scholarly journals Mechanistic Study of Synergistic Antimicrobial Effects between Poly (3-hydroxybutyrate) Oligomer and Polyethylene Glycol

2020 ◽  
Author(s):  
Ziheng Zhang ◽  
Jun Li ◽  
Linlin Ma ◽  
Xingxing Yang ◽  
Bin Fei ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Antimicrobial Agents ◽  
Antimicrobial Effect ◽  
Mechanistic Study ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Drug Resistant ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Drug Resistant Bacteria

We reported previously that poly (3-hydroxybutyrate) (PHB) oligomer is an effective antimicrobial agent against gram-positive bacteria, gram-negative bacteria, fungi and multi-drug resistant bacteria. In this work, it was further found that polyethylene glycol (PEG) can promote the antimicrobial effect of PHB oligomer synergistically. Three hypothetic mechanisms were proposed, that is, generation of new antimicrobial components, degradation of PHB macromolecules and dissolution/dispersion of PHB oligomer by PEG. With a series of systematic experiments and characterizations of HPLC-MS, it was deducted that dissolution/dispersion of PHB oligomer dominated the synergistic antimicrobial effect between PHB oligomer and PEG. This work demonstrates a way for promoting antimicrobial effect of PHB oligomer and other antimicrobial agents through improving hydrophilicity.

scholarly journals Mechanistic Study of Synergistic Antimicrobial Effects between Poly (3-hydroxybutyrate) Oligomer and Polyethylene Glycol

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2735
Author(s):  
Ziheng Zhang ◽  
Jun Li ◽  
Linlin Ma ◽  
Xingxing Yang ◽  
Bin Fei ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
High Performance ◽  
Antimicrobial Effect ◽  
Mechanistic Study ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Drug Resistant ◽  
Liquid Chromatography Mass Spectrometry ◽  
Gram Positive Bacteria ◽  
Drug Resistant Bacteria

Extended from our previous finding that poly (3-hydroxybutyrate) (PHB) oligomer is an effective antimicrobial agent against gram-positive bacteria, gram-negative bacteria, fungi and multi-drug resistant bacteria, this work investigates the effect of polyethylene glycol (PEG) on the antimicrobial effect of PHB oligomer. To investigate and explain this promoting phenomenon, three hypothetic mechanisms were proposed, that is, generation of new antimicrobial components, degradation of PHB macromolecules and dissolution/dispersion of PHB oligomer by PEG. With a series of systematic experiments and characterizations of high-performance liquid chromatography–mass spectrometry (HPLC-MS), it was deducted that PEG promotes the antimicrobial effect of PHB oligomer synergistically through dissolution/dispersion, owing to its amphipathy, which improves the hydrophilicity of PHB oligomer.

scholarly journals Bacteriocins, Antimicrobial Peptides from Bacterial Origin: Overview of Their Biology and Their Impact against Multidrug-Resistant Bacteria

2020 ◽  
Vol 8 (5) ◽  
pp. 639 ◽  
Author(s):  
Alexis Simons ◽  
Kamel Alhanout ◽  
Raphaël E. Duval
Keyword(s):  
Antimicrobial Resistance ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Multidrug Resistant Bacteria ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Further Development

Currently, the emergence and ongoing dissemination of antimicrobial resistance among bacteria are critical health and economic issue, leading to increased rates of morbidity and mortality related to bacterial infections. Research and development for new antimicrobial agents is currently needed to overcome this problem. Among the different approaches studied, bacteriocins seem to be a promising possibility. These molecules are peptides naturally synthesized by ribosomes, produced by both Gram-positive bacteria (GPB) and Gram-negative bacteria (GNB), which will allow these bacteriocin producers to survive in highly competitive polymicrobial environment. Bacteriocins exhibit antimicrobial activity with variable spectrum depending on the peptide, which may target several bacteria. Already used in some areas such as agro-food, bacteriocins may be considered as interesting candidates for further development as antimicrobial agents used in health contexts, particularly considering the issue of antimicrobial resistance. The aim of this review is to present an updated global report on the biology of bacteriocins produced by GPB and GNB, as well as their antibacterial activity against relevant bacterial pathogens, and especially against multidrug-resistant bacteria.

scholarly journals Lysophosphatidylcholine Potentiates Antibacterial Activity of Polymyxin B

