Antibacterial and antibiofilm effects of iron chelators against Prevotella intermedia

Prevotella intermedia, a major periodontopathogen, has been shown to be resistant to many antibiotics. In the present study, we examined the effect of the FDA-approved iron chelators deferoxamine (DFO) and deferasirox (DFRA) against planktonic and biofilm cells of P. intermedia in order to evaluate the possibility of using these iron chelators as alternative control agents against P. intermedia. DFRA showed strong antimicrobial activity (MIC and MBC values of 0.16 mg ml−1) against planktonic P. intermedia. At subMICs, DFRA partially inhibited the bacterial growth and considerably prolonged the bacterial doubling time. DFO was unable to completely inhibit the bacterial growth in the concentration range tested and was not bactericidal. Crystal violet binding assay for the assessment of biofilm formation by P. intermedia showed that DFRA significantly decreased the biofilm-forming activity as well as the biofilm formation, while DFO was less effective. DFRA was chosen for further study. In the ATP-bioluminescent assay, which reflects viable cell counts, subMICs of DFRA significantly decreased the bioactivity of biofilms in a concentration-dependent manner. Under the scanning electron microscope, P. intermedia cells in DFRA-treated biofilm were significantly elongated compared to those in untreated biofilm. Further experiments are necessary to show that iron chelators may be used as a therapeutic agent for periodontal disease.

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In VitroEffects of Polyphosphate against Prevotella intermedia in Planktonic Phase and Biofilm

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01861-15 ◽

2015 ◽

Vol 60 (2) ◽

pp. 818-826 ◽

Cited By ~ 4

Author(s):

Eun-Young Jang ◽

Minjung Kim ◽

Mi Hee Noh ◽

Ji-Hoi Moon ◽

Jin-Yong Lee

Keyword(s):

Biofilm Formation ◽

Sodium Tripolyphosphate ◽

Dilution Method ◽

Agar Dilution Method ◽

Prevotella Intermedia ◽

Dependent Manner ◽

Bacterial Cells ◽

Concentration Dependent Manner ◽

Content Type ◽

Planktonic Phase

ABSTRACTPolyphosphate (polyP) has gained a wide interest in the food industry due to its potential as a decontaminating agent. In this study, we examined the effect of sodium tripolyphosphate (polyP3; Na5P3O10) against planktonic and biofilm cells ofPrevotella intermedia, a major oral pathogen. The MIC of polyP3 againstP. intermediaATCC 49046 determined by agar dilution method was 0.075%, while 0.05% polyP3 was bactericidal againstP. intermediain time-kill analysis performed using liquid medium. A crystal violet binding assay for the assessment of biofilm formation byP. intermediashowed that sub-MICs of polyP3 significantly decreased biofilm formation. Under the scanning electron microscope, decreased numbers ofP. intermediacells forming the biofilms were observed when the bacterial cells were incubated with 0.025% or higher concentrations of polyP3. Assessment of biofilm viability with LIVE/DEAD staining and viable cell count methods showed that 0.05% or higher concentrations of polyP3 significantly decreased the viability of the preformed biofilms in a concentration-dependent manner. The zone sizes of alpha-hemolysis formed on horse blood agar produced byP. intermediawere decreased in the presence of polyP3. The expression of the genes encoding hemolysins and the genes of the hemin uptake (hmu) locus was downregulated by polyP3. Collectively, our results show that polyP is an effective antimicrobial agent againstP. intermediain biofilms as well as planktonic phase, interfering with the process of hemin acquisition by the bacterium.

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Antibacterial Effects of Bicarbonate in Media Modified to Mimic Cystic Fibrosis Sputum

International Journal of Molecular Sciences ◽

10.3390/ijms21228614 ◽

2020 ◽

Vol 21 (22) ◽

pp. 8614

Author(s):

Pongsiri Jaikumpun ◽

Kasidid Ruksakiet ◽

Balázs Stercz ◽

Éva Pállinger ◽

Martin Steward ◽

...

