scholarly journals Antibiofilm Effects of Azithromycin and Erythromycin on Porphyromonas gingivalis

2011 ◽  
Vol 55 (12) ◽  
pp. 5887-5892 ◽  
Author(s):  
H. Maezono ◽  
Y. Noiri ◽  
Y. Asahi ◽  
M. Yamaguchi ◽  
R. Yamamoto ◽  
...  
Keyword(s):  
Porphyromonas Gingivalis ◽  
Laser Scanning ◽  
Cell Model ◽  
Static Model ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Chronic Infections ◽  
Content Type ◽  
Periapical Periodontitis

ABSTRACTAntibiotic resistance of biofilm-grown bacteria contributes to chronic infections, such as marginal and periapical periodontitis, which are strongly associated withPorphyromonas gingivalis. Concurrent azithromycin (AZM) administration and mechanical debridement improve the clinical parameters of periodontal tissuein situ. We examined thein vitroefficacy of AZM againstP. gingivalisbiofilms. The susceptibilities of adherentP. gingivalisstrains 381, HW24D1, 6/26, and W83 to AZM, erythromycin (ERY), ampicillin (AMP), ofloxacin (OFX), and gentamicin (GEN) were investigated using a static model. The optical densities of adherentP. gingivaliscells were significantly decreased by using AZM and ERY at sub-MIC levels compared with those of the controls in all the strains tested, except for the effect of ERY on strain W83. AMP and OFX inhibitedP. gingivalisadherent cells at levels over their MICs, and GEN showed no inhibition in the static model. The effects of AZM and ERY against biofilm cells were investigated using a flow cell model. The ATP levels ofP. gingivalisbiofilms were significantly decreased by AZM at concentrations below the sub-MICs; however, ERY was not effective for inhibition ofP. gingivalisbiofilm cells at their sub-MICs. Furthermore, decreased density ofP. gingivalisbiofilms was observed three-dimensionally with sub-MIC AZM, using confocal laser scanning microscopy. These findings suggest that AZM is effective againstP. gingivalisbiofilms at sub-MIC levels and could have future clinical application for oral biofilm infections, such as chronic marginal and periapical periodontitis.

scholarly journals Enhancement of Vancomycin Activity against Biofilms by Using Ultrasound-Targeted Microbubble Destruction

2011 ◽  
Vol 55 (11) ◽  
pp. 5331-5337 ◽  
Author(s):  
Nianan He ◽  
Jian Hu ◽  
Huayong Liu ◽  
Tao Zhu ◽  
Beijian Huang ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Laser Scanning ◽  
Rabbit Model ◽  
Antibiotic Activity ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Content Type ◽  
Implanted Medical Devices

ABSTRACTTreating biofilm infections on implanted medical devices is formidable, even with extensive antibiotic therapy. The aim of this study was to investigate whether ultrasound (US)-targeted microbubble (MB) destruction (UTMD) could enhance vancomycin activity againstStaphylococcus epidermidisRP62A biofilms. Twelve-hour biofilms were treated with vancomycin combined with UTMD. The vancomycin and MB (SonoVue) were used at concentrations of 100 μg/ml and 30% (vol/vol), respectively, in studiesin vitro. After US exposure (0.08 MHz, 1.0 W/cm2, 50% duty cycle, and 10-min duration), the biofilms were cultured at 37°C for another 12 h. The results showed that many micropores were found in biofilms treated with vancomycin combined with UTMD. Biofilm densities (A570values) and the viable counts ofS. epidermidisrecovered from the biofilm were significantly decreased compared with those of any other groups. Furthermore, the highest percentage of dead cells was found, using confocal laser scanning microscopy, in the biofilm treated with vancomycin combined with UTMD. The viable counts of bacteria in biofilms in anin vivorabbit model also confirmed the enhanced effect of vancomycin combined with UTMD. UTMD may have great potential for improving antibiotic activity against biofilm infections.

scholarly journals Characterization of a mucoid-like Pseudomonas aeruginosa biofilm

Fine Focus ◽  
2015 ◽  
Vol 1 (2) ◽  
pp. 121-137
Author(s):  
Brandon M. Bauer ◽  
Lewis Rogers ◽  
Monique Macias ◽  
Gabriella Iacovetti ◽  
Alexander M. Woodrow ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Laser Scanning ◽  
Growth Conditions ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Chronic Infections ◽  
Planktonic Bacteria ◽  
The Difference

