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Detection of Mycobacterium avium ssp. paratuberculosis in ileocaecal lymph nodes collected from elderly slaughter
Pia Münster1, Inger Völkel, Wilhelm Wemheuer
1Department of Animal Sciences, Institute of Veterinary Medicine, Division of Microbiology and Animal Hygiene, Faculty of Agricultural Sciences, Georg-August-University, Burckhardtweg 2, D-37077 Göttingen, Germany.
Abstract:
The aim of this study was to investigate the occurrence of subclinical Mycobacterium avium spp. paratuberculosis (MAP) infections at slaughter by testing ileocaecal lymph nodes with a semi-nested IS900 PCR. Tissue samples were available within the framework of a parallel study investigating BSE-susceptibility factors in members of BSE-cohorts in the German Federal State of Lower Saxony. Ileocaecal lymph nodes were collected over a 2-year sampling period from 99 slaughter cattle of a mean age of 6.5 years (5.5-7.5 years). A recently developed IS900 semi-nested polymerase chain reaction (snPCR) assay offering a sensitivity of 1 genome equivalent was used for the detection of MAP-DNA. Based on this snPCR, 17 out of the 99 samples gave positive results, indicating a MAP occurrence of 17.17% in the random sample. All PCR products were sequenced for screening of polymorphisms. Nucleotide homologies of 98.5-100% were found with respect to the MAP K10 reference sequence IS900 (GenBank: AE16958). PCR analysis of ileocaecal lymph nodes collected from slaughter cattle proved to be a suitable technique to determine MAP occurrence in the local cattle population.
Insights
Subclinical Mycobacterium avium spp. paratuberculosis (MAP) infections were detected in 17.17% of German slaughter cattle using a sensitive IS900 PCR assay on ileocaecal lymph nodes. This study confirms PCR
Area of Science:
- Veterinary Microbiology
- Bovine Infectious Diseases
Background:
- Subclinical infections of Mycobacterium avium spp. paratuberculosis (MAP) pose a significant challenge in cattle populations.
- Early detection of MAP is crucial for effective herd management and disease control.
Purpose of the Study:
- To investigate the prevalence of subclinical MAP infections in slaughter cattle in Lower Saxony, Germany.
- To evaluate the efficacy of a semi-nested IS900 PCR assay for detecting MAP DNA in ileocaecal lymph nodes.
Main Methods:
- Collection of ileocaecal lymph nodes from 99 slaughter cattle over a 2-year period.
- Utilization of a highly sensitive IS900 semi-nested polymerase chain reaction (snPCR) assay (1 genome equivalent sensitivity).
- Sequencing of PCR products to confirm MAP identity and assess genetic polymorphisms.
Main Results:
- A MAP occurrence rate of 17.17% was identified in the sampled cattle population (17 out of 99 positive samples).
- Sequencing revealed high nucleotide homology (98.5-100%) with the MAP K10 reference sequence IS900.
- The snPCR assay demonstrated suitability for detecting MAP DNA in ileocaecal lymph nodes.
Conclusions:
- The study highlights a notable prevalence of subclinical MAP infections in the investigated cattle population.
- Semi-nested IS900 PCR on ileocaecal lymph nodes is an effective method for determining MAP occurrence in local cattle.
- Findings underscore the importance of diagnostic surveillance for MAP in slaughter animals.
