Introduction: The purpose of this review was to evaluate the available literature for in vitro and in vivo effectiveness of antimicrobial Photodynamic therapy (aPDT) in the field of bacteriology. Methods: A review of the relevant articles carried out in PubMed and Scopus to determine the efficiency of aPDT used in the reduction of microbial infection. Thirty-one relevant documents retrieved from PubMed, Scopus by inserting "antimicrobial photodynamic therapy" and "bacterial infection" and "photodynamic therapy" keywords. Results: According to different results, aPDT can be used as an adjuvant for the treatment of infectious diseases. The use of photosensitizer methylene blue, toluidine blue O (TBO), indocyanine green with light diode laser centered at (630±10 nm) and (650±10 nm) wavelengths have been shown to have significant results for the treatment of infectious diseases and bactericidal properties Conclusion: These findings suggest that, aPDT can be an efficient method in the treatment of localized and superficial infections.

Antimicrobial potential of synthesized zinc oxide (ZnO) nanoparticles against four bacteria strains (Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853, as gram negative bacteria, Staphylococcus epidermidis PTCC 1114 and Staphylococcus aureus ATCC 25923 as gram-positive bacteria) in liquid and solid phases was studied in this work. Firstly, nanoparticle ZnO was prepared by the chemical method with an organic chemical inhibitor. The detail characterization of the nanoparticles was carried out using UV–vis spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. From SEM image analysis, the average particle size was found to be 50 nm. Also, the mean surface area was determined as 90 m² g⁻¹ by Brauner–Emmet–Teller (BET) analysis. We studied the antibacterial assay, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and disk diffusion method as per CLSI recommendations and time–kill studies were performed. Disk diffusion studies revealed greater effectiveness for P. aeroginosa. In vitro time–kill studies were performed for one or two times; the MICs and its results showed that the efficiency of particles increases with rising particle dose in suspension and treatment time. From this work, it is possible to suggest that ZnO nanoparticles are excellent antibacterial agents.