Anti-biofilm activity of chlorhexidine digluconate against Candida albicans vaginal isolates

What is the most advantageous lavage solution to use for fungal prosthetic joint infections

Background

Fungal prosthetic joint infections (PJI) are increasing yet we have a poor understanding on the proper treatment of these complex infections especially with respect to most advantageous lavage solutions to use clinically. Consequently, the objective of this study was to determine which commonly used lavage solutions are most advantageous at dispersing fungal biofilms.

Methods

Nine clinical isolates from past fungal prosthetic joint infections were used to form biofilms in 24 microwell plates. Then different lavage solutions were instilled, and residual biofilm were measured and compared to normal saline lavage solutions. Moreover, fungal biofilms were directly observed with scanning electron microscopy.

Results

All lavage solutions evaluated significantly (p < 0.05) reduced fungal biofilms compared to normal saline. However, chlorhexidine gluconate and sodium hypochlorite were able to disperse fungal biofilms significantly (p˂0.05) more than the other lavage solutions. As well, scanning electron microscopy showed fungal biofilms are typically composed of hyphae and yeast forms for most Candidal species.

Conclusion

All lavage solutions can reduce Candidal biofilms, but chlorhexidine gluconate and sodium hypochlorite were the most advantageous agents in disrupting Candidal biofilms. Yet given the potential tissue toxicity associated with sodium hypochlorite should prioritize the use of chlorohexidine as lavage solutions in the clinical treatment of fungal PJI to help degrade biofilms on retained hardware and tissues. However, further studies are needed to determine the mechanism associated with degradation of fungal biofilms as well as evaluating novel ways to prevent Candidal hyphae formation in PJI.

Repurposing Mouthwashes: Antifungal and Antibiofilm Abilities of Commercially Available Mouthwashes Against Candida spp

Background/Objectives: The main objective was to evaluate and compare the antifungal efficacy against Candida spp. in commercially available mouthwashes distributed in the European market. Indeed, the solution to emerging infectious diseases may no longer lie in costly new drug development but rather in unlocking the untapped potential of existing substances. Materials and Methods: Eighteen mouthwashes, chosen based on their composition, were tested in vitro against ten Candida strains, including clinical isolates of oral origin and reference strains, in both planktonic and biofilm forms. The antifungal susceptibility testing was conducted using the European Committee on Antimicrobial Susceptibility Testing (EUCAST) disc diffusion method and the evaluation of the kinetic growth in planktonic Candida. Biofilm reduction was determined by the evaluation of the minimal biofilm eradication concentration (MBEC). Scanning electron microscopy (SEM) analysis was performed to evaluate potential morphological alterations of Candida biofilms. Results: Most mouthwashes effectively reduced biomass production and colony-forming unit (CFU) count. Parodontax Extra showed the highest efficacy. In the disc diffusion assay, Gum Paroex 0.12% exhibited the largest average inhibition zone diameter. Some unusual trends in the data may be explained by a higher reaction of fungal cells and the release of excess biomass during co-incubation in higher concentration of mouthwashes. SEM images revealed significant morphological alterations. Conclusion: Mouthwashes containing chlorhexidine digluconate, either alone or in combination with cetylpyridinium chloride and other active compounds, emerged as a common factor among the most efficacious formulations. In vivo studies will be essential to validate these findings, but mouthwashes may serve as a valuable adjuvant in the treatment of oral candidiasis.

ML-AMPs designed through machine learning show antifungal activity against C. albicans and therapeutic potential on mice model with candidiasis

AIMS

C. albicans resistant strains have led to increasingly severe treatment challenges. Antimicrobial peptides with low resistance-inducing propensity for pathogens have been developed. A series of antimicrobial peptides de novo designed through machine learning by our research team were named ML-AMPs. In the present research, the antifungal activity of ML-AMPs against C. albicans and its therapeutic potential on Candidiasis mice model were studied.

