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Background Methods Results Conclusion Chronic rhinosinusitis (CRS) is a persistent inflammatory condition of the sinus mucosa. While Staphylococcus aureus has been shown to play a significant role in mucosal barrier disruption in CRS patients, coagulase‐negative staphylococci (CoNS) such as Staphylococcus epidermidis and Staphylococcus lugdunensis are also implicated in CRS pathophysiology. This study investigates the effects of exoproteins secreted by planktonic and biofilm forms of clinical isolates of S. epidermidis and S. lugdunensis on the nasal epithelial barrier.Thirty‐one clinical isolates of CoNS were grown in planktonic and biofilm forms, and their exoproteins were concentrated. The epithelial barrier structure was assessed by measuring transepithelial electrical resistance (TEER) and the permeability of fluorescein isothiocyanate‐dextran. Toxicity and inflammatory response were also studied.Our findings demonstrate that exoproteins from all planktonic forms of S. lugdunensis disrupted the mucosal barrier, whereas only nine of 16 biofilm‐derived exoproteins had similar effects. Conversely, 11 of 15 exoproteins from planktonic S. epidermidis significantly disrupted barrier integrity; however, biofilm exoproteins did not. The study also showed that some exoproteins from planktonic S. epidermidis significantly reduced cell viability, while exoproteins from planktonic and biofilm forms of S. lugdunensis and biofilm S. epidermidis did not induce any statistically significant change in cell viability. Notably, four of 16 biofilm exoproteins from S. lugdunensis induced higher interleukin‐6 (IL‐6) secretion, whereas none of the S. epidermidis isolates showed a significant increase in IL‐6 secretion.Our results suggest that CoNS exoproteins may contribute to CRS etiopathogenesis. [ABSTRACT FROM AUTHOR]

Introduction: In chronic rhinosinusitis (CRS), the congestion and blockage of the nose can cause anaerobic conditions within the sinus cavities which may promote the expression of virulence and antibiotic resistance genes in invading pathogens. Pseudomonas aeruginosa is a facultative anaerobic bacteria and causes severe recalcitrant CRS. In this study, we aimed to evaluate the antimicrobial resistance of P. aeruginosa isolates of CRS patients in planktonic and biofilm form grown in aerobic and anaerobic conditions. Methods: P. aeruginosa clinical isolates of CRS patients (n = 25) were grown in planktonic and biofilm form in aerobic and anaerobic conditions. Minimum inhibitory concentrations (MIC) of planktonic forms and minimum biofilm eradication concentrations (MBEC) were determined. Additionally, metabolic activity by fluorescein diacetate assay, biofilm biomass by crystal violet assay and eDNA concentration were assessed in both conditions. Results: P. aeruginosa planktonic cells grown in anaerobic condition exhibited increased gentamicin resistance (p < .01), whereas P. aeruginosa biofilms grown in anaerobic condition displayed significantly increased MBEC values for gentamicin (p < .0001) and levofloxacin (p < .001). The metabolic activity of anaerobic biofilms was significantly higher compared with aerobic biofilms (p < .0001). However, the biofilm biomass of isolates grown in aerobic conditions was higher than anaerobic conditions (p < .5). Conclusion: P. aeruginosa isolates from CRS patients grown in anaerobic conditions showed significantly increased resistance to antibiotics with an increased metabolic activity but decreased biofilm biomass. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) have widespread applications. Recently, the synthesis of NPs using plant extract has attracted much attention. In this study, with an easy and rapid process at room temperature, AgNPs were produced by the aqueous extract of dried Juglans regia green husk, which is considered as a waste. The first sign of AgNPs synthesis was the color change of the sample from light green to yellowish brown. In addition, the production of AgNPs was examined by UV-Vis spectroscopy, dynamic light scattering (DLS), energy dispersive X-ray (EDX), Fourier transform infrared (FT-IR), X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis. The antibacterial effect of AgNP on Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus and anticoagulation activity were determined. Synthesized silver colloid had electromagnetic absorbance at approximately 450 nm. The hydrodynamic diameter of monodisperse AgNPs was approximately 67 nm. The face center cubic metallic silver, which was spherical in shape, was in the range 3–50 nm with the average size of 7 nm. The extract showed antioxidant activity against 1,1-diphenyl-2-picryl hydrazyl (DPPH). Phenolic compounds, tannins, flavonoids, reducing sugars, proteins, ascorbic acid and carotenoids existing in the extract acted as reducing agents. AgNPs may be capped by biomolecules having O-H, C=O, N-H and other stabilizing functional groups.