This research was initiated by an outbreak of fowl adenovirus (FAdV) associated inclusion body hepatitis (IBH) in South Africa (SA) during 2008. The fowl adenoviruses involved in this outbreak could be identified by restriction enzyme fragment length polymorphisms (RFLP) and sequencing of the PCR amplification products from the FAdV L1 hexon loop. The relationship of these strains to the International Committee on Taxonomy of Viruses (ICTV) reference strains for FAdV could be established by phylogenetic analysis. The SA FAdV isolates showed close relationship (99 %) to the ICTV reference strain T8-A and 764 for FAdV-8b and the reference strain P7-A for FAdV-2. Although a complete epidemiological study was not performed data obtained from the phylogenetic analysis data also suggested that the fowl adenoviruses involved in this outbreak of IBH might have been introduced into the country. A dose of 106.00 EID50 /mℓ virulent FAdV-2 and 105.97 EID50 /mℓ virulent FAdV-8b was sufficient to cause 80-87 % mortality rates for embryos challenged with FAdV-2 and 65-80 % mortality in SPF embryos challenged with FAdV-8b. v Fowl adenovirus type-specific antibodies are masked by group-specific antibodies in ELISA. The L1 hexon loop of the fowl adenoviral capsid contains type-specific epitopes located between group-specific regions which could be used for development of a type-specific ELISA. A novel approach to include additional type-specific FAdV epitopes to select for type-specific antibody binding was followed during the development of the ELISA described in this study. A dimeric protein which targets the type-specific region within the L1 loop region of the FAdV-2 and FAdV-8b hexon was designed to include additional type-specific epitopes. Amino acid alignment of this region showed less than 46 % homology which presented an opportunity to investigate its use as coating antigen to detect type-specific antibodies in an indirect ELISA. The purified expression products of dimeric codon optimised genes encoding the variable regions within the FAdV L1 hexon loop for FAdV-2 and FAdV-8b were used as coating antigen in ELISA. The assay conditions were optimised with the Taguchi method for optimisation of experiments with multiple variables. The diagnostic performances of the ELISA were evaluated using 100 serum samples from vaccinated birds and birds with no previous history of exposure. The assay was able to detect type-specific antibodies with an overall assay accuracy of 85.1 % for FAdV-2 and 92.3 % for FAdV-8b. An embryo challenge model to measure the ability of maternal antibodies to protect against challenge with virulent FAdV was developed in this study. This challenge model was supported by macroscopical, histopathological and PCR data and was sensitive enough to be used for vaccine efficacy studies. A comparative study to evaluate the performance of formalin inactivated autogenous vaccine which contained whole virus to a fiber subunit vaccine which contained insoluble and refolded fiber proteins of both FAdV-2 and FAdV-8b. Synthetic genes encoding the complete fiber proteins of both FAdV-2 and FAdV-8b were cloned and expressed in E. coli. Both the fiber proteins were insoluble but were used as crude extracts in an experimental vaccine for vaccination of SPF birds. Purified refolded fiber protein fractions were also prepared from these insoluble fractions and were used for vaccination of another group of SPF parent birds. The autogenous bivalent formalin inactivated FAdV vaccine completely protected embryos from vaccinated parent birds against in ovo challenge with both FAdV-2 and FAdV-8b. Whilst the insoluble FAdV-8b fiber protein subunit vaccine protected against challenge, the FAdV-2 fiber protein did not. Vaccine prepared from purified refolded fiber proteins of FAdV-2 and FAdV-8b did not protect embryos from vaccinated parents upon in ovo challenge. / Thesis (PhD)--University of Pretoria, 2013. / gm2014 / Veterinary Tropical Diseases / Unrestricted

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