Pseudomonas aeruginosa biofilms are implicated in chronic infections. A key element of P. aeruginosapathogenicity is the formation of a biofilm, a community of bacteria encased in an exopolymeric substance (EPS) that shields the bacteria from the host immune response and antibiotic treatment. A crucial step in biofilm production is a switch in motility from freely swimming, planktonic bacteria to twitching movement and then to attached and sedentary bacteria that develop into a mature pillar-shaped biofilm. A mucoid biofilm produces an excess of alginate and is clinically the most pathogenic and the most resistant to antibiotics. Biofilms from patients exhibit a wide variety of structure, motility, and levels of attachment. In vitrobiofilms do not exhibit such a wide variety of structure and physiology. The difference between in vivo and in vitro biofilms has made the translation of in vitro studies into in vivo treatments difficult. Under different growth conditions in our lab, the P. aeruginosa strain PAO1 demonstrates two phenotypes: a non-mucoid and a mucoid-like phenotype. Confocal laser scanning microscopy (CLSM) indicates the mucoid-like phenotype is intermediate in height to the non-mucoid phenotype and biofilms formed in a once-flow-through chamber. Both mucoid-like and non-mucoid phenotypes exhibit a significant increase in twitching between 24 and 72 hours of development. The mucoid-like phenotype had greater attachment at 72 hours compared to non-mucoid phenotype. Therefore, the two phenotypes observed in our lab may represent the effect of environment to stimulate development of two types of biofilms by PAO1.

scholarly journals Novel Model for Multispecies Biofilms That Uses Rigid Gas-Permeable Lenses

2011 ◽  
Vol 77 (10) ◽  
pp. 3413-3421 ◽  
Author(s):  
Rebecca Peyyala ◽  
Sreenatha S. Kirakodu ◽  
Jeffrey L. Ebersole ◽  
Karen F. Novak
Keyword(s):  
Laser Scanning ◽  
Bacterial Species ◽  
Disease Process ◽  
Laser Scanning Microscopy ◽  
Host Cells ◽  
Confocal Laser ◽  
Content Type ◽  
Oral Biofilms ◽  
Multispecies Biofilms

ABSTRACTOral biofilms comprise complex multispecies consortia aided by specific inter- and intraspecies interactions occurring among commensals and pathogenic bacterial species. Oral biofilms are primary initiating factors of periodontal disease, although complex multifactorial biological influences, including host cell responses, contribute to the individual outcome of the disease. To provide a system to study initial stages of interaction between oral biofilms and the host cells that contribute to the disease process, we developed a novelin vitromodel system to grow biofilms on rigid gas-permeable contact lenses (RGPLs), which enable oxygen to permeate through the lens material. Bacterial species belonging to early- and late-colonizing groups were successfully established as single- or three-species biofilms, with each group comprisingStreptococcus gordonii,Streptococcus oralis, andStreptococcus sanguinis;S. gordonii,Actinomyces naeslundii, andFusobacterium nucleatum; orS. gordonii,F. nucleatum, andPorphyromonas gingivalis. Quantification of biofilm numbers by quantitative PCR (qPCR) revealed substantial differences in the magnitude of bacterial numbers in single-species and multispecies biofilms. We evaluated cell-permeable conventional nucleic acid stains acridine orange, hexidium iodide, and Hoechst 33258 and novel SYTO red, blue, and green fluorochromes for their effect on bacterial viability and fluorescence yield to allow visualization of the aggregates of individual bacterial species by confocal laser scanning microscopy (CLSM). Substantial differences in the quantity and distribution of the species in the multispecies biofilms were identified. The specific features of these biofilms may help us better understand the role of various bacteria in local challenge of oral tissues.

scholarly journals Interactions between Polymorphonuclear Leukocytes and Pseudomonas aeruginosa Biofilms on Silicone ImplantsIn Vivo

2012 ◽  
Vol 80 (8) ◽  
pp. 2601-2607 ◽  
Author(s):  
Maria van Gennip ◽  
Louise Dahl Christensen ◽  
Morten Alhede ◽  
Klaus Qvortrup ◽  
Peter Østrup Jensen ◽  
...  
Keyword(s):  
Immune Response ◽  
Pseudomonas Aeruginosa ◽  
Polymorphonuclear Leukocytes ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Chronic Infections ◽  
Content Type ◽  
Biofilm Development

