Antibacterial activity of Staphylococcus aureus biofilm under combined exposure of glutaraldehyde, near-infrared light, and 405-nm laser

• Published in: PloS one Vol. 13; no. 8; p. e0202821
• Main Authors: Tran, Van Nam, Dasagrandhi, Chakradhar, Truong, Van Gia, Kim, Young-Mog, Kang, Hyun Wook
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 27.08.2018; Public Library of Science (PLoS)
• Subjects: Anti-Bacterial Agents - pharmacology; Antibacterial activity; Antibiotics; Antimicrobial agents; Bacteremia; Bacteria; Bacterial infections; Biofilms; Biofilms - drug effects; Biofilms - radiation effects; Biology and Life Sciences; Biomedical engineering; Crosslinking; Cytotoxicity; Deformation; Deoxyribonucleic acid; DNA; DNA biosynthesis; E coli; Endoscopes; Engineering and Technology; Enzymes; Exposure; Fluorescence; Glutaral - pharmacology; Glutaraldehyde; Growth; Health aspects; Health care; I.R. radiation; Infrared lasers; Infrared radiation; Infrared Rays; Lasers; Light; Medicine and Health Sciences; Microbial mats; Microorganisms; Microscopy, Electron, Scanning; Oxygen; Pathogens; Physical Sciences; Protein biosynthesis; Protein synthesis; Proteins; Reactive oxygen species; Reactive Oxygen Species - metabolism; Research and Analysis Methods; Salmonella; Scanning electron microscopy; Secondary infection; Staphylococcus aureus; Staphylococcus aureus - physiology; Staphylococcus infections
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0202821

Healthcare-associated infections have increasingly become problematic in the endoscopic procedures resulting in several severe diseases such as carbapenem-resistant Enterobacteriaceae (CRE)-related infections, pneumonia, and bacteremia. Especially, some bacterial strains are resistant to traditional antimicrobials. Therefore, the necessity of developing new antibiotics or management to deal with bacterial infections has been increasing. The current study combined a low concentration of glutaraldehyde (GTA) with near-infrared (NIR) light and 405-nm laser to entail antibacterial activity on Staphylococcus aureus biofilm. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and colony forming unit (CFU) counting were used to quantify the viable cells while fluorescent and scanning electron microscopic images were used to qualitatively evaluate the cell membrane integrity and structural deformation, respectively. Practically, S. aureus biofilm was highly susceptible (7% cell viability and 6.8-log CFU/cm2 bacterial reduction for MTT assay and CFU analysis, respectively) to the combination of GTA (0.1%), NIR light (270 J/cm2), and 405-nm laser (288 J/cm2) exposure. GTA could form either DNA-protein or protein-protein crosslinks to inhibit DNA and protein synthesis. The NIR light induced the thermal damage on protein/enzymes while 405-nm laser could induce reactive oxygen species (ROS) to damage the bacterial membrane. Thus, the proposed technique may be a feasible modality for endoscope cleaning to prevent any secondary infection in the healthcare industry.