Para verificar a permissividade de células de origem hematopoiéticas à infecção por HAdV-41, foram infectados PBMC e IEL de voluntários. Os ensaios foram comparados com células HEK-293 infectadas. Foram analisadas as expressões dos genes virais E1A, E1B (55K), E3 (14K), VARNA, hexon e fibra curta (FC) e do gene celular GAPDH. O mRNA foi detectado por RT-PCR em tempo real e a produção de proteínas foi visualizada por IFI. Em HEK-293, a transcrição dos genes E1A, E1B e E3 iniciou-se às 11h p.i, hexon,às 13h pi.,VARNA e FC às 14h p.i. Em PBMC a transcrição de E1A, E1B e VARNA iniciou-se 17h p.i e a expressão dos genes hexon e fibra curta foi detectada 18h p.i e 20 h p.i. respectivamente. O nível de expressão dos genes virais em HEK-293 foi quase 200 vezes maior em relação à PBMC. Os IELs também mostraram-se permissivos à infecção pelo HAdV-41 como mostrado pela expressão dos genes virais. Essa é a primeira evidência de que este vírus possa infectar tais células. Os resultados obtidos ajudam a elucidar os mecanismos de interação do vírus com a célula-hospedeira. / In order to verify the permissiveness of hematopoietic cells to HAdV-41 infection, PBMC and IEL from volunteers were infected. The infection assays were compared with infected HEK -293 cells. We analysed the E1A, E1B (55K), E3 (14K), VARNA, hexon and short fiber (SF) viral gene expression and GAPDH cellular gene expression. The mRNA were detected by real time PCR and the viral protein synthesis were detected by IIF. In HEK-293 cells E1A, E1B and E3 gene expression were detected 11h p.i Hexon gene expression was detected at 13h p.i, while VARNA and SF were detected 14h p.i In PBMC, E1A, E1B and VARNA gene expression were detected 17h p.i and the hexon and SF were detected 18h p.i and 20h p.i, respectively. The viral gene expression level in infected HEK-293 cells was 200 fold higher than infected PBMC. The IEL also were permissive to HAdV-41 infection showed by viral gene expressions. This is the first evidence that HAdV-41 is able to infect these cells types. These results helps to understand the virus-cell interaction mechanisms.

Mucopolysaccharidosis type IIIA (MPS IIIA) is an autosomal-recessively inherited disorder caused by the deficiency of lysosomal sulphamidase (NS) enzyme activity, resulting in the accumulation of the glycosaminoglycan (GAG) heparan sulphate (HS). MPS IIIA patients experience progressive and severe neurological deterioration with death usually occurring in the mid-late teenage years. A naturally-occurring mouse model of MPS IIIA has been characterised and the biochemical, histological and behavioural changes closely parallel the human condition. In order to treat the neurological effects of MPS IIIA, it is anticipated that a continual supply of replacement enzyme to affected cells will be required. Consequently, this study aimed to evaluate the efficacy, longevity and safety of gene therapy as a potential treatment for MPS IIIA. Canine adenoviral vectors (CAV-2) were selected on the basis of several important properties. They are non-integrating, are predicted to be less immunogenic in humans than human-derived viral vectors and mediate transgene expression for at least 1 year in vivo. An E1-deleted (∆E1) CAV-2 vector, CAV-NS, co-expressing recombinant human NS (rhNS) and Green Fluorescent Protein (GFP) was constructed and purified. In vitro testing revealed rhNS produced by CAV-NS significantly decreased sulphated GAG storage in human MPS IIIA fibroblasts in a mannose-6-phosphate-dependent manner. Preliminary studies in young adult guinea pigs with CAV-GFP demonstrated widespread GFP expression in the absence of a humoral response. In contrast, minimal GFP expression was found in CAV-injected adult mice due to formation of neutralising antibodies against the CAV-2 capsid. Consequently, intraventricular delivery of CAV-NS was evaluated in newborn mice at various doses. Widespread and dose-dependent GFP expression was observed and the optimal dose for large-scale studies was determined to be 109 CAV-NS particles/hemisphere. Antibodies against CAV-2, rhNS or GFP were not detected. Concurrently, the cognitive function and anxiety-related behaviours of unaffected and MPS IIIA mice were evaluated. MPS IIIA mice had significantly impaired memory and spatial learning in the Morris Water Maze (16-wks) and reduced anxiety in the Elevated Plus Maze (18-wks) when compared to unaffected animals. In a large therapeutic assessment trial, newborn MPS IIIA or unaffected mice received 109 particles of CAV-NS, saline or remained