Photodynamic Antimicrobial Chemotherapy (PACT) in osteomyelitis induced by Staphylococcus aureus: Microbiological and histological study.

Abstract

Osteomyelitis is an inflammation either of medullar spaces or of the surface of cortical bones, which represents a bacterial infection. Photodynamic Antimicrobial Chemotherapy (PACT) is a treatment based on a cytotoxic photochemical reaction that induces a series of metabolic reactions and culminates in bacterial suppression. Such effect led to the idea that it could be used as a treatment of osteomyelitis. Following approval by the Animal Experimentation Committee of the School of Dentistry of the Federal University of Bahia, the present randomized study used eighty Wistar rats with the aim to evaluate, by microbiological and histological analysis, the effects of Photodynamic Antimicrobial Chemotherapy - PACT on tibial surgical bone defects in rats infected by Staphylococcus aureus. The animals were divided in groups: Control (non-infected); Control Osteomyelitis Induction; Saline solution; Photosensitizer; Red Laser and PACT - on this group, a diode laser (40mW; λ660nm ∅=0.04cm(2), CW, 10J/cm(2)) was used in combination with 5μg/ml of toluidine blue as the photosensitizer. On the microbiological study, immediately after treatment, the PACT group presented a bacterial reduction of 97.4% (p<0.001). Thirty days after treatment, there was a bacterial reduction of more than 99.9% (p<0.001). In the histological study, it was observed that the PACT group demonstrated an intense presence of osteocytes and absence of bone sequestration and micro-abscesses. The PACT using toluidine blue was effective in reducing the number of S. aureus enabling a better quality bone repair.

• Authors: João Alves Dos Reis Jr, Jean Nunes Dos Santos, Brunna Santos Barreto, Patrícia Nascimento de Assis, Paulo Fernando Almeida, Antônio Luiz Barbosa Pinheiro
• Journal: Journal of photochemistry and photobiology. B, Biology (J Photochem Photobiol B) Vol. 149 Pg. 235-42 (Aug 2015) ISSN: 1873-2682 [Electronic] Switzerland
• PMID: 26111990 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015 Elsevier B.V. All rights reserved.

Chemical References

• Anti-Bacterial Agents
• Photosensitizing Agents

Topics

• Animals
• Anti-Bacterial Agents (pharmacology, therapeutic use)
• Laser Therapy
• Male
• Osteomyelitis (drug therapy, microbiology, pathology)
• Photochemotherapy (methods)
• Photosensitizing Agents (pharmacology)
• Rats
• Rats, Wistar
• Staphylococcal Infections (drug therapy, microbiology, pathology)
• Staphylococcus aureus (drug effects, physiology, radiation effects)
• Tibia (drug effects, microbiology, radiation effects)