Abstract

THE EFFECT OF LOW POWER LASER AND A PHOTOSENSITIZER ON SUSCEPTIBILITY OF Pseudomonas aeruginosa TO ANTIMICROBIAL AGENTS

*Mohemid M Al-Jebouri and Balsam Y Al-Shakarchy

ABSTRACT

P.aeruginosa is a major opportunistic pathogen and one of the most frequent hospital – acquired pathogens. The organism only infrequently infects human, but it can cause disease, particularly in the hospital environment, where it is associated with pneumonia, wound infections, urinary tract disease, cystic fibrosis, diabetes, and neutropenia all predispose to infection with P.aeruginosa. Due to its notorious elevated intrinsic resistance to antimicrobial agents and its ability to attach to and to form biofilms on medical devices, this microorganism is difficult to eradicate in the hospital environment. The present study is an attempt to assess the effect of low- power diode Laser on susceptibility of this pathogen to seleted antimicrobial agents. Samples were taken from hospitalized patients at Tikrit Teaching Hospital in Tikrit city. Surgical wound swabs were taken on third post – operative day. Surgical and burn wounds were sampled using sterile cotton applicators moistened with 2 ml of a nutrient broth (oxoid). Each sample was subcultured on Pseudomonas selective agar (oxiod) containing cetrimide which used as a selective media for Pseudomonas aeruginosa and inocubated at 37 ˚C for 24 hours. The purified colonies were further identified using the conventional methods. Antimicrobials sensitivity testing was done after exposure of pathogens to low power laser and its combinations with photosensitizer, providon-iodine. It was found that povidone –iodine were good photosensitizer at concentration 256 μg/ml with different exposure times to sensitive P.aeruginosa for killing by low-power diode laser light and there were synergistic effect between laser light and the photosensitizers. The effect of low-power diode laser light with or without photochemical agents ( povidone-iodine ) on susceptibility to antibiotics ,Minimal Inhibitory Concentrations (MICs) of disinfectants for isolates and non-, firstly-, secondly- disinfectants exposed of Pseudomonas aeruginosa were studied. From this study, it was concluded, that P.aeruginosa could be killed by low-power diode laser in combination with photochemical agents which considered the most effective and most suitable than other agents.

Keywords: Pseudomonas aeruginosa, laser, providon-iodine, antimicrobials, resistance.