Coxiellosis in domestic livestock of Puducherry and Tamil Nadu: Detection of DNA by polymerase chain reaction in slaughtered ruminants.

BACKGROUND AND AIM

In the course of our Indian Council of Medical Research project on coxiellosis in Puducherry and Tamil Nadu, 5.64% goat, 1.85% sheep, 1.06% buffaloes, and 0.97% cattle were positive for antibodies by enzyme linked immunosorbent assay kit (IDEXX, Liebefeld, Switzerland). In this preliminary study, we have proceeded to look for DNA in those antibody positive specimens employing an imported commercial polymerase chain reaction (PCR) kit.

MATERIALS AND METHODS

Blood samples were collected during slaughtering. All 15 blood samples of antibody positive ruminants and three antibody negative samples were subjected to conventional Trans-PCR assay with a commercial PCR kit (Genekam Biotechnology AG, Duisburg, Germany). An in-house Trans-PCR was included in the study for comparison.

RESULTS

A total of 15 antibody positive and three antibody-negative serum samples belonging to 11 goat, 4 sheep, 1 cattle, and 2 buffaloes were tested in duplicate for the presence of DNA by the commercial agar gel PCR kit and an in-house Trans-PCR. Only one buffalo serum sample was positive for with a band at 243 bp in in-house Trans-PCR.

DISCUSSION

Seropositivity for need not necessarily translate into infectivity status of the animal. Conversely, seronegative ruminants can shed . Rapid disintegration of DNA during the storage period is an important impediment in QF-PCR research. This is the first time the performance of this commercial PCR kit is being validated in India.

CONCLUSION

Commercial PCR kit, Genekam did not identify any positive sample, probably because it targeted a larger amplicon of 687 bp.