Cholesterol-Assisted Bacterial Cell Surface Engineering for Photodynamic Inactivation of Gram-Positive and Gram-Negative Bacteria

2017 ◽  
Vol 9 (19) ◽  
pp. 15943-15951 ◽  
Author(s):  
Hao-Ran Jia ◽  
Ya-Xuan Zhu ◽  
Zhan Chen ◽  
Fu-Gen Wu
2014 ◽  
Vol 13 (11) ◽  
pp. 1541-1548 ◽  
Author(s):  
Kamola R. Kasimova ◽  
Magesh Sadasivam ◽  
Giacomo Landi ◽  
Tadeusz Sarna ◽  
Michael R. Hamblin

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.


1952 ◽  
Vol 30 (4) ◽  
pp. 486-489 ◽  
Author(s):  
Russell E. MacDonald ◽  
Charles J. Bishop

A crystalline antibacterial substance isolated from apple leaves has been identified as phloretin. It has been shown to inhibit the growth of a number of Gram-positive and Gram-negative bacteria. The activity of the compound is bacteriostatic in nature and is shown in concentrations as low as 30 p.p.m. Its antibacterial action may be related to inhibition of the uptake of phosphorus by the bacterial cell.


2011 ◽  
Vol 55 (5) ◽  
pp. 1883-1890 ◽  
Author(s):  
Tsuimin Tsai ◽  
Hsiung-Fei Chien ◽  
Tze-Hsien Wang ◽  
Ching-Tsan Huang ◽  
Yaw-Bee Ker ◽  
...  

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.


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