uninjected. GFP expression was visualised for at least 20-wks post-injection. Reductions in the vacuolation of ependymal and choroidal cells of the lateral ventricle and the cerebral cortex of treated MPS IIIA animals were observed in some GFP-positive (and presumably rhNS-expressing) regions. Furthermore, improvements in reactive astrogliosis, but not in the number of activated microglia, were measured in CAVNS- treated MPS IIIA mice. However, insufficient CAV-NS-mediated rhNS expression was generated to improve functional changes as assessed by a behavioural test battery (motor function, open field activity, Elevated Plus Maze, Morris Water Maze), potentially due to chronic inflammatory responses against the CAV-2 vector. Collectively, these data suggest that early intervention with ∆E1 CAV-NS gene therapy was able to improve several components of neuropathology in MPS IIIA animals but was unable to significantly alter the clinical progression of murine MPS IIIA. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1295758 / Thesis (Ph.D.) -- University of Adelaide, School of Paediatrics and Reproductive Health, 2007

Οι εντεροϊοί έχουν ιδιαίτερη σημασία για τη δημόσια υγεία, δεδομένου ότι σχετίζονται με επιδημίες γαστρεντερίτιδας (μη βακτηριογενούς προέλευσης) από την κατανάλωση μολυσμένου νερού. Οι ιοί αυτοί μπορούν να απομονωθούν σε μεγάλες ποσόστητες από κόπρανα και ούρα ανθρώπινης προέλευσης, καθώς και από λύματα και μολυσμένα νερά. Επιπλέον, οι Αδενοϊοί είναι παθογόνοι για τον άνθρωπο και η παρουσία τους σε περιβαλλοντικά δείγματα δύναται να προκαλέσει σημαντικές μολύνσεις. Οι Αδενοϊοί είναι ιοί ανθρώπινης εντερικής προέλευσης που περιέχουν DNA και ορισμένοι ορότυποι τους είτε δεν καλλιεργούνται, είτε καλλιεργούνται δύσκολα στις συνήθεις κυτταρικές σειρές. Γι’ αυτόν το λόγο, η ανίχνευσή τους σε μολυσμένο νερό και ο ρόλος τους ως παραγόντων πρόκλησης γαστρεντερίτιδας έχουν υποτιμηθεί. Οι Ρότα ιοί είναι υπεύθυνοι για οξεία περιστατικά γαστρεντερίτιδας στον άνθρωπο και τα ζώα. Κατόπιν του διπλασιασμού του γενετικού τους υλικού στον γαστρεντερικό σωλήνα οι ιοί αυτοί εκκρίνονται και δύνανται να διασπαρούν στο περιβάλλον και το νερό. Γενικά, οι Ρότα ιοί έχουν εμπλακεί σε περιστατικά γαστρεντερίτιδας σε πολλές χώρες. Η σταθερότητα των ανθρωπίνων Ρότα ιών στο νερό και η ανθεκτικότητά τους σε φυσικοχημικές διαδικασίες εξυγίανσης κατά την επεξεργασία των λυμάτων συντείνουν στην εξάπλωσή τους. Στην παρούσα διατριβή ανιχνεύθηκαν και απομονώθηκαν εντεροϊοί, αδενοϊοί και ρότα ιοί από ακατέργαστα λύματα, τα οποία ελήφθησαν από την είσοδο τεσσάρων σταθμών βιολογικού καθαρισμού (δύο στην Αττική και δύο στην Αχαΐα). Συνολικά ελήφθησαν 118 δείγματα ακατέργαστων λυμάτων κατά την περίοδο Σεπτέμβριο 2000 – Σεπτέμβριο 2003. Η μεθοδολογία αφορούσε στην συμπύκνωση των ιών ακολουθούμενη από RT-nested PCR, προκειμένου να επιτευχθεί αύξηση της ευαισθησίας απομόνωσης των ιών. Μετά την απομόνωση γενετικού υλικού των ιών πραγματοποιήθηκε τυποποίησή τους εφαρμόζοντας nucleotide sequencing analysis. Οι Ρότα ιοί ανιχνεύθηκαν σε 17 δείγματα (14.2%). Τα αποτελέσματα της τυποποίησής τους ήταν rotavirus τύπος G1 (88.2%) και τύπος G2 (11.8%). Οι Αδενοϊοί βρέθηκαν σε 55 δείγματα (45.8%). Η Sequencing ανάλυση είχε ως αποτέλεσμα την παρουσία στα δείγματα αδενοϊών της ομάδας F [τύποι 40 (34.6%) και 41 (63.6%)] και της ομάδας C [τύπος 2 (1.8%)]. Οι Εντεροϊοί ανιχνεύθηκαν σε 30 δείγματα (40%) και η sequencing ανάλυση είχε ως αποτέλεσμα την παρουσία αρκετών τύπων όπως (α) coxsackievirus (τύποι A6 - 3.3%, A9 - 3.3%, A16 - 3.3%, B4 - 16.7%, B5 - 3.3%), (β) echovirus (τύποι 2 -6.7%, 6 - 13.3%, 30 -10%), (γ) εντεροϊοί τύποι 68 - 3.3%, 71 - 13.3% καθώς και porcine εντεροϊός (6.7%), poliovirus 1 (6.7%) και poliovirus 2 (10%). Η μικροβιολογική ποιότητα του νερού επομένως και η ανθρώπινη υγεία επηρεάζονται σημαντικά από την παρουσία μικροοργανισμών εντερικής προέλευσης, οι οποίοι προέρχονται από λύματα που καταλήγουν στο υδάτινο περιβάλλον. Πολλές επιδημίες από ιούς εντερικής προέλευσης έχουν κατά καιρούς συνδυαστεί με το νερό. Οι υδατογενείς επιδημίες γενικά εξαπλώνονται στον πληθυσμό από κατανάλωση μολυσμένου νερού, κολύμβηση σε ακατάλληλα νερά αναψυχής καθώς επίσης μεταδίδονται απο τη σωματική επαφή και την εισπνοή. Τα μη επεξεργασμένα λύματα της μελέτης περιέχουν πολλούς και διαφορετικούς