Anaerobic and microaerophilic pathogens in the biofilm formation on voice prostheses: A pilot study

Is Oral Microflora Related to Development of Malfunction in Patients Using Voice Prosthesis?

Background: this prospective study investigated the correlation between the oral bacterial microflora and the microflora found in voice prostheses (VPs) among 20 patients who had undergone laryngectomy. The aim was to explore the associations between the microflora's presence and the malfunction of VPs, along with the association between the predominant microorganism and the longevity of VPs. Methods: the research process included gathering medical histories, conducting ENT examinations, replacing VPs, and performing check-ups every four months for a period of 15.5 months. Additionally, microbiological examinations, blood tests, and voice change surveys were conducted. Results: a correlation between the microflora isolated from VPs and that from oral rinses was demonstrated in a large percentage of patients who experienced a loss of prosthetic functional efficiency. The correlation analysis between the type of microorganism and the lifespan of VPs showed a non-significant Pearson correlation coefficient (r = 0.043, p = 0.678). Conclusions: there is no significant linear correlation between the predominant microorganism and the average lifespan of VPs.

Effect of silver sulfadiazine on mature mixed bacterial biofilms on voice prostheses

BACKGROUND

Biofilm formation on voice prostheses disrupts the function and limits the lifespan of voice prostheses. There is still no effective clinical strategy for inhibiting or removing these biofilms. Silver sulfadiazine (SSD), as an exogenous antibacterial agent, has been widely used in the prevention and treatment of infection, however, its effect on voice prosthesis biofilms is unknown. The purpose of this study was to explore the effect of SSD on the mature mixed bacterial biofilms present on voice prostheses.

METHODS

Quantitative and qualitative methods, including the plate counting method, real-time fluorescence quantitative PCR, crystal violet staining, the 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) (XTT) reduction assay, scanning electron microscopy, and laser confocal microscopy, were used to determine the effect of SSD on the number of bacterial colonies, biofilm formation ability, metabolic activity, and ultrastructure of biofilms in a mature mixed bacterial (Staphylococcus aureus, Streptococcus faecalis and Candida albicans) voice prosthesis biofilm model. The results were verified in vitro on mature mixed bacterial voice prosthesis biofilms from patients, and the possible mechanism of action was explored.

RESULTS

Silver sulfadiazine decreased the number of bacterial colonies on mature mixed bacterial voice prosthesis biofilm, significantly inhibited the biofilm formation ability and metabolic activity of mature voice prosthesis biofilms, inhibited the formation of the complex spatial structure of voice prosthesis biofilms, and inhibited the synthesis of polysaccharides and proteins in the biofilm extracellular matrix. The degree of inhibition and removal effect increased with SSD concentration.

CONCLUSIONS

Silver sulfadiazine can effectively inhibit and remove mature mixed bacterial voice prosthesis biofilms and decrease biofilm formation ability and metabolic activity; SSD may exert these effects by inhibiting the synthesis of polysaccharides and proteins among the extracellular polymeric substances of voice prosthesis biofilms.

Inhibition and Removal of Mature Mixed-Bacteria Biofilms on Voice Prostheses by Sodium Selenite

Purpose

Biofilms on voice prostheses are important factors shortening their service life. Sodium selenite has been used to prevent and treat various diseases. Whether sodium selenite can inhibit and remove mature biofilms on voice prostheses is still unknown.

Methods

To verify the effects of sodium selenite on mature mixed-bacteria biofilms (Staphylococcus aureus, Candida albicans, and Streptococcus faecalis) on voice prostheses, we used quantitative and qualitative methods, eg, real-time fluorescence quantitative PCR, crystal violet staining, 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) (XTT) reduction assays, and scanning electron microscopy, to measure the effects of sodium selenite on the number of bacterial colonies, biofilm formation ability, metabolic activity, and ultrastructure in a model of mature mixed-bacteria biofilms on voice prostheses and validated the effects in vitro on mature biofilms on voice prostheses from patients.

Results

When exploring the possible mechanism of biofilm inhibition and removal by sodium selenite, we found that it significantly inhibited and removed biofilms on voice prostheses and effectively destroyed the spatial structure of the biofilms. The inhibition and removal effects became more significant with increasing sodium selenite concentrations.

Conclusion

We demonstrated that sodium selenite can inhibit and remove biofilms of mature mixed strains on voice prostheses, providing a novel basis for treating patients' voice prosthesis biofilms.

Biocompatible Materials in Otorhinolaryngology and Their Antibacterial Properties

For decades, biomaterials have been commonly used in medicine for the replacement of human body tissue, precise drug-delivery systems, or as parts of medical devices that are essential for some treatment methods. Due to rapid progress in the field of new materials, updates on the state of knowledge about biomaterials are frequently needed. This article describes the clinical application of different types of biomaterials in the field of otorhinolaryngology, i.e., head and neck surgery, focusing on their antimicrobial properties. The variety of their applications includes cochlear implants, middle ear prostheses, voice prostheses, materials for osteosynthesis, and nasal packing after nasal/paranasal sinuses surgery. Ceramics, such as as hydroxyapatite, zirconia, or metals and metal alloys, still have applications in the head and neck region. Tissue engineering scaffolds and drug-eluting materials, such as polymers and polymer-based composites, are becoming more common. The restoration of life tissue and the ability to prevent microbial colonization should be taken into consideration when designing the materials to be used for implant production. The authors of this paper have reviewed publications available in PubMed from the last five years about the recent progress in this topic but also establish the state of knowledge of the most common application of biomaterials over the last few decades.

