Oral hygiene in intensive care unit patients with photodynamic therapy: study protocol for randomised controlled trial

Is the Oral Cavity of Intensive Care Unit Pediatric Patients More Susceptible to Methicillin-Resistant Staphylococcus aureus Infection?

Objective: The aim of this study was to assess the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in the oral cavity of pediatric patients hospitalized at an intensive care unit (ICU). Methodology: Thirty ICU patients (group 1) and 30 healthy patients (group 2), between 1 and 12 years of age, matched by sex and age, were selected from a public hospital in Brazil. After oral examinations, biological specimens (nostril swab, oral mucosa, and supragingival biofilm) were collected from both groups to verify the presence of Staphylococcus aureus. Identification occurred after growth in Tryptic Soy Broth with 7.5% of NaCl for 48 hours, growth in Mannitol Salt Agar, gram staining, catalase, and coagulase tests. S. aureus isolates were submitted to antibiotic sensitivity test. Results: Only 36.7% of patients in the ICU perform oral hygiene during the hospitalization period and 41.7% presented high level of dental biofilm accumulation. The presence of S. aureus was similar in patients from group 1 (43.3%, 13) and group 2 (50.0%, 15) (p = 0.60). Both groups presented 18 samples each that tested positive for S. aureus. However, when considering patients infected by MRSA, the prevalence was higher in group 1 (eight; 26.7%) than in group 2 (five; 16.7%) but no statistical difference was observed (p = 0.53). In group 1, nine MRSA samples were resistant to erythromycin and seven to clindamycin. In group 2, two MRSA samples were resistant to erythromycin and two to clindamycin. Conclusions: Although ICU children did not show a significant higher carriage of MRSA when compared with the healthy group in the population studied, the number of highly resistant strains in the oral cavity isolated from ICU patients adds an important risk factor to be considered by the medical team as possible source of systemic infections, extended hospital stay, and poor outcomes.

Oral colonization of Acinetobacter baumannii in intensive care units: Risk factors, incidence, molecular epidemiology, association with the occur of pneumonia and sepsis, and infection control measures

Objectives

Oral colonization of Acinetobacter baumannii can lead to infections such as pneumonia and sepsis. We aimed to evaluate oral colonization of hospitalized patients in ICUs and to examine risk factors for oral colonization, molecular epidemiology, and incidence of pneumonia and sepsis.

Materials and Methods

The study began in February 2021. Oral cultures were taken. The microorganisms were identified by a Maldi-tof MS mass spectrometry device. Colistin resistance genes were investigated by polymerase chain reaction. Clonal relationships were determined by pulsed-field gel electrophoresis.

Results

A. baumannii was found in 21 of 96 patients' oral cultures. Pneumonia and sepsis due to A. baumannii were detected in 14 and 5 patients, respectively. The mean growth time of A. baumannii from oral cultures was 11.8 days, and the meantime for the occurrence of pneumonia after oral growth was 5.2 days. We determined a plasmid mediated mcr-2 colistin resistance gene in a colistin susceptible A. baumannii strain. It is the first report of the plasmid mediated mcr-2 colistin resistance gene in our country. In total, fourteen different A. baumannii genotypes were determined in PFGE. It was determined that the effects of antibiotic use, oral motor dysfunction, mechanical ventilation, intubation, orogastric tube use, and total parenteral nutrition intake on oral colonization were statistically significant.

Conclusion

Oral colonization of A. baumannii is a significant concern in ICUs. We believe that it is important to take oral cultures and follow the risk factors and take infection control measures to prevent oral colonization of resistant isolates in ICUs.

A combination of preoperative or intraoperative MB-PDT and surgery in the treatment of giant cutaneous squamous cell carcinoma with infection

BACKGROUND

Giant cutaneous squamous cell carcinoma (cSCC) with infection is a major clinical issue, as the infection not only promotes the progress of tumor, but also effects the success of surgery. Traditional antibiotic treatment is not always sufficient to clear the infection, especially for cSCC infected with multidrug-resistant bacteria. Photodynamic therapy (PDT) has broad-spectral antibacterial activity and non-selective pressure, which makes it difficult to induce antibiotic resistance. Here, we aim to evaluate the safety and efficacy of PDT, along with photosensitizers MB (Methylene blue) - in the treatment of cSCC infected with multidrug-resistant bacteria.

