Evolution of surviving Streptoccocus pyogenes from pharyngotonsillitis patients submit to multiple cycles of antimicrobial photodynamic therapy

Autor(es)

Soares, Jennifer Machado ^[1] ; Inada, Natalia Mayumi ^[1] ; Bagnato, Vanderlei Salvador ^{[2, 1]} ; Blanco, Kate Cristina ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sao Carlos Inst Phys, Box 369, BR-13566590 Sao Carlos, SP - Brazil

^[2] Texas A&M Univ, College Stn, TX - USA

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY; v. 210, SEP 2020.
• Citações Web of Science: 0

Resumo

It is estimated over 600 million pharyngotonsillitis (PT) cases worldwide per year and 30% of this total are caused by Streptococcus pyogenes with standard antibiotic treatment. Antimicrobial Photodynamic Therapy (aPDT) has been studied for the clinical research in infectious diseases. The study aim was to analyze the evolution of aPDT on inactivation of clinical strains of multiple cycles. S. pyogenes and clinical strains isolated from patients with PT were incubated with curcumin in formulation (2.25 mg/ml) and irradiated at 450 nm in Light fluence rates. A mortality was a measure of the counting colony forming units per milliliter (CFU/ml) surviving. Parameters of bacterial biofilm formation, uptake of photosensitizer (PS) and efficacy of antibiotics on survival of bacteria of each cycle were tested. The bacteria profile remains unchanged between 10 aPDT cycles was observed. The bacterial colony survival presented a reduction in capacity to form biofilm due adhesion of strains and PS uptake rate. The antibiotic remained efficient after aPDT cycles. Our in vitro results suggested a low-level of development of PDT resistance, however a decrease of photosensitizer uptake was observed. Furthermore, there is no cross effect on aPDT cycles and the first application of antibiotics. (AU)

• Processo FAPESP: 19/13569-8 - Estudo dos Mecanismos de Ação em Terapia Fotodinâmica: Do Fotossensibilizador à Aplicação Prática
• Beneficiário: Lucas Danilo Dias
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 13/07276-1 - CEPOF - Centro de Pesquisa em Óptica e Fotônica
• Beneficiário: Vanderlei Salvador Bagnato
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs