newcastle. A análise das amostras demonstrou alta identidade com vírus vacinais, o que demonstra que estirpes vacinais utilizadas na imunização de aves de produção circulam em aves silvestres e de produção de subsistência. / Wild birds are an important reservoir of different viruses that can affect poultry. Viral surveillance in wild birds is, thus, extremely important to ensure the poultry heal in Brazil. In recent years, the number of species of birds in which avian coronaviruses have been found skyrocketed in several countries. However, few studies involving the detection of avian coronaviruses in captive wild birds or wild life birds were conducted in Brazil. Thus, the present study aimed to identify the presence of avian coronaviruses in Brazil and characterize them molecularly. Samples were tested by RRT-PCR test for detection of the UTR gene of IBV, as well as a nested-PCR for detection of S1 gene. In total, 300 samples of wild birds (147 oropharyngeal swabs and 153 cloacal swabs) were tested. In total, 27 samples were positive in RT-PCR assay. Two positive samples in RRT-PCR assay were selected for Next-generation sequencing. In both sequenced samples, co-infection with infectious bronchitis virus and Newcastle disease virus was found. The analysis of samples showed identity with vaccinal strains used in immunization of commercial flocks circulate in wild birds and subsistence flocks.

As aves silvestres são importantes reservatórios de vírus que podem acometer as aves domésticas. O monitoramento da circulação viral em aves silvestres é de extrema importância para garantir a sanidade dos plantéis avícolas. O presente estudo teve como objetivo 1) comparar dois testes moleculares de RT-PCR para a detecção dos vírus da família Paramyxoviridae em aves silvestres e sinantrópicas; 2) caracterizar os vírus detectados nestas amostras. Dois testes de RT-PCR e testes específicos de RT-PCR em tempo real (RRT-PCR) para o vírus da doença de Newcastle (NDV) e o metapneumovírus aviário (aMPV) foram utilizados para comparar o limite de detecção entre as amostras. As amostras de aves silvestres foram testadas por dois testes de RT-PCR. Um pequeno fragmento da região do sítio de clivagem do gene F das amostras positivas foi sequenciado. Os testes de RT-PCR foram validados com sucesso, mas apresentaram diferenças entre os limites de detecção quando comparados aos testes específicos de RRT-PCR utilizando diferentes vírus. No total, 100 amostras de aves (suabes) foram testados pelo teste RT-PCR que apresentou um limite de detecção similar entre os diferentes agentes virais. O teste selecionado foi capaz de detectar duas amostras de aves silvestres que foram também detectadas pelo testes específico para NDV e relacionadas às amostras de NDV vacinais do genótipo II da classe II referentes aos vírus de NDV lentogênico (113RQGR ↓ L117). Nosso estudo demonstra a deficiência na biosseguridade adotada pelos sistemas avícolas por permitir a saída dos vírus vacinais para as aves silvestres / Wild birds are important reservoirs of viruses can affect poultry. Surveillance of circulating viruses in wild birds is of the most importance tool to ensure the poultry health. The present study aimed to 1) compare two molecular tests for detection of family Paramyxoviridae viruses in wild and feral birds; 2) characterize the detected viruses in those samples. Two RT-PCR techniques and specific real time RT-PCR (RRT-PCR) assays for detection of Newcastle disease virus (NDV) and avian metapneumovirus (aMPV) were used to compare the limit of detection among them. Wild bird samples were tested by using two RT-PCR tests. A small fragment of cleavage site region in F gene from positive samples was sequenced. The RT-PCR were successfully validated, however they had differences in the limit of detection when compared to specific RRT-PCR assays using different viruses. In total, 100 wild bird samples (swabs) were tested by the selected RT-PCR with similar limit of detection between tested viruses. Two samples were positive by this test and they were also detected by the specific RRT-PCR for NDV. These samples were closed related to vaccinal NDV strains belonging to genotype II class II. Deduced amino acid sequences of cleavage site region from detected samples were characterized as lentogenic NDV strains (113RQGR ↓ L117). Our study demonstrates the poor biosafety used by poultry industry allowing the vaccinal escape to wild bird species