2020 ◽  
Vol 64 (12) ◽  
Author(s):  
Jitender Yadav ◽  
Sana Ismaeel ◽  
Ayub Qadri
Keyword(s):  
Antibacterial Activity ◽  
Polymyxin B ◽  
Resistant Bacteria ◽  
Bacterial Membrane ◽  
Gram Negative Bacteria ◽  
Drug Resistant ◽  
Antibiotic Resistant ◽  
Gram Negative ◽  
Drug Resistant Bacteria

ABSTRACT Polymyxin B, used to treat infections caused by antibiotic-resistant Gram-negative bacteria, produces nephrotoxicity at its current dosage. We show that a combination of nonbactericidal concentration of this drug and lysophosphatidylcholine (LPC) potently inhibits growth of Salmonella and at least two other Gram-negative bacteria in vitro. This combination makes bacterial membrane porous and causes degradation of DnaK, the regulator of protein folding. Polymyxin B-LPC combination may be an effective and safer regimen against drug-resistant bacteria.

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.

scholarly journals Isolation of Multidrug Resistant Bacteria from Aspirates of Cancer Patients

2019 ◽  
Vol 35 (1) ◽  
pp. 61-66
Author(s):  
Sunjukta Ahsan ◽  
Rayhan Mahmud ◽  
Kajal Ahsan ◽  
Shamima Begum
Keyword(s):  
Cancer Patients ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Drug Resistant ◽  
Multidrug Resistant Bacteria ◽  
Esbl Producer ◽  
Drug Resistant Bacteria ◽  
Treatment Facilities ◽  
Isolated Species

Infections due to Gram-negative bacteria are common affairs in cancer patients during aggressive therapy. The present study characterizedmulti-drug resistant bacteria (MDR) isolated from cancer aspirates collected from patients admitted to the National Cancer Hospital in Dhaka, Bangladesh. A total of 210 aspirate samples were collected from cancer patients. Out of 210 samples Acinetobacter spp.led the list of isolates (8.89%, n=45). Of these species, 50% exhibited resistance to Amoxycillin and Nitrofurantoin, each, 25% exhibited resistant to Cefotaxime, Azithromycin, Ciprofloxacin, Clindamycin, and Sulfamethoxazole. A total of 33.33% of the Bordetella spp.which accounted 6.67%of the total isolates exhibited resistance to Cefotaxime. All oftheLegionellapneumophila,comprising 4.4%of the isolated species, wereresistant to Cefotaxime, Azithromycin, and Clindamycin.In contrast, 50% were resistant to Cefotaxime, Azithromycin, and Ceftriaxone. Of the Escherichia coli(4.4%, n=45) isolated,50% exhibited resistance to Cefotaxime, Clindamycin, Ceftriaxone, Amoxycillinand Sulfamethoxazole.The only isolate of Klebsiella sp. was demonstrated to be an ESBL producer. The isolation of multidrug resistant bacteria from cancer patients is of particular concern in Bangladesh where cancer and drug resistance are both common phenomena but treatment facilities are poor. To our knowledge this is the first report of the isolation of drug resistant bacteria from cancer patients from Dhaka city. Bangladesh J Microbiol, Volume 35 Number 1 June 2018, pp 61-66

scholarly journals Nanoparticles Functionalized with Ampicillin Destroy Multiple-Antibiotic-Resistant Isolates of Pseudomonas aeruginosa and Enterobacter aerogenes and Methicillin-Resistant Staphylococcus aureus

2012 ◽  
Vol 78 (8) ◽  
pp. 2768-2774 ◽  
Author(s):  
Ashley N. Brown ◽  
Kathryn Smith ◽  
Tova A. Samuels ◽  
Jiangrui Lu ◽  
Sherine O. Obare ◽  
...  
Keyword(s):  
Methicillin Resistant Staphylococcus Aureus ◽  
Enterobacter Aerogenes ◽  
Resistance Mechanisms ◽  
Resistant Bacteria ◽  
Multiple Drug ◽  
Drug Resistant ◽  
Antibiotic Resistant ◽  
Gram Positive Bacteria ◽  
Drug Resistant Bacteria ◽  
Multiple Drug Resistant

ABSTRACTWe show here that silver nanoparticles (AgNP) were intrinsically antibacterial, whereas gold nanoparticles (AuNP) were antimicrobial only when ampicillin was bound to their surfaces. Both AuNP and AgNP functionalized with ampicillin were effective broad-spectrum bactericides against Gram-negative and Gram-positive bacteria. Most importantly, when AuNP and AgNP were functionalized with ampicillin they became potent bactericidal agents with unique properties that subverted antibiotic resistance mechanisms of multiple-drug-resistant bacteria.

