IADR Abstract Archives
Antibacterial Photodynamic Therapy in Amazonian Intensive Care Unit Inpatients
Objectives: Photodynamic Therapy (PDT) combines a particular type of light with a photosensitizing chemical agent to generate a high level of reactive oxygen species (ROS) leading to reduced colonies of microorganisms such as bacteria and yeasts. This pilot study aimed to evaluate the contamination of the oral cavity and the antimicrobial effect of PDT on oral microorganisms of inpatients in an Amazonian intensive care unit (ICU).
Methods: Ten patients were randomly selected and accepted participating in the study by signing a consent form. PDT was applied for 1.5 minutes in a single session on the retromolar space 48 hours after the patient’s admission to the ICU. Methylene blue (photosensitizer) and red laser (660nm, 90J/cm2) (source of light) were used for the phototherapy. In order to evaluate microorganisms’ colonies, three salivary samples were collected: on admission, after 48 hours of hospitalization before the PDT session, after PDT. Samples were seeded in blood agar culture media and incubated at 37°C for 24 hours for counting the colony-forming units (CFU). Gram’s method classified bacteria species into Gram-positive and Gram-negative groups. Catalase, coagulase, and Dnase tests then identified Gram-positive cocci. Gram-negative bacilli were identified using the biochemical test series. This protocol was approved by the Research Ethics Board of the Federal University of Amapá (#2.349.36) and was registered on the Brazilian Registry of Clinical Trials (#6VZH6P).
Results: The CFU counting increased by 40% on average after 48 hours of ICU hospitalization. Gram-positive cocci, followed by Gram-negative bacilli and Gram-negative cocci were the most prevalent bacteria colonies. After the PDT session, the CFU counting reduced by 76.8%.
Conclusions: Inpatients of this Amazonian ICU had increased bacteria counting after two days of hospitalization. PDT is a promising therapy to reduce oral bacteria in ICU patients and is viable to be tested in a large clinical trial.
Methods: Ten patients were randomly selected and accepted participating in the study by signing a consent form. PDT was applied for 1.5 minutes in a single session on the retromolar space 48 hours after the patient’s admission to the ICU. Methylene blue (photosensitizer) and red laser (660nm, 90J/cm2) (source of light) were used for the phototherapy. In order to evaluate microorganisms’ colonies, three salivary samples were collected: on admission, after 48 hours of hospitalization before the PDT session, after PDT. Samples were seeded in blood agar culture media and incubated at 37°C for 24 hours for counting the colony-forming units (CFU). Gram’s method classified bacteria species into Gram-positive and Gram-negative groups. Catalase, coagulase, and Dnase tests then identified Gram-positive cocci. Gram-negative bacilli were identified using the biochemical test series. This protocol was approved by the Research Ethics Board of the Federal University of Amapá (#2.349.36) and was registered on the Brazilian Registry of Clinical Trials (#6VZH6P).
Results: The CFU counting increased by 40% on average after 48 hours of ICU hospitalization. Gram-positive cocci, followed by Gram-negative bacilli and Gram-negative cocci were the most prevalent bacteria colonies. After the PDT session, the CFU counting reduced by 76.8%.
Conclusions: Inpatients of this Amazonian ICU had increased bacteria counting after two days of hospitalization. PDT is a promising therapy to reduce oral bacteria in ICU patients and is viable to be tested in a large clinical trial.
