Acta Veterinaria Brasilica December 13 (2019) 224-227 ____________________________ * Corresponding author: thomassalles@id.uff.br http://dx.doi.org/10.21708/avb.2019.13.4.8532 Acta Veterinaria Brasilica Journal homepage: https://periodicos.ufersa.edu.br/index.php/acta/index Original Article Evaluation of two DNA extraction techniques in the detection of Mycoplasma hyopneumoniae by PCR in lungs samples of pigs with and without pneumonia Avaliação de duas técnicas de extração de DNA na detecção de Mycoplasma hyopneumoniae por PCR em amostras de pulmões de suínos com e sem lesão de pneumonia Elmiro Rosendo do Nascimento 1,2 , Kênia de Fátima Carrijo 3 , Liana Lumi Ogino 4 , Virginia Léo de Almeida Pereira 1,2 , Thomas Salles Dias 2* , Leandro dos Santos Machado 1,2 1 Departamento de Saúde Coletiva Veterinária e Saúde Pública, Faculdade de Veterinária, Universidade Federal Fluminense (UFF). 2 Programa de Pós-Graduação em Medicina Veterinária (Higiene Veterinária e Processamento Tecnológico de Produtos de Origem Animal), Faculdade de Veterinária, Universidade Federal Fluminense (UFF). 3 Faculdade de Medicina Veterinária, Universidade Federal de Uberlândia (UFU). 4 Instituto Estadual do Cérebro Paulo Niemeyer. ARTICLE INFO ABSTRACT Article history Swine Enzootic Pneumonia (PES) has as the primary etiologic agent the Mycoplasma hyopneumoniae. The diagnosis of PES involves clinical manifestations on farms, macroscopic lesions visualized in the slaughterhouse and laboratory techniques, such as isolation by culture, histopathology, immunohistochemistry, ELISA and other serological tests and PCR. This work aimed to establish the comparison between PCR results and typical macroscopic findings in lungs with PES and to evaluate the efficacy of PCR results with extraction by phenol-chloroform and commercial kit in fragments of swine lungs. The efficacy of PCR was evaluated by comparing the classic method of DNA extraction by phenol-chloroform and by commercial Kit. Fragments of lungs of 18 pigs with characteristic lesions of PES and 17 without lesions were subjected to DNA extraction and posterior PCR. The pulmonary lesions with PES were PCR-positive in 94.44%, compared to 76.47% of the non-PES lungs. Kappa concordance between macroscopic and PCR was 18%, which was not significant (P > 0.05). Of the 35 lung fragments processed by phenol-chloroform, 85.71% were positive by PCR, compared to 28.57% by the commercial kit. Kappa agreement between DNA extraction methods was 57%, which was statistically significant (p <0.05), but Odds ratio was 15 (CI 4.52 to 49.68), which means that the probability of PCR positivity by the phenol-chloroform method was 15 times higher than that by the commercial kit. Macroscopy and PCR results were discordant, with phenol-chloroform extraction being the best between both procedures. Received 16 June 2019 Accepted 23 September 2019 Keywords: Mycoplasma hyopneumoniae PCR Enzootic Swine Pneumonia RESUMO Palavras-chave: A Pneumonia Enzoótica Suína (PES) tem como agente etiológico primário a bactéria Mycoplasma hyopneumoniae. O diagnóstico da PES envolve manifestações clínicas na granja, lesões macroscópicas visualizadas no frigorífico e técnicas laboratoriais, tais como isolamento por cultura, histopatologia, imunoistoquímica, ELISA e outros testes sorológicos e PCR. O objetivo deste trabalho foi estabelecer a comparação entre resultados da PCR e achados macroscópicos típicos em pulmão com PES e avaliar a eficácia dos resultados da PCR com extração por fenol-clorofórmio e kit comercial, em fragmentos de pulmão de suínos. A eficácia da PCR foi avaliada pela comparação entre o método clássico de extração de DNA por fenol-clorofórmio e por Kit comercial. Fragmentos de pulmões de 18 suínos com lesões características de PES e 17 sem lesões foram submetidos a extração de DNA e posterior PCR. As lesões pulmonares com PES, foram PCR positivas na PCR em 94.44%, contra 76.47% dos pulmões sem PES. A concordância por Kappa entre macroscopia e PCR foi 18%, não significativo, (p>0.05). Mycoplasma hyopneumoniae PCR Pneumonia Enzoótica Suína