Indexed on: 30 Mar '99Published on: 30 Mar '99Published in: Pharmacological Research
The antibacterial photodynamic effect of arginine haematoporphyrin derivative (HpD-Arg2) was investigated using two methods. The effect proved to be highly antibacterial when it was employed against P. aeruginosa and S. aureus cells floating in the nutrient broth. The reduction of approximately four logarithms of CFU ml-1 after light exposition, as compared to a dark control, was observed. In the second step of the study the photodynamic effect was employed against the same strains of bacteria after their colonization on isolated mouse muscles. In this case the antibacterial effect was observed as well. However, the reduction of CFU ml-1 achieved was much lower and reached one logarithm only. The optimal concentration of photoactivated HpD-Arg2 for S. aureus and P. aeruginosa was 25 microg ml-1 and 800 microg ml-1 for the floating bacteria, and 200 microg ml-1 and 1000 microg ml-1 for sessile bacteria, respectively. We have concluded from our study that the antibacterial effect investigated may offer, in the future, an alternative method for treatment of the tissues superficially infected with pathogens resistant to antibiotics. However, further studies in this field are necessary.