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Wang S, McCoy CP, Li P, Li Y, Zhao Y, Andrews GP, Wylie MP, Ge Y. Carbon Dots in Photodynamic/Photothermal Antimicrobial Therapy. NANOMATERIALS (BASEL, SWITZERLAND) 2024; 14:1250. [PMID: 39120355 PMCID: PMC11314369 DOI: 10.3390/nano14151250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2024] [Revised: 07/22/2024] [Accepted: 07/23/2024] [Indexed: 08/10/2024]
Abstract
Antimicrobial resistance (AMR) presents an escalating global challenge as conventional antibiotic treatments become less effective. In response, photodynamic therapy (PDT) and photothermal therapy (PTT) have emerged as promising alternatives. While rooted in ancient practices, these methods have evolved with modern innovations, particularly through the integration of lasers, refining their efficacy. PDT harnesses photosensitizers to generate reactive oxygen species (ROS), which are detrimental to microbial cells, whereas PTT relies on heat to induce cellular damage. The key to their effectiveness lies in the utilization of photosensitizers, especially when integrated into nano- or micron-scale supports, which amplify ROS production and enhance antimicrobial activity. Over the last decade, carbon dots (CDs) have emerged as a highly promising nanomaterial, attracting increasing attention owing to their distinctive properties and versatile applications, including PDT and PTT. They can not only function as photosensitizers, but also synergistically combine with other photosensitizers to enhance overall efficacy. This review explores the recent advancements in CDs, underscoring their significance and potential in reshaping advanced antimicrobial therapeutics.
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Affiliation(s)
| | - Colin P. McCoy
- School of Pharmacy, Queen’s University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK; (S.W.)
| | | | | | | | | | | | - Yi Ge
- School of Pharmacy, Queen’s University Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK; (S.W.)
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Malik Z. Photodynamic inactivation of antibiotic‐resistant Gram‐positive bacteria: Challenges and opportunities. TRANSLATIONAL BIOPHOTONICS 2020. [DOI: 10.1002/tbio.201900030] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Zvi Malik
- Faculty of Life ScienceBar‐Ilan University Ramat‐Gan Israel
- Zefat Academic College Zefat Israel
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Gao Z, Van Nostrand JD, Zhou J, Zhong W, Chen K, Guo J. Anti-listeria Activities of Linalool and Its Mechanism Revealed by Comparative Transcriptome Analysis. Front Microbiol 2019; 10:2947. [PMID: 31921091 PMCID: PMC6938037 DOI: 10.3389/fmicb.2019.02947] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 12/06/2019] [Indexed: 01/17/2023] Open
Abstract
Listeria monocytogenes, which causes serious foodborne infections and public health problems worldwide, is one of the most important foodborne pathogens. Linalool has been identified as an antimicrobial agent against some microorganism, but its mechanism of action is currently unclear. Here, we investigated the efficacy of linalool against L. monocytogenes while planktonic and as a biofilm and explored potential mechanisms of action. Linalool exhibited strong anti-listeria activity in the planktonic stage. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations revealed seven stages were classified of cells at microscopic level. Mesosome-like structures were observed for the first time in L. monocytogenes after linalool treatment. Linalool also showed significant anti-biofilm activity through both dispersal and killing of cells in the biofilm based on confocal scanning laser microscopy (CLSM) and SEM imaging, crystal violet staining, XTT and COMSTAT assays. Moreover, comparative transcriptome analysis demonstrated many potential mechanisms of action for linalool and some important pathways were screened out through the analysis of GO enrichment and KEGG. Our study provides evidence that linalool exhibits a strong antimicrobial activity against both the planktonic and biofilm forms of L. monocytogenes and gives insight into its mechanism of action.