MAIN METHODS

MTT methodology was performed to measure the minimum inhibitory concentrations. Absorbance photometry was utilized to evaluate the erythrocyte toxicity. Optical microscopy was operated to observe C. albicans hyphae. Crystal violet staining was employed to assess biofilm inhibition and reduction. Colony counting was performed to determine the time-kill kinetics. Scanning electron microscopy and fluorescent staining were used to investigate the underlying mechanism of antifungal action. Candidiasis mice model was established to evaluate the in vivo efficacy of ML-AMP2.

KEY FINDINGS

ML-AMPs exhibited strong anti-Candida activity, with minimum inhibitory concentrations against C. albicans ranging from 3.85 to 12.37 μg/mL. Notably, they exhibited robust fungicidal effects on fluconazole-resistant C. albicans. Moreover, they exhibited fast-killing kinetics, as well as low resistance potential. Additionally, ML-AMPs could effectively inhibit the formation of mycelium and biofilm, and more prominently, their ability to reduce biofilm was higher than that of fluconazole. ML-AMPS increased the permeability of C. albicans cell membrane and induced ROS accumulation. Among ML-AMPs, ML-AMP2 performed the best, which promoted the recovery of Candidiasis mice model.

SIGNIFICANCE

ML-AMP2 holds great promise as a candidate molecule for effectively treating drug-resistant C. albicans infections.

Enhancing Presurgical Infant Orthopedic Appliances: Characterization, Mechanics, and Biofilm Inhibition of a Novel Chlorhexidine-Halloysite Nanotube-Modified PMMA

Objectives

This in vitro study aimed to develop a novel nanocomposite acrylic resin with inherent antimicrobial properties. This study evaluated its effectiveness against microbial biofilm formation, while also assessing its physical and mechanical properties.

Methods

Polymethylmethacrylate (PMMA) was modified with four different concentrations of chlorhexidine halloysite nanotubes (CHX-HNTs): 1%, 1.5%, 3%, and 4.5 wt.% by weight, along with a control group (0 wt.% CHX-HNTs). The biofilm inhibition ability of the modified CHX-HNTs acrylic against Candida albicans, Staphylococcus aureus, Streptococcus pneumoniae, and Streptococcus agalactiae was assessed using microtiter biofilm test. In addition, ten samples from each group were then tested for flexural strength, surface roughness, and hardness. Statistical analysis was performed using one-way ANOVA and Tukey's test for comparison (P < 0.05).

Results

CHX-HNTs effectively reduced the adhesion of Candida albicans and bacteria to the PMMA in a dose-dependent manner. The higher the concentration of CHX-HNTs, the greater the reduction in microbial adhesion, with the highest concentration (4.5 wt.%) showing the most significant effect with inhibition rates ≥98%. The addition of CHX-HNTs at any tested concentration (1%, 1.5%, 3%, and 4.5 wt.%) did not cause any statistically significant difference in the flexural strength, surface roughness, or hardness of the PMMA compared to the control group.

Conclusions

The novel integration of CHX-HNT fillers shows promising results as an effective biofilm inhibitor on acrylic appliances. This new approach has the potential to successfully control infectious diseases without negatively affecting the mechanical properties of the acrylic resin. Clinical Relevance. The integration of CHX-HNTs into presurgical infant orthopedic appliances should be thoroughly assessed as a promising preventive measure to mitigate microbial infections. This evaluation holds significant potential for controlling infectious diseases among infants with cleft lip and palate, thereby offering a valuable contribution to their overall well-being.

