Vanessa Demonfort Nkamga, Ahmed Loukil, Elisabeth Sogodogo, Mustapha Fellag, Michel Drancourt, Patrick Dessi, Justin Michel, Pierre-Edouard Fournier, Microbes évolution phylogénie et infections (MEPHI), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Vecteurs - Infections tropicales et méditerranéennes (VITROME), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut de Recherche Biomédicale des Armées (IRBA), and Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut de Recherche Biomédicale des Armées [Brétigny-sur-Orge] (IRBA)
The authors report the cases of 9 patients eventually diagnosed with methanogenic archaea refractory or recalcitrant chronic rhinosinusitis, a condition known to involve various anaerobic bacteria but in which the role of methanogenic archaea is unknown. The authors retrospectively searched these microorganisms by PCR in surgically-collected sinusal pus specimens from patients diagnosed with refractory sinusitis, defined by the persistance of sinus inflammation and related-symptoms for more than 12 weeks despite appropriate treatment. Of the 116 tested sinus surgical specimens, 12 (10.3%) from 9 patients (six females, three males; aged 20–71 years) were PCR-positive. These specimens were further investigated by fluorescence in-situ hybridization, PCR amplicon-sequencing and culture. Methanobrevibacter smithii was documented in four patients and Methanobrevibacter oralis in another four, one of whom was also culture-positive. They were associated with a mixed flora including Gram-positive and Gram-negative bacteria. In the latter patient, “Methanobrevibacter massiliense” was the sole microorganism detected. These results highlight methanogenic archaea as being part of a mixed anaerobic flora involved in refractory sinusitis, and suggest that the treatment of this condition should include an antibiotic active against methanogens, notably a nitroimidazole derivative.