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Affiliation(s)
- Zhipeng Gao
- Hunan Engineering Technology Research Center of Featured Aquatic Resources Utilization, College of Animal Science and Technology, Hunan Agricultural University, Changsha, China
| | - Joy D Van Nostrand
- Institute for Environmental Genomics, University of Oklahoma, Norman, OK, United States
| | - Jizhong Zhou
- Institute for Environmental Genomics, University of Oklahoma, Norman, OK, United States
| | - Weiming Zhong
- Hunan Engineering Technology Research Center of Featured Aquatic Resources Utilization, College of Animal Science and Technology, Hunan Agricultural University, Changsha, China
| | - Kangyong Chen
- Hunan Engineering Technology Research Center of Featured Aquatic Resources Utilization, College of Animal Science and Technology, Hunan Agricultural University, Changsha, China
| | - Jiajing Guo
- International Joint Lab on Fruits and Vegetables Processing, Quality and Safety, Hunan Key Lab of Fruits and Vegetables Storage, Processing, Quality and Safety, Hunan Agriculture Product Processing Institute, Hunan Academy of Agricultural Sciences, Changsha, China
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Iluz N, Maor Y, Keller N, Malik Z. The synergistic effect of PDT and oxacillin on clinical isolates of Staphylococcus aureus. Lasers Surg Med 2018; 50:535-551. [PMID: 29333608 DOI: 10.1002/lsm.22785] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2017] [Indexed: 01/13/2023]
Abstract
BACKGROUND Staphylococcus aureus is a major pathogen in clinical microbiology. It is known to cause infections at various body sites and can be life-threatening. The development of resistance to many well-established antibiotic treatments and the prevalence of methicillin-resistant S. aureus (MRAS) among hospital patients and the general community pose challenges in treating the pathogen. The antimicrobial effect of photodynamic therapy (PDT) has been a subject of study for a long time and can offer new strategies for dealing with resistant strains. OBJECTIVE In our study, we searched for a positive synergistic relationship between PDT and the standard antibiotics used to treat S. aureus and MRSA infections. MATERIALS AND METHODS The phototoxic profile of deuteroporphyrin (DP) in both resistant and susceptible clinical strains of S. aureus was determined by plating of treated and untreated broth cultures. Electron microscopy imaging was done to explore possible sites of damage and free-radical accumulation in the cells during DP-PDT. Minimal inhibitory concentration (MIC) of oxacillin, gentamicin, vancomycin, rifampin, and fusidic acid was determined using the broth dilution method, and the checkerboard method was used to detect and evaluate the synergistic potential of DP-PDT and antibiotic combinations. A synergistic combination was further characterized using broth cultures and plating. RESULTS DP-PDT using a light dose of 15 J/cm2 showed a bactericidal effect even with a small concentration of 17 μM DP. Transmission electron microscopy indicated profound damage in the cell wall and cell membrane, and the appearance of mesosome-like structures. Free radicals tend to localize in the cell membrane and inside the mesosome. No synergistic effect was detected by combining PDT with gentamicin, vancomycin, rifampin, and fusidic acid treatments. A positive synergistic effect was observed only in DP-PDT-oxacillin combined treatment using the checkerboard method. The effect was observed in clinical antibiotic-resistant isolates after DP-PDT using a light dose of 46 J/cm2 and small concentrations of DP. Oxacillin MIC decreased below 2 μg/ml in resistant strains under such conditions. Cultures which did not undergo new cycles of DP-PDT recovered their original oxacillin resistance after a few generations. CONCLUSIONS PDT with porphyrins shows possible new therapeutic options in treating drug-resistant S. aureus at body sites suitable for irradiation. The synergistic effect of DP-PDT with oxacillin on clinical strains illustrates the potential of PDT to augment traditional antibiotic treatment based on cell wall inhibitors. Lasers Surg. Med. 50:535-551, 2018. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Natanel Iluz
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel.,Laboratory of Clinical Microbiology, Sheba Medical Center, Ramat-Gan, Israel
| | - Yasmin Maor
- Infectious Diseases Control Unit, Wolfson Medical Center, Holon, Israel
| | - Natan Keller
- Laboratory of Clinical Microbiology, Sheba Medical Center, Ramat-Gan, Israel.,Health Systems Management, Ariel University, Ariel, Israel
| | - Zvi Malik
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel.,The Zefat Academic College, Zefat, Israel
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Antibacterial effects of the tellurium compound OTD on E. coli isolates. Arch Microbiol 2013; 196:51-61. [PMID: 24322541 DOI: 10.1007/s00203-013-0941-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 10/21/2013] [Accepted: 11/05/2013] [Indexed: 11/27/2022]
Abstract
The antibacterial effects of a new organo-tellurium compound [Octa-O-bis-(R,R)-tartarate ditellurane (OTD)] on Escherichia coli isolates as a model are shown. OTD was found to be a bactericidal drug. It exhibits inhibition zones on a protein-rich agar medium but not in a protein-poor medium unless a thiol is added. When applied at the lag phase, OTD inhibits more efficiently than at the log phase. Thiols enhance the efficiency at the log phase. OTD inhibits biofilm formation of E. coli. X-ray microanalysis demonstrated damage caused to the Na⁺/K⁺ pumps and leakage of potassium and phosphorous. Scanning electron microscopy demonstrated an incomplete surface of the bacterial cell wall with a concavity in the center that looks like a hole. Transmission electron microscopy demonstrated severe damage, such as depletion, perforation, and holes in the inner membrane. These results indicate for the first time that the new tellurium compound has antibacterial activities.
