Influence of the incubation conditions on culture media to optimize primary isolation of Mycobacterium bovis
DOI:
https://doi.org/10.5433/1679-0359.2016v37n5Supl2p3693Palabras clave:
Primary isolation, Bovine tuberculosis, Mycobacterium bovis, Culture media, Incubation conditions.Resumen
The isolation of Mycobacterium bovis is critical to a surveillance system for bovine tuberculosis based on detection of lesions in abattoirs. Thus, four solid culture media and three incubation conditions were investigated to elucidate which combination overcomes the others by assessing growth, time to the first appearance of colonies and their number. Ninety-seven samples of granulomatous lesions were submitted to the decontamination procedure by 1-hexadecylpyridinium chloride at 0.75% w/v, and inoculated on two egg-based media, Stonebrink’s (ST) and Löwenstein-Jensen’s with sodium pyruvate (LJp), and two agar-based media, tuberculosis blood agar (B83) and Middlebrook 7H11 medium (7H11). Each medium was incubated at 37°C for 90 days in three incubation conditions: in air, in air containing 10% carbon dioxide (CO2), and in air in slopes closed with burned hydrophobic cotton and subsequently plugged with a cork to create a microaerophilic atmosphere. The colonies appeared faster and in higher number when incubated in air containing 10% CO2 (p < 0.01), independent of media. B83 showed a faster growth and detected more isolates at 30 days of incubation, when compared to ST (0.0178), LJp (p < 0.0001) and 7H11 (p < 0.0001), though there was no difference between B83, ST and LJp at 60 and 90 days of incubation. 7H11 presented the lowest number of isolates (p < 0.0001) and a longer period for the appearance of the first colony (p < 0.001). According to our findings, the concomitant use of ST and B83 media incubated in air containing 10% CO2 increases the isolation of M. bovis in a shorter period of time, which improves bovine tuberculosis diagnosis.Descargas
Publicado
Cómo citar
Número
Sección
Licencia
Derechos de autor 2016 Semina: Ciências Agrárias
Esta obra está bajo una licencia internacional Creative Commons Atribución-NoComercial 4.0.
Os Direitos Autorais para artigos publicados são de direito da revista. Em virtude da aparecerem nesta revista de acesso público, os artigos são de uso gratuito, com atribuições próprias, em aplicações educacionais e não-comerciais.
A revista se reserva o direito de efetuar, nos originais, alterações de ordem normativa, ortográfica e gramatical, com vistas a manter o padrão culto da língua e a credibilidade do veículo. Respeitará, no entanto, o estilo de escrever dos autores.
Alterações, correções ou sugestões de ordem conceitual serão encaminhadas aos autores, quando necessário. Nesses casos, os artigos, depois de adequados, deverão ser submetidos a nova apreciação.
As opiniões emitidas pelos autores dos artigos são de sua exclusiva responsabilidade.