scholarly journals Antimicrobial Activity and Mechanism of Functionalized Quantum Dots

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1670 ◽  
Author(s):  
Keerthiga Rajendiran ◽  
Zizhen Zhao ◽  
De-Sheng Pei ◽  
Ailing Fu
Keyword(s):  
Quantum Dots ◽  
Antimicrobial Activity ◽  
Polyvinylidene Fluoride ◽  
Resistant Bacteria ◽  
Animal Cells ◽  
Antimicrobial Efficiency ◽  
Drug Resistant Bacteria ◽  
Poly Ethylene ◽  
Bacteria And Fungi ◽  
Conventional Antibiotics

An essential characteristic of quantum dots (QDs) is their antimicrobial activity. Compared with conventional antibiotics, QDs not only possess photoluminescence properties for imaging and photodynamic therapy but also have high structural stability. To enhance their antimicrobial efficiency, QDs usually are functionalized by polymers, including poly(ethylene glycol), polyethyleneimine, and poly-l-lysine. Also, QDs conjugated with polymers, such as poly(vinylpyrrolidone) and polyvinylidene fluoride, are prepared as antimicrobial membranes. The main antimicrobial mechanisms of QDs are associated with inducing free radicals, disrupting cell walls/membranes, and arresting gene expression. The different mechanisms from traditional antibiotics allow QDs to play antimicrobial roles in multi-drug-resistant bacteria and fungi. Since the toxicity of the QDs on animal cells is relatively low, they have broad application in antimicrobial research as an effective alternative of traditional antibiotics.

scholarly journals The Design of Alapropoginine, a Novel Conjugated Ultrashort Antimicrobial Peptide with Potent Synergistic Antimicrobial Activity in Combination with Conventional Antibiotics

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 712
Author(s):  
Ali Salama ◽  
Ammar Almaaytah ◽  
Rula M. Darwish
Keyword(s):  
Antimicrobial Activity ◽  
Hemolytic Activity ◽  
Antimicrobial Agents ◽  
Antimicrobial Activities ◽  
Resistant Bacteria ◽  
Human Red Blood Cells ◽  
Drug Resistant Bacteria ◽  
Different Strains ◽  
Conventional Antibiotics

(1) Background: Antimicrobial resistance represents an urgent health dilemma facing the global human population. The development of novel antimicrobial agents is needed to face the rising number of resistant bacteria. Ultrashort antimicrobial peptides (USAMPs) are considered promising antimicrobial agents that meet the required criteria of novel antimicrobial drug development. (2) Methods: Alapropoginine was rationally designed by incorporating arginine (R), biphenylalanine (B), and naproxen to create an ultrashort hexapeptide. The antimicrobial activity of alapropoginine was evaluated against different strains of bacteria. The hemolytic activity of alapropoginine was also investigated against human erythrocytes. Finally, synergistic studies with antibiotics were performed using the checkerboard technique and the determination of the fractional inhibitory index. (3) Results: Alapropoginine displayed potent antimicrobial activities against reference and multi-drug-resistant bacteria with MIC values of as low as 28.6 µg/mL against methicillin-resistant S. aureus. Alapropoginine caused negligible toxicity toward human red blood cells. Moreover, the synergistic studies showed improved activities for the combined conventional antibiotics with a huge reduction in their antimicrobial concentrations. (4) Conclusions: The present study indicates that alapropoginine exhibits promising antimicrobial activity against reference and resistant strains of bacteria with negligible hemolytic activity. Additionally, the peptide displays synergistic or additive effects when combined with several antibiotics.

Vacancy‐Induced Antibacterial Activity of XS 2– y Quantum Dots against Drug‐Resistant Bacteria for Treatment of Bacterial Keratitis

Small ◽  
2020 ◽  
Vol 16 (42) ◽  
pp. 2004677
Author(s):  
Huiyuan Li ◽  
Xiao Wang ◽  
Xiaofei Zhao ◽  
Guanhua Li ◽  
Fengyan Pei ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Antibacterial Activity ◽  
Resistant Bacteria ◽  
Bacterial Keratitis ◽  
Drug Resistant ◽  
Drug Resistant Bacteria

scholarly journals In vitro Antimicrobial Activity of Acne Drugs Against Skin-Associated Bacteria

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mark A. T. Blaskovich ◽  
Alysha G. Elliott ◽  
Angela M. Kavanagh ◽  
Soumya Ramu ◽  
Matthew A. Cooper
Keyword(s):  
Antimicrobial Activity ◽  
Resistant Bacteria ◽  
Microbial Infection ◽  
Antibiotic Resistant ◽  
Drug Resistant Bacteria ◽  
Cutibacterium Acnes ◽  
Common Skin ◽  
Sebum Production ◽  
Resistant Strains