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Ma Q, Liu T, Tang T, Yin H, Ai S. Drinking water disinfection by hemin-modified graphite felt and electrogenerated reactive oxygen species. Electrochim Acta 2011. [DOI: 10.1016/j.electacta.2011.06.088] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Ashkenazi H, Malik Z, Harth Y, Nitzan Y. Eradication of Propionibacterium acnes by its endogenic porphyrins after illumination with high intensity blue light. FEMS IMMUNOLOGY AND MEDICAL MICROBIOLOGY 2003; 35:17-24. [PMID: 12589953 DOI: 10.1111/j.1574-695x.2003.tb00644.x] [Citation(s) in RCA: 239] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Propionibacterium acnes is a Gram-positive, microaerophilic bacterium that causes skin wounds. It is known to naturally produce high amounts of intracellular porphyrins. The results of the present study confirm that the investigated strain of P. acnes is capable of producing endogenic porphyrins with no need for any trigger molecules. Extracts from growing cultures have demonstrated emission peaks around 612 nm when excited at 405 nm, which are characteristic for porphyrins. Endogenic porphyrins were determined and quantified after their extraction from the bacterial cells by fluorescence intensity and by elution retention time on high-performance liquid chromatography (HPLC). The porphyrins produced by P. acnes are mostly coproporphyrin, as shown by the HPLC elution patterns. Addition of delta-aminolevulinic acid (ALA) enhanced intracellular porphyrin synthesis and higher amounts of coproporphyrin have been found. Eradication of P. acnes by its endogenic porphyrins was examined after illumination with intense blue light at 407-420 nm. The viability of 24 h cultures grown anaerobically in liquid medium was reduced by less than two orders of magnitude when illuminated once with a light dose of 75 J cm(-2). Better photodynamic effects were obtained when cultures were illuminated twice or three times consecutively with a light dose of 75 J cm(-2) and an interval of 24 h between illuminations. The viability of the culture under these conditions decreased by four orders of magnitude after two illuminations and by five orders of magnitude after three illuminations. When ALA-triggered cultures were illuminated with intense blue light at a light dose of 75 J cm(-2) the viability of the treated cultures decreased by seven orders of magnitude. This decrease in viability can occur even after a single exposure of illumination for the indicated light intensity. X-ray microanalysis and transmission electron microscopy revealed structural damages to membranes in the illuminated P. acnes. Illumination of the endogenous coproporphyrin with blue light (407-420 nm) apparently plays a major role in P. acnes photoinactivation. A treatment protocol with a series of several illuminations or illumination after application of ALA may be suitable for curing acne. Treatment by both pathways may overcome the resistance of P. acnes to antibiotic treatment.
