scholarly journals Furanone at Subinhibitory Concentrations Enhances Staphylococcal Biofilm Formation by luxS Repression

2009 ◽  
Vol 53 (10) ◽  
pp. 4159-4166 ◽  
Author(s):  
Richard Kuehl ◽  
Sameer Al-Bataineh ◽  
Oliver Gordon ◽  
Reto Luginbuehl ◽  
Michael Otto ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Poly Ethylene Glycol ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Murine Fibroblasts ◽  
Delisea Pulchra ◽  
Subinhibitory Concentrations ◽  
Poly Ethylene ◽  
Brominated Furanones

ABSTRACT Brominated furanones from marine algae inhibit multicellular behaviors of gram-negative bacteria such as biofilm formation and quorum sensing (QS) without affecting their growth. The interaction of furanone with QS in gram-positive bacteria is unknown. Staphylococci have two QS systems, agr and luxS, which lower biofilm formation by two different pathways, RNAIII upregulation and bacterial detachment, and polysaccharide intercellular adhesin (PIA) reduction, respectively. We synthesized natural furanone compound 2 [(5Z)-4-bromo-5-(bromomethylene)-3-butyl-2(5H)-furanone] from Delisea pulchra and three analogues to investigate their effect on biofilm formation in gram-positive bacteria. Compound 2, but not the analogues, enhanced the biofilms of Staphylococcus epidermidis 1457 and 047 and of S. aureus Newman at concentrations between 1.25 and 20 μM. We show the growth inhibition of S. epidermidis and S. aureus by free furanone and demonstrate bactericidal activity. An induction of biofilm occurred at concentrations of 10 to 20% of the MIC and correlated with an increase in PIA. The biofilm effect was agr independent. It was due to interference with luxS, as shown by reduced luxS expression in the presence of compound 2 and independence of the strong biofilm formation in a luxS mutant upon furanone addition. Poly(l-lysine)-grafted/poly(ethylene glycol)-grafted furanone was ineffective on biofilm and not bactericidal, indicating the necessity for free furanone. Free furanone was similarly toxic for murine fibroblasts as for staphylococci, excluding a therapeutic application of this compound. In summary, we observed a biofilm enhancement by furanone in staphylococci at subinhibitory concentrations, which was manifested by an increase in PIA and dependent on luxS.

scholarly journals Clinical Evaluation of the iCubate iC-GPC Assay for Detection of Gram-Positive Bacteria and Resistance Markers from Positive Blood Cultures

2018 ◽  
Vol 56 (9) ◽  
Author(s):  
Paul A. Granato ◽  
Melissa M. Unz ◽  
Raymond H. Widen ◽  
Suzane Silbert ◽  
Stephen Young ◽  
...  
Keyword(s):  
Blood Culture ◽  
Staphylococcus Epidermidis ◽  
Bloodstream Infections ◽  
Blood Cultures ◽  
Gram Positive ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Sequencing Method ◽  
Resistance Markers ◽  
Gram Positive Cocci

ABSTRACT The iC-GPC Assay (iCubate, Huntsville, AL) is a qualitative multiplex test for the detection of five of the most common Gram-positive bacteria (Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pneumoniae, Enterococcus faecalis, and Enterococcus faecium) responsible for bacterial bloodstream infections, performed directly from positive blood cultures. The assay also detects the presence of the mecA, vanA, and vanB resistance determinants. This study comparatively evaluated the performance of the iC-GPC Assay against the Verigene Gram-positive blood culture (BC-GP) assay (Luminex Corp., Austin, TX) for 1,134 patient blood culture specimens positive for Gram-positive cocci. The iC-GPC Assay had an overall percent agreement with the BC-GP assay of 95.5%. Discordant specimens were further analyzed by PCR and a bidirectional sequencing method. The results indicate that the iC-GPC Assay together with the iCubate system is an accurate and reliable tool for the detection of the five most common Gram-positive bacteria and their resistance markers responsible for bloodstream infections.

