scholarly journals Photodynamic inactivation of antibiotic‐resistant Gram‐positive bacteria: Challenges and opportunities

2020 ◽  
Vol 2 (1-2) ◽  
Author(s):  
Zvi Malik
Keyword(s):  
Photodynamic Inactivation ◽  
Gram Positive ◽  
Antibiotic Resistant ◽  
Gram Positive Bacteria ◽  
Challenges And Opportunities

scholarly journals Antimicrobial compounds from the Kenyan Ganoderma adspersum (Schulz.) Donk species

2020 ◽  
Vol 13 (7) ◽  
pp. 3390-3397
Author(s):  
Regina Kemunto Mayaka ◽  
Alice Wanjiku Njue ◽  
Moses Kiprotich Langat ◽  
Peter Kiplagat Cheplogoi ◽  
Josiah Ouma Omolo
Keyword(s):  
Antimicrobial Activity ◽  
Ethyl Acetate ◽  
Gram Positive ◽  
Streptococcus Pneumonia ◽  
Antibiotic Resistant ◽  
1H And 13C Nmr ◽  
Gram Positive Bacteria ◽  
Chemical Structures ◽  
Zones Of Inhibition ◽  
Antibacterial And Antifungal

The emergence of antibiotic resistant pathogens has continuously increased, leading to a growing worldwide health threat due to infectious diseases. And therefore in our search for antibacterial and antifungal compounds from the polypore Ganoderma adspersum, the dried, ground fruiting bodies of G. adspersum were extracted with methanol and solvent removed in a rotary evaporator. The extract was suspended in distilled water, then partitioned using ethyl acetate solvent to obtain an ethyl acetate extract. The extract was fractionated and purified using column chromatographic method and further purification on sephadex LH20. The chemical structures were determined on the basis of NMR spectroscopic data from 1H and 13C NMR, HSQC, HMBC, 1H-1H COSY, and NOESY experiments. Antimicrobial activity against clinically important bacterial and fungal strains was assessed and zones of inhibition were recorded. Compound (1), ergosta-7,22-dien-3-one weakly inhibited the growth of Gram positive bacteria Streptococcus pneumonia and a fungus Cryptococcus neoformans. Compounds ergosta-7,22-dien-3-ol (2) and ergosta-5,7,22-trien-3-ol (3) also inhibited gram positive Streptococcus pyogenes bacteria.Keywords: Polypores, steroid compounds, antimicrobial activity.

A maltoheptaose-decorated BODIPY photosensitizer for photodynamic inactivation of Gram-positive bacteria

2019 ◽  
Vol 43 (38) ◽  
pp. 15057-15065 ◽  
Author(s):  
Jie Hao ◽  
Zhi Song Lu ◽  
Chang Ming Li ◽  
Li Qun Xu
Keyword(s):  
Singlet Oxygen ◽  
Photodynamic Inactivation ◽  
Gram Positive ◽  
Oxygen Generation ◽  
Gram Positive Bacteria ◽  
Singlet Oxygen Generation

A maltoheptaose-decorated BODIPY with high singlet oxygen generation efficacy was synthesized for photodynamic inactivation of Gram-positive bacteria in planktonic forms and biofilms.

scholarly journals Novel Type of Water-Soluble Photosensitizer from Trichoderma reesei for Photodynamic Inactivation of Gram-Positive Bacteria

Langmuir ◽  
2020 ◽  
Vol 36 (44) ◽  
pp. 13227-13235
Author(s):  
Zihuayuan Yang ◽  
Ying Qiao ◽  
Junying Li ◽  
Fu-Gen Wu ◽  
Fengming Lin
Keyword(s):  
Trichoderma Reesei ◽  
Water Soluble ◽  
Photodynamic Inactivation ◽  
Gram Positive ◽  
Gram Positive Bacteria

scholarly journals Auranofin exerts broad-spectrum bactericidal activities by targeting thiol-redox homeostasis

2015 ◽  
Vol 112 (14) ◽  
pp. 4453-4458 ◽  
Author(s):  
Michael B. Harbut ◽  
Catherine Vilchèze ◽  
Xiaozhou Luo ◽  
Mary E. Hensler ◽  
Hui Guo ◽  
...  
Keyword(s):  
Redox Homeostasis ◽  
Thioredoxin Reductase ◽  
Redox Balance ◽  
Resistant Bacteria ◽  
Gram Positive ◽  
Antibiotic Resistant ◽  
Gram Positive Bacteria ◽  
Bactericidal Activities ◽  
Orally Bioavailable ◽  
Thiol Redox

Infections caused by antibiotic-resistant bacteria are a rising public health threat and make the identification of new antibiotics a priority. From a cell-based screen for bactericidal compounds againstMycobacterium tuberculosisunder nutrient-deprivation conditions we identified auranofin, an orally bioavailable FDA-approved antirheumatic drug, as having potent bactericidal activities against both replicating and nonreplicatingM. tuberculosis. We also found that auranofin is active against other Gram-positive bacteria, includingBacillus subtilisandEnterococcus faecalis, and drug-sensitive and drug-resistant strains ofEnterococcus faeciumandStaphylococcus aureus. Our biochemical studies showed that auranofin inhibits the bacterial thioredoxin reductase, a protein essential in many Gram-positive bacteria for maintaining the thiol-redox balance and protecting against reactive oxidative species. Auranofin decreases the reducing capacity of target bacteria, thereby sensitizing them to oxidative stress. Finally, auranofin was efficacious in a murine model of methicillin-resistantS. aureusinfection. These results suggest that the thioredoxin-mediated redox cascade of Gram-positive pathogens is a valid target for the development of antibacterial drugs, and that the existing clinical agent auranofin may be repurposed to aid in the treatment of several important antibiotic-resistant pathogens.

