[Pneumomediastinum after minor wound to the neck]. / Pijnlijke gevolgen van een wond aan de hals.

A 47-year old male presented to the emergency department with a pneumomediastinum following a small penetrating wound to the neck.

Biofilm formation on the Provox ActiValve: Composition and ingrowth analyzed by Illumina paired-end RNA sequencing, fluorescence in situ hybridization, and confocal laser scanning microscopy.

BACKGROUND: The most frequent cause of voice prosthesis failure is microbial biofilm formation on the silicone valve, leading to destruction of the material and transprosthetic leakage. The Provox ActiValve valve is made of fluoroplastic, which should be insusceptible to destruction. The purpose of this study was to determine if fluoroplastic is insusceptible to destruction by Candida species. METHODS: Thirty-three dysfunctional Provox ActiValves (collected 2011-2013). Biofilm analysis was performed with Illumina paired-end sequencing (IPES), assessment of biofilm-material interaction with fluorescence in situ hybridization (FISH), and confocal laser scanning microscopy (CLSM). RESULTS: IPES (n = 10) showed that Candida albicans and Candida tropicalis are dominant populations on fluoroplastic and silicone. Microbial diversity is significantly lower on fluoroplastic. Lactobacillus gasseri is the prevalent bacterial strain on most voice prostheses. FISH and CLSM (n = 23): in none of the cases was ingrowth of Candida species present in the fluoroplastic. CONCLUSION: Fluoroplastic material of Provox ActiValve seems insusceptible to destruction by Candida species, which could help improve durability of voice prostheses. © 2015 Wiley Periodicals, Inc. Head Neck 38: E432-E440, 2016.

Voice prosthetic biofilm formation and Candida morphogenic conversions in absence and presence of different bacterial strains and species on silicone-rubber.

Morphogenic conversion of Candida from a yeast to hyphal morphology plays a pivotal role in the pathogenicity of Candida species. Both Candida albicans and Candida tropicalis, in combination with a variety of different bacterial strains and species, appear in biofilms on silicone-rubber voice prostheses used in laryngectomized patients. Here we study biofilm formation on silicone-rubber by C. albicans or C. tropicalis in combination with different commensal bacterial strains and lactobacillus strains. In addition, hyphal formation in C. albicans and C. tropicalis, as stimulated by Rothia dentocariosa and lactobacilli was evaluated, as clinical studies outlined that these bacterial strains have opposite results on the clinical life-time of silicone-rubber voice prostheses. Biofilms were grown during eight days in a silicone-rubber tube, while passing the biofilms through episodes of nutritional feast and famine. Biofilms consisting of combinations of C. albicans and a bacterial strain comprised significantly less viable organisms than combinations comprising C. tropicalis. High percentages of Candida were found in biofilms grown in combination with lactobacilli. Interestingly, L. casei, with demonstrated favorable effects on the clinical life-time of voice prostheses, reduced the percentage hyphal formation in Candida biofilms as compared with Candida biofilms grown in absence of bacteria or grown in combination with R. dentocariosa, a bacterial strain whose presence is associated with short clinical life-times of voice prostheses.

Composition and architecture of biofilms on used voice prostheses.

BACKGROUND: Biofilms on medical devices are a frequent reason for failure of the device. Voice prostheses in laryngectomized patients deteriorate within 3 to 4 months due to adhering biofilms, impeding proper functioning. Recently, we showed that these biofilms are dominated by Candida and lactobacilli. However, the early report of this finding lacked an in depth analysis of the species diversity and community structure. METHODS: Denaturing gradient gel electrophoresis (DGGE) and sequence analysis of amplified rRNA genes was used to identify microorganisms. Fluorescence in situ hybridization (FISH) was used to analyze biofilm architecture. RESULTS: Candida are the predominant fungi in the biofilms, while lactobacilli are the predominant bacteria in all investigated biofilms, followed by streptococci. FISH shows that lactobacilli and streptococci seem to have an important interaction with fungi. CONCLUSION: The results give a better understanding of biofilm formation and can be used in further development to prevent biofilm formation on voice prostheses.

Development of a questionnaire for the assessment of bronchial hyperresponsiveness.