METHODS

In our study, 6 patients with giant csCC accompanied infection were diagnosed by pathological examination and the depth of tumor tissues was examined by X-Ray or MRI. All patients' tumor wounds were firstly irradiated with MB-PDT (635 nm, 120 J/cm², 100 mW/cm²) using the red LED to control the infection. After the control of infection was confirmed by the culture of secretion, tumor underwent expanded resection. Multi-point pathological monitoring was performed during the operation to assure that there was no residual tumor tissue on the wound, and the primary or secondary repair was performed according to the condition of the wound. If the wound requires the tissue flaps transplation in secondary stage, the wound was irradiated again with intraoperative MB-PDT to remove the possible residual tumor cells, as well as to prevent wound infection. All patients were followed up for 0.8-3 years after flap transplation.

RESULTS

In 6 patients, the cSCC infection was completely controlled by MB-PDT, and the flap survival was 100%. There was no recurrence of cSCC in the follow-up of 1.6 years (range, 0.8-3 years) after the comminated treatment with MB-PDT and surgery.

CONCLUSIONS

Multi-drug resistant bacteria could efficiently be killed by MB-PDT, and the combination of surgery with MB-PDT is a safe and effective approach for treating giant cSCC with infection.

The effects of removing dead bacteria by propidium monoazide on the profile of salivary microbiome

Background

Oral microbiome played an important role in maintaining healthy state and might exhibit certain changes under circumstances of diseases. However, current microbiological research using sequencing techniques did not regard dead bacteria as a separate part, causing findings based on subsequent analyses on dynamic equilibrium and functional pathways of microbes somewhat questionable. Since treatment by propidium monoazide (PMA) was able to remove dead bacteria effectively, it would be worth studying how the sequencing results after PMA treatment differed from those focusing on the whole microbiota.

Methods

Unstimulated whole saliva samples were obtained from 18 healthy people from 3 age groups (children, adults, and the elderly). After removal of dead bacteria by propidium monoazide (PMA), changes in the profile of salivary microbiome were detected using 16S rRNA sequencing technology, and differences among age groups were compared subsequently.

Results

Dead bacteria accounted for nearly a half of the whole bacteria flora in saliva, while freezing had little effect on the proportion of deaths. After treatment with PMA, the numbers of OTUs reduced by 4.4–14.2%, while the Shannon diversity indices decreased significantly (P < 0.01). Only 35.2% of positive and 6.1% of negative correlations were found to be shared by the whole microbiota and that with dead bacteria removed. Differences in significantly changed OTUs and functional pathways among different age groups were also observed between the group of PMA and the control.

Conclusions

It was necessary to take the influence of living state of bacteria into account in analytic studies of salivary microbiome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01832-5.

Oral hygiene care for critically ill patients to prevent ventilator-associated pneumonia

BACKGROUND

Ventilator-associated pneumonia (VAP) is defined as pneumonia developing in people who have received mechanical ventilation for at least 48 hours. VAP is a potentially serious complication in these patients who are already critically ill. Oral hygiene care (OHC), using either a mouthrinse, gel, swab, toothbrush, or combination, together with suction of secretions, may reduce the risk of VAP in these patients.

OBJECTIVES

To assess the effects of oral hygiene care (OHC) on incidence of ventilator-associated pneumonia in critically ill patients receiving mechanical ventilation in hospital intensive care units (ICUs).