scholarly journals Trends in the Susceptibility of Clinically Important Resistant Bacteria to Tigecycline: Results from the TigecyclineIn VitroSurveillance in Taiwan Study, 2006 to 2010

2011 ◽  
Vol 56 (3) ◽  
pp. 1452-1457 ◽  
Author(s):  
Yen-Hsu Chen ◽  
Po-Liang Lu ◽  
Cheng-Hua Huang ◽  
Chun-Hsing Liao ◽  
Chin-Te Lu ◽  
...  
Keyword(s):  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Drug Resistant ◽  
Content Type ◽  
E Coli ◽  
Drug Resistant Bacteria ◽  
Vancomycin Resistant ◽  
Susceptibility Rate ◽  
Important Drug

ABSTRACTThe TigecyclineIn VitroSurveillance in Taiwan (TIST) study, a nationwide, prospective surveillance during 2006 to 2010, collected a total of 7,793 clinical isolates, including methicillin-resistantStaphylococcus aureus(MRSA) (n= 1,834), penicillin-resistantStreptococcus pneumoniae(PRSP) (n= 423), vancomycin-resistant enterococci (VRE) (n= 219), extended-spectrum β-lactamase (ESBL)-producingEscherichia coli(n= 1,141), ESBL-producingKlebsiella pneumoniae(n= 1,330),Acinetobacter baumannii(n= 1,645), andStenotrophomonas maltophilia(n= 903), from different specimens from 20 different hospitals in Taiwan. MICs of tigecycline were determined following the criteria of the U.S. Food and Drug Administration (FDA) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST-2011). Among drug-resistant Gram-positive pathogens, all of the PRSP isolates were susceptible to tigecycline (MIC90, 0.03 μg/ml), and only one MRSA isolate (MIC90, 0.5 μg/ml) and three VRE isolates (MIC90, 0.125 μg/ml) were nonsusceptible to tigecycline. Among the Gram-negative bacteria, the tigecycline susceptibility rates were 99.65% for ESBL-producingE. coli(MIC90, 0.5 μg/ml) and 96.32% for ESBL-producingK. pneumoniae(MIC90, 2 μg/ml) when interpreted by FDA criteria but were 98.7% and 85.8%, respectively, when interpreted by EUCAST-2011 criteria. The susceptibility rate forA. baumannii(MIC90, 4 μg/ml) decreased from 80.9% in 2006 to 55.3% in 2009 but increased to 73.4% in 2010. A bimodal MIC distribution was found among carbapenem-susceptibleA. baumanniiisolates, and a unimodal MIC distribution was found among carbapenem-nonsusceptibleA. baumanniiisolates. In Taiwan, tigecycline continues to have excellentin vitroactivity against several major clinically important drug-resistant bacteria, with the exception ofA. baumannii.

scholarly journals Antimicrobial Effect of Bacteriocin produced Pediococcus pentosaceus on some clinical isolates

2017 ◽  
Vol 27 (5) ◽  
pp. 26 ◽  
Author(s):  
Nehad A. Taher
Keyword(s):  
Antimicrobial Activity ◽  
Protein Concentration ◽  
Antimicrobial Effect ◽  
Clinical Isolates ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Pediococcus Pentosaceus ◽  
Gram Positive Bacteria ◽  
Agar Plug ◽  
Made In

About 10 isolates of Pediococcus sp were isolated from different cheese made in Iraq, These isolates were identified morphologically and biochemically and Api20 kit, thus there was only 6 isolate were identified as Pediococcus pentosaceus (60%).In this study, we investigate, the effect of crude Bacteriocin from Pediococcus pentosaceus on 30 clinical isolates (5 E.coli, 5 Klepsiella pneumoniae, 5 Staphylococcus aureus, 5 Pseudomonas aeroginosa, 5 Bacillus subtilis, 5 Candida albicans). The protein concentration of this Bacteriocin was measured 67mg\ml by Bradford method and used as (1:2) by vol during the measuring the antimicrobial activity against the above clinical isolates by two methods wells and  agar plug assay. The results showed that  the inhibitory activity of this Bacteriocin was higher by wells method than agar pluq assay against Gram–positive bacteria or Gram-negative bacteria and yeast under this study.

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