© The Author(s) 2023. Published by Oxford University Press on behalf of Applied Microbiology International.Fernández Carrillo, JuanDel Olmo Monge, JavierSellek Cano, Ricela, RicelaOrtega García, María VictoriaCabria Ramos, Juan CarlosBassy Alvarez, Olga2026-09-102026-09-102023-02-25Letters in Applied Microbiology 76(3): ovad030https://academic.oup.com/lambio/article-abstract/76/3/ovad030/7058245https://hdl.handle.net/20.500.12666/1893Coxiella burnetii, the causative agent of Q fever, is a small, coccoid, Gram-negative strict intracellular pathogen. One of the most common ways of acquiring Q fever is through inhalation of aerosols containing the bacteria. Because C. burnetii is highly infectious, spreads easily through the air, and is very resistant to environmental conditions, it is considered a biological threat. This paper presents the development and validation of a specific real-time polymerase chain reaction (real-time PCR or qPCR) assay for the detection of C. burnetii, based on the amplification of a fragment of the isocitrate dehydrogenase (icd) encoding gene. This real-time PCR is highly specific, reproducible, and sensitive, allowing the detection of as few as 5 genome equivalents (GEs) of C. burnetii per reaction. The method enables a rapid preliminary differentiation among strains, based on a point mutation at nucleotide 745 of the icd gene. The assay was successfully evaluated in environmental soil samples; a limit of detection of 3 × 104 colony forming units per 0.5 g of soil (∼3 GEs per reaction) was achieved. The newly developed real-time PCR offers a valuable tool for differential detection of C. burnetii strains in environmental soil samples.engCoxiella burnetiiDetectionPCR (polymerase chain reaction)Soil samplesinfo:eu-repo/semantics/articlehttps://doi.org/10.1093/lambio/ovad030info:eu-repo/semantics/restrictedAccess