Molecular detection of Coxiella burnetii using an alternative loop-mediated isothermal amplification assay (LAMP)

Q fever, caused by Coxiella burnetii, is a worldwide zoonosis with important consequences for human and animal health. In livestock, the diagnosis, using direct and indirect techniques, is challenging even if to tackle coxiellosis in domesticated animals a rapid diagnosis is crucial. In the recent years, new molecular methods have been developed to overcome these issues. Several polymerase chain reaction (PCR) assays have been studied, but loop mediated isothermal amplification (LAMP) has not been fully developed. This new methodology is emerging due to simplicity and speed in diagnosis of microbial diseases. In this study, we design a new LAMP assay against C. burnetii targeting the com1 gene as an actual alternative to conventional PCR. The assay was specific to C. burnetii reactive with sensitivity comparable to standard PCR. The application of the com1 LAMP on 10 clinical samples from water buffalo, sheep, and goats, previously tested positive, confirmed the presence of C. burnetii. To our knowledge, this study is the first report of LAMP targeting C. burnetii in Europe and the results also suggest that it may be an useful and cost-effective tool for the clinical and epidemiological surveillance of Q Fever.