Instruct: Identify the main category of Biorxiv papers based on the titles and abstracts
Query: Pathogens in exacerbations of chronic rhinosinusitis differ in sensitivity to silver nanoparticles IntroductionThe significance of the microbiome in chronic rhinosinusitis (CRS) is not clear. Antimicrobials are recommended in acute exacerbations of the disease (AECRS). Increasing rates of antibiotic resistance stimulate research on alternative therapeutic options including silver nanoparticles (AgNPs), sometimes referred to as "colloidal silver". However, there are concerns regarding the safety of silver administration and the emergence of silver resistance. In this cross-sectional observational study, we assessed the sensitivity of sinonasal pathogens to AgNPs and compared it with the toxicity of AgNPs for nasal epithelial cells.

MethodNegatively charged AgNPs (13{+/-}5 nm) were obtained with the use of tannic acid. Minimal inhibitory concentrations (MIC) of the AgNPs were determined for pathogens isolated from patients with AECRS. Cytotoxicity was tested on human nasal epithelial cells line in vitro.

Results48 clinical isolates and 4 reference strains were included in the study (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Acinetobacter baumanii, Serratia marcescens, Enterobacter cloacae). The MIC values differed between isolates, even within the same species. All of the strains were sensitive to AgNPs in concentrations nontoxic to human cells during 24 hours exposition. However, 48h exposition to AgNPs increased toxicity to human cells, narrowing their therapeutic window and enabling 19% of pathogens to resist the AgNPs biocidal action.

ConclusionsAgNPs can potentially be used in intranasal drugs to treat most episodes of AECRS. Sensitivity testing may be necessary before application. Results of sensitivity testing for reference strains cannot be extrapolated to other strains of the same species.

ImportanceChronic rhinosinusitis is characterized by nasal congestion, discharge and facial pain. Bacterial infections cause acute exacerbations of the disease when the symptoms temporarily get worse. Exacerbations are usually treated with antibiotics. Increasing rates of antibiotic resistance stimulate research on alternative antibacterial agents. Various forms of silver, including silver nanoparticles, are suggested as intranasal antibacterial drugs. However, there are concerns regarding the safety of silver administration and reports of silver-resistant bacteria in various clinical settings. In our study, we attempted to assess whether silver nanoparticles could be used to treat patients with exacerbations of chronic rhinosinusitis. We found out that most of the bacteria isolated from the patients were sensitive to silver nanoparticles at concentrations that were still safe for the nasal epithelium. It suggests that silver nanoparticles could potentially be used as intranasal drugs but sensitivity testing should be obligatory before their administration to prevent the development of silver resistance.
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The categories of this paper are: systems
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The categories of this paper are: zoology
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The categories of this paper are: developmental
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The categories of this paper are: cognition
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The categories of this paper are: physiology
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The categories of this paper are: synthetic
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The categories of this paper are: pharmacology
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The categories of this paper are: behavior
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The categories of this paper are: biophysics
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The categories of this paper are: ecology
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The categories of this paper are: animal
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The categories of this paper are: toxicology
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The categories of this paper are: bioengineering
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The categories of this paper are: epidemiology
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The categories of this paper are: genetics
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The categories of this paper are: evolutionary