Keyword(s):

Cystic Fibrosis ◽

Biofilm Formation ◽

Pathogenic Bacteria ◽

Culture Media ◽

Anion Channel ◽

Ambient Air ◽

Hereditary Disease ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

Cell Counts

Cystic fibrosis (CF) is a hereditary disease caused by mutations in the gene encoding an epithelial anion channel. In CF, Cl− and HCO3− hyposecretion, together with mucin hypersecretion, leads to airway dehydration and production of viscous mucus. This habitat is ideal for colonization by pathogenic bacteria. We have recently demonstrated that HCO3− inhibits the growth and biofilm formation of Pseudomonas aeruginosa and Staphylococcus aureus when tested in laboratory culture media. Using the same bacteria our aim was to investigate the effects of HCO3− in artificial sputum medium (ASM), whose composition resembles CF mucus. Control ASM containing no NaHCO3 was incubated in ambient air (pH 7.4 or 8.0). ASM containing NaHCO3 (25 and 100 mM) was incubated in 5% CO2 (pH 7.4 and 8.0, respectively). Viable P. aeruginosa and S. aureus cells were counted by colony-forming unit assay and flow cytometry after 6 h and 17 h of incubation. Biofilm formation was assessed after 48 h. The data show that HCO3− significantly decreased viable cell counts and biofilm formation in a concentration-dependent manner. These effects were due neither to extracellular alkalinization nor to altered osmolarity. These results show that HCO3− exerts direct antibacterial and antibiofilm effects on prevalent CF bacteria.

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Inhibitory effect of a gel paste containing surface pre-reacted glass-ionomer (S-PRG) filler on the cariogenicity of Streptococcus mutans

Scientific Reports ◽

10.1038/s41598-021-02924-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Ryota Nomura ◽

Takahiro Kitamura ◽

Saaya Matayoshi ◽

Jumpei Ohata ◽

Yuto Suehiro ◽

...

Keyword(s):

Dental Caries ◽

Streptococcus Mutans ◽

Bacterial Growth ◽

Biofilm Formation ◽

Dental Materials ◽

Self Care ◽

Dependent Manner ◽

Glass Ionomer ◽

Inhibitory Effects ◽

Concentration Dependent Manner

AbstractSurface pre-reacted glass-ionomer (S-PRG) filler is a bioactive functional glass that releases six different ions. Although several dental materials containing S-PRG filler have been developed, few self-care products containing S-PRG filler have been reported. We investigated the inhibitory effects of PRG gel paste containing S-PRG filler on Streptococcus mutans, a major pathogen of dental caries. PRG gel paste inhibited bacterial growth of S. mutans in a concentration-dependent manner, and all S. mutans were killed in the presence of ≥ 1% PRG gel paste. Additionally, it was difficult for S. mutans to synthesize insoluble glucan from sucrose in the presence of 0.1% PRG gel paste. A biofilm formation model was prepared in which slices of bovine enamel were infected with S. mutans after treatment with or without PRG gel paste. Biofilm formation was inhibited significantly more on the enamel treated with PRG gel paste than on enamel without PRG gel paste (P < 0.001). The inhibitory effects on bacterial growth and biofilm formation were more prominent with PRG gel paste than with S-PRG-free gel paste, suggesting that PRG gel paste may be effective as a self-care product to prevent dental caries induced by S. mutans.

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An Alanine-Rich Peptide Attenuates Quorum Sensing-Regulated Virulence and Biofilm Formation in Staphylococcus aureus

Journal of AOAC International ◽

10.5740/jaoacint.18-0251 ◽

2019 ◽

Vol 102 (4) ◽

pp. 1228-1234 ◽

Cited By ~ 1

Author(s):

Raid Al Akeel ◽

Ayesha Mateen ◽

Rabbani Syed

Keyword(s):

Gene Expression ◽

Staphylococcus Aureus ◽

Quorum Sensing ◽

Biofilm Formation ◽

Bacterial Attachment ◽

The Body ◽

Dependent Manner ◽

Virulence Determinants ◽

Microarray Gene Expression ◽

Concentration Dependent Manner

Abstract Background: Alanine-rich proteins/peptides (ARP), with bioactivity of up to 20 amino acid residues, can be observed by the body easily during gastrointestinal digestion. Objective: Populus trichocarpa extract’s capability to attenuate quorum sensing-regulated virulence and biofilm formation in Staphylococcus aureus is described. Methods: PT13, an ARP obtained from P. trichocarpa, was tested for its activity against S. aureus using the broth microdilution test; a crystal-violet biofilm assay was performed under a scanning electron microscope. The production of various virulence factors was estimated with PT13 treatment. Microarray gene expression profiling of PT13-treated S. aureus was conducted and compared with an untreated control. Exopolysaccharides (EPS) was estimated to observe the PT13 inhibition activity. Results: PT13 was antimicrobial toward S. aureus at different concentrations and showed a similar growth rate in the presence and absence of PT13 at concentrations ≤8 μg/mL. Biofilm production was interrupted even at low concentrations, and biofilm-related genes were down-regulated when exposed to PT13. The genes encoding cell adhesion and bacterial attachment protein were the major genes suppressed by PT13. In addition, hemolysins, clumping activity, and EPS production of S. aureus decreased after treatment in a concentration-dependent manner. Conclusions: A long-chain PT13 with effective actions that, even at low concentration levels, not only regulated the gene expression in the producer organism but also blocked the virulence gene expression in this Gram-positive human pathogen is described. Highlights: We identified a PT13 as a potential antivirulence agent that regulated production of bacterial virulence determinants (e.g., toxins, enzymes and biofilm), downwards and it may be a promising anti-virulence agent to be further developed as an anti-infective agent.

