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 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 Characteristics of Two Crustins from Alvinocaris longirostris in Hydrothermal Vents

Marine Drugs ◽  
2021 ◽  
Vol 19 (11) ◽  
pp. 600
Author(s):  
Lu-Lu Guo ◽  
Shao-Lu Wang ◽  
Fang-Chao Zhu ◽  
Feng Xue ◽  
Li-Sheng He
Keyword(s):  
Hydrothermal Vents ◽  
Room Temperature ◽  
Amino Acid Level ◽  
Antibacterial Activities ◽  
Gram Negative Bacteria ◽  
Drug Resistant ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Antibacterial Spectrum

Crustins are widely distributed among different crustacean groups. They are characterized by a whey acidic protein (WAP) domain, and most examined Crustins show activity against Gram-positive bacteria. This study reports two Crustins, Al-crus 3 and Al-crus 7, from hydrothermal vent shrimp, Alvinocaris longirostris. Al-crus 3 and Al-crus 7 belong to Crustin Type IIa, with a similarity of about 51% at amino acid level. Antibacterial assays showed that Al-crus 3 mainly displayed activity against Gram-positive bacteria with MIC50 values of 10–25 μM. However, Al-crus 7 not only displayed activity against Gram-positive bacteria but also against Gram-negative bacteria Imipenem-resistant Acinetobacter baumannii, in a sensitive manner. Notably, in the effective antibacterial spectrum, Methicillin-sensitive Staphylococcus aureus, Escherichia coli (ESBLs) and Imipenem-resistant A. baumannii were drug-resistant pathogens. Narrowing down the sequence to the WAP domain, Al-crusWAP 3 and Al-crusWAP 7 demonstrated antibacterial activities but were weak. Additionally, the effects on bacteria did not significantly change after they were maintained at room temperature for 48 h. This indicated that Al-crus 3 and Al-crus 7 were relatively stable and convenient for transportation. Altogether, this study reported two new Crustins with specific characteristics. In particular, Al-crus 7 inhibited Gram-negative imipenem-resistant A. baumannii.

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 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 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

Re-thinking treatment strategies for febrile neutropenia in paediatric oncology population: A perspective from a developing country.

2020 ◽  
Author(s):  
Vinson James ◽  
Anand Prakash ◽  
Kayur Mehta ◽  
Tarangini Durugappa
Keyword(s):  
Escherichia Coli ◽  
Drug Resistance ◽  
Febrile Neutropenia ◽  
Tertiary Care ◽  
Automated System ◽  
Multi Drug Resistance ◽  
Gram Negative Bacteria ◽  
Drug Resistant ◽  
Gram Positive ◽  
Gram Negative

Abstract Background: This study was conducted to evaluate the microbiological profile of bacterial isolates in febrile neutropenia in a pediatric oncology unit, thereby, reviewing the use of restricted antibiotics and need for aggressive medical treatment accordingly.Methods: A prospective observational study was conducted in a paediatric haemat-oncology division of a tertiary care teaching hospital in southern India from September 2014 to August 2016. Children with febrile neutropenia were enrolled in the study. Blood cultures were performed using automated system. Cultures from other sites were obtained if needed, based on the clinical profile. Standard antibiotic susceptibility testing was done. Statistical analysis was done using SPSS.Results: One hundred and thirty children were enrolled for the study. Two hundred and fifty episodes of febrile neutropenia were studied. Three hundred and eighty four cultures were sent and 92 (24%) cultures were positive. There were 52.2% gram negative isolates followed 35.8% gram positive isolates, 6.5% fungal isolates and 5.5% poly-microbial cultures. Lactose fermenting gram negative bacteria (29 isolates, 31.5%) were the most frequently isolated in the gram negative group, with Escherichia coli being the most common organism (19 isolates, 20.6%). Amongst gram positive coagulase negative staphylococcus (CONS) was the most common (29%). Escherichia coli and NFGNB had only 36%, 25% sensitivity to ceftazidime respectively. Most gram negative bacteria were found to have better sensitivity to amikacin (mean: 57). There was a higher prevalence of extended spectrum beta lactamase producing organisms. 36 out of 48 GNB were found to be either multi/extremely/pan drug resistant. Escherichia coli and Klebsiella were often drug resistant. Significantly higher mortality was associated with gram negative isolates (61.5%)Conclusions: In view of higher prevalence of gram negative isolates and emergence of multi drug resistance, frequent audits of resistance patterns should guide the choice of antimicrobials in febrile neutropenia management. Our results show the importance of surveillance, monitoring resistance frequencies and identifying risk factors specific to each region. Given that significant mortality is attributed to drug resistant gram negative bacteria, early initiation of appropriate antibiotics to cover for drug resistance is required while formulating empirical antibiotic policies for febrile neutropenia in the oncology units in the developing world.

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