Hypervirulent and hypermucoviscous strains of Klebsiella pneumoniae challenged by antimicrobial strategies using visible light

Author(s)

dos Anjos, Carolina ^[1] ; Sabino, Caetano P. ^{[2, 3]} ; Sellera, Fabio P. ^[1] ; Esposito, Fernanda ^[2] ; Pogliani, Fabio C. ^[1] ; Lincopan, Nilton ^{[4, 2]}

Affiliation

^[1] Univ Sao Paulo, Sch Vet Med & Anim Sci, Dept Internal Med, Sao Paulo - Brazil

^[2] Univ Sao Paulo, Fac Pharmaceut Sci, Dept Clin Anal, Sao Paulo - Brazil

^[3] BioLambda Sci & Commercial LTD, Sao Paulo - Brazil

^[4] Univ Sao Paulo, Inst Ciencias Biomed, Dept Microbiol, Sao Paulo - Brazil

• Document type: Journal article
• Source: INTERNATIONAL JOURNAL OF ANTIMICROBIAL AGENTS; v. 56, n. 1 JUL 2020.
• Web of Science Citations: 0

Abstract

Introduction: Infections caused by hypervirulent and/or hypermucoviscous Klebsiella pneumoniae (K. pneumoniae) strains are frequently reported worldwide. Since convergence of hypervirulence and drugresistance emerged as a serious clinical problem, novel therapeutic strategies are worthy of investigation. In this regard, antimicrobial photodynamic therapy and blue light have proven to be effective against a broad-spectrum of clinically relevant pathogens but have never been tested for hypervirulent/hypermucoviscous strains. Thus, this study investigated the influence of hypermucoviscosity and hypervirulence over the photoinactivation efficacy of blue light alone or antimicrobial photodynamic therapy mediated by methylene blue and red light. Methods: Five clinical isolates of K. pneumoniae were screened for hypermucoviscosity by string test and for hypervirulence by a Galleria mellonella model of systemic infection. Strains were then challenged by both photoinactivation methods performed in vitro. All tests also included a nonhypervirulent/hypermucoviscous control strain for comparison. Results: All K. pneumoniae strains were effectively inactivated by both light-based antimicrobial strategies. Hypervirulent/hypermucoviscous strains exposed to photodynamic therapy presented rapid and consistent inactivation kinetics, while blue light led to slower and more variable inactivation kinetics. Conclusion: Hypermucoviscosity and hypervirulence does not confer tolerance in K. pneumoniae against photoinactivation. Antimicrobial photodynamic therapy represents an interesting alternative to treat localised infections because it is a fast procedure with high effectiveness. On the other hand, antimicrobial blue light could be used to decontaminate hospital environments since no photosensitiser administration is required and harmful effects of ultraviolet light are avoided. Therefore, visible light-based strategies present great potential for the development of safe and effective antimicrobial technologies against such aggressive pathogens. (c) 2020 Elsevier B.V. and International Society of Chemotherapy. All rights reserved. (AU)

• FAPESP's process: 19/10851-4 - SYNERGISTIC ACTIVITY OF BLUE LIGHT IN COMBINATION WITH CHEMOTHERAPEUTIC ANTIMICROBIAL AGAINST DRUG-RESISTANT PATHOGENS
• Grantee: Carolina dos Anjos
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 16/25095-2 - BACTERIAL PHOTOINACTIVATION OF MASTITIS PATHOGENS BY BLUE LIGHT: MECHANISMS OF ACTION AND CELL SECURITY - PRE-CLINICAL STUDY
• Grantee: Carolina dos Anjos
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 19/15578-4 - Virulome and pathogenicity of carbapenem- and polymyxin-resistant priority pathogens
• Grantee: Fernanda Ribeiro dos Santos Esposito
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 17/22406-0 - Development of a smart clinical equipment for phototherapies with automatic dosimetry calibration and on demand payment
• Grantee: Caetano Padial Sabino
• Support Opportunities: Research Grants - Innovative Research in Small Business - PIPE