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 25 February 2020), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2020, Issue 1), MEDLINE Ovid (1946 to 25 February 2020), Embase Ovid (1980 to 25 February 2020), LILACS BIREME Virtual Health Library (1982 to 25 February 2020) and CINAHL EBSCO (1937 to 25 February 2020). We also searched the VIP Database (January 2012 to 8 March 2020). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) evaluating the effects of OHC (mouthrinse, gel, swab, toothbrush or combination) in critically ill patients receiving mechanical ventilation for at least 48 hours.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed search results, extracted data and assessed risk of bias in included studies. We contacted study authors for additional information. We reported risk ratio (RR) for dichotomous outcomes and mean difference (MD) for continuous outcomes, using the random-effects model of meta-analysis when data from four or more trials were combined.

MAIN RESULTS

We included 40 RCTs (5675 participants), which were conducted in various countries including China, USA, Brazil and Iran. We categorised these RCTs into five main comparisons: chlorhexidine (CHX) mouthrinse or gel versus placebo/usual care; CHX mouthrinse versus other oral care agents; toothbrushing (± antiseptics) versus no toothbrushing (± antiseptics); powered versus manual toothbrushing; and comparisons of other oral care agents used in OHC (other oral care agents versus placebo/usual care, or head-to-head comparisons between other oral care agents). We assessed the overall risk of bias as high in 31 trials and low in two, with the rest being unclear. Moderate-certainty evidence from 13 RCTs (1206 participants, 92% adults) shows that CHX mouthrinse or gel, as part of OHC, probably reduces the incidence of VAP compared to placebo or usual care from 26% to about 18% (RR 0.67, 95% confidence intervals (CI) 0.47 to 0.97; P = 0.03; I2 = 66%). This is equivalent to a number needed to treat for an additional beneficial outcome (NNTB) of 12 (95% CI 7 to 128), i.e. providing OHC including CHX for 12 ventilated patients in intensive care would prevent one patient developing VAP. There was no evidence of a difference between interventions for the outcomes of mortality (RR 1.03, 95% CI 0.80 to 1.33; P = 0.86, I2 = 0%; 9 RCTs, 944 participants; moderate-certainty evidence), duration of mechanical ventilation (MD -1.10 days, 95% CI -3.20 to 1.00 days; P = 0.30, I2 = 74%; 4 RCTs, 594 participants; very low-certainty evidence) or duration of intensive care unit (ICU) stay (MD -0.89 days, 95% CI -3.59 to 1.82 days; P = 0.52, I2 = 69%; 5 RCTs, 627 participants; low-certainty evidence). Most studies did not mention adverse effects. One study reported adverse effects, which were mild, with similar frequency in CHX and control groups and one study reported there were no adverse effects. Toothbrushing (± antiseptics) may reduce the incidence of VAP (RR 0.61, 95% CI 0.41 to 0.91; P = 0.01, I2 = 40%; 5 RCTs, 910 participants; low-certainty evidence) compared to OHC without toothbrushing (± antiseptics). There is also some evidence that toothbrushing may reduce the duration of ICU stay (MD -1.89 days, 95% CI -3.52 to -0.27 days; P = 0.02, I2 = 0%; 3 RCTs, 749 participants), but this is very low certainty. Low-certainty evidence did not show a reduction in mortality (RR 0.84, 95% CI 0.67 to 1.05; P = 0.12, I2 = 0%; 5 RCTs, 910 participants) or duration of mechanical ventilation (MD -0.43, 95% CI -1.17 to 0.30; P = 0.25, I2 = 46%; 4 RCTs, 810 participants).

AUTHORS' CONCLUSIONS

Chlorhexidine mouthwash or gel, as part of OHC, probably reduces the incidence of developing ventilator-associated pneumonia (VAP) in critically ill patients from 26% to about 18%, when compared to placebo or usual care. We did not find a difference in mortality, duration of mechanical ventilation or duration of stay in the intensive care unit, although the evidence was low certainty. OHC including both antiseptics and toothbrushing may be more effective than OHC with antiseptics alone to reduce the incidence of VAP and the length of ICU stay, but, again, the evidence is low certainty. There is insufficient evidence to determine whether any of the interventions evaluated in the studies are associated with adverse effects.