τύπους ιών εντερικής προέλευσης οι οποίοι κατά κύριο λόγο προκαλούν γαστρεντερίτιδα. Επομένως καθίσταται αναγκαία η επξεργασία των λυμάτων στο μέγιστο δυνατό βαθμό στους σταθμούς βιολογικού καθαρισμού. Η Sequencing ανάλυση έδειξε την παρουσία ανθρώπινων Ρότα ιών A (τύποι G1 και G2), οι οποίοι προκαλούν παγκοσμίως διάρροια σε παιδιά καθώς επίσης και την παρουσία αδενοϊών τύπου 40 και 41, οι οποίοι είναι σημαντικοί αιτιολογικοί παράγοντες γαστρεντερίτιδας, κυρίως σε θερμά κλίματα. Από την άλλη πλευρά η ποικιλία των εντεροϊών που ανιχνεύθηκε στα ακατέργαστα λύματα ήταν μεγαλύτερη συγκρινόμενη με την αντίστοιχη των υπολοίπων ιών της μελέτης. Η παρούσα διατριβή αναδεικνύει την αποτελεσματικότητα της μεθόδου «nucleotide sequencing analysis», ως μέσου επιδημιολογικής μελέτης και ανάλυσης της συσχέτισης ιών που εμπλέκονται σε ανθρώπινες ασθένειες κι εκέινων που ανιχνεύονται σε ακατέργαστα λύματα. / Enteroviruses have been associated with outbreaks of waterborne non-bacterial gastroenteritis and are of important concern for public health. Significant numbers of viruses can be isolated from faeces and urine of humans as well as from sewage and polluted waters. Adenoviruses are also pathogenic to humans and their presence in environmental samples (polluted waters) may cause infections. Like rotaviruses, adenoviruses are causative agents of gastroenteritis, are the only human enteric viruses to contain DNA and many serotypes are difficult to culture in regular cell lines For this reason, and because adenoviruses are slow growing, their presence in polluted water and their role as originators of gastroenteritis have probably been underestimated. Rota viruses are responsible for severe gastroenteritis in humans and animals. After replicating in the gastrointestinal tract, these viruses are excreted and may be dispersed in environmental waters. Rota viruses have been implicated in waterborne gastroenteritis outbreaks in many countries. The stability of human rotaviruses in environmental water and their resistance to physicochemical treatment processes in sewage treatment plants may facilitate their transmission. In the present study, enteroviruses, adenoviruses and rota viruses were detected in raw sewage samples from inlets of four biological treatment plants in Greece (two in Athens, two in Patras}. Raw sewage samples (118) were analyzed for the presence of these viruses during the period September 2000 to September 2003. Our approach consisted of a simple concentration of viruses from raw sewage followed by RT-nested PCR in order to increase the sensitivity of virus detection. The viral sequences detected were then characterized by nucleotide sequencing analysis. Rota viruses were detected in 17 samples (14.2%). Sequencing analysis of the positive sewage samples revealed the presence of rotavirus type G1 (88.2%) and type G2 (11.8%). Adenoviruses were found in 55 samples (45.8%). Sequencing analysis of the positive sewage samples revealed the presence of adenovirus group F type 40 (34.6%), type 41 (63.6%) and group C type 2 (1.8%). Enteroviruses were detected in 30 samples (40%) and sequencing analysis of the positive sewage samples revealed the presence of several types such as (a) coxsackievirus types (A6 - 3.3%, A9 - 3.3%, A16 - 3.3%, B4 - 16.7%, B5 - 3.3%), (b) echovirus types (2 -6.7%, 6 - 13.3%, 30 -10%), (c) enterovirus types (68 - 3.3%, 71 - 13.3%) as well as porcine enterovirus (6.7%). poliovirus 1 (6.7%) and poliovirus 2 (10%). Water quality and, therefore human health, may be significantly affected by the presence of pathogenic enteric microorganisms derived from sewage discharged to the aquatic environment. Outbreaks of enteric virus disease have been linked to water at various times and to different causes. Waterborne disease may be transmitted by consumption of polluted drinking water, by immersion in recreational water or by contact with skin or inhalation. Raw sewage was found to be contaminated by different types of enteric viruses that mainly cause gastroenteritis; therefore, it is necessary to use the most efficient water treatment measures in sewage treatment plants. Sequencing analysis showed the presence of human rotavirus A type G1 and G2 which cause childhood diarrhea worldwide and enteric adenoviruses (types 40 and 41) which are important etiological agents of pediatric gastroenteritis, principally in temperate climates. On the other hand, the variety of enteroviruses identified in the raw sewage samples was more extensive compared to the other viruses of the study. The present study demonstrated the efficiency of the nucleotide sequencing analysis for studying epidemiological relationships between strains involved in human infections and those found in raw sewage.