Artemisinin May Disrupt Hyphae Formation by Suppressing Biofilm-Related Genes of Candida albicans: In Vitro and In Silico Approaches

This study aimed to assess the antifungal and antibiofilm efficacy of artemisinin against Candida (C.) species, analyze its impact on gene expression levels within C. albicans biofilms, and investigate the molecular interactions through molecular docking. The antifungal efficacy of artemisinin on a variety of Candida species, including fluconazole-resistant and -susceptible species, was evaluated by the microdilution method. The effect of artemisinin on C. albicans biofilm formation was investigated by MTT and FESEM. The mRNA expression of the genes related to biofilm was analyzed by qRT-PCR. In addition, molecular docking analysis was used to understand the interaction between artemisinin and C. albicans at the molecular level with RAS1-cAMP-EFG1 and EFG1-regulated genes. Artemisinin showed higher sensitivity against non-albicans Candida strains. Furthermore, artemisinin was strongly inhibitory against C. albicans biofilms at 640 µg/mL. Artemisinin downregulated adhesion-related genes ALS3, HWP1, and ECE1, hyphal development genes UME6 and HGC1, and hyphal CAMP-dependent protein kinase regulators CYR1, RAS1, and EFG1. Furthermore, molecular docking analysis revealed that artemisinin and EFG1 had the highest affinity, followed by UME6. FESEM analysis showed that the fluconazole- and artemisinin-treated groups exhibited a reduced hyphal network, unusual surface bulges, and the formation of pores on the cell surfaces. Our study suggests that artemisinin may have antifungal potential and showed a remarkable antibiofilm activity by significantly suppressing adhesion and hyphal development through interaction with key proteins involved in biofilm formation, such as EFG1.

Synergistic effect of chlorhexidine and azoles on candida biofilm on titanium surface

BACKGROUND

Candida infections of orthopedic implants are one of the most detrimental orthopedic implant-related complications with unsuccessful treatment and a poor prognosis. Most orthopedic Candida infections form biofilms and have resistance to the commonly used antifungal agents. This study aimed to develop a novel combination of normally prescribed drugs against Candida biofilm on orthopedic implants.

METHODS

We cultured 26 clinical isolates of Candida strains to form biofilm without titanium sheets or on titanium sheets, which are the most commonly used materials for permanent or orthopedic implants. The checkerboard method was used to evaluate the synergistic effects of chlorhexidine (CHL) and azoles on these Candida biofilms. For the evaluation of synergistic effects, we constructed the cell viability assay by fluorescence staining and CFU reduction hot map of Candida.

RESULTS

Twenty-six clinical isolates of Candida strains formed biofilm in 96-well plates without titanium sheets, and we selected 9 of them to form biofilm on titanium sheets in 24-well plates. In Candida biofilm formed in 96-wells, the synergistic rates of CHL with fluconazole, itraconazole, and voriconazole were 61% (16/26), 65% (17/26), and 23% (6/26), respectively. When compared to the blank control group, CHL monotherapy significantly inhibited biofilm formation on titanium sheets (P < 0.05). We demonstrated 100% synergistic rates of the CHL and fluconazole combination against Candida biofilm formation on titanium sheets, and the minimum inhibitory concentration of CHL and FLU decreased four- to eight-fold.

CONCLUSIONS

We concluded that CHL combined with azoles inhibited the Candida biofilm formation 96-wells or on titanium sheets and has the potential to control the infections of orthopedic implants.

In vitro activity of sanitizers against mono- and polymicrobial biofilms of C. parapsilosis and S. aureus