Influenza virus is a RNA virus that exists as different types and subtypes. Influenza A virus strains are known to cause disease in several bird and mammalian species. Wild birds are believed to constitute the natural reservoir for influenza A virus. In humans, influenza A virus causes yearly seasonal influenza epidemics of respiratory disease resulting in high morbidity and severe economic consequences. Due to the virus’ ability to change its antigenic properties by mutation, yearly vaccination is required for protection from the disease. There are many different subtypes of influenza virus which are characterized according to two surface structures - the hemagglutinin and neuraminidase proteins - , for example; H5N1. These subtypes have the ability to recombine, and thereby creating new variant combinations. If a subtype that the living population of humans has not encountered before starts to spread among humans, it can result in a pandemic. Pandemic outbreaks have occurred at irregular intervals throughout history and have had a devastating impact on mankind. For example the Spanish influenza pandemic of 1918 is thought to have killed more than 50 million people. Influenza A virus is also an important cause of disease in poultry where virus strains of some subtypes may change into forms that are highly pathogenic. These virus strains may transmit directly to man and multiple other species. This has been the case in the ongoing outbreak that started in South East Asia in 2003. All known subtypes of influenza A virus have been isolated from wild birds living in aquatic environments, mainly dabbling ducks. These species are considered to be the reservoir for influenza A virus. The virus causes sub clinical gastrointestinal infection in ducks. High amounts of virus are excreted in the feces and spread via the fecal-oral route through water where it can persist for a prolonged time. There are still many unknowns about the ecology of influenza virus in the wild bird reservoir. This thesis includes five articles where data are presented that add new knowledge on this subject. We add proof that wild ducks are indeed the host for most influenza A virus subtypes by presenting data from a meta-analysis on all published screening data from wild birds and by presenting data from a four year screening of migratory ducks that were caught and sampled at Ottenby Bird Observatory. Our investigations have shown that the prevalence of influenza virus in the wild duck population of western Eurasia shows temporal differences in comparison to the results found in studies in North America. The prevalence in western Eurasian ducks is high during the period August to December and also rises in the spring. These findings are of importance for the understanding of how influenza virus is perpetuated in nature. During the course of the study only low pathogenic subtypes were isolated. Of concern is the high frequency of isolation of virus strains of the H5 and H7 subtypes that are prone to change into highly pathogenic variants in poultry. Many of the strains isolated in our study are similar to the ones that have caused influenza outbreaks in poultry in Europe during the last seven years. This indicates that wild bird surveillance for influenza A virus can be of major value as a sentinel system to prevent outbreaks in domestic poultry. Studies on Black-headed Gulls (Larus ridibundus) revealed a previously unknown subtype, H16. This finding widened the spectra of known influenza A virus subtypes in nature. Influenza A virus was also isolated in samples from Guillemots (Uria aalge) in the Baltic Sea. This was the first time influenza A virus was isolated from this species in Europe. The isolated virus strains contained a mix of genes, some of which must have been derived from influenza A virus strains present in the North American bird population. This finding proves that limited exchanges between the virus strains present on the American and the Eurasian continents exist, which is of concern for evaluating the risk of spread of highly pathogenic virus strains by wild birds to the Americas. / Influensavirus är RNA virus och indelas i olika typer och subtyper. Influensa A virus orsakar sjukdom hos ett flertal fågel- och däggdjursarter. Vilda fåglar anses utgöra den viktigaste reservoaren för influensa A virus. Hos människa orsakar influensa A virus årliga epidemier av luftvägssjukdom med hög sjuklighet och stora ekonomiska konsekvenser för samhället. Eftersom frekventa mutationer orsakar ändringar i virusets ytstrukturer krävs årlig vaccination med nytt anpassat vaccin för att ge skydd mot sjukdom. Det finns många olika subtyper av influensa A virus. Dessa karaktäriseras med två av virusets ytstrukturer; hemagglutinin och neuraminidas, vilket till exempel skrivs H5N1. Virus av olika subtyper kan rekombinera och på så sätt