Biochemical and chemical analyses of black-pigmented Gram-negative anaerobes

Shah, Haroun N.

doi:10.1016/0928-8244(93)90074-e

Cited by 9 publications

(8 citation statements)

References 24 publications

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“…Previously, P. asaccharof)rtjca cellular fatty acids have been examined by gas liquid chromatography (GLC) of their meth!-l carboxylic esters (Shah and Gharbia 1993). The major fatty acid present in whole cell lipid extracts has been found to be tso-Clso, 13-methj I tetradecanoic acid, which agrees Hith the finding of the most intense lower mass peak having m/z 241.…”

Section: Discussionsupporting

confidence: 63%

“…The association of this species with disease has prompted chemotaxonomic studies which have included analysis both of cellular fatty acid profiles and classes of lipids present (Shah and Gharbia 1993). It is now possible to determine distribution of individual molecular species of phospholipids (PL) rapidly using fast atom bombardment mass spectrometry (FAB-MS) (Drucker 1994).…”

Section: Introductionmentioning

confidence: 99%

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Phospholipid molecular species distribution of Porphyromonas asaccharolytica ATCC 25260T: effects of temperature, culture age and pH

Tavana

Drucker

Boote

1998

Journal of Applied Microbiology

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Section: Discussionsupporting

confidence: 63%

Section: Introductionmentioning

confidence: 99%

Phospholipid molecular species distribution of Porphyromonas asaccharolytica ATCC 25260T: effects of temperature, culture age and pH

Tavana

Drucker

Boote

1998

Journal of Applied Microbiology

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“…The phenomenon has been noted in a group of anaerobic species that are mainly oral pathogens and were previously known as black-pigmented Bacteroides species but have now been reclassified as Porphyromonas and Prevotella species (17). These bacteria depend largely on external heme (either hemoglobin or hemopexin) to satisfy their demand for iron (20) and to a greater or lesser extent accumulate a black pigment intracellularly that consists of an iron-containing heme aggregate (e.g., hematin) together with various amounts of iron-free PPIX (28,29). If they accumulate PPIX they will be photosensitive (13), however, if they mainly have hematin they will not be photo- showed that these species were more sensitive when grown on media containing hemin as an iron source compared to hemoglobin (14).…”

Section: Discussionmentioning

confidence: 99%

Helicobacter pylori Accumulates Photoactive Porphyrins and Is Killed by Visible Light

Hamblin

Viveiros

Yang

et al. 2005

Antimicrob Agents Chemother

207

161

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Helicobacter pylori colonizes the mucus layer of the human stomach and duodenum, causes chronic gastritis, gastric ulcer, and is a risk factor for gastric adenocarcinoma. There is a 20% failure rate in antibiotic therapy, which is increasingly due to antibiotic resistance and necessitates the search for alternative antimicrobial methods. We have discovered that H. pylori when cultured in liquid medium, accumulates significant quantities of coproporphyrin and protoporphyrin IX, both in the cells and secreted into the medium. These photoactive porphyrins lead to cell death (up to 5 logs) by photodynamic action upon illumination with low doses of visible light, with blue/violet light being most efficient. The degree of killing increases with the age of the culture and is greater than that found with Propionibacterium acnes (another bacterium known to be photosensitive due to porphyrin accumulation). Both virulent and drug-resistant strains are killed. The data suggest that phototherapy might be used to treat H. pylori infection in the human stomach.Helicobacter pylori is a gram-negative microaerophilic bacterium which selectively colonizes the mucus layer of the human stomach and duodenum (7). As more than 50% of the world population is infected and in some countries infection rates approach 90%, H. pylori can be termed the world's commonest infectious agent (19). H. pylori infection has been shown to be strongly associated with the presence of inflammation and chronic gastritis, and once acquired, H. pylori persists, usually for life, unless eradicated by antimicrobial therapy (15). It is now known that H. pylori is a major cause of peptic ulcer disease, and in 1994, the International Agency for Cancer Research declared that H. pylori was a carcinogen of humans and was implicated in the development of gastric cancer (11).The most common antibacterial treatment regimens include bismuth, metronidazole, tetracycline, and a proton pump inhibitor, or clarithromycin in combination with a proton pump inhibitor and amoxicillin (10). Combinations such as the above lead to eradication rates of about 80% but at the expense of side effects and possible poor patient compliance. Increasing development of antibiotic resistance among H. pylori isolates and the existence of nonresponsive patients suggest that alternative strategies for H. pylori eradication be sought (22).Photodynamic therapy uses the combination of nontoxic dyes (frequently porphyrins or their derivatives) and harmless visible light to produce cytotoxicity via generation of reactive oxygen species (25). Photodynamic therapy has been clinically approved for various malignant, premalignant, and ophthalmologic conditions (6). It has long been known that many microorganisms including gram-negative and gram-positive bacteria, mycoplasma, fungi, and viruses can be killed by photodynamic therapy, and recently photodynamic therapy has been investigated as a treatment for infectious disease (12). The grampositive bacterium that causes acne, Propionibacterium acnes, is kil...

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“…These species depend largely on external heme as an iron source for their growth (20) and accumulate a cell surface black pigment that mainly consists of -oxobisheme of iron protoporphyrin IX (PpIX) in P. gingivalis (25) and monomeric iron PpIX (hematin) in P. intermedia and P. nigrescens (26). Although iron PpIX is the predominant pigment in black-pigmented bacteria (BPB), these species also accumulate various amounts of iron-free PpIX (23,24), which is photosensitive (18). The UV-visible absorption spectrum of porphyrins exhibits an intense peak at around 405 nm, followed by several weaker peaks at 505, 540, 575, and 630 nm (27).…”

mentioning

confidence: 99%

Phototargeting Oral Black-Pigmented Bacteria

Soukos¹,

Som²,

Abernethy³

et al. 2005

Antimicrob Agents Chemother

182

165

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We have found that broadband light (380 to 520 nm) rapidly and selectively kills oral black-pigmented bacteria (BPB) in pure cultures and in dental plaque samples obtained from human subjects with chronic periodontitis. We hypothesize that this killing effect is a result of light excitation of their endogenous porphyrins. Cultures of Prevotella intermedia and P. nigrescens were killed by 4.2 J/cm2, whereas P. melaninogenica required 21 J/cm2. Exposure to light with a fluence of 42 J/cm2 produced 99% killing of P. gingivalis. High-performance liquid chromatography demonstrated the presence of various amounts of different porphyrin molecules in BPB. The amounts of endogenous porphyrin in BPB were 267 (P. intermedia), 47 (P. nigrescens), 41 (P. melaninogenica), and 2.2 (P. gingivalis) ng/mg. Analysis of bacteria in dental plaque samples by DNA-DNA hybridization for 40 taxa before and after phototherapy showed that the growth of the four BPB was decreased by 2 and 3 times after irradiation at energy fluences of 4.2 and 21 J/cm2, respectively, whereas the growth of the remaining 36 microorganisms was decreased by 1.5 times at both energy fluences. The present study suggests that intraoral light exposure may be used to control BPB growth and possibly benefit patients with periodontal disease.

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Biochemical and chemical analyses of black-pigmented Gram-negative anaerobes

Cited by 9 publications

References 24 publications

Phospholipid molecular species distribution of Porphyromonas asaccharolytica ATCC 25260T: effects of temperature, culture age and pH

Phospholipid molecular species distribution of Porphyromonas asaccharolytica ATCC 25260T: effects of temperature, culture age and pH

Helicobacter pylori Accumulates Photoactive Porphyrins and Is Killed by Visible Light

Phototargeting Oral Black-Pigmented Bacteria

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