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Effect of Lonicera caerulea var. emphyllocalyx Fruit on Biofilm Formed by Porphyromonas gingivalis

BioMed Research International ◽

10.1155/2019/3547858 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Masaaki Minami ◽

Hiroshi Takase ◽

Mineo Nakamura ◽

Toshiaki Makino

Keyword(s):

Oral Cavity ◽

Porphyromonas Gingivalis ◽

Aspiration Pneumonia ◽

Biofilm Formation ◽

Bacterial Colonization ◽

Bacterial Biofilm ◽

Dependent Manner ◽

Electron Microscopic ◽

Concentration Dependent Manner ◽

Lonicera Caerulea

Porphyromonas gingivalis is an important pathogenic anaerobic bacterium that causes aspiration pneumonia. This bacterium frequently forms biofilms in the oral cavity and in respiratory tract-associated medical devices. Bacterial colonization that occurs in association with this biofilm formation is the main reason for incurable aspiration pneumonia. The Lonicera caerulea var. emphyllocalyx (LCE) fruit has been used in folk medicine in Hokkaido, the northern part of Japan. The aim of this study was to elucidate one of the antimicrobial mechanisms of LCE methanol extract (LCEE)—the inhibitory effect of LCEE on biofilm formation by P. gingivalis. Our results show that LCEE significantly reduced biofilm formation by three different P. gingivalis isolates in a concentration- and time-dependent manner that were quantified by the adsorption of safranin red. When LCEE was added to biofilms already formed by P. gingivalis, LCEE did not degrade the biofilm. However, treatment with LCEE significantly promoted the removal of existing biofilm by vibration compared to that of control. We also confirmed biofilm formation in LCEE-treated P. gingivalis in tracheal tubes using scanning electron microscopic (SEM) analysis. Cyanidin 3-O-glucoside (C3G), one of the components of LCE, also inhibited the formation of biofilm by P. gingivalis in a concentration-dependent manner. Our results reveal that LCEE may be an effective antibacterial substance for P. gingivalis-induced aspiration pneumonia because of its role in the suppression of bacterial biofilm formation in the oral cavity.

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PYED-1 Inhibits Biofilm Formation and Disrupts the Preformed Biofilm of Staphylococcus aureus

Antibiotics ◽

10.3390/antibiotics9050240 ◽

2020 ◽

Vol 9 (5) ◽

pp. 240 ◽

Cited By ~ 1

Author(s):

Adriana Vollaro ◽

Anna Esposito ◽

Eliana Pia Esposito ◽

Raffaele Zarrilli ◽

Annalisa Guaragna ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Quorum Sensing ◽

Biofilm Formation ◽

Surface Proteins ◽

Transcriptional Analysis ◽

Capsular Polysaccharides ◽

Dependent Manner ◽

Chronic Infections ◽

Concentration Dependent Manner ◽

Expression Of Genes

Pregnadiene-11-hydroxy-16α,17α-epoxy-3,20-dione-1 (PYED-1), a heterocyclic corticosteroid derivative of deflazacort, exhibits broad-spectrum antibacterial activity against Gram-negative and Gram-positive bacteria. Here, we investigated the effect of PYED-1 on the biofilms of Staphylococcus aureus, an etiological agent of biofilm-based chronic infections such as osteomyelitis, indwelling medical device infections, periodontitis, chronic wound infections, and endocarditis. PYED-1 caused a strong reduction in biofilm formation in a concentration dependent manner. Furthermore, it was also able to completely remove the preformed biofilm. Transcriptional analysis performed on the established biofilm revealed that PYED-1 downregulates the expression of genes related to quorum sensing (agrA, RNAIII, hld, psm, and sarA), surface proteins (clfB and fnbB), secreted toxins (hla, hlb, and lukD), and capsular polysaccharides (capC). The expression of genes that encode two main global regulators, sigB and saeR, was also significantly inhibited after treatment with PYED-1. In conclusion, PYED-1 not only effectively inhibited biofilm formation, but also eradicated preformed biofilms of S. aureus, modulating the expression of genes related to quorum sensing, surface and secreted proteins, and capsular polysaccharides. These results indicated that PYED-1 may have great potential as an effective antibiofilm agent to prevent S. aureus biofilm-associated infections.