The emergence of disinfectant-resistant microorganisms poses a significant threat to public health. These resilient pathogens can survive and thrive in hospital settings despite routine disinfection practices, leading to persistent infections and the potential for outbreaks. In this study, we investigated the impact of 11 different commercial sanitizers at various concentrations and exposure times on biofilms consisting of clinical and nosocomial environmental isolates of Candida parapsilosis and Staphylococcus aureus. Among the sanitizers tested, 0.5% and 2.0% chlorhexidine (CLX), 10% polyvinyl pyrrolidone (PVP-I), a disinfectant based on quaternary ammonium compound (QAC), 2% glutaraldehyde, and 0.55% orthophthalaldehyde (OPA) demonstrated efficacy against both C. parapsilosis and S. aureus in monospecies and mixed biofilms. Analysis showed that 0.5% CLX and 10% PVP-I had fungicidal and bactericidal activity against all biofilms. However, the sanitizer based on QAC and 0.55% OPA proved to be bacteriostatic and fungicidal against both monospecies and mixed biofilms. In mixed biofilms, despite the last four sanitizers exerting fungicidal action, the reduction of fungal cells was approximately 4 log10 CFU/mL compared to monospecies biofilms, showing that the interaction provided more resistance of the yeast to the sanitizer. Formation of mixed biofilms in hospital settings can create an ecological niche that enhances the survival of pathogens against routine sanitization procedures. Therefore, effective sanitization practices, including regular cleaning with effective sanitizers, should be implemented to prevent C. parapsilosis/S. aureus biofilm formation in healthcare settings.

A graphene microelectrode array based microfluidic device for in situ continuous monitoring of biofilms

In situ continuous monitoring of bacterial biofilms has been a challenging job so far, but it is fundamental to the screening of novel anti-biofilm reagents. In this work, a microfluidic system utilizing a graphene-modified microelectrode array sensor was proposed to realize the dynamic state of bacterial biofilm monitoring by electrochemical impedance. The results illustrated that the observation window period of the biofilm state is significantly prolonged due to the increment of bacterial cell load on the sensing interface, thereby greatly improving the sensing signal quality. Simulation of anti-biofilm drug screening demonstrated that the performance of this method manifestly exceeded that of its endpoint counterparts.

Identification of potent anti-Candida metabolites produced by the soft coral associated Streptomyces sp. HC14 using chemoinformatics

Candida albicans is the most common pathogen responsible for both spontaneous and recurrent candidiasis. The available treatment of Candida infections has several adverse effects, and the development of new drugs is critical. The current study looked at the synthesis of anti-Candida metabolites by Streptomyces sp. HC14 recovered from a soft coral. Using the Plackett Burman design, the medium composition was formulated to maximize production. Using GC-MS, the compounds have been identified, and a cheminformatics approach has been used to identify the potential source of activity. The compounds that showed high potential for activity were identified as pyrrolo[1,2-a]pyrazine-1,4-dione, hexahydro-3-(phenylmethyl)-3 and di-n-octyl based on their docking score against the cytochrome monooxygenase (CYP51) enzyme in Candida albicans. As a result of their discovery, fewer molecules need to be chemically synthesized, and fermentation optimization maximizes their synthesis, providing a strong foundation for the development of novel anti-Candida albicans agents.

Fungal quorum-sensing molecules and antiseptics: a promising strategy for biofilm modulation?

New strategies to control fungal biofilms are essential, especially those that interfere in the biofilm organization process and cellular communication, known as quorum sensing. The effect of antiseptics and quorum-sensing molecules (QSMs) have been considered with regard to this; however, little has been elucidated, particularly because studies are often restricted to the action of antiseptics and QSMs against a few fungal genera. In this review, we discuss progress reported in the literature thus far and analyze, through in silico methods, 13 fungal QSMs with regard to their physicochemical, pharmacological, and toxicity properties, including their mutagenicity, tumorigenicity, hepatotoxicity, and nephrotoxicity. From these in silico analyses, we highlight 4-hydroxyphenylacetic acid and tryptophol as having satisfactory properties and, thus, propose that these should be investigated further as antifungal agents. We also recommend future in vitro approaches to determine the association of QSMs with commonly used antiseptics as potential antibiofilm agents.

Fungal gut microbiota dysbiosis in systemic lupus erythematosus

Introduction

Despite recent developments in our comprehension of how the gut microbiota and systemic lupus erythematosus (SLE) are related. The mycobiome: which is a small but crucial part of the gut microbiota and is involved in hosts’ homeostasis and physiological processes, remained unexplored in SLE.