Thesis (doctoral)--Rijksuniversiteit te Utrecht.

Thesis (M.S.)--Brigham Young University. Dept. of Microbiology and Molecular Biology, 2005. / Includes bibliographical references.

Thesis (Ph. D.)--University of Hong Kong, 2006.

O presente estudo foi realizado com o objetivo de identificar genomas de vírus em fezes de lobos marinhos sul-americanos (Arctocephalus australis) e lobos marinhos subantárticos (Arctocephalus tropicalis), duas espécies de pinípedes encontradas no litoral do Rio Grande do Sul. Embora já existam estudos sobre esse tema em outras espécies de pinípedes, nas espécies aqui trabalhadas o tema permanece inexplorado. Amostras de fezes foram obtidas de vinte e um lobos marinhos sul-americanos e dois lobos marinhos subantárticos encontrados no litoral rio-grandense com indícios de morte recente, durante os meses de Junho e Julho de 2012. Através de técnicas de PCR e sequenciamento buscou-se identificar genomas de circovírus, adenovírus, morbilivírus, calicivírus e coronavírus. A amplificação de um fragmento do gene rep permitiu a identificação de prováveis circovírus em amostras de seis lobos marinhos sul-americanos. Análises filogenéticas revelaram que três dos seis segmentos são sugestivos de prováveis membros do gênero Cyclovirus. Os genes amplificados de outras duas amostras provavelmente correspondem a membros do gênero Circovirus. Uma das amostras deu origem a um segmento gênico que não apresenta similaridade com nenhum gênero já proposto da família Circoviridae. Além disso, foi possível detectar também fragmentos de genomas de adenovírus em duas amostras; estes apresentam alto grau de similaridade de nucleotídeos com amostras de adenovírus humano tipo C. Nenhum fragmento genômico indicativo da presença de morbilivírus, calicivírus ou coronavírus foi encontrado. Os resultados aqui obtidos sugerem a presença de circovírus, ciclovírus e adenovírus em populações de lobos marinhos encontrados na costa do Rio Grande do Sul. Estes achados reforçam a necessidade da ampliação do conhecimento a respeito da ocorrência de infecções virais nestas espécies. / This study was conducted with the objective of identifying genomes of viruses in feces of south american fur seals (Arctocephalus australis) and subantarctic fur seals (Arctocephalus tropicalis), two species of pinnipeds found on the coast of Rio Grande do Sul. Although there are studies about this topic in other species of pinnipeds, it remains unexplored in these two species. Stool samples were obtained from twenty-one south american fur seals and two subantarctic fur seals found in Rio Grande do Sul coastline with evidences of recent death, during the months of June and July 2012. PCR and sequencing techniques were utilized to identify circovirus, adenovirus, morbillivirus, calicivirus and coronavirus genomes. The amplification of a rep gene fragment allowed the identification of supposed circoviruses in samples of six south american fur seals. Phylogenetic analysis revealed that three of the six segments are suggestive of probable members of the genus Cyclovirus. The amplified genes from two other samples probably correspond to members of the genus Circovirus. One of the samples gave rise to a gene segment that has no similarity with any genera already proposed of the Circoviridae family. Furthermore, it was also possible to detect fragments of adenovirus genomes in two samples: these have a high degree of nucleotide similarity with a human adenovirus type C genomic fragment. No indication of the presence of morbillivirus, calicivirus and coronavirus genomes was found. The work reported here provide evidence for the occurrence of circoviruses, cicloviruses and adenoviruses in fur seal populations found in Rio Grande do Sul. These findings reinforce the need to expand the knowledge about the occurrence of viral infections in these species.

