On the possibility of photodynamic inactivation of tracheobronchial tree pathogenic microbiota using methylene blue
Irina G Tiganova1, Gennady A Meerovich2, Indira D Zulufova3
1Gamaleya National Research Center of Epidemiology and Microbiology, Moscow, 123098 Russia.
Background:
The treatment of patients after mechanical ventilation of lungs suffering from a multi-species infection of the tracheobronchial tree can be complicated.. The situation is aggravated in patients with post-intubation tracheal stenosis, where infection plays a leading pathogenetic role in damage to the tracheal wall. As a result of such a pathological process, cicatricial stenosis of the trachea of purulent-inflammatory infectious genesis or infected tracheal stenosis (ITS) may occur.
Methods:
In this work, we studied the possibility of photodynamic inactivation of pathogenic microbiota typical for patients with ITS using methylene blue (MB) as a photosensitizer.
Results:
13 clinical isolates of 8 species of bacteria from 9 patients were susceptible to photodynamic inactivation with MB. 30 μM of MB at a light irradiation dose of 25 J/cm2 and incubation with MB for 15 min allows to completely inactivate bacteria found in the tracheobronchial secretions of patients with ITS.
Conclusions:
MB retains its optico-physical properties in the range of 3-30 μM and provides effective inactivation of isolated Gram-positive and Gram-negative bacteria, including multi- and pan-resistant to antibiotics.
Insights
Photodynamic inactivation using methylene blue (MB) effectively eliminates multi-drug resistant bacteria in infected tracheal stenosis patients. This method shows promise for treating complex airway infections post-ventilation.
Area of Science:
- Microbiology
- Photochemistry
- Medical Science
Background:
- Treating multi-species infections in mechanically ventilated patients with tracheobronchial tree involvement is challenging.
- Post-intubation tracheal stenosis is often exacerbated by infection, leading to tracheal wall damage and purulent-inflammatory genesis.
- This pathological process can result in infected tracheal stenosis (ITS), a complex clinical condition.
Purpose of the Study:
- To investigate the efficacy of photodynamic inactivation (PDI) for eliminating pathogenic bacteria commonly found in patients with ITS.
- To evaluate methylene blue (MB) as a photosensitizer for PDI in this context.
Main Methods:
- Studied the photodynamic inactivation of pathogenic microbiota from ITS patients.
- Utilized methylene blue (MB) as the photosensitizer.
- Tested MB concentrations and light irradiation doses on bacterial isolates.
Main Results:
- Photodynamic inactivation with MB demonstrated susceptibility in 13 clinical isolates from 8 bacterial species obtained from 9 ITS patients.
- A concentration of 30 μM MB with 25 J/cm² light irradiation and 15 minutes incubation effectively inactivated bacteria in tracheobronchial secretions.
- MB maintained its optico-physical properties within the 3-30 μM range, ensuring consistent efficacy.
Conclusions:
- Methylene blue-based photodynamic inactivation is effective against Gram-positive and Gram-negative bacteria, including multi- and pan-resistant strains.
- This approach offers a viable method for combating infections in patients with infected tracheal stenosis.
- MB-PDI presents a promising therapeutic strategy for complex airway infections, particularly in the context of post-intubation complications.