Methods

We profiled the gut fungal mycobiota based on internal transcribed spacer region 1 (ITS1) sequencing for the gut microbial DNA from the SLE individuals with lupus nephritis (LN) (n = 23), SLE without LN (n = 26) and healthy controls (n = 14) enrolled in Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School.

Results

The ITS sequencing generated a total of 4.63 million valid tags which were stratified into 4,488 operational taxonomic units (OTUs) and identified about 13 phyla and 262 genera. Patients with SLE were characterized with unique fungal flora feature. The fungal microbiomes of the three groups displayed distinct beta diversity from each other. Compared with HC group, the abundance of fungal dysbiosis was reflected in a higher ratio of opportunistic fungi in SLE or LN group, as well as the loss of Rhizopus and Malassezia. The main principal components of the flora between the SLE and LN group were generally consistent. The relative abundance of Vanrija in the fecal fungal community was higher in LN group, while the relative abundance of Fusarium was higher in SLE group. Moreover, our data revealed superior diagnostic accuracy for SLE with the fungal species (e.g. Candida, Meyerozyma). Correlations between gut fungi and clinical parameters were identified by Spearman’s correlation analysis. Interestingly, Aspergillus in SLE patients was positively correlated with ACR, 24 h proteinuria, proteinuria, anti-dsDNA, ANA, and SLEDAI, while Rhizopus was negatively correlated with lymphocytes and Hb. Finally, we successfully cultured the fungi and identified it as Candida glabrata by microscopic observation and mass spectrometry.

Discussion

We first explored the highly significant gut fungal dysbiosis and ecology in patients with SLE, and demonstrated the applicability of fungal species as SLE diagnostic tools, signifying that the gut fungal mycobiome-host interplay can potentially contribute in disease pathogenesis.

Role of Chlorhexidine and Herbal Oral Rinses in Managing Periodontitis

OBJECTIVE

The aim of this research was to assess the effect of 0.12% chlorhexidine (CHX) and a Salvadora persica-based mouthwash on whole salivary tumour necrosis factor-alpha (TNF-α) levels and periodontal inflammation in patients with type 2 diabetes mellitus (T2DM).

METHODS

Patients with and without medically diagnosed T2DM were included. Patients' medical records were evaluated to confirm the diagnosis of T2DM. All patients underwent nonsurgical periodontal therapy (NSPT). Patients were divided into 2 subgroups. In the test and control group, patients were advised to rinse with an S persica-based mouthwash and a non-alcoholic 0.12% CHX after NSPT twice daily for 2 weeks, respectively. Demographic data were collected. Full-mouth plaque index (PI), gingival index (GI), probing depth (PD), and clinical attachment loss (AL) were measured, and whole salivary TNF-α levels were gauged at baseline and at 3-month follow-up. Haemoglobin A1c (HbA1c) levels were measured in all patients at baseline and at 3-month follow-up. Sample size estimation was done, and group comparison was performed. Level of significance was set at P < .01.

RESULTS

Twenty-one nondiabetic individuals and 21 patients with T2DM were included. At baseline, there was no significant difference in clinical and radiographic periodontal parameters amongst in patients with and without T2DM. At 3-month follow-up, HbA1c, TNF-α, PI, PD, and clinical AL were comparable with their respective baseline values in the test and control groups amongst patients with T2DM. In nondiabetic individuals, there was a significant reduction in PI (P < .01), GI (P < .01), and PD (P < .01), and TNF-α (P < .01) at 3-month follow-up in the test and control groups compared with their respective baseline scores.

CONCLUSIONS

In the short term, NSPT with 0.12% CHX or S persica-based mouthwashes is more effective in reducing periodontal inflammation and whole salivary TNF-α levels in nondiabetic individuals than in patients with T2DM with periodontal inflammation.

