Low antibodies titer and serological cross-reaction between Coxiella burnetii and Legionella pneumophila challenge the diagnosis of mediastinitis, an emerging Q fever clinical entity
Authors: Bernard Amphoux
Jean-Paul Casalta
Didier Raoult
Sophie Edouard
Frédéric Collart
Matthieu Million
Journal: Infection (2017)
Discipline: IMMUNOLOGY
Keywords: Coxiella burnetii; Cross-reaction; Legionella pneumophila; Mediastinitis; Q fever
Affiliations: Aix Marseille Univ, CNRS, IRD, INSERM, AP-HM, URMITE, IHU Méditerranée-Infection, 19-21 Boulevard Jean Moulin, 13005, Marseille, France., Department of Cardiac Surgery, Centre Hospitalier Universitaire, Hôpital de La Timone, AP-HM, Aix-Marseille University, Marseille, France., Aix Marseille Univ, CNRS, IRD, INSERM, AP-HM, URMITE, IHU Méditerranée-Infection, 19-21 Boulevard Jean Moulin, 13005, Marseille, France. .

Abstract:  Background: Coxiella burnetii is an intracellular and fastidious bacterium responsible of acute and persistent Q fever infection. Endocarditis and vascular infections are the most common serious complications of acute Q fever. Case report: We report the case of a 63-year-old man that presented a mediastinitis associated with a prosthetic vascular infection. Serological cross-reaction was observed between Coxiella burnetii, the agent of Q fever, and Legionella pneumophila with higher antibodies titer for L. pneumophila (IgG = 1:512) than for C. burnetii (phase I IgG = 1:400). We performed western blot with cross-adsorption that supports the diagnosis of C. burnetii infection. Two weeks later, a positive qPCR and culture for C. burnetii on swab taken from the mediastinal cutaneous fistula confirmed the definitive microbiological diagnosis of Q fever mediastinitis. Conclusion: Cross-reactivity between C. burnetii and Legionella spp. has long been known and should be considered in patients with persistent infections. It is important to establish the definite diagnosis because the antibiotic treatment regimens and duration are significantly different. To the best of our knowledge, we reported here the first case of mediastinitis associated to C. burnetii and we diagnosed this persistent infection despite low anti-C. burnetii phase I IgG levels. 

Retracted: No

PubPeer comments:
 **Duplication!** For the same images presented, the authors stated in the *[Left side]* paper that **the 5-mm-thick Mylar membrane** was used, but the authors in the *[Right side]* paper stated that: ** The material used for diaphragms in the shock tube is polyethylene terephthalate (PET) commonly known by the DuPont trademark name Mylar. Experiments were performed using 0.254 mm (10 mil) PET. ** ![file] What is the purpose of ** High Resolution ** in the caption for Figure 4 in the *[Right side]* paper? **Figure 4:** Schematic of the CCNY **High Resolution** Shock Tube Facility! , 
 **Duplication!** ![file] , 
 **Duplication!** ![file] , 
 **Duplication!** ![file] , 
 **Duplication!** ![file] , 
 **Duplication!** ![file] , 
 **Examples of DUPLICATION!** ![file] , 
 **Duplicated set of images from the high-speed video camera (one time imaging only)! While the D.A. results from their transducers (as plotted) for 2016 and 2019 are different, expectedly.** ![file] , 
 ![file] , 
 #8 **Replication!** (*High-speed video camera imaging system*) *[Left]* above and *[Left]* below images are the same from the *[Right]s*! ![file] ,