Detecção e quantificação de Campylobacter spp. em carcaças de frango resfriadas e congeladas por PCR em tempo real associada a propídeo monoazida (PMA)

• Ano de defesa: 2015
• Autor(a) principal: Andrea Guicheney Salgado e Almeida Castro
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: PMA; PCR em tempo real; carcaças de frangos de corte; temperatura de armazenamento; Frango de corte Carcaças; Campylobacter; Reação em cadeia de polimerase
• Link de acesso: http://hdl.handle.net/1843/SMOC-A7ER7D

The contamination of broiler carcasses by Campylobacter spp. is common and its assessment is difficult because of its tedious feature. Methods such as Real-Time Polymerase Chain Reaction (PCR) were developed to verify the presence of the microorganism, but it is also necessary to determine their viability as only live bacteria are capable of causing foodborne disease. The Propidium monoazide (PMA) is a DNA intercalator that can penetrate only in non-viable cells, preventing their DNA to be amplified by real time PCR. In order to detect and verify the viability of Campylobacter spp., frozen and refrigerated broiler carcasses were analysed. Sixty samples of broiler carcasses were collected in a poultry slaughterhouse under federal inspection (30 refrigerated and 30 frozen) and analysed by Real-Time PCR and Real-Time PCR after PMA treatment. It was observed that when samples were treated with PMA, both frozen and refrigerated carcasses, had the lowest positivity rate compared to untreated samples with DNA intercalator (p <0.001). Fifty three out of 60 samples analysed by Real-Time PCR (88.33%) were positive for Campylobacter spp., while 11 (18.33%) tested positive by Real-Time PCR with treatment by PMA. For the Real-Time PCR, 26 (86.67%) refrigerated samples and 27 (90%) frozen samples were positive for Campylobacter spp. When PMA was used, nine (30%) refrigerated samples and two (6.67%) frozen samples tested positive for the bacteria. It was also observed that a smaller number of frozen carcasses contained viable microorganism compared to the refrigerated carcasses (p <0.05). It is concluded that the use of low temperatures in storage of carcases was effective in controlling contamination of carcasses by Campylobacter spp. using Real-Time PCR with PMA comparing with Real-Time PCR without PMA treatment. Furthermore, the microorganism keeps viable more frequently in refrigerated carcass, comparing with frozen carcass