scholarly journals Iron-Stimulated Production and Antimicrobial Potential of a Novel Biosurfactant Produced by a Drilling Waste-Degrading Pseudomonas citronellolis Strain

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 686
Author(s):  
Argyro Tsipa ◽  
Konstantina Stylianou ◽  
Maria Papalli ◽  
Erato Papageorgiou ◽  
Loucas Kyriakou ◽  
...  
Keyword(s):  
Inhibitory Concentration ◽  
Low Cost ◽  
Antimicrobial Properties ◽  
Toxicity Testing ◽  
Resistant Bacteria ◽  
Peptide Structure ◽  
Optimization Strategy ◽  
Drug Resistant Bacteria ◽  
Drilling Waste ◽  
Processing Cost

A Pseudomonas citronellolis strain was isolated from drilling waste (DW). This strain utilizes DW as the sole energy and carbon source to produce biosurfactants (BSs). The BS produced was thermally stable, amorphous and includes a peptide structure. FeSO4, FeCl3 and Fe(NO3)3 were supplemented at various concentration levels to assess possible enhancement of BS production and DW biodegradation. The limit concentration of Fe compounds between the increase in BS formation and microbial toxicity was 0.1 mM. FeCl3 enhanced DW biodegradation and more than doubled the BS formation yield, determining an optimization strategy for BS production. The BS was then partially purified and used against several Gram-negative and positive multi-drug resistant bacteria (such as Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli spp, Acinetobacter baumaniii, Enterococcus faecalis spp, Streptococcus pneumoniae, Staphylococcus aureus, Salmonella enterica). The minimum inhibitory concentration was defined at a range of 0.25 to 10 mg/mL. The antimicrobial properties of the partially purified BS established its effectiveness and suggested a down-stream processing cost reduction, as no additional purification steps were necessary. The study could lead to a sustainable low-cost bioprocess towards a circular bioeconomy because waste, a non-expensive substrate, is used; while the BS holds great potential as a novel compound with antibiotic and disinfectant-like action, following toxicity testing with human cells.

scholarly journals Novel Seleno- and Thio-Urea Containing Dihydropyrrol-2-One Analogues as Antibacterial Agents

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 321
Author(s):  
Shekh Sabir ◽  
Tsz Tin Yu ◽  
Rajesh Kuppusamy ◽  
Basmah Almohaywi ◽  
George Iskander ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Antibiotic Resistance ◽  
Quorum Sensing ◽  
Antibacterial Agents ◽  
Inhibitory Concentration ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Positive Bacterium ◽  
Quorum Sensing Inhibition ◽  
Drug Resistant Bacteria

The quorum sensing (QS) system in multi-drug-resistant bacteria such as P. aeruginosa is primarily responsible for the development of antibiotic resistance and is considered an attractive target for antimicrobial drug discovery. In this study, we synthesised a series of novel selenourea and thiourea-containing dihydropyrrol-2-one (DHP) analogues as LasR antagonists. The selenium DHP derivatives displayed significantly better quorum-sensing inhibition (QSI) activities than the corresponding sulphur analogues. The most potent analogue 3e efficiently inhibited the las QS system by 81% at 125 µM and 53% at 31 µM. Additionally, all the compounds were screened for their minimum inhibitory concentration (MIC) against the Gram-positive bacterium S. aureus, and interestingly, only the selenium analogues showed antibacterial activity, with 3c and 3e being the most potent with a MIC of 15.6 µM.

scholarly journals Nanoparticles Enable Efficient Delivery of Antimicrobial Peptides for the Treatment of Deep Infections

2021 ◽  
Author(s):  
Yingxue Deng ◽  
Rui Huang ◽  
Songyin Huang ◽  
Menghua Xiong
Keyword(s):  
Antimicrobial Peptides ◽  
Broad Spectrum ◽  
Antimicrobial Properties ◽  
Therapeutic Index ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Drug Resistant Bacteria ◽  
Efficient Delivery ◽  
Delivery Vehicles

Antimicrobial peptides (AMPs) have emerged as promising alternatives of traditional antibiotics against drug-resistant bacteria owing to their broad-spectrum antimicrobial properties and low tendency to drugresistance. However, their therapeutic efficacy in vivo, especially for infections in deep organs, is limited owing to their systemic toxicity and low bioavailability. Nanoparticles-based delivery systems offer a strategy to increase the therapeutic index of AMPs by preventing proteolysis, increasing the accumulation at infection sites, and reducing toxicity. Herein, we will discuss the current progress of using nanoparticles as delivery vehicles for AMPs for the treatment of deep infections.