scholarly journals In vitro activity of para-guanidinoethylcalix[4]arene against susceptible and antibiotic-resistant Gram-negative and Gram-positive bacteria

2007 ◽  
Vol 60 (3) ◽  
pp. 575-581 ◽  
Author(s):  
Marion Grare ◽  
Maxime Mourer ◽  
Stéphane Fontanay ◽  
Jean-Bernard Regnouf-de-Vains ◽  
Chantal Finance ◽  
...  
Keyword(s):  
Vitro Activity ◽  
In Vitro Activity ◽  
Gram Positive ◽  
Antibiotic Resistant ◽  
Gram Negative ◽  
Gram Positive Bacteria

scholarly journals Antibacterial Activity of Ticagrelor in Conventional Antiplatelet Dosages Against Antibiotic-Resistant Gram-Positive Bacteria

2019 ◽  
Vol 4 (6) ◽  
pp. 596 ◽  
Author(s):  
Patrizio Lancellotti ◽  
Lucia Musumeci ◽  
Nicolas Jacques ◽  
Laurence Servais ◽  
Eric Goffin ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Gram Positive ◽  
Antibiotic Resistant ◽  
Gram Positive Bacteria

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 Identifikasi Bakteri dengan Pewarnaan Gram pada Penderita Infeksi Mata Luar di Rumah Sakit Mata Kota Manado

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Trijeri Bulele ◽  
Fredine E. S. Rares ◽  
John Porotu'o
Keyword(s):  
Bacterial Culture ◽  
Resistant Bacteria ◽  
Ocular Infection ◽  
Gram Positive ◽  
Cross Sectional ◽  
Antibiotic Resistant ◽  
Gram Positive Bacteria ◽  
Gram Staining ◽  
Ocular Infections ◽  
Cross Sectional Design

Abstract: Bacteria are the main cause of external ocular infection worldwide. Therefore, it is necessary to improve the treatment according to the cause of the infection in order to prevent the emergence of antibiotic-resistant bacteria. This study was aimed to identify the bacteria by using the Gram staining method in patients with external ocular infections. This was a descriptive study with a cross sectional design using bacterial culture of purulent secretion obtained from conjunctival and palpebral swabs in patients with external ocular infections at Manado Eye Hospital Manado. Based on the types of external ocular infections, conjunctivitis was the leading cause (50%), followed by keratitis (30%), blepharitis (13.3%), and keratoconjunctivitis (6.7%). Females were more frequeny than males (63.3% vs 36.7%). The youngest age in this study was 9 years and the oldest was 81 years, meanwhile, the most common age group was adults >40 years. The most common type of occupation was housewives. The results of bacterial culture were as follows: 19 samples showed no growth; 6 samples (54.5%) of Gram-positive bacteria in the form of staphylococcus, coccus, diplococcus; 3 samples (27.3%) of Gram-negative bacteria in the form of bacillus; and 2 samples (18.2%) of mixed Gram positive and negative bacteria in the form of bacillus and coccus. Conclusion: Gram-positive bacterium in the form of coccus is the most common cause of external ocular infection.Keywords: external ocular infection, bacteria, Gram staining Abstrak: Bakteri ialah penyebab utama infeksi mata luar di seluruh dunia. Pengobatan yang sesuai dengan penyebab infeksi dapat mencegah munculnya bakteri yang resistan terhadap antibiotik. Penelitian ini bertujuan untuk mengidentifikasi bakteri dengan menggunakan metode pewarnaan Gram pada penderita infeksi mata luar. Jenis penelitian ialah deskriptif dengan desain potong lintang menggunakan kultur bakteri hasil swab sekret purulen dari konjungtiva dan palpebra pada penderita infeksi mata luar di Rumah Sakit Mata Kota Manado. Hasil penelitian mendapatkan bahwa jenis infeksi mata luar terbanyak ialah konjungtivitis (50%), diikuti oleh keratitis (30%), blefaritis (13,3%), dan keratokonjungtivitis (6,7%). Perempuan lebih banyak (63,3%) menderita infeksi mata luar dibandingkan laki-laki (36,7%). Usia termuda ialah 9 tahun dan tertua 81 tahun. Kelompok usia terbanyak ialah dewasa >40 tahun. Jenis pekerjaan ibu rumah tangga yang terbanyak dibandingkan dengan pekerjaan lainnya. Hasil proses kultur mendapatkan 19 sampel tidak menunjukan adanya pertumbuhan, 6 sampel (54,5%) bakteri Gram positif dengan bentuk staphylococcus, coccus, diplococcus, 3 sampel (27,3%) bakteri Gram negatif dengan bentuk bacillus, dan 2 sampel (18.2%) campuran bakteri Gram positif dan negatif dengan bentuk bacillus dan coccus. Simpulan: Bakteri Gram positif berbentuk coccus yang paling sering menjadi penyebab infeksi mata luar.Kata kunci: infeksi mata luar, bakteri, pewarnaan Gram

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