Prodigiosin from an Endofungal Bacterium Serratia marcescens D1 Inhibits Biofilm Formation in Gram-Positive Bacteria

Microbiology ◽  
2021 ◽  
Vol 90 (6) ◽  
pp. 829-838
Author(s):  
D. J. Hazarika ◽  
M. Kakoti ◽  
R. Kalita ◽  
T. Gautom# ◽  
G. Goswami ◽  
...  
Keyword(s):  
Serratia Marcescens ◽  
Biofilm Formation ◽  
Gram Positive ◽  
Gram Positive Bacteria

scholarly journals In-Silico Identified New Natural Sortase A Inhibitors Disrupt S. aureus Biofilm Formation

2020 ◽  
Vol 21 (22) ◽  
pp. 8601
Author(s):  
Kishore Reddy Venkata Thappeta ◽  
Li Na Zhao ◽  
Choy Eng Nge ◽  
Sharon Crasta ◽  
Chung Yan Leong ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Natural Compound ◽  
Microbial Growth ◽  
Bacterial Pathogenesis ◽  
Bacterial Virulence ◽  
Sortase A ◽  
Compound Library ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Mammalian Toxicity

Sortase A (SrtA) is a membrane-associated enzyme that anchors surface-exposed proteins to the cell wall envelope of Gram-positive bacteria such as Staphylococcus aureus. As SrtA is essential for Gram-positive bacterial pathogenesis but dispensable for microbial growth or viability, SrtA is considered a favorable target for the enhancement of novel anti-infective drugs that aim to interfere with key bacterial virulence mechanisms, such as biofilm formation, without developing drug resistance. Here, we used virtual screening to search an in-house natural compound library and identified two natural compounds, N1287 (Skyrin) and N2576 ((4,5-dichloro-1H-pyrrol-2-yl)-[2,4-dihydroxy-3-(4-methyl-pentyl)-phenyl]-methanone) that inhibited the enzymatic activity of SrtA. These compounds also significantly reduced the growth of S. aureus but possessed moderate mammalian toxicity. Furthermore, S. aureus strains treated with these compounds exhibited reduction in adherence to host fibrinogen, as well as biofilm formation. Hence, these compounds may represent an anti-infective therapy without the side effects of antibiotics.

scholarly journals Effects of oregano, carvacrol and thymol on Staphylococcus aureus and Staphylococcus epidermidis biofilms

2007 ◽  
Vol 56 (4) ◽  
pp. 519-523 ◽  
Author(s):  
Antonia Nostro ◽  
Andrea Sudano Roccaro ◽  
Giuseppe Bisignano ◽  
Andreana Marino ◽  
Maria A. Cannatelli ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Essential Oil ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Inhibitory Concentration ◽  
Oregano Essential Oil ◽  
Planktonic Growth ◽  
Subinhibitory Concentrations

The aim of this study was to evaluate the effect of oregano essential oil, carvacrol and thymol on biofilm-grown Staphylococcus aureus and Staphylococcus epidermidis strains, as well as the effects of the oils on biofilm formation. For most of the S. aureus (n=6) and S. epidermidis (n=6) strains tested, the biofilm inhibitory concentration (0.125–0.500 %, v/v, for oregano, and 0.031–0.125 %, v/v, for carvacrol and thymol) and biofilm eradication concentration (0.25–1.0 %, v/v, for oregano and 0.125–0.500 %, v/v, for carvacrol and thymol) values were twofold or fourfold greater than the concentration required to inhibit planktonic growth. Subinhibitory concentrations of the oils attenuated biofilm formation of S. aureus and S. epidermidis strains on polystyrene microtitre plates.

Influences of graphene oxide on biofilm formation of gram-negative and gram-positive bacteria

2017 ◽  
Vol 25 (3) ◽  
pp. 2853-2860 ◽  
Author(s):  
Chao Song ◽  
Chun-Miao Yang ◽  
Xue-Fei Sun ◽  
Peng-Fei Xia ◽  
Jing Qin ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Biofilm Formation ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

scholarly journals Enterococcus faecalis and pathogenic streptococciinactivate daptomycin by releasing phospholipids

2017 ◽  
Author(s):  
Elizabeth V. K. Ledger ◽  
Vera Pader ◽  
Andrew M. Edwards
Keyword(s):  
Staphylococcus Aureus ◽  
Enterococcus Faecalis ◽  
Staphylococcus Epidermidis ◽  
Defence Mechanism ◽  
Membrane Phospholipids ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Group A ◽  
Partial Inactivation ◽  
Lipopeptide Antibiotic

