Design of a novel antimicrobial peptide 1018M targeted ppGpp to inhibit MRSA biofilm formation

AbstractMethicillin-resistant staphylococcus aureus (MRSA) and its biofilm infection were considered as one of the main international health issues. There are still many challenges for treatment using traditional antibiotics. In this study, a mutant peptide of innate defense regulator (IDR-)1018 named 1018M was designed based on molecular docking and amino acid substitution technology. The antibacterial/biofilm activity and mechanisms against MRSA of 1018M were investigated for the first time. The minimum inhibitory concentration (MIC) of 1018M was reduced 1 time (MIC = 2 μg/mL) compared to IDR-1018. After treatment with 32 μg/mL 1018M for 24 h, the percentage of biofilm decreased by 78.9%, which was more effective than the parental peptide. The results of mechanisms exploration showed that 1018M was more potent than IDR-1018 at destructing bacterial cell wall, permeating cell membrane (20.4%–50.1% vs 1.45%–10.6%) and binding to stringent response signaling molecule ppGpp (increased 27.9%). Additionally, the peptides could also exert their activity by disrupting genomic DNA, regulating the expression of ppGpp metabolism and biofilm forming related genes (RSH, relP, relQ, rsbU, sigB, spA, codY, agrA and icaD). Moreover, the higher temperature, pH and pepsase stabilities provide 1018M better processing, storage and internal environmental tolerance. These data indicated that 1018M may be a potential candidate peptide for the treatment of MRSA and its biofilm infections.

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The Inhibition Activity of Tannin on the Formation of Mono-Species and Polymicrobial Biofilm Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans

Majalah Obat Tradisional ◽

10.22146/mot.44532 ◽

2019 ◽

Vol 24 (2) ◽

pp. 110 ◽

Cited By ~ 1

Author(s):

Hasyrul Hamzah ◽

Triana Hertiani ◽

Sylvia Utami Tunjung Pratiwi ◽

Titik Nuryastuti

Keyword(s):

Biofilm Formation ◽

Inhibitory Concentration ◽

Potential Candidate ◽

Inhibition Activity ◽

Middle Phase ◽

Biofilm Inhibition ◽

E Coli ◽

The Social ◽

The Matrix ◽

Anti Fungal

Biofilm acts as the mediator for infection nowadays. Approximately, more than 80% infection incidents are biofilm-formation related. Biofilm as bacteria's defense system is more difficult to eradicate by antibiotic; therefore, pathogen bacteria on their biofilm forms can make serious problems for human health. The invention of a new candidate for polymicrobial biofilm can be an essential challenge to be studied, in order to prevent infections related to biofilm. Tannin is a polyphenol compound with anti-bacterial and anti-fungal potential. This study aims to acknowledge the effectiveness of tannin in inhibition and degradation of C. albicans, P. aeruginosa, E. coli, S. aureus, and polymicrobial biofilm. The assay for biofilm inhibition and degradation were determined with microtiter broth method. The effectivity of tannin antibiofilm against polymicrobial biofilm were analyzed by calculating minimum biofilm inhibitory concentration (MBIC50) and minimum biofilm eradication concentration (MBEC50) values. The mechanism of action of tannin against polymicrobial biofilm was tested using scanning electron microscopy (SEM). The data were analyzed using the Statistical Package for the Social Sciences (SPSS) with a 95% confidence level. Tannin 1% gave inhibition activity of mono-species biofilm formation S. aureus in the middle phase and maturation of 79.04±0.01, 61.48±0.03, E. coli 74.56±0.01, 67.91±0.02, P. aeruginosa 67.32±0.05, 35.13± 0.01, C. albicans 60.62±0.01, 47.16±0.01. The results also provide evidence that tannin activity can degrade and damage the matrix of extracellular polymeric substance (EPS) polymicrobial biofilms. Hence, tannins can be a potential candidate for new antibiofilm for polymicrobial biofilm.

