Application of a 5′ Nuclease Assay for Detection of Lawsonia intracellularis in Fecal Samples from Pigs
Open Access
- 1 March 2002
- journal article
- Published by American Society for Microbiology in Journal of Clinical Microbiology
- Vol. 40 (3), 984-987
- https://doi.org/10.1128/jcm.40.3.984-987.2002
Abstract
A 5′ nuclease assay was developed to detect Lawsonia intracellularis in porcine fecal samples. The specific probe and primers were chosen by using the 16S ribosomal DNA gene as a target. The 5′ nuclease assay was used with a total of 204 clinical samples, and the results were compared to those of immunohistochemistry (IM) on ileal sections of the same animals. There was 91% agreement between the results of IM and the 5′ nuclease assay. In the 5′ nuclease assay, 111 (54%) of the pigs tested positive for L. intracellularis infection, with a mean cycle threshold (Ct) value of 27.2, whereas 98 (48%) of the pigs tested positive by IM. On average, the Ct and ΔRn values for the positive samples were 27.2 (standard deviation [SD], 3.7) and 1.6 (SD, 0.7), respectively. A Ct value of 27.2 corresponds to a fecal excretion of approximately 10 7 L. intracellularis cells per g of feces. Furthermore, a total of 40 fecal samples derived from a herd known to be free from infection with L. intracellularis all tested negative, with a Ct value of 40. By using a Ct value of 36 as the cutoff limit, the detection limit of the assay was 1 L. intracellularis cell per PCR tube. In conclusion, the 5′ nuclease assay that has been developed represents an applicable fast method for detection of L. intracellularis in fecal samples, with a sensitivity and specificity comparable to those of IM.Keywords
This publication has 18 references indexed in Scilit:
- Evaluation of 5′ Nuclease Assay for Detection of Actinobacillus pleuropneumoniaeJournal of Clinical Microbiology, 2001
- Improved diagnosis of porcine proliferative enteropathy caused by Lawsonia intracellularis using polymerase chain reaction-enzyme-linked oligosorbent assay (PCR-ELOSA)Molecular and Cellular Probes, 2000
- Detection of Lawsonia intracellularis in the tonsils of pigs with proliferative enteropathyResearch in Veterinary Science, 2000
- Development of persistent intestinal infection and excretion of Lawsonia intracellularis by pigletsResearch in Veterinary Science, 1997
- Diagnosis of proliferative enteritis in frozen and formalin-fixed, paraffin-embedded tissues from a hamster, horse, deer and ostrich using a Lawsonia intracellularis-specific multiplex PCR assayVeterinary Microbiology, 1997
- A novel method for real time quantitative RT-PCR.Genome Research, 1996
- Real time quantitative PCR.Genome Research, 1996
- Specific in situ Hybridization of the Intracellular Organism of Porcine Proliferative EnteropathyVeterinary Pathology, 1994
- Ileal Symbiont Intracellularis, an Obligate Intracellular Bacterium of Porcine Intestines Showing a Relationship to Desulfovibrio SpeciesInternational Journal of Systematic and Evolutionary Microbiology, 1993
- Monoclonal antibodies to intracellular campylobacter-like organisms of the porcine proliferative enteropathiesPublished by Wiley ,1987