Comparison of the postoperative anti-inflammatory efficacy of chlorhexidine, saline rinses and herbal mouthwashes after mechanical debridement in patients with peri-implant mucositis: A randomized controlled trial

AIM

The null hypothesis is that there is no difference in the post-operative anti-inflammatory efficacy of chlorhexidine (CHX), 2% saline rinses (SR) and a herbal mouthwash (MW) after non-surgical mechanical debridement (MD) for treatment of peri-implant mucositis (PiM). The aim was to compare the post-operative anti-inflammatory efficacy of CHX, 2% SR and a herbal oral rinse after non-surgical MD of PiM.

MATERIALS AND METHODS

The present randomized controlled trial had a single-blinded parallel arm design. Patients diagnosed with PiM were enrolled. Demographic information was recorded. All patients underwent MD and were randomly divided into 4 groups: CHX-group: 0.12% non-alcoholic CHX; Sodium chloride (NaCl) group: 2% NaCl rinses; Herbal MW group: Herbal-based MW and H₂ O group: distilled water with peppermint flavour. After MD, all the participants were advised to rinse twice daily (every 12 hrs) for 2 weeks with their respective MWs. In all groups, peri-implant modified plaque index (mPI), modified gingival index (mGI) and probing depth (PD) were measured at baseline and at 12 weeks of follow-up. Sample size was estimated using data from a pilot investigation; and group-comparisons were performed. Statistical significance was confirmed when P-values were below 0.01.

RESULTS

Sixty individuals (15 patients/group) were included. At baseline, mPI, mGI and PD were comparable in all groups. At baseline, there was no significant difference in peri-implant mPI, mGI and PD in all groups. At 12-weeks' follow-up, there was a statistically significant reduction in peri-implant mPI (p < 0.01), mGI (p < 0.01) and PD (p < 0.01) in CHX, NaCl and herbal MW groups compared with H₂ O group. There was no significant relation between implant location, duration for which, implants were functional, gender and peri-implant clinical parameters in all groups.

CONCLUSION

After non-surgical MD, post-operative use of CHX and herbal and NaCl MWs is useful for the management of PiM in the short-term.

The antibiofilm activity of selected substances used in oral health prophylaxis

Oral health is a window to a patient’s general well-being. Balance in oral microbiome functions is crucial for health maintenance. A state of oral dysbiosis may lead to a variety of local and systemic pathological conditions. The presence of dental plaque is related to the majority of oral infections. Proper oral hygiene is crucial and the most economic practice contributing to oral health prophylaxis. Aside from prophylactic treatments provided by dental practitioners, mouth rinses, containing antimicrobial agents, are one of the possible tools used for oral care. Our study was to determine whether available mouth rinses and selected products dedicated for professional use are efficient to eradicate biofilm formed by reference and clinical strains of Streptococcus mutans, Streptococcus sanguinis, Streptococcus oralis, Streptococcus mitis, Staphylococcus aureus, Enterococcus faecalis, Lactobacillus rhamnosus and Candida albicans on the surface of hydroxyapatite – major mineral component of a tooth. Therefore, such antimicrobials as chlorhexidine, cetylpyridine chloride, polyhexanide, silver nanoparticles, sulphonated phenolics, and natural antiplaque essential oils and coconut oil were analyzed. Applied experimental settings in in vitro models were designed to reflect accurately the recommended use of the tested substances, therefore four types of eradication procedure were conducted. Sialorrhea simulation was also performed to evaluate antibiofilm potential of diluted mouth rinses. Biofilm was investigated with quantitative method where absorbance values were measured. Statistical differences were assessed using the Kruskal–Wallis test with a post-hoc Dunnett’s analysis. Results have shown that biofilms displayed a diversified sensitivity to the tested antimicrobials. The highest antibiofilm activity was detected for cetylpyridine chloride while the lowest for chlorhexidine. However the differences in E. faecalis biofilm reduction observed after the use of these two compounds were not statistically significant (p > 0.05), whereas all observed differences in S. aureus survival after exposure to the examined antimicrobial agents were statistically significant (p < 0.5). The PHMB, both in standard and in sialorrhea simulated conditions had the highest potential against streptococci. The coconut oil reduced C. albicans fungus biofilm by 65.48% but low eradication level was observed in case of bacterial biofilms. The dehydrating mechanism of action of sulfonated phenolics turned out to be ineffective against streptococcal biofilm which in turn was effectively eradicated by silver nanoparticles. The implementation of Antibiofilm Dressing's Activity Measurement method allowed to observe strain-related differences in terms of antimicrobial sensitivity. The obtained results may be introduced in everyday out-patient dental plaque prophylaxis as well as clinical environment.