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Comparative Proteomics of Marinobacter sp. TT1 Reveals Corexit Impacts on Hydrocarbon Metabolism, Chemotactic Motility, and Biofilm Formation

Microorganisms ◽

10.3390/microorganisms9010003 ◽

2020 ◽

Vol 9 (1) ◽

pp. 3

Author(s):

Saskia Rughöft ◽

Nico Jehmlich ◽

Tony Gutierrez ◽

Sara Kleindienst

Keyword(s):

Biofilm Formation ◽

Oil Spills ◽

Carbon Sources ◽

Comparative Proteomics ◽

Hydrocarbon Biodegradation ◽

Solvent Tolerance ◽

Marine Microorganisms ◽

Degrading Bacteria ◽

Oil Spill Response ◽

First Time

The application of chemical dispersants during marine oil spills can affect the community composition and activity of marine microorganisms. Several studies have indicated that certain marine hydrocarbon-degrading bacteria, such as Marinobacter spp., can be inhibited by chemical dispersants, resulting in lower abundances and/or reduced biodegradation rates. However, a major knowledge gap exists regarding the mechanisms underlying these physiological effects. Here, we performed comparative proteomics of the Deepwater Horizon isolate Marinobacter sp. TT1 grown under different conditions. Strain TT1 received different carbon sources (pyruvate vs. n-hexadecane) with and without added dispersant (Corexit EC9500A). Additional treatments contained crude oil in the form of a water-accommodated fraction (WAF) or chemically-enhanced WAF (CEWAF; with Corexit). For the first time, we identified the proteins associated with alkane metabolism and alginate biosynthesis in strain TT1, report on its potential for aromatic hydrocarbon biodegradation and present a protein-based proposed metabolism of Corexit components as carbon substrates. Our findings revealed that Corexit exposure affects hydrocarbon metabolism, chemotactic motility, biofilm formation, and induces solvent tolerance mechanisms, like efflux pumps, in strain TT1. This study provides novel insights into dispersant impacts on microbial hydrocarbon degraders that should be taken into consideration for future oil spill response actions.

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Antimicrobial and Immunomodulating Activities of Two Endemic Nepeta Species and Their Major Iridoids Isolated from Natural Sources

Pharmaceuticals ◽

10.3390/ph14050414 ◽

2021 ◽

Vol 14 (5) ◽

pp. 414

Author(s):

Neda Aničić ◽

Uroš Gašić ◽

Feng Lu ◽

Ana Ćirić ◽

Marija Ivanov ◽

...

Keyword(s):

Biofilm Formation ◽

Food Industry ◽

Balkan Peninsula ◽

Antimicrobial Activities ◽

Natural Sources ◽

E Coli ◽

Food Borne ◽

Metabolite Profiles ◽

Aspergillus Sp ◽

First Time

Two Balkan Peninsula endemics, Nepeta rtanjensis and N. argolica subsp. argolica, both characterized by specialized metabolite profiles predominated by iridoids and phenolics, are differentiated according to the stereochemistry of major iridoid aglycone nepetalactone (NL). For the first time, the present study provides a comparative analysis of antimicrobial and immunomodulating activities of the two Nepeta species and their major iridoids isolated from natural sources—cis,trans-NL, trans,cis-NL, and 1,5,9-epideoxyloganic acid (1,5,9-eDLA), as well as of phenolic acid rosmarinic acid (RA). Methanol extracts and pure iridoids displayed excellent antimicrobial activity against eight strains of bacteria and seven strains of fungi. They were especially potent against food-borne pathogens such as L. monocytogenes, E. coli, S. aureus, Penicillium sp., and Aspergillus sp. Targeted iridoids were efficient agents in preventing biofilm formation of resistant P. aeruginosa strain, and they displayed additive antimicrobial interaction. Iridoids are, to a great extent, responsible for the prominent antimicrobial activities of the two Nepeta species, although are probably minor contributors to the moderate immunomodulatory effects. The analyzed iridoids and RA, individually or in mixtures, have the potential to be used in the pharmaceutical industry as potent antimicrobials, and in the food industry to increase the shelf life and safety of food products.

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Transporters and Efflux Pumps Are the Main Mechanisms Involved in Staphylococcus epidermidis Adaptation and Tolerance to Didecyldimethylammonium Chloride

Microorganisms ◽

10.3390/microorganisms8030344 ◽

2020 ◽

Vol 8 (3) ◽

pp. 344 ◽

Cited By ~ 1

Author(s):

Urška Ribič ◽

Jernej Jakše ◽

Nataša Toplak ◽

Simon Koren ◽

Minka Kovač ◽

...

