29 resultados para NDV carrier

em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"


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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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A total of 120 Pekin ducks were distributed at random into four experimental groups, vaccinated or not against Newcastle disease (ND): G1 (Ulster 2C strain), G2 (B1 strain), G3 (LaSota strain), and G4 (nonvaccinated group). At 60 days of age, all groups were challenged with a pathogenic ND virus (NDV) suspension, and a group of specific pathogen free (SPF) chicks (G5) was also inoculated. Cloacal and tracheal swabs from all birds were collected after six, 14, 20, and 30 days post-challenge for virus isolation. NDV was isolated in 100% of SPF chicks. Pekin ducks from all groups, vaccinated or not, did not show any ND clinical signs, demonstrating that these birds are not susceptible to ND clinical disease. In the control group (G4), the virus was isolated 20 to 30 days after challenge, suggesting their possible NDV carrier state. In the vaccinated groups, no virus was isolated. This demonstrates that vaccination of white Pekin ducks against NDV is important to reduce NDV shedding in the field.

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This study aimed to characterize the true epidemiological role played by the Chinese goose (Anser cygnoides) as a potential source of infection by the Newcastle disease virus (NDV). For this, Specific-Pathogen-Free chicks (SPF) were used and were housed with Chinese geese that had been inoculated with a pathogenic strain (velogenic viscerotropic, strain São João do Meriti) of NDV (DIE50=108.15/0.1 mL) pathogenic to chickens, by the ocular-nasal route. Each group was composed of 6 SPF Leghorn chicks and 3 geese. At 6 days (Group I) and 14 days (Group II) after inoculation of the Chinese geese with NDV, SPF chicks were put into direct contact with each goose group. Cloacal swabs were collected from both species (Chinese geese and SPF chicks) 6, 10 and 20 days after challenge to genome viral excretion by Reverse Transcription Polymerase Chain Reaction (RT-PCR). Chinese geese did not demonstrate any clinical signs of Newcastle disease (ND). They were refractory to the clinical disease with the NDV. However, NDV genome was detected 20 days after challenge. Therefore, NDV carrier status was demonstrated by Chinese geese. Moreover, 100% of SPF chicks housed with the infected Chinese geese had died by 6 (Group I) and 14 days (Group II) after challenge. Thus, the transmission of the pathogenic virus from the Chinese geese to cohabiting SPF chicks was evident within 20 days of the experimental infection. This reveals the epidemiological importance of Chinese geese as a potential transmitter of NDV infection to other commercial birds that could be raised in close proximity.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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The aim of this study was to evaluate the importance of vaccination against Newcastle Disease (ND) in lovebirds (Agapornis roseicollis) and to investigate the state of carrier of the virus (NDV) in this species. There were used 48 lovebirds, distributed at random into 4 experimental groups: GI (Ulster 2C strain), Gil (B1 strain), Gill (LaSota strain) and GIV (non-vaccinated group). At 12 months of age, all groups were challenged with a pathogenic virus (NDV) suspension (ElD50 = 1081510.1 mL) and a group of Specific-Pathogen-Free (SPF) chicks were used as control of the virus. Cloaca) swabs from each bird were collected after 9, 14 and 21 days post-challenge for detection of genome viral excretion by Reverse Transcription Polymerase Chain Reaction RT-PCR. Lovebirds of GI, Gil and Gill did not demonstrate any signs of ND. They were refractory to the clinical disease. In lovebirds from the control group, NDV genome was detected 9 and 21 days after challenge. Therefore it was demonstrated the state of carrier of NDV by lovebirds. In birds from the vaccinated groups, genome viral excretion was not detected by RT-PCR. It was also demonstrated the importance of the vaccination in the suppression of the state of virus carrier of ND in lovebirds.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Haemophilia A is an X-linked, recessively inherited bleeding disorder of varying severity, which results from the deficiency of procoagulant factor VIII f(8). Linkage diagnosis using polymorphic markers in the f8 gene is widely used to detect carriers. The objective of this study was to verify the informativeness of three polymorphic markers in the Brazilian population, to evaluate the usefulness of such markers in carrier detection procedures. Sixty-three unrelated healthy volunteers and 10 haemophilic families were studied. Two microsatellite repeats and one HindIII RFLP markers were used. Carrier and non-carrier status could be determined in 80% of females investigated. Intron 13 markers presented the highest heterozygosity rate (79%) followed by intron 22 (68%) and intron 19 (57%). When all three markers were used together, linkage analysis informativeness increased significantly. We conclude that these markers are suitable for carrier detection in the Brazilian population and we recommend their use in combination to maximize diagnostic efficiency.

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Capacitance spectra of thin (< 200 nm) Alq(3) electron-only devices have been measured as a function of bias voltage. Capacitance spectra exhibit a flat response at high frequencies (> 10(3) Hz) and no feature related to the carrier transit time is observed. Toward low frequencies the spectra reach a maximum and develop a negative excess capacitance. Capacitance response along with current-voltage (J-V) characteristics are interpreted in terms of the injection of electrons mediated by surface states at the metal organic interface. A detailed model for the impedance of the injection process is provided that highlights the role of the filling/releasing kinetics of energetically distributed interface states. This approach connects the whole capacitance spectra to the occupancy of interface states, with no additional information about bulk trap levels. Simulations based on the model allow to derive the density of interface states effectively intervening in the carrier injection (similar to 1.5 x 10(12) cm (2)). (C) 2008 Elsevier B.V. All rights reserved.

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This study was carried out to clarify the real role that was played by the budgerigars (Melopsittacus undulatus) in the epidemiological plan, under the perspective of its being an infection source of the Newcastle Disease Virus (NDV). For this, the study used Specific-Pathogen-Free chicks (SPF) that were housed with budgerigars that were inoculated with a pathogenic strain (velogenic viscerotropic) of NDV (EID5o =10815/0.1 mL) pathogenic to chickens, by the ocular-nasal via. Each group was composed by 10 SPF chicks and 5 budgerigars. After 5 days of the inoculation of the budgerigars with NDV, SPF chicks were put together with each group of budgerigars, so that there was a direct contact between both species. Cloaca) swabs and blood samples were collected in both species (budgerigars and SPF chicks) after 13 and 19 days post-challenge, respectively, for genome viral excretion by Reverse Transcription Polymerase Chain Reaction (RTPCR) and antibody's search by the inhibition of hemmaglutination test (HI). Budgerigars did not demonstrate any clinical signs of Newcastle Disease (ND). They were refractory to the clinical disease with the NDV. However, antibody titres from inhibition of Hemagglutination (HI) test were detected 9 and 21 days after challenge. Therefore, it was demonstrated the state of carrier of NDV in this species. In SPF chicks allocated with infected budgerigars, NDV genome was detected 13 and 19 days after challenge. Thus, the transmission of the pathogenic virus from the budgerigars to SPF chicks that were housed together was evident until 19 days of the experimental infection with this pathogen. This reveals the importance of the budgerigars from the epidemiological point of view as a potential source of infection of the NDV to commercial chickens that could be raised near this species.