Detection of Mycobacterium avium subspecies paratuberculosis in Swiss dairy cattle by real-time PCR and culture: a comparison of the two assays

J Appl Microbiol. 2005;99(3):587-97. doi: 10.1111/j.1365-2672.2005.02645.x.

Abstract

Aims: To compare the two different diagnostic assays for the detection of Mycobacterium avium ssp. paratuberculosis, the aetiological agent of paratuberculosis.

Methods and results: Faecal samples were derived from 310 cows, representing 13 commercial dairy herds in various locations in Switzerland with expected increased risk because of a past history of disease. Detection assays for M. avium ssp. paratuberculosis were culture (gold standard) and a newly designed real-time PCR. Real-time PCR identified 31 of 310 animals as positive within this risk population whereas culture identified 20 positive animals. The specificity of real-time PCR was confirmed by DNA sequencing of the PCR product. Depending on the test used, the paratuberculosis prevalence in our tested risk population ranged from 6.5 to 10%.

Conclusions: Real-time PCR and culture data were in good agreement, and real-time PCR generates data in a short time in contrast to culture.

Significance and impact of the study: We consider real-time PCR as a suitable alternative method to culture for the detection of M. avium ssp. paratuberculosis in a national surveillance programme.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Base Sequence
  • Cattle
  • Cattle Diseases / diagnosis*
  • Cattle Diseases / genetics
  • Cattle Diseases / microbiology
  • Culture Media
  • DNA, Bacterial / genetics
  • Feces / microbiology
  • Female
  • Mycobacterium avium subsp. paratuberculosis / genetics
  • Mycobacterium avium subsp. paratuberculosis / isolation & purification*
  • Paratuberculosis / diagnosis*
  • Paratuberculosis / genetics
  • Paratuberculosis / microbiology
  • Polymerase Chain Reaction / methods
  • Sensitivity and Specificity
  • Sequence Analysis, DNA / methods

Substances

  • Culture Media
  • DNA, Bacterial