Search

Objectives: Maxitrol (Novartis) is a topical ophthalmic medication that contains polymyxin B, neomycin, and dexamethasone. If it possesses antibiofilm activity, it may be useful for treating diseases of the head and neck in which biofilms are implicated, including chronic rhinosinusitis, chronic suppurative otitis media and osteoradionecrosis. We investigated the in vitro efficacy of Maxitrol against Staphylococcus aureus and Pseudomonas aeruginosa biofilms. Methods: Minimum biofilm eradication concentration (MBEC) assays were performed using biofilms of P. aeruginosa ATCC 27853 and S. aureus ATCC 6538 type strains, grown on 96-pin lids and treated in Maxitrol for 30 min, 1 h, or 6 h. Isolates of both species were collected from the middle meatuses of patients with cystic fibrosis. Biofilms of clinical isolates were grown and treated in vitro for 6 h with Maxitrol, both undiluted at full concentration and at the identified MBEC, then cultured to identify bacterial survival. Results: Neither type strain was eradicated at 30 min nor S. aureus at 1 h at any tested concentration. P. aeruginosa was eradicated by a median of 90% and 5.6% Maxitrol at 1 and 6 h, respectively, and S. aureus with 90% Maxitrol at 6 h. Undiluted Maxitrol reliably eradicated all clinical isolates of P. aeruginosa but only one of five S. aureus isolates. Conclusions: Maxitrol reliably eradicates P. aeruginosa biofilm but not S. aureus biofilm in vitro. It may have a therapeutic role against biofilms in which P. aeruginosa is the dominant pathogen. [ABSTRACT FROM AUTHOR]

Objectives: Bacterial biofilms on the sinonasal mucosa, especially biofilms of Staphylococcus aureus, are associated with greater severity and recalcitrance of chronic rhinosinusitis (CRS). There are few, if any, antibiofilm agents suitable for sinonasal application available for the management of this problem. Nasodine® Nasal Spray (Nasodine) is a 0.5% povidone‐iodine‐based formulation that has been developed for sinonasal application. We investigated the antibiofilm efficacy of Nasodine to determine whether it may be a candidate for the treatment of biofilm‐associated CRS. Methods: Biofilms of S. aureus ATCC 6538 were grown in vitro using the Centers for Disease Control biofilm reactor. Intact biofilms were treated by immersion in 0.9% saline (control), half concentration Nasodine, or full concentration Nasodine for between 5 min and 6 h. Further biofilm cells were dispersed into suspension then treated for between 30 s and 5 min. Surviving bacteria were then enumerated by culture and counting colonies, and the log10 reduction in viable bacteria was compared with control. Results: Nasodine demonstrated time and concentration‐dependent bacterial killing against intact biofilm. Statistically significant reductions in viable bacteria from intact biofilms were seen with exposures as brief as 5 min. Nasodine consistently eradicated dispersed biofilm within 1 min. Conclusion: Nasodine is highly active against biofilms of S. aureus ATCC 6538 in vitro. Biofilm killing is impeded by the presence of the intact biofilm structure. Lay summary: In chronic rhinosinusitis (CRS), bacterial communities called biofilms are associated with more severe inflammation. An iodine‐based nasal spray called Nasodine almost completely eradicates bacterial biofilms after 6 h of exposure. Nasodine may be useful for treating CRS. Laryngoscope, 133:2490–2495, 2023 [ABSTRACT FROM AUTHOR]

The chronic inflammatory nature of chronic rhinosinusitis (CRS) makes it a morbid condition for individuals with the disease and one whose pathogenesis is poorly understood. To date, proteomic approaches have been applied successfully in a handful of CRS studies. In this study we use a multifaceted approach, including proteomics (iTRAQ labeling) and microbiome (bacterial 16S rRNA gene sequencing) analyses of middle meatus swabs, as well as immune cell analysis of the underlying tissue, to investigate the host-microbe interaction in individuals with CRS (n = 10) and healthy controls (n = 9). Of the total 606 proteins identified in this study, seven were significantly (p < 0.05) more abundant and 104 were significantly lower in the CRS cohort compared with healthy controls. The majority of detected proteins (82% of proteins identified) were not significantly correlated with disease status. Elevated levels of blood and immune cell proteins in the CRS cohort, together with significantly higher numbers of B-cells and macrophages in the underlying tissue, confirmed the inflammatory status of CRS individuals. Protein PRRC2C and Ras-related protein (RAB14) (two of the seven elevated proteins) showed the biggest fold difference between the healthy and CRS groups. Validation of the elevated levels of these two proteins in CRS samples was provided by immunohistochemistry. Members of the bacterial community in the two study cohorts were not associated with PRRC2C, however members of the genus Moraxella did correlate with RAB14 (p < 0.0001, rho = -0.95), which is a protein involved in the development of basement membrane. In addition, significant correlations between certain members of the CRS bacterial community and 33 lower abundant proteins in the CRS cohort were identified. Members of the genera Streptococcus, Haemophilus and Veillonella were strongly correlated with CRS and were significantly associated with a number of proteins with varying functions. The results from this study reveal a strong association between the host and microbes in the sinonasal cavity. Proteins identified as associated with CRS could be new targets for drug therapies and biomarkers for assessment of treatment efficacy. [ABSTRACT FROM AUTHOR]

The human gut contains dense and diverse microbial communities which have profound influences on human health. Gaining meaningful insights into these communities requires provision of high quality microbial nucleic acids from human fecal samples, as well as an understanding of the sources of variation and their impacts on the experimental model. We present here a systematic analysis of commonly used microbial DNA extraction methods, and identify significant sources of variation. Five extraction methods (Human Microbiome Project protocol, MoBio PowerSoil DNA Isolation Kit, QIAamp DNA Stool Mini Kit, ZR Fecal DNA MiniPrep, phenol:chloroform-based DNA isolation) were evaluated based on the following criteria: DNA yield, quality and integrity, and microbial community structure based on Illumina amplicon sequencing of the V4 region of bacterial and archaeal 16S rRNA genes. Our results indicate that the largest portion of variation within the model was attributed to differences between subjects (biological variation), with a smaller proportion of variation associated with DNA extraction method (technical variation) and intra-subject variation. A comprehensive understanding of the potential impact of technical variation on the human gut microbiota will help limit preventable bias, enabling more accurate diversity estimates. [ABSTRACT FROM AUTHOR]

Key points Novel topical therapeutics require extensive pre‐clinical testing to assess efficacy and safety. Antibiofilm or immunosuppressant agents can utilize ex vivo models to measure ciliotoxicity. Agents that are found to be effective and non‐toxic ex vivo warrant further investigation in vivo. [ABSTRACT FROM AUTHOR]