Photodynamic Activity on Biofilm in Endotracheal Tubes of Patients Admitted to an Intensive Care Unit

Ventilator-associated pneumonia (VAP) is an infection that arises after endotracheal intubation affecting patients under intensive care. The presence of the endotracheal tube (ETT) is a risk factor since it is colonized by multispecies biofilm. Antimicrobial photodynamic therapy (aPDT) could be a strategy to decontaminate ETTs. We verify if methylene blue (MB) associated with external illumination of the ETT could be an alternative to destroy biofilm. We performed an in vitro and ex vivo study. In vitro study was performed with P. aeruginosa biofilm grew over ETT for 7 days. After treatment, the surviving cells were cultured for 3 days and the biofilm was analyzed by crystal violet absorbance. Ex vivo study employed ETT obtained from extubated patients. aPDT was performed with MB (100 µm) and red LED (λ = 640±20 nm). We quantified the biofilm thickness and used scanning electron microscopy and fluorescence technique to verify morphological and functional changes after aPDT. Our results showed that bacteria remain susceptible to aPDT after sequential treatments. We also attested that aPDT can reduce biofilm thickness, disrupt biofilm attachment from ETT surface and kill microbial cells. These data suggest that aPDT should be investigated to decrease VAP incidence via ETT decontamination.

Human serum albumin nanoparticles loaded with phthalocyanine dyes for potential use in photodynamic therapy for atherosclerotic plaques

Diseases caused by obstruction or rupture of vulnerable plaques in the arterial walls such as cardiovascular infarction or stroke are the leading cause of death in the world. In the present work, we developed human serum albumin nanoparticles loaded by physisorption with zinc phthalocyanine, TT1, mainly used for industrial application as near-infrared photosensitizer and compared these to HSA NPs loaded with the well-known silicone phthalocyanine (Pc4). The use of NIR light allows for better tissue penetration, while the use of nanoparticles permits high local concentrations. The particles were characterized and tested for toxicity and stability as well as for their potential use as a contrast agent and NIR photosensitizer for photodynamic therapy in cardiovascular disease. We focused on the distribution of the nanoparticles in RAW264.7 macrophage cells and atherosclerotic mice. The nanoparticles had an average size of 120 nm according to dynamic light scattering, good loading capacity for zinc phthalocyanine, and satisfying stability in 50% (v/v) fetal bovine serum for 8 hours and in an aqueous environment at 4°C for 4–6 weeks. Under light irradiation we found a high production of singlet oxygen and the products showed no dark toxicity in vitro with macrophages (the target cells in vulnerable plaques), but at a low g/mL nanoparticle concentration killed efficiently the macrophages upon LED illumination. Injection of the contrast agent in atherosclerotic mice led to a visible fluorescence signal of zinc phthalocyanine in the atherosclerotic plaque at 30 minutes and in the lungs with a fast clearance of the nanoparticles. Zinc phthalocyanine loaded human serum albumin nanoparticles present an interesting candidate for the visualization and potentially photodynamic treatment of macrophages in atherosclerotic plaques.

Evaluation of photodynamic therapy in pericoronitis: Protocol of randomized, controlled, double-blind study

INTRODUCTION

Pericoronitis is a common disease in the eruption phase of third molars, sometimes debilitating, with an impact on the quality of life. The most indicated treatment in the initial phase is the irrigation for cleanliness of the region. In order to reduce the chances of systemic dissemination of the infection and antibiotics use, it is mandatory to test effective treatments in the initial phase of pericoronitis avoiding the evolution of the infectious disease. Photodynamic therapy (PDT) is an interesting alternative because it is an effective antimicrobial treatment that is easy to perform and does not select bacterial resistance. The methylene blue (MB) used in PDT has been studied in an oral formulation, which optimizes the formation of monomers increasing its antimicrobial action.

OBJECTIVE

The aim of this study is to evaluate the effectiveness of PDT with MB in an astringent vehicle in pericoronitis on the initial phase in healthy patients through microbiological, clinical, and immune response. The impact of pericoronitis on oral health-related quality of life (OHRQoL) of these patients will also be evaluated.