Keyword(s):

Staphylococcus Epidermidis ◽

Biofilm Formation ◽

Efflux Pump ◽

Thioredoxin Reductase ◽

Multidrug Transporter ◽

Acid Biosynthesis ◽

Tolerance Mechanisms ◽

Down Regulation ◽

Didecyldimethylammonium Chloride ◽

First Time

Staphylococcus epidermidis cleanroom strains are often exposed to sub-inhibitory concentrations of disinfectants, including didecyldimethylammonium chloride (DDAC). Consequently, they can adapt or even become tolerant to them. RNA-sequencing was used to investigate adaptation and tolerance mechanisms of S. epidermidis cleanroom strains (SE11, SE18), with S. epidermidis SE11Ad adapted and S. epidermidis SE18To tolerant to DDAC. Adaptation to DDAC was identified with up-regulation of genes mainly involved in transport (thioredoxin reductase [pstS], the arsenic efflux pump [gene ID, SE0334], sugar phosphate antiporter [uhpT]), while down-regulation was seen for the Agr system (agrA, arC, agrD, psm, SE1543), for enhanced biofilm formation. Tolerance to DDAC revealed the up-regulation of genes associated with transporters (L-cysteine transport [tcyB]; uracil permease [SE0875]; multidrug transporter [lmrP]; arsenic efflux pump [arsB]); the down-regulation of genes involved in amino-acid biosynthesis (lysine [dapE]; histidine [hisA]; methionine [metC]), and an enzyme involved in peptidoglycan, and therefore cell wall modifications (alanine racemase [SE1079]). We show for the first time the differentially expressed genes in DDAC-adapted and DDAC-tolerant S. epidermidis strains, which highlight the complexity of the responses through the involvement of different mechanisms.

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Fructose Enhanced Reduction of Bacterial Growth on Nanorough Surfaces

MRS Proceedings ◽

10.1557/opl.2013.35 ◽

2013 ◽

Vol 1498 ◽

pp. 73-78 ◽

Cited By ~ 2

Author(s):

N. Gozde Durmus ◽

Erik N. Taylor ◽

Kim M. Kummer ◽

Thomas J. Webster

Keyword(s):

Bacterial Growth ◽

Biofilm Formation ◽

Antibacterial Agents ◽

Bacteria Growth ◽

Planktonic Bacteria ◽

Combined Use ◽

Wide Range ◽

Metabolic Stimulation ◽

Antibacterial Surfaces ◽

First Time

ABSTRACTBiofilms are a major source of medical device-associated infections, due to their persistent growth and antibiotic resistance. Recent studies have shown that engineering surface nanoroughness has great potential to create antibacterial surfaces. In addition, stimulation of bacterial metabolism increases the efficacy of antibacterial agents to eradicate biofilms. In this study, we combined the antibacterial effects of nanorough topographies with metabolic stimulation (i.e., fructose metabolites) to further decrease bacterial growth on polyvinyl chloride (PVC) surfaces, without using antibiotics. We showed for the first time that the presence of fructose on nanorough PVC surfaces decreased planktonic bacteria growth and biofilm formation after 24 hours. Most importantly, a 60% decrease was observed on nanorough PVC surfaces soaked in a 10 mM fructose solution compared to conventional PVC surfaces. In this manner, this study demonstrated that bacteria growth can be significantly decreased through the combined use of fructose and nanorough surfaces and thus should be further studied for a wide range of antibacterial applications.

