scholarly journals Sodium nitrite potentiates antimicrobial photodynamic inactivation: possible involvement of peroxynitrate

2019 ◽  
Vol 18 (2) ◽  
pp. 505-515 ◽  
Author(s):  
Ying-Ying Huang ◽  
Paweł J. Rajda ◽  
Grzegorz Szewczyk ◽  
Brijesh Bhayana ◽  
Long Y. Chiang ◽  
...  
Keyword(s):  
Sodium Nitrite ◽  
Gram Negative Bacteria ◽  
Photodynamic Inactivation ◽  
Gram Positive ◽  
Gram Negative

Antimicrobial photodynamic inactivation using different photosensitizers of Gram-positive and Gram-negative bacteria can be potentiated up to one million times by addition of sodium nitrite. The mechanism is proposed to involve formation of peroxynitrate.

scholarly journals Potentiation of photoinactivation of Gram-positive and Gram-negative bacteria mediated by six phenothiazinium dyes by addition of azide ion

2014 ◽  
Vol 13 (11) ◽  
pp. 1541-1548 ◽  
Author(s):  
Kamola R. Kasimova ◽  
Magesh Sadasivam ◽  
Giacomo Landi ◽  
Tadeusz Sarna ◽  
Michael R. Hamblin
Keyword(s):  
Singlet Oxygen ◽  
Hydroxyl Radicals ◽  
Gram Negative Bacteria ◽  
Photodynamic Inactivation ◽  
Gram Positive ◽  
Gram Negative ◽  
Azide Ion

Antimicrobial photodynamic inactivation (APDI) using six different phenothiazinium dyes is mediated by singlet oxygen (quenched by azide) and hydroxyl radicals (potentiated by azide) depending on Gram-classification of the bacteria and whether the dye is washed from the cells.

scholarly journals Chitosan Augments Photodynamic Inactivation of Gram-Positive and Gram-Negative Bacteria

2011 ◽  
Vol 55 (5) ◽  
pp. 1883-1890 ◽  
Author(s):  
Tsuimin Tsai ◽  
Hsiung-Fei Chien ◽  
Tze-Hsien Wang ◽  
Ching-Tsan Huang ◽  
Yaw-Bee Ker ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Light Exposure ◽  
Gram Negative Bacteria ◽  
Photodynamic Inactivation ◽  
Gram Positive ◽  
Gram Negative ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Microbial Infections ◽  
Promising Treatment

ABSTRACTAntimicrobial photodynamic inactivation (PDI) was shown to be a promising treatment modality for microbial infections. This study explores the effect of chitosan, a polycationic biopolymer, in increasing the PDI efficacy against Gram-positive bacteria, includingStaphylococcus aureus,Staphylococcus epidermidis,Streptococcus pyogenes, and methicillin-resistantS. aureus(MRSA), as well as the Gram-negative bacteriaPseudomonas aeruginosaandAcinetobacter baumannii. Chitosan at <0.1% was included in the antibacterial process either by coincubation with hematoporphyrin (Hp) and subjection to light exposure to induce the PDI effect or by addition after PDI and further incubation for 30 min. Under conditions in which Hp-PDI killed the microbe on a 2- to 4-log scale, treatment with chitosan at concentrations of as low as 0.025% for a further 30 min completely eradicated the bacteria (which were originally at ∼108CFU/ml). Similar results were also found with toluidine blue O (TBO)-mediated PDI in planktonic and biofilm cells. However, without PDI treatment, chitosan alone did not exert significant antimicrobial activity with 30 min of incubation, suggesting that the potentiated effect of chitosan worked after the bacterial damage induced by PDI. Further studies indicated that the potentiated PDI effect of chitosan was related to the level of PDI damage and the deacetylation level of the chitosan. These results indicate that the combination of PDI and chitosan is quite promising for eradicating microbial infections.

scholarly journals Protochlorophyllide: a new photosensitizer for the photodynamic inactivation of Gram-positive and Gram-negative bacteria

2008 ◽  
Vol 290 (2) ◽  
pp. 156-163 ◽  
Author(s):  
Johannes Walther ◽  
Markus J. Bröcker ◽  
Denise Wätzlich ◽  
Manfred Nimtz ◽  
Manfred Rohde ◽  
...  
Keyword(s):  
Gram Negative Bacteria ◽  
Photodynamic Inactivation ◽  
Gram Positive ◽  
Gram Negative

scholarly journals BODIPY-embedded electrospun materials in antimicrobial photodynamic inactivation

2019 ◽  
Vol 18 (8) ◽  
pp. 1923-1932 ◽  
Author(s):  
Kevin R. Stoll ◽  
Frank Scholle ◽  
Jiadeng Zhu ◽  
Xiangwu Zhang ◽  
Reza A. Ghiladi
Keyword(s):  
Gram Negative Bacteria ◽  
Photodynamic Inactivation ◽  
Drug Resistant ◽  
Detection Level ◽  
Gram Positive ◽  
Gram Negative

Electrospun BODIPY(+)-embedded nanofiber materials were capable of the detection-level photodynamic inactivation of drug-resistant Gram-positive and Gram-negative bacteria and viruses.