skapa nya varianter. Om en subtyp som tidigare ej cirkulerat bland världens befolkning orsakar ett utbrott kan detta leda till en världsomfattande epidemi, en så kallad pandemi. Pandemier har drabbat mänskligheten med viss regelbundenhet genom historien och haft förödande konsekvenser. Till exempel orsakade pandemin ”Spanska sjukan” under åren 1918-1920 mer än 50 miljoner dödsfall. Influensa A virus orsakar också förödande utbrott i fjäderfäbesättningar. Virus av vissa subtyper kan mutera till högpatogena varianter och orsaka så kallad högpatogen aviär influensa. Dessa högpatogena varianter kan även överföras till och orsaka sjukdom hos människa och andra djur vilket varit fallet under det pågående utbrott av H5N1 som startade i sydöstra Asien 2003. Alla kända subtyper av influensa A virus har isolerats i material från vilda fåglar vilka lever i vattenmiljö, framförallt från änder. Dessa arter anses därför utgöra influensavirusets reservoar i naturen. Hos änder orsakar viruset framförallt en subklinisk infektion i gastrointestinalkanalen och sprids genom faekal-oral överföring via vatten i vilket viruset kan förbli aktivt en längre tid. Det finns fortfarande många obesvarade frågor angående influensa A virus ekologi bland vilda fåglar. I denna avhandling presenteras fem artiklar som tillför ny kunskap inom detta område. I avhandlingen styrks bevisen för att vilda änder utgör virusets reservoar i naturen dels genom en metaanalys av samtliga publicerade data rörande fynd av influensa A virus hos vilda fåglar, dels med hjälp av data från fyra års provtagning från flyttande vilda änder vid Ottenby fågelstation. Resultaten påvisar temporala skillnader i influensvirusets prevalens i den västeuroasiatiska andpopulationen jämfört med den nordamerikanska. Prevalensen i den västeuroasiatiska andpopulationen är hög under perioden augusti till december och i viss mån även under våren. Dessa fynd talar för att influensavirus kontinuerligt cirkulerar i andpopulationen. Under studien av förekomsten av influensa A virus hos änder isolerades enbart olika lågpatogena subtyper. Subtyperna H5 och H7 var vanligt förekommande. Dessa subtyper är benägna att utvecklas till högpatogena varianter om de sprids till fjäderfäbesättningar med svåra konsekvenser som följd. Genom studier av virus släktskap visas att de virus vi isolerat från vilda änder är snarlika de som orsakat utbrott bland fjäderfä i Europa under de senaste sju åren. Detta styrker värdet av att övervaka förekomsten av influensavirus hos vilda fåglar för att på så sätt förhindra utbrott av sjukdom bland fjäderfä. Undersökning av prover från skrattmås (Larus ridibundus) ledde fram till upptäckten av en helt ny subtyp av influensavirus; H16. Därmed utvidgades spektret av kända subtyper i naturen. Influensa A virus isolerades från sillgrisslor (Uria aalge) i Östersjön vilket inte tidigare gjorts hos denna art i Europa. Dessa virus innehöll gener från både nordamerikanska och euroasiatiska fågelpopulationers virus. Det visar att det finns ett utbyte av virus mellan fågelpopulationerna på de skilda kontinenterna. / On the day of the defence data the status on article IV was Submitted and the title was "Multi-year surveillance of influenza virus type A in migratory waterfowl in northern Europe".

DNA fingerprinting was used to assess levels of genetic variation within the captive colony of pedigreed American kestrels (Falco sparverius) which have been maintained for over twenty years at the Avian Science and Conservation Centre of McGill University. Several instances of apparent linkage and allelism were observed. The high probability of fortuitous co-segregation of parental bands as if linked or allelic resulting from the small number of offspring was most likely responsible. Otherwise, the kestrel fingerprints displayed germ-line stability and high levels of heterozygosity characteristic of other species. A positive linear and quasi-linear relationship was found between pedigree-based and DNA fingerprint-based relatedness coefficients. High levels of genetic variation and minimal inbreeding were detected via genetic analyses. Genetic similarity coefficients between colony-bred and free-ranging American kestrels were not significantly different (P $>$ 0.5), indicating minimal genetic drift within the colony. Managed mating combined with immigration of new members into the breeding pool can maintain genetic diversity within a captive population of 200 to 300 American kestrels for a long term management scale. The captive-bred kestrel population can be fully exploited for general research, management and care techniques and as a genetic and demographic reservoir.