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Molecular diversity of bacteria in commercially available “Spirulina” food supplements

PeerJ ◽

10.7717/peerj.1610 ◽

2016 ◽

Vol 4 ◽

pp. e1610 ◽

Cited By ~ 9

Author(s):

Elisabeth Vardaka ◽

Konstantinos A. Kormas ◽

Matina Katsiapi ◽

Savvas Genitsaris ◽

Maria Moustaka-Gouni

Keyword(s):

Natural Product ◽

454 Pyrosequencing ◽

Molecular Diversity ◽

Arthrospira Platensis ◽

Food Supplements ◽

Health Issues ◽

Operational Taxonomic Units ◽

Health Promoting ◽

First Time ◽

Pyrosequencing Analysis

The cyanobacteriumArthrospirais among the most well-known food supplements worldwide known as “Spirulina.” While it is a widely recognized health-promoting natural product, there are no reports on the molecular diversity of commercially available brands of “Spirulina” supplements and the occurrence of other cyanobacterial and heterotrophic bacterial microorganisms in these products. In this study, 454-pyrosequencing analysis of the total bacterial occurrence in 31 brands of “Spirulina” dietary supplements from the Greek market was applied for the first time. In all samples, operational taxonomic units (OTUs) ofArthrospira platensiswere the predominant cyanobacteria. Some products contained additional cyanobacterial OTUs including a few known potentially toxic taxa. Moreover, 469 OTUs were detected in all 31 products collectively, with most of them being related to the Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria and Verrucomicrobia. All samples included heterotrophic bacterial OTUs, ranging from 9–157 per product. Among the most common OTUs were ones closely related to taxa known for causing health issues (i.e.,Pseudomonas,Flavobacterium,Vibrio,Aeromonas,Clostridium,Bacillus,Fusobacterium,Enterococcus). The observed high cyanobacterial and heterotrophic bacterial OTUs richness in the final product is a point for further research on the growth and processing ofArthrospirabiomass for commercial purposes.

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Action ofCoriandrum sativumL. Essential Oil upon OralCandida albicansBiofilm Formation

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2011/985832 ◽

2011 ◽

Vol 2011 ◽

pp. 1-9 ◽

Cited By ~ 38

Author(s):

V. F. Furletti ◽

I. P. Teixeira ◽

G. Obando-Pereda ◽

R. C. Mardegan ◽

A. Sartoratto ◽

...

Keyword(s):

Essential Oil ◽

Biofilm Formation ◽

Plant Material ◽

Inhibitory Concentration ◽

Chemical Characterization ◽

Synergistic Action ◽

Biofilm Growth ◽

Water Distillation ◽

Microdilution Method

The efficacy of extracts and essential oils fromAllium tuberosum, Coriandrum sativum, Cymbopogon martini, Cymbopogon winterianus,andSantolina chamaecyparissuswas evaluated againstCandidaspp. isolates from the oral cavity of patients with periodontal disease. The most active oil was fractionated and tested againstC. albicansbiofilm formation. The oils were obtained by water-distillation and the extracts were prepared with macerated dried plant material. The Minimal Inhibitory Concentration—MIC was determined by the microdilution method. Chemical characterization of oil constituents was performed using Gas Chromatography and Mass Spectrometry (GC-MS). C. sativum activity oil upon cell and biofilm morphology was evaluated by Scanning Electron Microscopy (SEM). The best activities against planktonicCandidaspp. were observed for the essential oil and the grouped F8–10fractions fromC. sativum. The crude oil also affected the biofilm formation inC. albicanscausing a decrease in the biofilm growth. Chemical analysis of the F8–10fractions detected as major active compounds, 2-hexen-1-ol, 3-hexen-1-ol and cyclodecane. Standards of these compounds tested grouped provided a stronger activity than the oil suggesting a synergistic action from the major oil constituents. The activity ofC. sativumoil demonstrates its potential for a new natural antifungal formulation.

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Starvation Survival and Biofilm Formation under Subminimum Inhibitory Concentration of QAMs

BioMed Research International ◽

10.1155/2021/8461245 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

Sanjay Kumar Tiwari ◽

Suping Wang ◽

Yannan Huang ◽

Xuedong Zhou ◽

Hockin H. K. Xu ◽

...