An unexpected discovery toward novel membrane active sulfonyl thiazoles as potential MRSA DNA intercalators

2020 ◽  
Vol 12 (19) ◽  
pp. 1709-1727 ◽  
Author(s):  
Yuan-Yuan Hu ◽  
Juan Wang ◽  
Tie-Jun Li ◽  
Rammohan R Yadav Bheemanaboina ◽  
Mohammad Fawad Ansari ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Antibacterial Agents ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Inhibitory Concentration ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Dna Intercalators ◽  
Dna Targeting ◽  
Drug Resistant Bacteria

Aim: With the increasing emergence of drug-resistant bacteria, the need for new antimicrobial agents has become extremely urgent. This work was to develop sulfonyl thiazoles as potential antibacterial agents. Results & methodology: Novel hybrids of sulfonyl thiazoles were developed from commercial acetanilide and acetylthiazole. Hybrids 6e and 6f displayed excellent inhibitory efficacy against clinical methicillin-resistant Staphylococcus aureus (MRSA) (minimum inhibitory concentration = 1 μg/ml) without obvious toxicity toward normal mammalian cells (RAW 264.7). The combination uses were found to improve the antimicrobial ability. Further preliminary antibacterial mechanism experiments showed that the active molecule 6f could effectively interfere with MRSA membrane and insert into MRSA DNA. Conclusion: Compounds 6e and 6f could serve as potential DNA-targeting templates toward the development of promising antimicrobial agents.

Multifunctional divalent vancomycin: the fluorescent imaging and photodynamic antimicrobial properties for drug resistant bacteria

2011 ◽  
Vol 47 (5) ◽  
pp. 1601-1603 ◽  
Author(s):  
Bengang Xing ◽  
Tingting Jiang ◽  
Wuguo Bi ◽  
Yanmei Yang ◽  
Lihua Li ◽  
...  
Keyword(s):  
Antimicrobial Properties ◽  
Fluorescent Imaging ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Drug Resistant Bacteria

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.

scholarly journals Synthesis of 4,4′-(4-Formyl-1H-pyrazole-1,3-diyl)dibenzoic Acid Derivatives as Narrow Spectrum Antibiotics for the Potential Treatment of Acinetobacter Baumannii Infections

Antibiotics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 650 ◽  
Author(s):  
Evan Delancey ◽  
Devin Allison ◽  
Hansa Raj KC ◽  
David F. Gilmore ◽  
Todd Fite ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Inhibitory Concentration ◽  
Organ Injury ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Antimicrobial Studies ◽  
Mammalian Cell Lines ◽  
Drug Resistant Bacteria

Acinetobacter baumannii has emerged as one of the most lethal drug-resistant bacteria in recent years. We report the synthesis and antimicrobial studies of 25 new pyrazole-derived hydrazones. Some of these molecules are potent and specific inhibitors of A. baumannii strains with a minimum inhibitory concentration (MIC) value as low as 0.78 µg/mL. These compounds are non-toxic to mammalian cell lines in in vitro studies. Furthermore, one of the potent molecules has been studied for possible in vivo toxicity in the mouse model and found to be non-toxic based on the effect on 14 physiological blood markers of organ injury.

scholarly journals Isolation and Identification of Multi-drug Resistant Bacteria from various sources and Antimicrobial Activity of Terminalia chebula Retz against isolated Multi-drug Resistant Bacteria

2021 ◽  
Vol 11 (4) ◽  
pp. 7338-7344
Author(s):  
Tamalika Chakraborty ◽  
Kanchan Chettri ◽  
Sumana Chatterjee ◽  
Lopamudra Datta ◽  
Abhijit Sengupta
Keyword(s):  
Drug Resistance ◽  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Bacterial Activity ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Terminalia Chebula ◽  
Isolation And Identification ◽  
Drug Resistant Bacteria

