%0 Journal Article %A Walid Hadid %A Zhihong Yuan %A Dipti Panchal %A Mansoor Syed %A Ruxana Sadikot %T Stomatococcus mucilaginosus in patients with bronchiectasis %D 2013 %J European Respiratory Journal %P P2080 %V 42 %N Suppl 57 %X Bronchiectasis is a debilitating, airways disease characterized by a vicious cycle of inflammation and bacterial colonization. Infections contribute to development of recurrent exacerbations and premature death. We found that 9% of patients with bronchiectasis were colonized with Stomatococcus mucilaginosa (SM), in their lower respiratory tract as determined from bronchoalveolar lavage (BAL). SM is a gram positive human pathogen found in oral cavity which has been reported to cause severe infections in immunocompromised patients. We hypothesized that SM is a low grade pathogen which may predispose individuals with bronchiectasis to other infections such as PA. To define the pathogenic profile of SM we performed in vivo studies in wild type mice. Similar to P.aeruginosa SM induced a neutrophilic influx with production of cytokines and chemokines in the lungs when given intratracheally (1010 cfu/ml). SM induced COX-2 in the lungs with production of PGE2. Furthermore, inhibition of COX-2 with NS-398 (specific inhibitor of COX-2) showed an enhanced clearance of SM with improved survival in mice that were treated with SM and PA103. The induction of COX-2 by SM was TLR2 dependent in vivo. In vitro studies in macrophages showed that treatment of cells with SM (MOI of 100) resulted in induction of pro-inflammatory cytokines, chemokines, enzymes (COX-2) and lipid mediators. Induction of COX-2 and production of PGE2 in macrophages by SM was dependent on MAP Kinase signaling pathway. In conclusion our data for the first time provide novel insights into the pathogenic role of SM which is often ignored as a contaminant. Our data strongly suggest that SM from lower respiratory tract should not be considered an innocent bystander. %U https://erj.ersjournals.com/content/erj/42/Suppl_57/P2080.full.pdf