INTRODUCTION: Bronchial hyperresponsiveness (BHR) is a hallmark of asthma. Treatment approaches based on BHR severity have been shown to be effective. However, challenge tests are expensive, inconvenient to patients, time consuming, and not easily accessible to general practitioners. Assessment of BHR by a questionnaire would be advantageous in the diagnosis and management of asthma. AIM: To select a set of respiratory symptoms and provoking stimuli related to BHR to compose a reliable Bronchial Hyperresponsiveness Questionnaire (BHQ). METHOD: A list of 33 symptoms and 68 stimuli were selected by in-depth interviews, focus group discussions with asthma patients, and literature review. After a histamine challenge test patients (n=302) were asked to score each question on a 7-point scale (0=no; 6=severe complaints). Factor analysis was performed to identify clusters of interrelated symptoms associated with PC20-histamine. The sensitivity to detect the presence of BHR was analysed by Receiver Operating Curves (ROC). The correlation between the PC20-score and the scores on the questions was analysed. RESULTS: 15 symptoms and 19 provoking stimuli were ultimately selected for the BHQ. CONCLUSION: The BHQ was developed according to FDA-approved standards and is a condition-specific questionnaire able to assess the presence of BHR.

Candida biofilm analysis in the artificial throat using FISH.

Biofilm formation is a common complication of the use of prosthetic devices. In clinical settings, biofilms can be comprised of one or more microbial species. In order to investigate the interaction between different species within a biofilm, a reproducible, reliable model system has to be utilized and an appropriate system for species identification applied. The present chapter describes the artificial throat model, a model system for growing mixed species biofilms on shunt prostheses. The model is used in conjugation with fluorescent in situ hybridization (FISH), which facilitates identification and localization of the resident microorganisms within biofilms.

Lactobacilli: important in biofilm formation on voice prostheses.

OBJECTIVE: We sought to identify bacterial strains responsible for biofilm formation on silicone rubber voice prostheses. STUDY DESIGN: We conducted an analysis of the bacterial population in biofilms on used silicone rubber voice prostheses by using new microbiological methods. METHODS: Two microbiological methods were used: polymerase chain reaction-denaturing gradient gel electrophoresis and fluorescence in situ hybridization. Twenty-six Provox2 and eight Groningen Ultra Low Resistance voice prostheses that were removed because of leakage through the prosthesis or because of increased airflow resistance were used in this study. RESULTS: The results showed that 33 of the 34 explanted voice prosthetic biofilms contained lactobacilli in close association with the Candida sp. present. CONCLUSION: Lactobacilli are general colonizers of tracheoesophageal voice prostheses in vivo, growing intertwined with Candida. This knowledge may be important in the development of new pathways directed to prevent or to influence biofilm formation on tracheoesophageal voice prostheses and elongate their lifespan.

Effects of quaternary ammonium silane coatings on mixed fungal and bacterial biofilms on tracheoesophageal shunt prostheses.

Two quaternary ammonium silanes (QAS) were used to coat silicone rubber tracheoesophageal shunt prostheses, yielding a positively charged surface. One QAS coating [(trimethoxysilyl)-propyldimethyloctadecylammonium chloride] was applied through chemical bonding, while the other coating, Biocidal ZF, was sprayed onto the silicone rubber surface. The sprayed coating lost its stability within an hour, while the chemically bonded coating appeared stable. Upon incubation in an artificial throat model, allowing simultaneous adhesion and growth of yeast and bacteria, all coated prostheses showed significant reductions in the numbers of viable yeast (to 12% to 16%) and bacteria (to 27% to 36%) compared with those for silicone rubber controls, as confirmed using confocal laser scanning microscopy after live/dead staining of the biofilms. In situ hybridization with fluorescently labeled oligonucleotide probes showed that yeasts expressed hyphae on the untreated and Biocidal ZF-coated prostheses but not on the QAS-coated prostheses. Whether this is a result of the positive QAS coating or is due to the reduced number of bacteria is currently unknown. In summary, this is the first report on the inhibitory effects of positively charged coatings on the viability of yeasts and bacteria in mixed biofilms. Although the study initially aimed at reducing voice prosthetic biofilms, its relevance extends to all biomedical and environmental surfaces where mixed biofilms develop and present a problem.