Antimicrobial Photodynamic Inactivation: An Alternative for Group B <i>Streptococcus</i> Vaginal Colonization in a Murine Experimental Model

• Main Authors: Michał K. Pierański (Author), Jan G. Kosiński (Author), Klaudia Szymczak (Author), Piotr Sadowski (Author), Mariusz Grinholc (Author)
• Format: Book
• Published: MDPI AG, 2023-04-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.3390/antiox12040847; 2076-3921
• Keywords: <i>Streptococcus agalactiae</i>; biofilm; murine model; photoinactivation; rose bengal; vaginal microbiome; Therapeutics. Pharmacology; RM1-950
• Source: Antioxidants, Vol 12, Iss 4, p 847 (2023)

Background: <i>Streptococcus agalactiae</i>, referred to as Group B <i>Streptococcus</i> (GBS), is a prominent bacterium causing life-threatening neonatal infections. Although antibiotics are efficient against GBS, growing antibiotic resistance forces the search for alternative treatments and/or prevention approaches. Antimicrobial photodynamic inactivation (aPDI) appears to be a potent alternative non-antibiotic strategy against GBS. Methods: The effect of rose bengal aPDI on various GBS serotypes, <i>Lactobacillus</i> species, human eukaryotic cell lines and microbial vaginal flora composition was evaluated. Results: RB-mediated aPDI was evidenced to exert high bactericidal efficacy towards <i>S. agalactiae</i> in vitro (>4 log₁₀ units of viability reduction for planktonic and >2 log₁₀ units for multispecies biofilm culture) and in vivo (ca. 2 log₁₀ units of viability reduction in mice vaginal GBS colonization model) in microbiological and metagenomic analyses. At the same time, RB-mediated aPDI was evidenced to be not mutagenic and safe for human vaginal cells, as well as capable of maintaining the balance and viability of vaginal microbial flora. Conclusions: aPDI can efficiently kill GBS and serve as an alternative approach against GBS vaginal colonization and/or infections.