Im Rahmen der vorliegenden Arbeit wurden die in der Fachliteratur am häufigsten beschriebenen Formen der aviären Frakturtherapie anhand von 147 Wildvogelpatienten mit 237 gebrochenen Knochen im Hinblick auf ihre Einsatzmöglichkeiten, den Stellenwert, sowie auf Vorteile und Risiken der jeweiligen Methoden überprüft und die in der Literatur getroffenen Aussagen den Ergebnissen der eigenen Untersuchungen gegenübergestellt. Weiterhin wurden die publizierten Informationen bezüglich therapiebegleitender Maßnahmen einer kritischen Prüfung unterzogen und um die eigenen Erkenntnisse ergänzt. Rund 55 % der therapierten Wildvögel konnten nach Abschluß der klinischen Versorgung ausgewildert werden, wobei die therapeutische Erfolgsquote von Patienten mit frischen Frakturen und denjenigen, deren Frakturereignis wenige Tage zurücklag nur unwesentlich differierte. Demgegenüber wiesen Tiere mit älteren oder bereits in Heilung befindlichen Knochenbrüchen eine schlechte Prognose auf. Fast 27 % der Vögel verstarben während der Behandlung an den Folgen ihres Traumas oder einer Begleiterkrankung, etwas mehr als 13 % wurden aufgrund eines unbefriedigenden Heilungsverlaufs oder Therapieversagens euthanasiert und in etwa 5 % der Fälle reichte das erzielte Ergebnis zur Wiedereingliederung in die freie Wildbahn nicht aus. Von den untersuchten Therapiemethoden erwies sich lediglich die intramedulläre Versorgung mittels kurzer Polyacrylstäbe nach der „Shuttle-Pin“-Methode sowie die Kombination dieser Implantate mit Knochenzement bei Patienten unter 300 g Körpergewicht als problematisch. Bei einem der auf diese Weise behandelten Patienten wurde zudem eine therapieresistente Osteomyelitis als Folge einer Fremdkörperreaktion auf das eingebrachte Material dokumentiert. Positive Erfahrung konnte in zwei Fällen mit der Verwendung eines die Markhöhle weitestgehend ausfüllenden Polyacrylstabes bei ausgedehnten Splitterfrakturen gesammelt werden – eine bislang nicht beschriebene Variante bei der Versorgung mit Markraumimplantaten. Sowohl die Therapie der geschädigten Knochen mit einem modifizierten Fixateur externe bei geeigneter Frakturcharakteristik, als auch die Markraumnagelung mit Kirschner-Drähten erbrachten zumeist die angestrebten Ergebnisse. Der in der Literatur häufig betonte Vorteil kurzer intramedullärer Implantate, wie auch des Fixateur externe gegenüber einer Markraumnagelung mit Stahlstiften aufgrund einer früheren Beübungsfähigkeit der verletzten Gliedmaße konnte anhand der eigenen Ergebnisse nicht bestätigt werden. Klinische Vorteile infolge einer ungehinderten endostalen Kallusbildung bei Verwendung des Fixateur externe im Vergleich zu intramedullären Implantaten waren nicht zu ermitteln. Die Zeitdauer bis zur Auswilderung der Patienten war in der überwiegenden Zahl der Fälle weniger von der Therapieform, als vielmehr von Frakturausmaß und -lokalisation bestimmt. Die Ergebnisse der konservativen Behandlung waren – eine entsprechende Eignung der Fraktur für das Verfahren vorausgesetzt – bei vergleichsweise geringem Risiko den operativen Methoden zumindest ebenbürtig. Für eine chirurgische Versorgung von Schultergürtelfrakturen ergab sich keine zwingende Indikation; selbst hochgradig dislozierte Coracoidfrakturen konnten mittels konservativer Behandlung funktionell wieder hergestellt werden. Die röntgenologische Kontrolluntersuchung in siebentägigen Intervallen während der ersten 3 Behandlungswochen bewährte sich dabei im Hinblick auf das zeitnahe Befunden von Therapiezwischenfällen, ausbleibenden Therapieerfolgen und insbesondere zur frühzeitigen Diagnose entzündlicher Knochenveränderungen. / This study examined the methods of avian fracture therapy most commonly described in scientific literature in regard to their usability, their significance/value as well as their advantages and risks. For this purpose 147 wild birds with 237 fractured bones were treated with different methods, depending on the type of fracture. The results were compared to relevant statements found in specialist literature. In addition, published information about supportive treatment was analysed and supplemented with specific additional findings. It was possible to release about 55% of