scholarly journals Fluorine-substituted tetracationic ABAB-phthalocyanines for efficient photodynamic inactivation of Gram-positive and Gram-negative bacteria

2020 ◽  
Vol 187 ◽  
pp. 111957 ◽  
Author(s):  
Miguel Á. Revuelta-Maza ◽  
Patricia González-Jiménez ◽  
Cormac Hally ◽  
Montserrat Agut ◽  
Santi Nonell ◽  
...  
Keyword(s):  
Gram Negative Bacteria ◽  
Photodynamic Inactivation ◽  
Gram Positive ◽  
Gram Negative

scholarly journals Potassium Iodide Potentiates Antimicrobial Photodynamic Inactivation Mediated by Rose Bengal in In Vitro and In Vivo Studies

2017 ◽  
Vol 61 (7) ◽  
Author(s):  
Xiang Wen ◽  
Xiaoshen Zhang ◽  
Grzegorz Szewczyk ◽  
Ahmed El-Hussein ◽  
Ying-Ying Huang ◽  
...  
Keyword(s):  
Potassium Iodide ◽  
Rose Bengal ◽  
Green Light ◽  
In Vivo Studies ◽  
Gram Negative Bacteria ◽  
Photodynamic Inactivation ◽  
Gram Positive ◽  
Gram Negative ◽  
Content Type

ABSTRACT Rose bengal (RB) is a halogenated xanthene dye that has been used to mediate antimicrobial photodynamic inactivation for several years. While RB is highly active against Gram-positive bacteria, it is largely inactive in killing Gram-negative bacteria. We have discovered that addition of the nontoxic salt potassium iodide (100 mM) potentiates green light (540-nm)-mediated killing by up to 6 extra logs with the Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa, the Gram-positive bacterium methicillin-resistant Staphylococcus aureus, and the fungal yeast Candida albicans. The mechanism is proposed to be singlet oxygen addition to iodide anion to form peroxyiodide, which decomposes into radicals and, finally, forms hydrogen peroxide and molecular iodine. The effects of these different bactericidal species can be teased apart by comparing the levels of killing achieved in three different scenarios: (i) cells, RB, and KI are mixed together and then illuminated with green light; (ii) cells and RB are centrifuged, and then KI is added and the mixture is illuminated with green light; and (iii) RB and KI are illuminated with green light, and then cells are added after illumination with the light. We also showed that KI could potentiate RB photodynamic therapy in a mouse model of skin abrasions infected with bioluminescent P. aeruginosa.

Rapid demonstration of septic or infectious arthritis due to Gram-negative bacteria

1992 ◽  
Vol 50 (1) ◽  
pp. 686-687
Author(s):  
Jacob S. Hanker ◽  
Paul R. Gross ◽  
Beverly L. Giammara
Keyword(s):  
Chronic Arthritis ◽  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Infectious Arthritis ◽  
Bacterial Arthritis ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Blood cultures are positive in approximately only 50 per cent of the patients with nongonococcal bacterial infectious arthritis and about 20 per cent of those with gonococcal arthritis. But the concept that gram-negative bacteria could be involved even in chronic arthritis is well-supported. Gram stains are more definitive in staphylococcal arthritis caused by gram-positive bacteria than in bacterial arthritis due to gram-negative bacteria. In the latter situation where gram-negative bacilli are the problem, Gram stains are helpful for 50% of the patients; they are only helpful for 25% of the patients, however, where gram-negative gonococci are the problem. In arthritis due to gram-positive Staphylococci. Gramstained smears are positive for 75% of the patients.

In-vitro Antioxidant and Antibacterial Activity of Methanolic Extract of Shorea robusta Gaertn. F. Resin

2016 ◽  
Vol 6 (4) ◽  
pp. 68
Author(s):  
Sushma Vashisht ◽  
Manish Pal Singh ◽  
Viney Chawla
Keyword(s):  
Antibacterial Activity ◽  
Methanolic Extract ◽  
Diffusion Method ◽  
Gram Negative Bacteria ◽  
Disc Diffusion ◽  
Gram Positive ◽  
Gram Negative ◽  
Shorea Robusta ◽  
Dose Dependent ◽  
Resin Extract

The methanolic extract of the resin of Shorea robusta was subjected to investigate its antioxidant and antibacterial properties its utility in free radical mediated diseases including diabetic, cardiovascular, cancer etc. The methanol extract of the resin was tested for antioxidant activity using scavenging activity of DPPH (1,1-diphenyl-2-picrylhydrazil) radical method, reducing power by FeCl3 and antibacterial activity against gram positive and gram negative bacteria using disc diffusion method. The phytochemical screening considered the presence of triterpenoids, tannins and flavoniods. Overall, the plant extract is a source of natural antioxidants which might be helpful in preventing the progress of various oxidative stress mediated diseases including aging. The half inhibition concentration (IC50) of resin extract of Shorea robusta and ascorbic acid were 35.60 µg/ml and 31.91 µg/ml respectively. The resin extract exhibit a significant dose dependent inhibition of DPPH activity. Antibacterial activity was observed against gram positive and gram negative bacteria in dose dependent manner.Key Words: Shorea robusta, antioxidant, antibacterial, Disc-diffusion, DPPH.

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