Keyword(s):

Lactic Acid ◽

Biofilm Formation ◽

Acid Production ◽

Inhibitory Concentration ◽

Lactic Acid Production ◽

Oral Bacteria ◽

Laser Scanning Microscopy ◽

Prolonged Starvation ◽

Survival And Development ◽

Development Of Tolerance

Quaternary ammonium methacrylates (QAMs) are useful antimicrobial compounds against oral bacteria. Here, we investigated the effects of two QAMs, dimethylaminododecyl methacrylate (DMADDM) and dimethylaminohexadecyl methacrylate (DMAHDM), on biofilm formation, survival and development of tolerance by biofilm, and survival and development of tolerance against QAMs after prolonged starvation. Enterococcus faecalis (E. faecalis), Streptococcus gordonii (S. gordonii), Lactobacillus acidophilus (L. acidophilus), and Actinomyces naeslundii (A. naeslundii) were used. Minimum inhibitory concentration (MIC) of QAMs against multispecies biofilm was determined. Biofilm formed under sub-MIC was observed by crystal violet staining and confocal laser scanning microscopy (CLSM). Metabolic activity was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and lactic acid production measurement. Development of tolerance was determined by MIC values before and after exposure to QAMs or after prolonged starvation. It was found that E. faecalis and S. gordonii could survive and form biofilm under sub-MIC of QAMs. Lactic acid production from biofilms formed under sub-MIC was significantly higher than control specimens ( p < 0.05 ). The exposure to sub-MIC of QAMs promoted biofilm formation, and prolonged starvation or prolonged contact with sub-MIC helped bacteria develop tolerance against killing by QAMs.

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Book Review: Urban Health Issues: Exploring the Impacts of Big-City Living

Reference & User Services Quarterly ◽

10.5860/rusq.59.2.7296 ◽

2020 ◽

Vol 59 (2) ◽

pp. 143

Author(s):

Tracy Carr

Keyword(s):

Climate Change ◽

Urban Health ◽

Urban Areas ◽

First Century ◽

Health Issues ◽

Health Concerns ◽

Accessible Volume ◽

Big City ◽

First Time

Due to poverty, climate change, and other factors, the world’s populations are becoming more urban. While “urban” is relative to various countries, the shift from rural to urban is happening worldwide. At the beginning of the twenty-first century, the world’s populations became, for the first time, evenly split between urban and rural. By midcentury, the prediction is that most populations will live in urban areas. It follows that where there are more people, there are also more health concerns. Richard V. Crume’s Urban Health Issues: Exploring the Impacts of Big-City Living is an eminently readable, accessible volume that addresses these health concerns.

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Antimicrobial Synergy of Silver-Platinum Nanohybrids With Antibiotics

Frontiers in Microbiology ◽

10.3389/fmicb.2020.610968 ◽

2021 ◽

Vol 11 ◽

Author(s):

Bansi Ranpariya ◽

Gayatri Salunke ◽

Srikanta Karmakar ◽

Kaushik Babiya ◽

Santosh Sutar ◽

...

Keyword(s):

Biofilm Formation ◽

Bacterial Infections ◽

Bacterial Biofilm ◽

Antimicrobial Drugs ◽

Mortality And Morbidity ◽

Green Route ◽

Antimicrobial Synergy ◽

First Time ◽

Tuber Extract ◽

Powerful Strategy

Various bacterial pathogens are responsible for nosocomial infections resulting in critical pathophysiological conditions, mortality, and morbidity. Most of the bacterial infections are associated with biofilm formation, which is resistant to the available antimicrobial drugs. As a result, novel bactericidal agents need to be fabricated, which can effectively combat the biofilm-associated bacterial infections. Herein, for the first time we report the antimicrobial and antibiofilm properties of silver-platinum nanohybrids (AgPtNHs), silver nanoparticles (AgNPs), and platinum nanoparticles (PtNPs) against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The AgPtNHs were synthesized by a green route using Dioscorea bulbifera tuber extract at 100°C for 5 h. The AgPtNHs ranged in size from 20 to 80 nm, with an average of ∼59 nm. AgNPs, PtNPs, and AgPtNHs showed a zeta potential of −14.46, −1.09, and −11.39 mV, respectively. High antimicrobial activity was observed against P. aeruginosa and S. aureus and AgPtNHs exhibited potent antimicrobial synergy in combination with antibiotics such as streptomycin, rifampicin, chloramphenicol, novobiocin, and ampicillin up to variable degrees. Interestingly, AgPtNHs could inhibit bacterial biofilm formation significantly. Hence, co-administration of AgPtNHs and antibiotics may serve as a powerful strategy to treat bacterial infections.

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