Banca de DEFESA: MAICOM VINÍCIOS FERREIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : MAICOM VINÍCIOS FERREIRA
DATA : 22/07/2019
HORA: 09:00
LOCAL: Sala de Reuniões - Embrapa Suínos e Aves. Concórdia-SC.
TÍTULO:

Detection and characterization of influenza A virus in pigs at nursery in the Midwest region of Santa Catarina State, Brazil.

PALAVRAS-CHAVES:

Swine, influenza A virus, Subtyping, RT-qPCR, HI.

PÁGINAS: 45
GRANDE ÁREA: Ciências Agrárias
ÁREA: Medicina Veterinária
RESUMO:

In Brazil since 2009, frequent outbreaks of acute respiratory diseases in swine caused by the influenza A virus (FLUAV) have been reported. Pandemic H1N1 (pH1N1), seasonal influenza viruses, H1N2 and H3N2 are common viruses subtypes in swine herds in Brazil, where they continue to evolve. Most of the studies conducted so far have been on finishing pigs. However, diseases of the respiratory disease complex, such as influenza, are responsible for most of the losses and for the use of pharmaceutical treatment in piglet nurseries. The objectives of this study were to evaluate the prevalence of FLUAV and detect the infection of FLUAV subtypes in piglet nurseries. The study was carried out in the Midwest region of Santa Catarina, Brazil's largest pork producer and exporter. The nurseries housed a total of 60,000 piglets. For the prediction of the sample, a confidence level of 95%, accuracy level of 5% and a prevalence of 40%, were considered, totaling 423 samples. In all 11 nurseries, FLUAV infection was identified by detection of viral RNA by RT-qPCR in nasal secretion samples (67.4%), as well as the presence of antibodies produced against FLUAV by Elisa, confirmed by HI. Among the pig farms, the mean percentage of seropositive piglets for FLUAV was 66.9%. The HI test revealed a higher prevalence of antibodies in piglets against the H3N2 virus (38.0%), followed by pH1N1 (23.8%) and H1N2 (3.23%). Eighteen out of 33 viruses sampled by nasal swabs (54.5%) subtyped by RT-qPCR were positive for the H3N2 virus (from six nurseries) and nine (27.0%) were positive for pH1N1 (from two nurseries). However, six samples (18.0%) from three nurseries could not be subtyped, probably due to low viral load. Our data also reveal that 10.3% of the swine sampled were exposed to at least two antigens, with different influenza virus strains infecting the pig herd analyzed, causing mixed infections and possibly contributing to viral genetic rearrangements. Our results corroborate the need to understand the evolution of FLUAV subtypes in nurseries to improve infection control and prevent future virus rearrangements that might cause new outbreaks.

MEMBROS DA BANCA:
Externo à Instituição - GIOVANI DA COSTA CAETANO
Externa à Instituição - DANIELLE GAVA - EMBRAPA
Externo à Instituição - JOÃO XAVIER DE OLIVEIRA FILHO - EMBRAPA
Presidente - 586.812.306-97 - JANICE REIS CIACCI ZANELLA - UFMG