Effects of pre-culture holding time and temperature on interferon-gamma responses in whole blood cultures from Mycobacterium bovis-infected cattle.
Vet Microbiol
; 119(2-4): 277-82, 2007 Jan 31.
Article
em En
| MEDLINE
| ID: mdl-16973310
ABSTRACT
The Bovigam assay is approved for use within the United States as a complementary tuberculosis test. Prior to whole blood culture and the ensuing ELISA to detect interferon-(IFN)-gamma, samples are subjected to various holding time/temperature combinations due, in part, to practical constraints associated with shipment of samples to approved laboratories. To evaluate these effects, 5-month-old Holstein calves (n = 7) received 10(3) cfu Mycobacterium bovis by aerosol. Heparinized blood was collected 2 months after challenge and held at 4 or 22 degrees C for 0, 8 or 24 h prior to culture with mycobacterial antigens or pokeweed mitogen (PWM). Responses of samples held for 8 or 24 h were comparable and lower than responses of cultures prepared immediately after collection, regardless of holding temperature. Differences in responses of samples held at 4 degrees C versus 22 degrees C were also minimal. A subset of samples was held for 2 h at 37 degrees C at the beginning of the holding period. This subset of samples had diminished responses to all stimulants and increased holding times (i.e., 24 h versus 8 h) negatively impacted the response. Pre-processing conditions, particularly delays in set-up and initial high sample temperatures, reduces IFN-gamma responses of cells from infected cattle increasing the risk of false negatives in this assay of regulatory importance.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Manejo de Espécimes
/
Tuberculose Bovina
/
Interferon gama
/
Mycobacterium bovis
Tipo de estudo:
Diagnostic_studies
Limite:
Animals
Idioma:
En
Revista:
Vet Microbiol
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Estados Unidos
País de publicação:
HOLANDA
/
HOLLAND
/
NETHERLANDS
/
NL
/
PAISES BAJOS
/
THE NETHERLANDS