Contribution to the Diagnosis of Johne’s Disease in Cattle.Comparative Studies on the Validity of Ziehl‐Neelsen Staining,Faecal Culture and a Commercially Available DNA‐Probe® Testb in Detecting Mycobacterium paratuberculosis in Faeces from Cattle

Abstract

In the present study, 132 selected faecal samples from clinically affected and subclinically infected cattle from dairy herds known to be affected by Johne's disease were investigated for the presence of Mycobacterium paratuberculosis using Ziehl-Neelsen staining, faecal culture and a commercially available DNAProbe ® test. The sensitivity was 36.4% for Ziehl-Neelsen staining, 85.6% for faecal culture and 47.7% for the DNA-Probe ® test. Proving the presence of acid-fast bacteria in 49.3% of the samples from clinically affected cattle and 19.3% of those from subclinically infected cattle, Ziehl-Neelsen staining had the lowest detection rate of the three tests under investigation. Faecal culture showed the highest detection rate of M. paratuberculosis in samples from both clinically affected (84.0%) and subclinically infected (87.7%) animals. The DNA-Probe ® test showed a positive result in 68.0% of the samples from clinically affected cattle and 21.1% of those from subclinically infected cattle. Ziehl-Neelsen staining proved unreliable in diagnosing Johne's disease. Faecal culture was the most sensitive method for detecting M. paratuberculosis both in clinically affected and subclinically infected cattle. The sensitivity of a commercially available DNAProbe ® test has to be enhanced to enable a quick and reliable diagnosis of Johne's disease.

Detection of Mycobacterium avium subsp. paratuberculosis by several diagnostics techniques in clinical suspected sheep

“…Our results are in accordance with previous studies that suggest that smears stained with Ziehl-Neelsen can be considered as good indicators of infection and could be used as a screening method using faeces and tissue as samples since this technique is inexpensive and low time consuming (Coelho et al, 2008). However, the low sensitivity of this technique, about 36%, (Zimmer et al, 1999) indicates that this diagnostic tool should be complemented with other diagnostic techniques.…”

Mycobacterium aviumSubspeciesparatuberculosisCultured from Locally and Commercially Pasteurized Cow's Milk in the Czech Republic

“…With the primary cultures, colonies resembling M. avium subsp. paratuberculosis were stained by the Ziehl-Neelsen (ZN) method (50) for the presence of acidfast bacilli. To distinguish M. avium subsp.…”

Mycobacterium aviumsubsp.paratuberculosisin Veterinary Medicine

“…In general, PCR analysis has been unable to match the sensitivity of fecal culture for identifying small numbers of bacteria (319,332), but attempts to increase the sensitivity of this diagnostic test have yielded promising results (72,202). In part, the lack of sensitivity of the PCR technique is due to the extreme difficulty of removing PCR inhibitors when preparing DNA from fecal extracts.…”