ISSN:
1432-0991
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract The photodynamic effects of deuteroporphyrin (DP), hematoporphyrin derivative (HPD), hematoporphyrin (HP), or protoporphyrin (PP) on a variety of anaerobic microorganisms were examined in this study. The majority of the species, among the 350 strains tested, were inhibited by concentrations of ≤2.5 μg/ml of light-activated DP. Species found to be resistant to this treatment includedBilophila wadsworthia, Fusobacterium mortiferum, Fusobacterium varium, andBacteroides gracilis. These species were inhibited by concentrations of 〉60 μg/ml of DP. The porphyrin-producing species,Porphyromonas andPrevotella spp, were all inhibited by ≤2.5 μg/ml DP and light. Comparing the photodynamic activity of the porphyrins used onPorphyromonas strains resulted in the following pattern: DP〉HPD〉HP〉PP.Porphyromonas spp., Gram-positive cocci, and many Gram-positive rods (excluding clostridia) were inactivated by hemin (a metal-containing porphyrin) at 10–20 μg/ml. Hemin inhibitory action was not affected by light. Binding and insertion of DP into bacteria (both inactivated and non-inactivated strains by DP and light) were monitored by the characteristic fluorescence band of bound DP at 622 nm.Porphyromonas spp. bound DP tightly, whereas only low binding was seen withB. wadsworthia and other DP-resistant species. High binding of DP toB. wadsworthia can be achieved by pretreatment of the bacteria with imipenem or cefoxitin, β-lactam agents known to interfere with the integrity of the cell wall. If cell wall integrity is disturbed (e.g., by these agents), inactivation ofB. wadsworthia by DP can occur.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01570752
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