Antimicrobial photodynamic therapy on Staphylococcus aureus and Escherichia coli using malachite green encapsulated mesoporous silica nanoparticles: an in vitro study

Parasuraman Paramanantham; Busi Siddhardha; Sruthil Lal Sb; Alok Sharan; Abdullah A Alyousef; Mohammed Saeed Al Dosary; Mohammed Arshad; Asad Syed

doi:10.7717/peerj.7454

Antimicrobial photodynamic therapy on Staphylococcus aureus and Escherichia coli using malachite green encapsulated mesoporous silica nanoparticles: an in vitro study

PeerJ. 2019 Sep 12:7:e7454. doi: 10.7717/peerj.7454. eCollection 2019.

Authors

Parasuraman Paramanantham¹, Busi Siddhardha¹, Sruthil Lal Sb², Alok Sharan², Abdullah A Alyousef³, Mohammed Saeed Al Dosary³, Mohammed Arshad³, Asad Syed⁴

Affiliations

¹ Department of Microbiology, School of Life Sciences, Pondicherry University, Pondicherry, India.
² Department of Physics, School of Physical, Chemical and Applied Sciences, Pondicherry University, Pondicherry, India.
³ Microbiology Research Group, Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
⁴ Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, Saudi Arabia.

Abstract

Background: Rise in the number of healthcare associated or hospital acquired infections is a major problem affecting the global healthcare sector. We evaluated superior antibacterial and antibiofilm photodynamic therapy (aPDT) using malachite green encapsulated mesoporous silica nanoparticles (MG-MSN) against Staphylococcus aureus and Escherichia coli, which are known to be major causative agents of nosocomial infections.

Methods: Malachite green (MG) was encapsulated on mesoporous silica nanoparticles (MSN). Fourier-transform infrared spectroscopy, Transmission electron microscopy, and spectroscopic analysis were performed to characterize the MG-MSN. The antimicrobial efficacies of MSN, MG, and MG-MSN were investigated and the results were recorded.

Results: MG-MSN was effective against both the tested bacteria. S. aureus was more phototoxic to MG-MSN compared to E. coli. The antibiofilm efficacy of MG-MSN on E. coli and S. aureus was also studied. Biofilm inhibition was 65.68 ± 2.62% in E. coli and 79.66 ± 3.82% in S. aureus. Cell viability assay, exopolysaccharides quantification, and confocal laser scanning microscopy studies also revealed the enhanced antibiofilm activity of MG-MSN when used as a potential photosensitizer for aPDT. This study can be extended to eradicate these strains from localized superficial infections and medical appliances, preventing nosocomial infections.

Keywords: Biofilms; CLSM; MG-MSN; Mesoporous silica nanoparticle; aPDT.

Grants and funding

Central Instrumentation Facility (CIF) of Pondicherry University, Department of Physics (Pondicherry University) and iThemba LABS-National Research Foundation (NRF), Somerset West, Western Cape Province, South Africa provided instrumentation facilities. The Deanship of Scientific Research at King Saud University funded this work through research group No (RG-1440-053). Bharathidasan University, Tiruchirappalli provided the Confocal Laser Scanning Microscopy facility. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.