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Evaluation of T-3811ME (BMS-284756), a New Des-F(6)-Quinolone, for Treatment of Meningitis Caused by Penicillin-Resistant Streptococcus pneumoniae in Rabbits

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.46.6.1760-1765.2002 ◽

2002 ◽

Vol 46 (6) ◽

pp. 1760-1765 ◽

Cited By ~ 2

Author(s):

Masahiro Takahata ◽

Hiroshi Yamada ◽

Teiichi Morita ◽

Shinichi Furubou ◽

Shinzaburo Minami ◽

...

Keyword(s):

Streptococcus Pneumoniae ◽

Viable Cell ◽

Treated Group ◽

Dependent Manner ◽

Free Base ◽

Time Curve ◽

Gram Positive Bacteria ◽

Cell Counts ◽

Concentration Time ◽

Dose Dependent

ABSTRACT T-3811ME (BMS-284756) is a new des-F(6)-quinolone with high levels of activity against gram-positive bacteria, including penicillin-resistant Streptococcus pneumoniae (PRSP) strains. T-3811, the free base of T-3811ME, exhibited potent activity against 28 clinical strains of PRSP isolated clinically (MIC at which 90% of the isolates tested are inhibited, 0.0625 μg/ml). After the intravenous dosing of T-3811ME (20 mg/kg of body weight as T-3811) in rabbits with meningitis caused by PRSP, the area under the concentration-time curve (AUC) of T-3811 in cerebrospinal fluid (CSF) was 5.79 μg · h/ml and was 4.5-fold higher than that of T-3811in the CSF of rabbits without meningitis. In addition, the AUC/MIC for T-3811ME (20 mg/kg as T-3811) in CSF was 185, which was 4.3-fold higher than that for ceftriaxone (administered intravenously at 100 mg/kg). After the administration of any dose of T-3811ME (5, 10, and 20 mg/kg as T-3811), the viable cell counts in CSF decreased in a dose-dependent manner. In particular, after dosing of 20 mg/kg (as T-3811), the viable cell counts in CSF were significantly less than those in the nontreated group (P < 0.01). By histopathological evaluation, 6 h after the administration of T-3811ME (20 mg/kg as T-3811), the thickening of the cerebral meninx and the infiltration of neutrophils into the cerebral meninx were less severe in the treated group than in the nontreated group. T-3811ME (BMS-284756) may be expected to be evaluated for the management of meningitis caused by highly penicillin-resistant pneumococci.

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Antimicrobial Effects of Equine Platelet Lysate

Frontiers in Veterinary Science ◽

10.3389/fvets.2021.703414 ◽

2021 ◽

Vol 8 ◽

Author(s):

Julie Gordon ◽

Sonsiray Álvarez-Narváez ◽

John F. Peroni

Keyword(s):

Bacterial Growth ◽

Antimicrobial Properties ◽

Normal Growth ◽

Platelet Lysate ◽

Resistant Bacteria ◽

Growth Media ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

E Coli

The development of antimicrobial resistant bacteria and the lack of novel antibiotic strategies to combat those bacteria is an ever-present problem in both veterinary and human medicine. The goal of this study is to evaluate platelet lysate (PL) as a biological alternative antimicrobial product. Platelet lysate is an acellular platelet-derived product rich in growth factors and cytokines that is manufactured via plateletpheresis and pooled from donor horses. In the current study, we sought to define the antimicrobial properties of PL on select gram-positive and gram-negative bacteria. Results from an end-point in vitro assay showed that PL did not support bacterial growth, and in fact significantly reduced bacterial content compared to normal growth media. An in vitro assay was then utilized to further determine the effects on bacterial growth dynamics and showed that all strains exhibited a slower growth rate and lower yield in the presence of PL. The specific effects of PL were unique for each bacterial strain: E. coli and P. aeruginosa growth was affected in a concentration-dependent manner, such that higher amounts of PL had a greater effect, while this was not true for S. aureus or E. faecalis. Furthermore, the onset of exponential growth was delayed for E. coli and P. aeruginosa in the presence of PL, which has significant clinical implications for developing a dosing schedule. In conclusion, our findings demonstrate the potential value of PL as a broad-spectrum antimicrobial that would offer an alternative to traditional antibiotics for the treatment of bacterial infection in equine species.