METHOD

In this randomized, controlled, double-blind clinical bioequivalence protocol, 64 healthy patients with pericoronitis will be evaluated. Patients will be randomized into the positive control group (G1) (n = 32): irrigation with sterile saline and PDT (conventional MB at 0.005% concentration and irradiation with low intensity laser λ = 660 nm, 9J per point and radiant exposure of 318 J/cm), and the experimental group (G2) (n = 32): treatment identical to G1, however, MB will be delivered in a new formulation for oral use. Microbiological analysis will be performed by RT-PCR for the bacterium Tannerella forsythia. Gingival crevicular fluid and saliva will be collected to evaluate cytokines by Luminex assay (Luminex Corporation, Austin, TX). The pain (visual analogue scale), swelling and buccal opening (digital caliper), and OHRQoL will also be evaluated through the OHIP-14 questionnaire. The variables will be evaluated in T1 (baseline), T2 (immediately after PDT), and T3 (4th day after PDT). Registration: clinicaltrials.gov NCT03576105. Registered in July 2018.

The use of antimicrobial photodynamic therapy in oral injuries of a pediatric patient with myelodysplastic syndrome: case report

AIM

To report a case of a pediatric patient carrier of myelodysplastic syndrome (MDS) with severe oral infectious disease, in which antimicrobial photodynamic therapy (aPDT) was used as a therapeutic choice to support systemic treatment.

METHODS AND RESULTS

This case report refers to a 1-year-old male patient with MDS and hospitalized for investigation and treatment of complications at a Pediatric Oncology and Hematology Center in Recife/PE, Brazil. The intraoral examination revealed a violaceous lesion surrounding the lower incisor teeth, which progressed with alteration of color to milky yellowish white, compromising the entire lower gingival border, leading to tooth mobility and consequent loss of teeth 71 and 81. The patient was treated under systemic antimicrobial therapy and aPDT was also performed, using a photosensitizing agent (methylene blue, 0.01%) and a low-intensity laser in the visible red spectrum. Oral clinical improvement was observed, but the patient died after 45 days of hospitalization in the Pediatric ICU due to other systemic complications.

CONCLUSION

MDS may present limiting oral repercussions interfering in patients' quality of life. The aPDT is presented as an adjuvant therapeutic modality in oral infections with satisfactory results.

An experimental study for rapid detection and quantification of endodontic microbiota following photo-activated disinfection via new multiplex real-time PCR assay

BACKGROUND

The infected root canal system harbors one of the highest accumulations of polymicrobial infections. Since the eradication of endopathogenic microbiota is a major goal in endodontic infection therapy, photo-activated disinfection (PAD) can be used as an alternative therapeutic method in endodontic treatment. Compared to cultivation-based approaches, molecular techniques are more reliable for identifying microbial agents associated with endodontic infections. The purpose of this study was to evaluate the ability of designed multiplex real-time PCR protocol for the rapid detection and quantification of six common microorganisms involved in endodontic infection before and after the PAD.

MATERIALS AND METHODS

Samples were taken from the root canals of 50 patients with primary and secondary/persistent endodontic infections using sterile paper points. PAD with toluidine blue O (TBO) plus diode laser was performed on root canals. Resampling was then performed, and the samples were transferred to transport medium. Then, six target microorganisms were detected using multiplex real-time PCR before and after the PAD.

RESULTS

Veillonella parvula was found using multiplex real-time PCR to have the highest frequency among samples collected before the PAD (29.4%), followed by Porphyromonas gingivalis (23.1%), Aggregatibacter actinomycetemcomitans (13.6%), Actinomyces naeslundii (13.0%), Enterococcus faecalis (11.5%), and Lactobacillus rhamnosus (9.4%). After TBO-mediated PAD, P. gingivalis strains, the most resistance microorganisms, were recovered in 41.7% of the samples using molecular approach (P > 0.05).

CONCLUSION

As the results shown, multiplex real-time PCR as an accurate detection approach with high-throughput and TBO-mediated PAD as an efficient antimicrobial strategy due to the significant reduction of the endopathogenic count can be used for detection and treatment of microbiota involved in infected root canals, respectively.