SummaryDaptomycin is a lipopeptide antibiotic with activity against Gram-positive bacteria. We have shown previously thatStaphylococcus aureuscan survive daptomycin exposure by releasing membrane phospholipids that inactivate the antibiotic. To determine whether other pathogens possess this defence mechanism, phospholipid release and daptomycin activity were measured after incubation ofStaphylococcus epidermidis, Group A or B streptococci,Streptococcus gordoniiorEnterococcus faecaliswith the antibiotic. All bacteria released phospholipid in response to daptomycin, which resulted in at least partial inactivation of the antibiotic. However,E. faecalisshowed the highest levels of lipid release and daptomycin inactivation. As shown previously forS. aureus, phospholipid release byE. faecaliswas inhibited by the lipid biosynthesis inhibitor platensimycin. In conclusion, several pathogenic Gram-positive bacteria, includingE. faecalis, inactivate daptomycin by releasing phospholipids, which may contribute to the failure of daptomycin to resolve infections caused by these pathogens.

scholarly journals Antibacterial activity of Beta vulgaris L. pomace extract

2011 ◽  
pp. 263-269 ◽  
Author(s):  
Aleksandra Velicanski ◽  
Dragoljub Cvetkovic ◽  
Sinisa Markov ◽  
Jelena Vulic ◽  
Sonja Djilas
Keyword(s):  
Antibacterial Activity ◽  
Beta Vulgaris ◽  
Staphylococcus Epidermidis ◽  
Control Sample ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Natural Isolates

Antibacterial activity of Beta vulgaris L. (beetroot) pomace extract (concentration 100 mg/ml) was tested against five Gram positive and seven Gram negative bacterial strains (reference cultures and natural isolates). Disc diffusion method with 15 ?l of extract and agar-well diffusion method with 50 and 100 ?l were used. Antibiotic (cefotaxime/clavulanic acid) was used as a control sample. The tested extract showed the highest activity against Staphylococcus aureus and Bacillus cereus, where clear zones (without growth) appeared. There was no any activity against other tested Gram-positive bacteria, except for Staphylococcus epidermidis, with a small zone of reduced growth. Growth of all tested Gram-negative bacteria was inhibited usually with 100 ?l of extract. The most susceptible were Citrobacter freundii and Salmonella typhymurium. The tested antibiotic gave clear, usually large zones for all tested strains except for Staphylococcus cohni spp. cohni, where only a zone of reduced growth appeared.

scholarly journals Polymer Adhesin Domains in Gram-Positive Cell Surface Proteins

2020 ◽  
Vol 11 ◽  
Author(s):  
Michael A. Järvå ◽  
Helmut Hirt ◽  
Gary M. Dunny ◽  
Ronnie P.-A. Berntsson
Keyword(s):  
Protein Function ◽  
Biofilm Formation ◽  
Lipoteichoic Acid ◽  
Surface Proteins ◽  
Protein Domain ◽  
Gram Positive ◽  
Surface Attachment ◽  
Gram Positive Bacteria ◽  
Different Types ◽  
Host Cell Interactions

Surface proteins in Gram-positive bacteria are often involved in biofilm formation, host-cell interactions, and surface attachment. Here we review a protein module found in surface proteins that are often encoded on various mobile genetic elements like conjugative plasmids. This module binds to different types of polymers like DNA, lipoteichoic acid and glucans, and is here termed polymer adhesin domain. We analyze all proteins that contain a polymer adhesin domain and classify the proteins into distinct classes based on phylogenetic and protein domain analysis. Protein function and ligand binding show class specificity, information that will be useful in determining the function of the large number of so far uncharacterized proteins containing a polymer adhesin domain.

Genetic tools derived from Staphylococcus aureus for biotechnological applications in Gram-positive bacteria

2021 ◽  
Author(s):  
◽  
Pedro Dorado Morales
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Small Rnas ◽  
Infectious Agents ◽  
Biotechnological Applications ◽  
Gram Positive ◽  
Genetic Tools ◽  
Cellular Processes ◽  
Gram Positive Bacteria ◽  
Regulatory Functions

Staphylococcus aureus is a versatile human pathogen that has emerged as one of the most successful infectious agents of recent times, able to cause a range of diseases including skin and soft tissue infections, endocarditis, sepsis, pneumonia, osteomyelitis, bacteremia, and abscesses in organ tissues. Besides its clinical relevance, S. aureus has served as a model to study fundamental cellular processes, such as biofilm formation, the regulatory functions of small RNAs or growth and division of spherical cocci. Based on the accumulated knowledge of S. aureus biology, the availability of database resources and the advances in high-throughput genome sequencing, in this work we have aimed at developing new genetic tools derived from S. aureus for biotechnological applications in Gram-positive bacteria.

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