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Antibiotic-Loaded Synthetic Calcium Sulfate Beads for Prevention of Bacterial Colonization and Biofilm Formation in Periprosthetic Infections

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.03676-14 ◽

2014 ◽

Vol 59 (1) ◽

pp. 111-120 ◽

Cited By ~ 102

Author(s):

R. P. Howlin ◽

M. J. Brayford ◽

J. S. Webb ◽

J. J. Cooper ◽

S. S. Aiken ◽

...

Keyword(s):

Biofilm Formation ◽

Calcium Sulfate ◽

Periprosthetic Infection ◽

Bacterial Colonization ◽

Viable Cell ◽

Surgical Removal ◽

Content Type ◽

Cell Counts ◽

Antibiotic Release ◽

Prosthesis Material

ABSTRACTPeriprosthetic infection (PI) causes significant morbidity and mortality after fixation and joint arthroplasty and has been extensively linked to the formation of bacterial biofilms. Poly(methyl methacrylate) (PMMA), as a cement or as beads, is commonly used for antibiotic release to the site of infection but displays variable elution kinetics and also represents a potential nidus for infection, therefore requiring surgical removal once antibiotics have eluted. Absorbable cements have shown improved elution of a wider range of antibiotics and, crucially, complete biodegradation, but limited data exist as to their antimicrobial and antibiofilm efficacy. Synthetic calcium sulfate beads loaded with tobramycin, vancomycin, or vancomycin-tobramycin dual treatment (in a 1:0.24 [wt/wt] ratio) were assessed for their abilities to eradicate planktonic methicillin-resistantStaphylococcus aureus(MRSA) andStaphylococcus epidermidisrelative to that of PMMA beads. The ability of the calcium sulfate beads to prevent biofilm formation over multiple days and to eradicate preformed biofilms was studied using a combination of viable cell counts, confocal microscopy, and scanning electron microscopy of the bead surface. Biofilm bacteria displayed a greater tolerance to the antibiotics than their planktonic counterparts. Antibiotic-loaded beads were able to kill planktonic cultures of 106CFU/ml, prevent bacterial colonization, and significantly reduce biofilm formation over multiple days. However, established biofilms were harder to eradicate. These data further demonstrate the difficulty in clearing established biofilms; therefore, early preventive measures are key to reducing the risk of PI. Synthetic calcium sulfate loaded with antibiotics has the potential to reduce or eliminate biofilm formation on adjacent periprosthetic tissue and prosthesis material and, thus, to reduce the rates of periprosthetic infection.

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Cellular Responses to Postsegregational Killing by Restriction-Modification Genes

Journal of Bacteriology ◽

10.1128/jb.182.8.2218-2229.2000 ◽

2000 ◽

Vol 182 (8) ◽

pp. 2218-2229 ◽

Cited By ~ 62

Author(s):

Naofumi Handa ◽

Asao Ichige ◽

Kohji Kusano ◽

Ichizo Kobayashi

Keyword(s):

Viable Cell ◽

Underlying Mechanism ◽

Temperature Sensitive ◽

Dependent Manner ◽

Bacterial Cells ◽

Gene Complex ◽

Cellular Processes ◽

Cell Counts ◽

Gene Complexes ◽

Restriction Modification

ABSTRACT Plasmids that carry one of several type II restriction modification gene complexes are known to show increased stability. The underlying mechanism was proposed to be the lethal attack by restriction enzyme at chromosomal recognition sites in cells that had lost the restriction modification gene complex. In order to examine bacterial responses to this postsegregational cell killing, we analyzed the cellular processes following loss of the EcoRI restriction modification gene complex carried by a temperature-sensitive plasmid in anEscherichia coli strain that is wild type with respect to DNA repair. A shift to the nonpermissive temperature blocked plasmid replication, reduced the increase in viable cell counts and resulted in loss of cell viability. Many cells formed long filaments, some of which were multinucleated and others anucleated. In a mutant defective in RecBCD exonuclease/recombinase, these cell death symptoms were more severe and cleaved chromosomes accumulated. Growth inhibition was also more severe in recA, ruvAB, ruvC,recG, and recN mutants. The cells induced the SOS response in a RecBC-dependent manner. These observations strongly suggest that bacterial cells die as a result of chromosome cleavage after loss of a restriction modification gene complex and that the bacterial RecBCD/RecA machinery helps the cells to survive, at least to some extent, by repairing the cleaved chromosomes. These and previous results have led us to hypothesize that the RecBCD/Chi/RecA system serves to destroy restricted “nonself” DNA and repair restricted “self” DNA.

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