Drug resistance is a threat to civilization, which results from over-prescription and irrational use of antibiotics. This has led to an increased demand for novel leads of herbal origin to overcome drug resistance. The present work involves the screening of various antibiotics against isolated Staphylococcus sp. from Hospital Effluent and the Minimum Inhibitory concentration for antibiotics namely Vancomycin, Erythromycin and Oxacillin were found to be 7.33+0.6 µg/ml 25.33+0.6 µg/ml and 27.33+0.6 µg/ml respectively whereas Minimum bactericidal concentration of Vancomycin, Erythromycin and oxacillin was found to be 180µg/ml; 146.67 + 0.3 µg/ml and 96.66 + 0.6 µg/ml respectively. Thus, the isolated bacteria were proved to be Multi-Drug Resistant. Haritaki (Terminalia chebula Retz) is given potential importance in Ayurveda for its properties to cure and prevent diseases. Terminalia chebula Retz is often known as “King of Medicines” and enlisted in Ayurveda for its extraordinary therapeutic contribution. The proved Multi-Drug Resistant bacteria was further subjected to a crude extract of Haritaki. Minimum Inhibitory Concentration for Terminalia chebula was found to be 1.33 +0.3 mg/ml and thus proved to be exhibiting potential anti-bacterial activity against isolated Multi-Drug Resistant Staphylococcus sp.

scholarly journals An Abundant New Saponin-Polybromophenol Antibiotic (CU1) from Cassia fistula Bark Against Multi-Drug Resistant Bacteria Targeting RNA Polymerase

2020 ◽  
Author(s):  
Asit Kumar Chakraborty ◽  
Sourajit Saha ◽  
Kousik Poria ◽  
Tanmoy Samanta ◽  
Sudhanshu Gautam ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Low Cost ◽  
Broad Band ◽  
Ethanol Extract ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Cassia Fistula ◽  
Major Band ◽  
Drug Resistant Bacteria ◽  
Mdr Tb

AbstractSpread of multidrug-resistant infections is a threat to human race and need for new drug development is great. Bark ethanol extract of Cassia fistula inhibited MDR bacteria isolated from Ganga River water, human and animal. On TLC, a gray colour major band ran fast (CU1; 6.6% of bark and ~30% of crude extract) which quickly purified on HPLC C18 column at 3 min. Chemical assays suggested a triterpene linked to polyphenol known as saponin. CHN Elements analysis (35.9% C; 5.5% H) did not identified nitrogen suggesting a polyphenol or glycoside. VU-Vis spectra gave high peak at below 200nm with a secondary peak at 275nm with minor hinge at 578nm indicating a fused ring with bromo-polyphenol. CU1 Mass (897 Daltons) with fragments of 515, 325, 269, 180 daltons and six halogen substitutions reflected by 82 molecular mass of DBr deviate six larger fragments. FT-IR suggested broad band at 3500-3000 cm−1 for −OH where as two strong peaks at 1552cm−1 for aromatic C=C and 1408cm−1 for phenol. Proton-NMR confirmed polymeric phenol at δ 4.86-4.91 ppm and tetratet at δ3.57-3.618 ppm with phenolic bromo-substituents. Carbon-NMR identified a strong peak at δ=23.7ppm for many C-Br and at 165ppm for a polybenzoid compound. CU1 inhibited the RNA Polymerase of E. coli (IC50=23μg/ml) and M. tuberculosis (IC50=34μg/ml) but not DNA polymerase. Gel shift assays demonstrated that CU1 drug interacted with enzyme and inhibited its binding to open promoter complex. Thus, CU1 phyto-chemical is an alternative safer and low cost drug against MDR-TB as well as other MDR pathogens.

scholarly journals Exploration of Antimicrobial Potency of Mangrove Symbiont Against Multi-Drug Resistant Bacteria

2021 ◽  
Vol 13 (2) ◽  
pp. 222
Author(s):  
Delianis Pringgenies ◽  
Wilis Ari Setyati ◽  
Ali Djunaedi ◽  
Rini Pramesti ◽  
Siti Rudiyanti ◽  
...  
Keyword(s):  
Antimicrobial Properties ◽  
Inhibition Zone ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
E Coli ◽  
Drug Resistant Bacteria ◽  
Acanthus Ilicifolius ◽  
Pathogenic Microbes ◽  
Microbial Isolates ◽  
Antimicrobial Potency