the treated wild birds back into the wild after therapy. The rate of success in therapy showed little difference between patients with fresh fractures and those with fractures that had occurred a few days previously. In contrast to this, animals with older fractures or fractures that were already in an advanced stage of untreated healing process showed a poor prognosis. Almost 27% of the birds died during therapy as a consequence of the initial trauma or accompanying diseases, a little more than 13% had to be euthanized because of an unsatisfactory healing process or failure of fracture repair and in about 5% of the cases the results were not sufficient for rehabilitation into the wild. Among the examined methods of therapy only intramedullary application of short polyacryl rods with the shuttle pin technique and the combination of these implants with bone cement in patients with a body-weight below 300g showed unsatisfactory results. One patient treated by this method developed a therapy-resistant osteomyelitis as a consequence of a foreign-body reaction. Positive results were achieved in two cases with the use of a polyacryl rod filling most of the bone cavity in extended comminuted fractures – a variation of internal fixation not previously described. Treatment with a modified external fixator as well as intramedullary fixation with Kirschner wires resulted in the required outcome in most cases whereas unimpaired endosteal callus formation, often associated with the use of an external fixator, did not result in clinical advantages. Trials did not confirm an earlier return to function by the use of short intramedullary implants or of the external fixator compared to internal fixation with intramedullary pins, which is often emphasised in scientific literature. In most cases duration of hospitlisation and of captivity depended on the extent and site of bone injury rather than on method of therapy. Results of conservative treatment and surgery were similar in terms of low risk – as long as the method of therapy matched the type of fracture. There was no requirement for surgical therapy of fractures of the shoulder girdle. Even severely dislocated fractures of the coracoid returned to normal function through conservative treatment. Weekly radiological examination at intervals of seven days during the first three weeks of therapy proved essential to identify early complications in the healing of the fracture, failure in the healing process, or, in particular, early diagnosis of osteomyelitis.

As aves silvestres são importantes reservatórios de vírus que podem acometer as aves domésticas. O monitoramento da circulação viral em aves silvestres é de extrema importância para garantir a sanidade dos plantéis avícolas. O presente estudo teve como objetivo 1) comparar dois testes moleculares de RT-PCR para a detecção dos vírus da família Paramyxoviridae em aves silvestres e sinantrópicas; 2) caracterizar os vírus detectados nestas amostras. Dois testes de RT-PCR e testes específicos de RT-PCR em tempo real (RRT-PCR) para o vírus da doença de Newcastle (NDV) e o metapneumovírus aviário (aMPV) foram utilizados para comparar o limite de detecção entre as amostras. As amostras de aves silvestres foram testadas por dois testes de RT-PCR. Um pequeno fragmento da região do sítio de clivagem do gene F das amostras positivas foi sequenciado. Os testes de RT-PCR foram validados com sucesso, mas apresentaram diferenças entre os limites de detecção quando comparados aos testes específicos de RRT-PCR utilizando diferentes vírus. No total, 100 amostras de aves (suabes) foram testados pelo teste RT-PCR que apresentou um limite de detecção similar entre os diferentes agentes virais. O teste selecionado foi capaz de detectar duas amostras de aves silvestres que foram também detectadas pelo testes específico para NDV e relacionadas às amostras de NDV vacinais do genótipo II da classe II referentes aos vírus de NDV lentogênico (113RQGR ↓ L117). Nosso estudo demonstra a deficiência na biosseguridade adotada pelos sistemas avícolas por permitir a saída dos vírus vacinais para as aves silvestres / Wild birds are important reservoirs of viruses can affect poultry. Surveillance