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Affiliation(s)
- Helena Ashkenazi
- Health Sciences Research Center, Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel
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Haematoporphyrin- and sodium chlorophyllin-induced phototoxicity towards bacteria and yeasts – a new approach for safe foods. Food Control 2001. [DOI: 10.1016/s0956-7135(01)00057-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Sailer R, Strauss WS, König K, Rück A, Steiner R. Correlation between porphyrin biosynthesis and photodynamic inactivation of Pseudomonas aeruginosa after incubation with 5-aminolaevulinic amid. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 1997. [DOI: 10.1016/s1011-1344(96)00019-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Nitzan Y, Dror R, Ladan H, Malik Z, Kimel S, Gottfried V. Structure-activity relationship of porphines for photoinactivation of bacteria. Photochem Photobiol 1995; 62:342-7. [PMID: 7480142 DOI: 10.1111/j.1751-1097.1995.tb05279.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The antibacterial photodynamic effects of uncharged (o-tetrahydroxyphenyl porphine [THPP], m-THPP and p-THPP), cationic (5,10,15,20-tetra[4-N-methylpyridyl]porphine [TMPyP]) and anionic (5,10,15,20-tetra[4-sulfonatophenyl porphine] [TPPS4]) porphines on Staphylococcus aureus and Escherichia coli bacteria inactivation were examined. The results show that uncharged porphines provoked antibacterial photodynamic activity on S. aureus, and also on E. coli in the presence of the membrane-disorganizing peptide polymixin B nonapeptide (PMNP). The TMPyP compound was highly photoactive toward gram-positive bacteria but only marginally effective on gram-negative cells, whereas TPPS4 showed no activity on either gram-positive or gram-negative bacteria. The photoactivity of TMPyP is due to the electrostatic attraction between the positively charged sensitizer molecule and the negatively charged membrane of the gram-positive target cells. For TPPS4, the inactivity toward gram-positive bacteria is due to electrostatic repulsion between the charged sensitizer molecule and the cell membrane. For gram-negative bacteria, the inactivity is conceivably due to preferential (electrostatic) binding to the positively charged PMNP, which is an adjuvant for membrane disorganization, but has no effect on cell viability. For hydrophobic sensitizers, the photoactivity depends on the state of aggregation. The extent of deaggregation of the different THPP isomers was determined by fluorescence measurements of bound sensitizers and could be positively correlated with their photoinactivation capacity. We conclude that the structure-activity relationships of these porphines are affected by their net charge and by aggregation.
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Affiliation(s)
- Y Nitzan
- Department of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
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Henry CA, Judy M, Dyer B, Wagner M, Matthews JL. Sensitivity of Porphyromonas and Prevotella species in liquid media to argon laser. Photochem Photobiol 1995; 61:410-3. [PMID: 7740086 DOI: 10.1111/j.1751-1097.1995.tb08631.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The phototoxicity of argon laser irradiation was studied in aqueous suspensions of Porphyromonas endodontalis (American Type Culture Collection [ATCC] 35406), Porphyromonas gingivalis (ATCC 33277), Prevotella denticola (ATCC 33184) and two strains of Prevotella intermedia (ATCC 15033 and 49046), all "black-pigmented bacteria," BPB, that accumulate cellular porphyrins. Several of these species have been implicated in the etiology of periodontal disease. Non-black-pigmented bacteria were also studied to test the specificity of irradiation as a potential photodynamic treatment for periodontal infections. Cell suspensions were irradiated with an argon laser at fluences of 20-200 J/cm2. When cultured in hemin-supplemented media, ATCC 15033 was the most sensitive to irradiation. However, a second strain of the same species (ATCC 49046) was resistant. The photosensitivity of other species ranked ATCC 33277 > 35406 = 33184 = 35496. When hemin was replaced in media by hemoglobin, ATCC 33277 became resistant to irradiation. Protoporphyrin IX content in BPB cells was shown not to be a major factor determining photosensitivity. Oxygen was required during irradiation for BPB species to be affected. Non-black-pigmented bacteria were much less sensitive to irradiation than BPB.
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Affiliation(s)
- C A Henry
- Department of Biomedical Sciences, Baylor College of Dentistry, Dallas, TX 75246, USA
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Malik Z, Babushkin T, Sher S, Hanania J, Ladan H, Nitzan Y, Salzberg S. Collapse of K+ and ionic balance during photodynamic inactivation of leukemic cells, erythrocytes and Staphylococcus aureus. THE INTERNATIONAL JOURNAL OF BIOCHEMISTRY 1993; 25:1399-406. [PMID: 8224355 DOI: 10.1016/0020-711x(93)90688-b] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
1. The immediate and fast ionic fluxes in Friend erythroleukemic cells (FELC), erythrocytes and Staphylococcus aureus during short intervals of porphyrin mediated photosensitization were determined uniquely by X-ray microanalysis (XRMA) combined with electron microscopy. 2. Photodynamic inactivation of FELC was mediated by either endogenous protoporphyrin induced by 5-amino levulinic acid (5-ALA), or Photofrin-II. We describe the predominant phenomena of > 85% K-loss within 2-10 min of photoactivation. However the accompanied Na inflow and the collapse of the cellular balance of elemental-composition were inconsistent and acted as a function of cell damage. 3. Erythrocytes treated with hematoporphyrin (HP) lost most of their intracellular K yet instantly gained Na. Nevertheless the K/Na molar ratio of the control erythrocytes was nearly 12/1 while after photosensitization and K loss it changed to 1/1. 4. The S. aureus bacteria photosensitized with HP showed entire K-loss as well as marked Na efflux which increased with irradiation time; this was accompanied by the decline of other cell elements. 5. The prevailing K loss in FELC, erythrocytes and bacteria during the first minutes of photosensitization is deduced to be an immediate primary consequence of the photodynamic effect, while other ionic changes are joined in order with the development of cellular damage.