Highlight ResearchAntimicrobial potential against the test microbesRhizhopora mucronata isolate showed 95% homology with Bacillus subtilis, and 97% homology with Bacillus oceanisediminis,Acanthus ilicifolius isolate showed 96% homology with Paracoccus caeni, and 89% homology with Bacillus circulans. The study found 4 isolates with antimicrobial potency against MDR pathogenic microbes.The symbiont microbes taken from Rhizophora mucronata and Acanthus ilicifolius were determined to be of the genus Bacillus and Paracoccus AbstractAntimicrobial property of mangrove symbiont have the ability to fight Multi Drug Resistant bacteria which were Staphylococcus aureus, Escherichia coli, and Vibrio haryeyi. This study aimed to determine the potential of symbiont microbes from the root of Rhizopora mucronata and Acanthus iilicifolius as antimicrobial agents against multi-drug resistant (MDR) pathogenic microbes. This research was conducted during July to November 2020. The MDR bacteria were S. aureus, E. coli, and V. harveyi MDR test microbes. The symbiont microbes were identified through molecular analyses (PCR 16S rDNA). Isolation of symbiont microbes from R. mucronata resulted in 16 isolates, while isolation from A. iilicifolius resulted in 14 isolates. Based on the antimicrobial qualitative test against S. aureus, 8 out of 16 microbial isolates from R. mucronata were found to show antimicrobial properties. The testing of A. ilicifolius symbiont microbes against S. aureus showed 8 out of 14 isolates with antimicrobial properties. The test against E. coli resulted in 2 out of 16 microbial isolates from R. mucronata and 5 out of 14 isolates from A. ilicifolius with antimicrobial properties. The test against V. harveyi resulted in two out of 16 microbial isolates from R.mucronata and 4 out of 14 isolates from A. ilicifolius with antimicrobial properties. The quantitative test found 2 isolates from R. mucronta, namely isolates RM10 and RM12, with antimicrobial properties against MDR strain E. coli, with the best isolate being RM10, which produced 11.22 mm of inhibition zone diameter. Furthermore, the selection of isolates was based on the size of the inhibition zone, the clearness of the inhibition zone and the potential for antibacterial activity. Based on their overall antimicrobial potential against the test microbes, four isolates were selected.  Molecular analyses of RM12 isolate showed 95% homology with Bacillus subtilis, of RM 10 isolate showed 97% homology with Bacillus oceanisediminis, of AC isolate showed 96% homology with Paracoccus caeni, and of AC 5 isolate showed 89% homology with Bacillus circulans. The study found four isolates with antimicrobial potency against MDR pathogenic microbes. The symbiont microbes taken from R. mucronata and A. ilicifolius were determined to be of the genus Bacillus and Paracoccus. 

Conjugation of Silver Nanoparticles with De Novo Engineered Cationic Antimicrobial Peptides: Proposal for Study (Preprint)

2021 ◽  
Author(s):  
Alvin Hu
Keyword(s):  
Antimicrobial Activity ◽  
Silver Nanoparticles ◽  
Minimum Inhibitory Concentration ◽  
Antimicrobial Peptides ◽  
Inhibitory Concentration ◽  
De Novo ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Cationic Antimicrobial Peptides ◽  
Drug Resistant Bacteria

BACKGROUND Cationic antimicrobial peptides have broad antimicrobial activity and provide a novel way of targeting multi drug resistant bacteria in an era of increasing antimicrobial resistance. Current developments show positive prospects for both antimicrobial peptides and silver nanoparticles individually. OBJECTIVE The primary objective is to propose another method of enhancing antimicrobial activity by conjugating silver nanoparticles with cationic antimicrobial peptides for a subsequent preliminary assessment on studying the minimum inhibitory concentration of multi drug resistant bacteria. The secondary objective would be to evaluate the safety of the conjugated compound to assess viability for in vivo use. METHODS The proposition is planned for approximately 3 overarching stages. Firstly, I propose synthesis of wlbu2c, a modified version of antimicrobial peptide wlbu2 with an added cysteine group, using standard Fmoc procedure. This will subsequently be attempted to stably conjugate with silver nanoparticles ideally through photochemical means. Secondly, the conjugate wlbu2c-AgNP will be tested for antimicrobial activity following Clinical & Laboratory Standards Institute Manual on standard minimum inhibitory concentration testing. If all of the above is completed the experiment can progress to the assessment of cytotoxicity using cell lysis assays. RESULTS I-TASSER simulation revealed that our modified peptide wlbu2c has similar secondary structure to original wlbu2 peptide. No other results have been obtained at this time other than aforementioned theoretical propositions. CONCLUSIONS The addition of silver nanoparticles to already developing de novo engineered antimicrobial peptides provide a second degree of freedom toward the development of potent antimicrobials. Future prospects include emergency last line therapy, treatment for current difficult to eradicate bacterial colonization such as in cystic fibrosis, implantable medical devices, cancer and immunotherapy. This proposal is intended to be provided to the public as I do not anticipate funding at this time.

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