Abstract Acne is a common skin affliction that involves excess sebum production and modified lipid composition, duct blockage, colonization by bacteria, and inflammation. Acne drugs target one or more of these steps, with antibiotics commonly used to treat the microbial infection for moderate to severe cases. Whilst a number of other acne therapies are purported to possess antimicrobial activity, this has been poorly documented in many cases. We conducted a comparative analysis of the activity of common topical acne drugs against the principal etiological agent associated with acne: the aerotolerant anaerobic Gram-positive organism Propionibacterium acnes (recently renamed as Cutibacterium acnes). We also assessed their impact on other bacteria that could also be affected by topical treatments, including both antibiotic-sensitive and antibiotic-resistant strains, using broth microdilution assay conditions. Drugs designated specifically as antibiotics had the greatest potency, but lost activity against resistant strains. The non-antibiotic acne agents did possess widespread antimicrobial activity, including against resistant strains, but at substantially higher concentrations. Hence, the antimicrobial activity of non-antibiotic acne agents may provide protection against a background of increased drug-resistant bacteria.

Antimicrobial activity of essential oil ofArtemisia judaicaL. from Algeria against multi-drug resistant bacteria from clinical origin

2015 ◽  
Vol 31 (2) ◽  
pp. 137-142 ◽  
Author(s):  
N. Benmansour ◽  
A. Benmansour ◽  
F. El Hanbali ◽  
M. C. González-Mas ◽  
M. A. Blázquez ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Essential Oil ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Drug Resistant Bacteria

scholarly journals Antimicrobial activity of Guava tree (Psidium Guajava) leaf extract and selected Commercial Antibiotics on Bacterial isolates from Kisubi Hospital

2020 ◽  
Author(s):  
◽  
David Serunjogi ◽  
Kizito Muwonge
Keyword(s):  
Antimicrobial Activity ◽  
Psidium Guajava ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Leaf Extracts ◽  
Drug Resistant Bacteria ◽  
The World ◽  
Guava Leaf ◽  
Tree Leaf

Background: Plant species such as the guava have been used in Uganda and elsewhere in the world to treat some of the medical conditions associated with bacteria, this is due to the increased number of drug resistant bacteria in the world. In this study, the antimicrobial activity of guava leaf extracts against some of the disease causing bacteria isolated from Kisubi hospital in Uganda is discussed. Methods: The guava leafs were collected from a plantation near Zika forest in Uganda (0°7′27″N 32°31′32″E / 0.12417°N 32.52556°E / 0.12417; 32.52556) and samples were put in a bag and transferred to the university laboratory where they were identified. The extracts were obtained by maceration using distilled water, 30%, 50% and 70 % methanol as the extraction solvents. Antimicrobial susceptibility testing was conducted using the disc diffusion method. Results: Gram-negative Escherichia coli was sensitive to the plant extract and synthetic commercial drugs such as trimethoprim-sulfamethozole, ciprofloxacin, and Gentamicin. Pseudomonas aeruginosa was resistant to all drugs. Streptococcus pneumonia and Staphylococcus aureus were all sensitive to the plant extracts with measurable inhibition zones. Conclusion: The Guava tree leaf crude extracts have antimicrobial activity against drug-resistant bacteria. More studies should be carried out to know the potency and the concentration of different plant origin extracts.

Bioprospecting of insect nest associated actinobacteria with special reference to antimicrobial and anti HIV activity

2021 ◽  
Vol 16 (8) ◽  
pp. 121-125
Author(s):  
Pooja Rao ◽  
Yasaswini Winchester ◽  
Rameshkumar Varatharajan ◽  
Gopikrishnan Venugopal ◽  
Radhakrishnan Manikkam
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Properties ◽  
Resistant Bacteria ◽  
Streptomyces Sp ◽  
Carbapenem Resistant ◽  
Drug Resistant Bacteria ◽  
Agar Plug ◽  
Ant Nest ◽  
Promising Source ◽  
Anti Hiv

The present study attempted to explore actinobacteria from different insect nest samples for antimicrobial activity. Totally, 43 actinobacterial colonies were recovered from ant nest, termite nest, wasp nest and blanket worm nest samples by adopting standard spread plate method. Screening of antimicrobial properties of actinobacterial strains was determined by agar plug method. Two actinobacterial strains AN1 and AN5 showed promising activity (14-18 mm inhibition) against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, carbapenem resistant Klebsiella pneumoniae and Mycobacterium smegmatis. Both the strains produced antimicrobial compound earlier on ISP2 agar when compared to ISP2 broth. Crude extracts from the strains AN1 and AN5 were produced by adopting agar surface fermentation and extracted using ethyl acetate. Based on the studied phenotypic characteristics, actinobacterial strains AN1 and AN5 isolated from ant nest were identified as Streptomyces sp. In addition to antimicrobial activity, extracts also showed anti-HIV activity. This study concluded that insect nest is a promising source for bioactive actinobacteria. Two potential Streptomyces sp. AN1 and AN5 isolated from ant nest will be promising sources for antimicrobial metabolites against drug resistant bacteria, retrovirus and mycobacterial pathogens.

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