Inactivation or clearance of Coxiella burnetii in rat serum samples to enable safe serological testing

To allow processing of serum samples from animals experimentally infected with Coxiella burnetii outside the BSL-3 facility, an inactivation or clearance protocol that does not hamper serological testing may be required. The effects of filtration (0.1 µm pore size), heating at 56 °C for 30 min, addition of NaN3 (0.09% w/v), and combinations thereof on the presence of viable C. burnetii as well as OD-values in ELISA were tested. Only filtration was shown to effectively clear all culturable C. burnetii.