Influence of Helium-Neon Laser on Some Virulence Factors of Staphylococcus Aureus and Escherichia Coli

Abstract

This work aims to investigate the effect of Helium-Neon laser on locally isolated Staphylococcus aureus and Escherichia coli bacteria; their resistance pattern, virulence factors, and their plasmid content. Bacteria were collected from patient suffering from urinary tract infections, septicemia, wound, and burn infections, then isolates were identified according to their characteristics, features; morphological, biochemical tests, and API systems. Out of Eighty-seven samples, twenty-seven isolates of S. aureus and thirteen isolates of E. coli were isolated. The results showed that after laser treatment, the diameter of inhibition zone increased for almost of the used antibiotics beside some isolates became sensitive especially after 2 min of laser exposure time. The hemolysin production was disappeared in (%40) of E. coli and (%20) of S. aureus after ten min of irradiation, while it decreased to half in another S. aureus isolate. All S. aureus and E. coli isolates loosed their ability to produce β-lactamase enzymes; some of these isolates loosed it after 5 minutes and the others after 10 minutes of irradiation. The results showed that laser irradiation hasn't any effect at any exposure time on adhesion factors of both S. aureus and E. coli isolates. Plasmid profile of Irradiated E. coli illustrated disappearing of DNA plasmid bands as well as RNA after ten min of irradiation.