of circulating viruses in wild birds is of the most importance tool to ensure the poultry health. The present study aimed to 1) compare two molecular tests for detection of family Paramyxoviridae viruses in wild and feral birds; 2) characterize the detected viruses in those samples. Two RT-PCR techniques and specific real time RT-PCR (RRT-PCR) assays for detection of Newcastle disease virus (NDV) and avian metapneumovirus (aMPV) were used to compare the limit of detection among them. Wild bird samples were tested by using two RT-PCR tests. A small fragment of cleavage site region in F gene from positive samples was sequenced. The RT-PCR were successfully validated, however they had differences in the limit of detection when compared to specific RRT-PCR assays using different viruses. In total, 100 wild bird samples (swabs) were tested by the selected RT-PCR with similar limit of detection between tested viruses. Two samples were positive by this test and they were also detected by the specific RRT-PCR for NDV. These samples were closed related to vaccinal NDV strains belonging to genotype II class II. Deduced amino acid sequences of cleavage site region from detected samples were characterized as lentogenic NDV strains (113RQGR ↓ L117). Our study demonstrates the poor biosafety used by poultry industry allowing the vaccinal escape to wild bird species

As aves silvestres são consideradas importantes reservatórios de diversos vírus aviários que podem afetar aves comerciais. Dessa forma, o monitoramento das aves silvestres é fundamental para garantir a sanidade dos plantéis avícolas brasileiros. Nos últimos anos, o número de espécies de aves nas quais os coronavírus aviários foram encontrados aumentou vertiginosamente em diversos países. Contudo, poucos estudos envolvendo a detecção de coronavírus aviários em aves de cativeiro e aves silvestres ou sinantrópicas foram realizados no Brasil. Assim, o presente estudo teve como objetivo identificar a presença dos coronavírus aviários em aves silvestres no Brasil e caracterizá-los molecularmente. As amostras foram testadas através do teste de RRT-PCR para detecção do gene UTR do IBV, bem como uma nested-PCR para detecção do gene S1 dos coronavírus aviários. O sequenciamento de alto desempenho foi utilizado para caracterizar os vírus detectados. No total, foram testadas 300 amostras de aves silvestres (147 suabes orofaringeanos e 153 suabes cloacais). No total, 27 amostras foram positivas pelo teste RRT-PCR. Duas amostras de Anseriformes das amostras positivas no teste de RRT-PCR foram selecionadas para sequenciamento de alto desempenho. Em ambas as amostras sequenciadas foi constatada a co-infecção pelos vírus da bronquite infecciosa e vírus da doença de Newcastle. A análise das amostras demonstrou alta identidade com vírus vacinais, o que demonstra que estirpes vacinais utilizadas na imunização de aves de produção circulam em aves silvestres e de produção de subsistência. / Wild birds are an important reservoir of different viruses that can affect poultry. Viral surveillance in wild birds is, thus, extremely important to ensure the poultry heal in Brazil. In recent years, the number of species of birds in which avian coronaviruses have been found skyrocketed in several countries. However, few studies involving the detection of avian coronaviruses in captive wild birds or wild life birds were conducted in Brazil. Thus, the present study aimed to identify the presence of avian coronaviruses in Brazil and characterize them molecularly. Samples were tested by RRT-PCR test for detection of the UTR gene of IBV, as well as a nested-PCR for detection of S1 gene. In total, 300 samples of wild birds (147 oropharyngeal swabs and 153 cloacal swabs) were tested. In total, 27 samples were positive in RT-PCR assay. Two positive samples in RRT-PCR assay were selected for Next-generation sequencing. In both sequenced samples, co-infection with infectious bronchitis virus and Newcastle disease virus was found. The analysis of samples showed identity with vaccinal strains used in immunization of commercial flocks circulate in wild birds and subsistence flocks.

No description available.

No description available.