O presente estudo foi realizado com o objetivo de identificar genomas de vírus em fezes de lobos marinhos sul-americanos (Arctocephalus australis) e lobos marinhos subantárticos (Arctocephalus tropicalis), duas espécies de pinípedes encontradas no litoral do Rio Grande do Sul. Embora já existam estudos sobre esse tema em outras espécies de pinípedes, nas espécies aqui trabalhadas o tema permanece inexplorado. Amostras de fezes foram obtidas de vinte e um lobos marinhos sul-americanos e dois lobos marinhos subantárticos encontrados no litoral rio-grandense com indícios de morte recente, durante os meses de Junho e Julho de 2012. Através de técnicas de PCR e sequenciamento buscou-se identificar genomas de circovírus, adenovírus, morbilivírus, calicivírus e coronavírus. A amplificação de um fragmento do gene rep permitiu a identificação de prováveis circovírus em amostras de seis lobos marinhos sul-americanos. Análises filogenéticas revelaram que três dos seis segmentos são sugestivos de prováveis membros do gênero Cyclovirus. Os genes amplificados de outras duas amostras provavelmente correspondem a membros do gênero Circovirus. Uma das amostras deu origem a um segmento gênico que não apresenta similaridade com nenhum gênero já proposto da família Circoviridae. Além disso, foi possível detectar também fragmentos de genomas de adenovírus em duas amostras; estes apresentam alto grau de similaridade de nucleotídeos com amostras de adenovírus humano tipo C. Nenhum fragmento genômico indicativo da presença de morbilivírus, calicivírus ou coronavírus foi encontrado. Os resultados aqui obtidos sugerem a presença de circovírus, ciclovírus e adenovírus em populações de lobos marinhos encontrados na costa do Rio Grande do Sul. Estes achados reforçam a necessidade da ampliação do conhecimento a respeito da ocorrência de infecções virais nestas espécies. / This study was conducted with the objective of identifying genomes of viruses in feces of south american fur seals (Arctocephalus australis) and subantarctic fur seals (Arctocephalus tropicalis), two species of pinnipeds found on the coast of Rio Grande do Sul. Although there are studies about this topic in other species of pinnipeds, it remains unexplored in these two species. Stool samples were obtained from twenty-one south american fur seals and two subantarctic fur seals found in Rio Grande do Sul coastline with evidences of recent death, during the months of June and July 2012. PCR and sequencing techniques were utilized to identify circovirus, adenovirus, morbillivirus, calicivirus and coronavirus genomes. The amplification of a rep gene fragment allowed the identification of supposed circoviruses in samples of six south american fur seals. Phylogenetic analysis revealed that three of the six segments are suggestive of probable members of the genus Cyclovirus. The amplified genes from two other samples probably correspond to members of the genus Circovirus. One of the samples gave rise to a gene segment that has no similarity with any genera already proposed of the Circoviridae family. Furthermore, it was also possible to detect fragments of adenovirus genomes in two samples: these have a high degree of nucleotide similarity with a human adenovirus type C genomic fragment. No indication of the presence of morbillivirus, calicivirus and coronavirus genomes was found. The work reported here provide evidence for the occurrence of circoviruses, cicloviruses and adenoviruses in fur seal populations found in Rio Grande do Sul. These findings reinforce the need to expand the knowledge about the occurrence of viral infections in these species.