Title Detection of Mycobacterium avium subsp. paratuberculosis from goats by Sequence Capture PCR
Author(s) Djønne B1, Olsen I1, Storset A2, Valheim M1, Nilsen S1, Haldorsdottir1, Holstad G1,2.
Institution(s) 1National Veterinary Institute, P. Box 8156, Dep., NO-0033 Oslo, Norway; 2Norwegian School of Veterinary Science, P. Box 8146, Dep., NO-0033 Oslo, Norway
Source Eighth International Colloquium on Paratuberculosis
Section 5: Diagnosis
Presentation Poster
Abstract
Isolation of Mycobacterium avium subsp. paratuberculosis by culture is time consuming, and four months incubation time is necessary. PCR methods, on the other hand, tend to have low sensitivity in clinical samples, due to excessive non-specific DNA, low number of bacteria and high content of inhibitors. Therefore, a sequence capture method, followed by a dot blot assay to identify M. a. paratuberculosis, has been developed (Halldórsdóttir et al., 2002). The aim of the present study was to evaluate this method on tissue samples from goats infected by M. a. paratuberculosis.Seven goat kids experimentally infected by M. a. paratuberculosis and one uninfected kid were used for the study. At week 106-117 post-infection the animals were euthanized, and necropsies and histopathological examination were performed. Lesions compatible with M. a. paratuberculosis infection were found in six infected goats and acid-fast bacilli were present in 5 of them. Samples from duodenum, jejunum, ileum, caecum, colon, and the jejunal, ileocolic, colic and mediastinal lymph nodes were examined by cultivation and sequence capture PCR. The PCR method could detect 100 cfu/gram tissue.M. a. paratuberculosis was detected by culture from five infected animals. From one goat bacteria were isolated from the intestinal lymph nodes only. In the other four animals, bacteria were cultured from different segments of the intestine and lymph nodes. Sequence capture PCR detected M. a. paratuberculosis from all infected goats, including the two goats where no bacteria could be isolated. From 3 goats, PCR positive samples were detected in the intestinal lymph nodes only. M. a. paratuberculosis was not detected by any method from the uninfected goat.The present study shows that sequence capture PCR might be an alternative to culture to detect M. a. paratuberculosis from goats.

References

Halldórsdóttir S, Englund S, Nilsen SF, Olsaker I. Vet Microbiol. 2002. 22, 327-40.

Sponsorship

Attendance to this congress was sponsored by the EU-funded project SSPE-CT-2004-501903.
Source: http://www.paratuberculosis.org/pubs/proc8/abst5_p137.htm
Contact: Click here to Send an inquiry email      Webmaster: Click here to email the webmaster
Copyright © 1999-2008 International Association for Paratuberculosis.