Oral cavity anaerobic pathogens in biofilm formation on voice prostheses

Application of Fluorescence In Situ Hybridization (FISH) in Oral Microbial Detection

Varieties of microorganisms reside in the oral cavity contributing to the occurrence and development of microbes associated with oral diseases; however, the distribution and in situ abundance in the biofilm are still unclear. In order to promote the understanding of the ecosystem of oral microbiota and the diagnosis of oral diseases, it is necessary to monitor and compare the oral microorganisms from different niches of the oral cavity in situ. The fluorescence in situ hybridization (FISH) has proven to be a powerful tool for representing the status of oral microorganisms in the oral cavity. FISH is one of the most routinely used cytochemical techniques for genetic detection, identification, and localization by a fluorescently labeled nucleic acid probe, which can hybridize with targeted nucleic acid sequences. It has the advantages of rapidity, safety, high sensitivity, and specificity. FISH allows the identification and quantification of different oral microorganisms simultaneously. It can also visualize microorganisms by combining with other molecular biology technologies to represent the distribution of each microbial community in the oral biofilm. In this review, we summarized and discussed the development of FISH technology and the application of FISH in oral disease diagnosis and oral ecosystem research, highlighted its advantages in oral microbiology, listed the existing problems, and provided suggestions for future development..

Probiotic E. coli Nissle 1917 biofilms on silicone substrates for bacterial interference against pathogen colonization

Bacterial interference is an alternative strategy to fight against device-associated bacterial infections. Pursuing this strategy, a non-pathogenic bacterial biofilm is used as a live, protective barrier to fence off pathogen colonization. In this work, biofilms formed by probiotic Escherichia coli strain Nissle 1917 (EcN) are investigated for their potential for long-term bacterial interference against infections associated with silicone-based urinary catheters and indwelling catheters used in the digestive system, such as feeding tubes and voice prostheses. We have shown that EcN can form stable biofilms on silicone substrates, particularly those modified with a biphenyl mannoside derivative. These biofilms greatly reduced the colonization by pathogenic Enterococcus faecalis in Lysogeny broth (LB) for 11days.

STATEMENT OF SIGNIFICANCE

Bacterial interference is an alternative strategy to fight against device-associated bacterial infections. Pursuing this strategy, we use non-pathogenic bacteria to form a biofilm that serves as a live, protective barrier against pathogen colonization. Herein, we report the first use of preformed probiotic E. coli Nissle 1917 biofilms on the mannoside-presenting silicone substrates to prevent pathogen colonization. The biofilms serve as a live, protective barrier to fence off the pathogens, whereas current antimicrobial/antifouling coatings are subjected to gradual coverage by the biomass from the rapidly growing pathogens in a high-nutrient environment. It should be noted that E. coli Nissle 1917 is commercially available and has been used in many clinical trials. We also demonstrated that this probiotic strain performed significantly better than the non-commercial, genetically modified E. coli strain that we previously reported.

Effect of the endOclear® Device on Biofilm in Endotracheal Tubes

BACKGROUND

Organisms trapped in biofilms cause more than 80% of medical infections. Significant investments are being made to develop methods of removing these biofilms. The endOclear^® device is reported to remove biofilm from endotracheal tubes (ETTs) and to decrease pneumonia rates and ventilator time.

METHODS

This was an observational study performed at a university Level 1 trauma center intensive care unit. A series of 40 ETTs were collected at extubation, with half of the patients having been treated daily with the endOclear^® device. Biofilms were quantified from a standardized point on the distal ETT. The patients' standard and biofilm cultures were reviewed.

RESULTS

The mean hours of intubation for the control group was 135 and for the device group 138. This difference was not statistically significant (p = 0.91). Eleven patients in the device group were found to have pneumonia compared with six in the control group (p = 0.34). Ventilator data after device use showed a mean increase of 29.9 cc in tidal volume and a mean decrease in peak pressures of 0.39 cm H₂O. Comparisons between biofilm stage or hours of intubation and a diagnosis of pneumonia found no correlation. Only nine of 40 ETTs had congruence between the microbiata of the biofilm and standard bronchoalveolar lavage (BAL) fluid, a divergence rate of 78%.

CONCLUSIONS

Comparison of the endOclear^® group and controls demonstrated a trend toward a higher pneumonia rate in the former. Additionally, the device achieved very small, clinically insignificant, changes in ventilator settings, and no difference was seen in the time on the ventilator. Comparisons between biofilm and standard BAL cultures continue to show the biofilm is more diverse than previously thought. In this study, no statistical significance was found between biofilm stage and the pneumonia rate. This study provides additional evidence that there is no correlation between biofilm stage and duration of intubation.

Oral health status and dental care behaviours of head and neck cancer patients: a cross-sectional study in an Austrian tertiary hospital

OBJECTIVES

This study aimed to assess the oral health status and dental care behaviours of patients treated for head and neck squamous cell carcinoma (HNSCC) in an Austrian tertiary hospital.

MATERIALS AND METHODS

Dental care behaviours, oral hygiene level, caries, and periodontal parameters were assessed in 48 patients treated for HNSCC >6 months ago.

RESULTS

Only 52 % requested a dental check-up after HNSCC diagnosis and prior to treatment, and of those, 80 % received some type of dental treatment. At time-point of clinical examination, 69 % of the patients had consulted a dentist within the last year, but 88 % still needed dental treatment; 75 % had at least one tooth with caries and 78 % had moderate to severe periodontitis.

CONCLUSION

Although it was recommended, only half of the patients did consult a dentist prior to HNSCC treatment and oral health appeared, in general, low prioritized.

CLINICAL RELEVANCE

About 90 % of the current group of head and neck squamous cell carcinoma cancer patients presented large treatment needs, both in regard with caries and periodontal disease, about 20 months after cancer treatment.