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Affiliation(s)
- Z Malik
- Life Sciences Department, Bar-Ilan University, Ramat-Gan, Israel
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Ladan H, Nitzan Y, Malik Z. The antibacterial activity of haemin compared with cobalt, zinc and magnesium protoporphyrin and its effect on potassium loss and ultrastructure of Staphylococcus aureus. FEMS Microbiol Lett 1993; 112:173-7. [PMID: 8405959 DOI: 10.1111/j.1574-6968.1993.tb06444.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The unique antibacterial properties of Fe-protoporphyrin (haemin) on Staphylococcus aureus, compared to Co-protoporphyrin (Co-PP), Mg-protoporphyrin (Mg-PP) and Zn-protoporphyrin (Zn-PP) are described. Only haemin (20 microM) exhibits a strong light-independent antibacterial effect on S. aureus; the other metalloporphyrins, Co-PP, Mg-PP or Zn-PP, have no antibacterial effect in the dark. Only light photosensitization of Mg-PP-treated cells resulted in the inhibition of the bacterial growth, while Co-PP or Zn-PP were photodynamically inactive. A notable effect of haemin on inactivation of S. aureus was the induction of immediate ion fluxes as determined by X-ray microanalysis (XRMA) of fast-frozen cells. A marked efflux of K (96%) and Cl (94%) was expressed immediately as determined by X-ray microanalysis of S. aureus cells treated with haemin for 5 min. Only 48% loss of Na was detected in the cells under these treatment conditions, while P content was increased by 150%. Electron microscopy analysis revealed the appearance of a mesosome-like structure connected to the new septa, filamentous chromosome and arrays of aggregated ribosomes in the cytoplasm. We propose that haemin has multiple cellular targets for its oxidative effect in S. aureus.
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Affiliation(s)
- H Ladan
- Department of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
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Malik Z, Ladan H, Nitzan Y. Photodynamic inactivation of Gram-negative bacteria: problems and possible solutions. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1992; 14:262-6. [PMID: 1432395 DOI: 10.1016/1011-1344(92)85104-3] [Citation(s) in RCA: 225] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Z Malik
- Health Sciences Research Center, Bar-Ilan University, Ramat-Gan, Israel 52900
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Nitzan Y, Gutterman M, Malik Z, Ehrenberg B. Inactivation of gram-negative bacteria by photosensitized porphyrins. Photochem Photobiol 1992; 55:89-96. [PMID: 1534909 DOI: 10.1111/j.1751-1097.1992.tb04213.x] [Citation(s) in RCA: 236] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Photosensitization of Escherichia coli and Pseudomonas aeruginosa cells by deuteroporphyrin (DP) is shown to be possible in the presence of the polycationic agent polymyxin nonapeptide (PMNP). Previous studies established complete resistance of Gram-negative bacteria to the photodynamic effects of porphyrins. The present results show that combined treatment of E. coli or P. aeruginosa cultures with DP and PMNP inhibit cell growth and viability. No antibacterial activity of PMNP alone could be demonstrated and cell viability remained unchanged. Spectroscopically, PMNP was found to bind DP, a mechanism which probably assists its penetration into the cell's membranes. Insertion of DP into the cells was monitored by the characteristic fluorescence band of bound DP at 622 nm. Binding times were 5-40 min and the extent of binding increased with decreasing the pH from 8.5 to 6.5. DP binding constants, as well as the concentrations of PMNP which were required for maximal effect on the various Gram-negative bacteria, were determined fluorometrically. By the treatment of DP, PMNP and light the growth of E. coli and P. aeruginosa cultures was stopped and the viability of the culture was dramatically reduced. Within 60 min of treatment the survival fraction of E. coli culture was 9 x 10(-6) and that of P. aeruginosa was 5.2 x 10(-4). Electron microscopy depicted ultrastructural alterations in the Gram-negative cells treated by DP and PMNP. The completion of cell division was inhibited and the chromosomal domain was altered markedly.