A stable cyclized antimicrobial peptide derived from LL-37 with host immunomodulatory effects and activity against uropathogens

The increasing antibiotic resistance among uropathogenic bacteria warrants alternative therapeutic strategies. We demonstrate the potential of the synthetic peptide CD4-PP, designed by dimerization and backbone cyclization of the shortest antimicrobial region of human cathelicidin, LL-37. CD4-PP is active against clinical and type strains of common uropathogens Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa at concentrations substantially below cellular cytotoxic levels and induced membrane deformation and leakage in E. coli and P. aeruginosa. Furthermore, CD4-PP treatment prevented the formation of new biofilm and dissolved mature biofilm created by E. coli and P. aeruginosa and targeted curli amyloid in E. coli biofilms. In addition, CD4-PP also induced production of LL-37 by uroepithelial cells and increased the expression of tight junction proteins claudin-14 and occludin. During uroepithelial cell infection, CD4-PP significantly reduced uropathogen survival when treatment was given at the start of infection. Low micromolar of CD4-PP treatment initiated after 2 h was successful with all tested species, except P. aeruginosa where CD4-PP was unable to reduce survival, which could be attributed by early biofilm formation. Finally, we demonstrated that urinary catheter pieces coated with saline fluid supplemented with CD4-PP reduced the attachment of E. coli, giving it a potential clinical application.

Sinonasal Stent Coated with Slow-Release Varnish of Chlorhexidine Has Sustained Protection against Bacterial Biofilm Growth in the Sinonasal Cavity: An In Vitro Study

The aim of the study was to develop a sustained-release varnish (SRV) containing chlorhexidine (CHX) for sinonasal stents (SNS) to reduce bacterial growth and biofilm formation in the sinonasal cavity. Segments of SNS were coated with SRV-CHX or SRV-placebo and exposed daily to bacterial cultures of Staphylococcus aureus subsp. aureus ATCC 25923 or Pseudomonas aeruginosa ATCC HER-1018 (PAO1). Anti-bacterial effects were assessed by disc diffusion assay and planktonic-based activity assay. Biofilm formation on the coated stents was visualized by confocal laser scanning microscopy (CLSM) and high-resolution scanning electron microscopy (HR-SEM). The metabolic activity of the biofilms was determined using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) method. Disc diffusion assay showed that SRV-CHX-coated SNS segments inhibited bacterial growth of S. aureussubsp. aureus ATCC 25923 for 26 days and P. aeruginosa ATCC HER-1018 for 19 days. CHX was released from coated SNS segments in a pH 6 medium up to 30 days, resulting in growth inhibition of S. aureussubsp. aureus ATCC 25923 for 22 days and P. aeruginosa ATCC HER-1018 for 24 days. The MTT assay showed a reduction of biofilm growth on the coated SNS by 69% for S. aureussubsp. aureus ATCC 25923 and 40% for P. aeruginosa ATCC HER-1018 compared to the placebo stent after repeated exposure to planktonic growing bacteria. CLSM and HR-SEM showed a significant reduction of biofilm formation on the SRV-CHX-coated SNS segments. Coating of SNS with SRV-CHX maintains a sustained delivery of CHX, providing an inhibitory effect on the bacterial growth of S. aureussubsp. aureus ATCC 25923 and P. aeruginosa ATCC HER-1018 for approximately 3 weeks.