The Detection of Coxiella Burnetii from Ovine Genital Swabs, Milk and Fecal Samples by the Use of a Single Touchdown Polymerase Chain Reaction

The polymerase chain reaction (PCR), targeting the repetitive transposon-like region of Coxiella burnetii (Trans-PCR), was evaluated for its ability to detect directly C. burnetii in genital swabs, milk and fecal specimens of ewes. By using a combination of centrifugation step, DNA purification using Qiamp Tissue kit followed by Trans-PCR assay, the efficiency for detection of coxiella in ewes milk samples was further improved and one C. burnetii-cell could be detected in 1ml of milk. In addition, an effective, simple and rapid method to remove PCR-inhibitory substances from fecal specimens by simply diluting the DNA template to 1:100 is described, which made the detection of one microorganism per mg of sample then possible. The results obtained from seropositive ewes proved that C. burnetii could also be detected in milk and fecal samples of naturally infected animals.