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Affiliation(s)
- Y Nitzan
- Department of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
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Nir U, Ladan H, Malik Z, Nitzan Y. In vivo effects of porphyrins on bacterial DNA. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1991; 11:295-306. [PMID: 1816365 DOI: 10.1016/1011-1344(91)80035-g] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The DNA damage in intact Staphylococcus aureus and E. coli cells induced by photosensitized deuteroporphyrin or hemin is described. Treatment of S. aureus cultures with hemin or photosensitized deuteroporphyrin (Dp) caused time-dependent changes in the plasmidial DNA profiles. The major observation was the disappearance of the plasmid supercoiled fraction. The chromosomal DNA was also affected by hemin and by photosensitized Dp, since its degradation products were detected after exposing the bacterial cells to the porphyrin drugs. Photosensitization of E. coli cells, pretreated with Dp and polymyxin B nonapeptide (PMBNP), also resulted in plasmidial damage. No such damage occurred when E. coli cultures were treated with hemin and PMBNP. The above results can be tightly correlated with the antimicrobial action of porphyrins. Their damage to the bacterial DNA seems to reflect one of the in vivo effects of these porphyrins.
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Affiliation(s)
- U Nir
- Department of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
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Malik Z, Ladan H, Nitzan Y, Ehrenberg B. The bactericidal activity of a deuteroporphyrin-hemin mixture on gram-positive bacteria. A microbiological and spectroscopic study. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1990; 6:419-30. [PMID: 2120409 DOI: 10.1016/1011-1344(90)85115-d] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The combined antibacterial activity of various porphyrins with hemin on Gram-positive bacteria was studied. Protoporphyrin, hematoporphyrin derivative and deuteroporphyrin show only a marginal inhibitory effect in the dark. However, hemin has a strong cytotoxic effect which is independent of illumination and is equally strong in the dark. The disadvantage of hemin treatment is that it is temporary. In this study, we have demonstrated that a combination of deuteroporphyrin and hemin has a unique cytotoxic activity on Staphylococcus aureus, Streptococcus faecalis and Bacillus cereus. The effect of the combined compound is stronger than that of the separate constituents, and is as strong in the dark as in the light. Only 0.005% of the initial S. aureus population survive after a 2 h treatment. Absorption and fluorescence spectra of hemin-deuteroporphyrin mixtures in water and liposomes suggest the formation of a species with spectroscopic properties which are different from those of the two constituents.
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Affiliation(s)
- Z Malik
- Department of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
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Malik Z, Hanania J, Nitzan Y. Bactericidal effects of photoactivated porphyrins--an alternative approach to antimicrobial drugs. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1990; 5:281-93. [PMID: 2115912 DOI: 10.1016/1011-1344(90)85044-w] [Citation(s) in RCA: 217] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Photoactivated porphyrins display a potent cytotoxic activity towards a variety of Gram positive bacteria, mycoplasma and yeasts, but not Gram negative cells. The prerequisite for photosensitization of a microbial cell is the binding of porphyrin to the cytoplasmic membrane in a pH-dependent manner. On illumination, the membrane bound, and possibly, cytoplasmic porphyrin molecules generate singlet oxygen and radicals which sensitize biomolecules and lead to cell death. The immediate inhibition of cell growth on photodynamic treatment is accompanied by alterations in cell wall and membrane synthesis, leading to the formation of large mesosomes adjacent to the unaccomplished septa. Hemin bound to microbial cells exerts cytotoxic activity by peroxidative and oxidative reactions independent of light. Future research in the field may enhance the possibility of using porphyrin photosensitization for treatment of microbial infections. Such clinical use will be unrelated to the antibiotic resistance of the pathogen. Resistance of Gram negative bacteria to porphyrin photosensitization is the main impediment to its use as a broad spectrum antibacterial method.
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Affiliation(s)
- Z Malik
- Life Science Department, Bar-Ilan University, Ramat-Gan, Israel
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