Biofilm Growth Causes Damage to Silicone Voice Prostheses in Patients after Surgical Treatment of Locally Advanced Laryngeal Cancer

Voice prosthesis implantation with the creation of a tracheoesophageal fistula is the gold standard procedure for voice rehabilitation in patients after a total laryngectomy. All patients implanted with a voice prosthesis (VP) have biofilms of fungi and bacteria grow on their surface. Biofilm colonization is one of the main reasons for VP degradation that can lead to VP dysfunction, which increases the high risk of pneumonia. In a 20-month evaluation period, 129 cases of prostheses after replacement procedures were investigated. Microbiological examination of the biofilms revealed that there were four of the most common fungi species (Candida spp.) and a large variety of bacterial species present. We studied the relationship between the time of proper function of Provox VP, the microorganism composition of the biofilm present on it, and the degradation level of the silicone material. Evaluation of the surface of the removed VP using an atomic force microscope (AFM) has demonstrated that biofilm growth might drastically change the silicone's mechanical properties. Changes in silicone stiffness and thermal properties might contribute to the failure of VP function. Our data can serve in future studies for the development of methods to prevent or inhibit biofilm formation on the VP surface that would translate to an increase in their durability and safety.

Biofilm in voice prosthesis: A prospective cohort study and laboratory tests using sonication and SEM analysis

OBJECTIVE

The objective of the study was to compare the biofilm growing pattern and its morphological extent on silicone and a teflon-like material using a sonication process and a Scanning Electron Microscope (SEM).

DESIGN

A prospective cohort study and a laboratory study.

SETTING

Otolaryngology -Head and Neck surgery Department and the Microbiology Institute.

PARTICIPANTS

The participants included fifteen laryngectomised patients with phonatory prostheses, which were removed because of device failure, and two different kinds of phonatory prostheses from the laboratory (Provox 2 and ActiValve) that were artificially colonised by Candida albicans.

MAIN OUTCOME MEASURES

Tracheo-oesophageal puncture (TEP) is currently considered the gold standard for post-laryngectomy voice rehabilitation. "Leakage" represents the most common cause of substitution and is generated by biofilm colonisation of the prosthesis by mixed mycotic and bacterial agents. New biomaterials have been developed that are deemed to be more resistant to the colonisation of micro-organisms and material deformation.

RESULTS

The devices showed colonisation by mixed bacterial flora (Staphylococci 13%, Streptococci 9%, and Haemophilus influenzae 5%) and by yeasts (Candida albicans 12%). Moreover, we observed a different distribution of biofilm layers in Provox ActiValve (22.56%) compared to Provox 2 (56.82%) after experimental colonisation by the previously isolated Candida strain.

CONCLUSION

Resident microbiological species from the upper airways unavoidably colonise the polymer surfaces, and no strategies have been effective except for the manipulation of the chemical-physical properties of the device's polymer. Our study confirms that Provox ActiValve, which is made with a fluoroplastic material (teflon-like), is less subject to in vitro colonisation by Candida, and thus showed a higher clinical resistance to biofilm and a longer lifespan. The sonication seems to significantly improve the knowledge of bacterial and mycotic flora in biofilm colonisation. The design of a device for the daily cleaning capable to reach and brush the oesophageal flange of the prosthesis preserving the valve mechanism could represent a practical and simple help in this still unsolved problem.

[Solving problems after rehabilitation with voice prostheses : Two rare cases of fistula-related complications]

During the past three decades, the use of voice prostheses has developed worldwide into the gold standard for voice rehabilitation after total laryngectomy. Insertion of a voice prosthesis is a simple and rapid surgical procedure, which is associated with a low rate of complications. The current article describes the cases of 2 patients showing a rapid development of granulation tissue around the voice fistula, leading to complete incarceration of the prosthesis and subtotal/total stenosis of the neopharynx.

Biofilm formation by clinical isolates and its relevance to clinical infections

Reports of biofilms have increased exponentially in the scientific literature over the past two decades, yet the vast majority of these are basic science investigations with limited clinical relevance. Biofilm studies involving clinical isolates are most often surveys of isolate collections, but suffer from lack of standardization in methodologies for producing and assessing biofilms. In contrast, more informative clinical studies correlating biofilm formation to patient data have infrequently been reported. In this chapter, biofilm surveys of clinical isolates of aerobic and anaerobic bacteria, mycobacteria, and Candida are reviewed, as well as those pertaining to the unique situation of cystic fibrosis. In addition, the influence of host components on in vitro biofilm formation, as well as published studies documenting the clinical impact of biofilms in human infections, are presented.

The development and treatment of periprosthetic leakage after prosthetic voice restoration. A literature review and personal experience part I: the development of periprosthetic leakage

In the past 30 years, the use of a voice prosthesis has become the treatment of choice for the restoration of speech following laryngectomy. Not only is the placement of a voice prosthesis a simple surgical procedure, but it is also associated with a low rate of complications and an excellent success rate. Approximately, 20-30 % of all patients with voice prostheses, however, develop periprosthetic leakage with aspiration over time. Periprosthetic leakage is usually caused by an enlargement of the tracheo-oesophageal fistula and substantially affects the quality of life of the patients concerned. In a retrospective analysis of our patients, the incidence of periprosthetic leakage was 35.7 % in a total of 232 patients who underwent laryngectomy during a period of 20 years. Substantial enlargement of the tracheo-oesophageal fistula which required multiple treatments occurred in 12.5 % of the patients. In this review, the various causes of fistula enlargement are discussed on the basis of the literature and the experience that we have accumulated during the past 20 years in the management of patients with voice prostheses.