ABSTRACTChronic infections withPseudomonas aeruginosapersist because the bacterium forms biofilms that are tolerant to antibiotic treatment and the host immune response. Scanning electron microscopy and confocal laser scanning microscopy were used to visualize biofilm developmentin vivofollowing intraperitoneal inoculation of mice with bacteria growing on hollow silicone tubes, as well as to examine the interaction between these bacteria and the host innate immune response. Wild-typeP. aeruginosadeveloped biofilms within 1 day that trapped and caused visible cavities in polymorphonuclear leukocytes (PMNs). In contrast, the number of cells of aP. aeruginosa rhlAmutant that cannot produce rhamnolipids was significantly reduced on the implants by day 1, and the bacteria were actively phagocytosed by infiltrating PMNs. In addition, we identified extracellular wire-like structures around the bacteria and PMNs, which we found to consist of DNA and other polymers. Here we present a novel method to study a pathogen-host interaction in detail. The data presented provide the first direct, high-resolution visualization of the failure of PMNs to protect against bacterial biofilms.

scholarly journals Biofilms of Mycobacterium abscessus Complex Can Be Sensitized to Antibiotics by Disaggregation and Oxygenation

2019 ◽  
Vol 64 (2) ◽  
Author(s):  
Mette Kolpen ◽  
Peter Østrup Jensen ◽  
Tavs Qvist ◽  
Kasper Nørskov Kragh ◽  
Cecillie Ravnholt ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Tween 80 ◽  
Drug Susceptibility Testing ◽  
Mycobacterium Abscessus ◽  
Growth Patterns ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Biofilm Growth ◽  
Content Type

ABSTRACT Pulmonary infection with the multidrug-resistant Mycobacterium abscessus complex (MABSC) is difficult to treat in individuals with cystic fibrosis (CF). MABSC grows as biofilm aggregates in CF patient lungs, which are known to have anaerobic niches. How aggregation and anoxic conditions affect antibiotic tolerance is not well understood. We sought to determine whether disaggregation and oxygen availability sensitize MABSC isolates to recommended antibiotics. We tested the susceptibilities of 33 isolates from 22 CF patients with MABSC infection and a reference strain to the following antibiotics: amikacin, azithromycin, cefoxitin, ciprofloxacin, clarithromycin, imipenem, kanamycin, linezolid, moxifloxacin, rifampin, tigecycline, and sulfamethoxazole-trimethoprim. Isolates were grown in Mueller-Hinton broth with and without the disaggregating detergent Tween 80 (5%). Time-kill curves at days 1 and 3 were generated for oxic and anoxic amikacin treatment in 4-fold dilutions ranging from 2 to 512 mg liter−1. Scanning electron microscopy was used to visualize the aggregation patterns, while confocal laser scanning microscopy and microrespirometry were used to visualize biofilm growth patterns. Disruption of MABSC aggregates increased susceptibility to amikacin, tigecycline, kanamycin, azithromycin, imipenem, cefoxitin, and clarithromycin (P < 0.05, n = 29 to 31). Oxygenation enhanced the killing of disaggregated MABSC isolates by amikacin (P < 0.05) by 1 to 6 log units when 2 to 512 mg liter−1 of amikacin was used. This study explains why current drug susceptibility testing results correlate poorly with treatment outcomes. The conditions achieved by oxic culturing of planktonic isolates in vitro do not resemble the hypoxic conditions in CF patient lungs. Biofilm disruption and increased O2 availability during antibiotic therapy may be new therapeutic strategies for chronic MABSC infection.

scholarly journals R-Thanatin Inhibits Growth and Biofilm Formation of Methicillin-Resistant Staphylococcus epidermidisIn VivoandIn Vitro

2013 ◽  
Vol 57 (10) ◽  
pp. 5045-5052 ◽  
Author(s):  
Zheng Hou ◽  
Fei Da ◽  
Baohui Liu ◽  
Xiaoyan Xue ◽  
Xiuli Xu ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Drug Candidate ◽  
Coagulase Negative Staphylococci ◽  
Methicillin Resistant ◽  
Content Type

ABSTRACTStaphylococcus epidermidisis one of the most frequent causes of device-associated infections, because it is known to cause biofilms that grow on catheters or other surgical implants. The persistent increasing resistance ofS. epidermidisand other coagulase-negative staphylococci (CoNS) has driven the need for newer antibacterial agents with innovative therapeutic strategies. Thanatin is reported to display potent antibiotic activities, especially against extended-spectrum-beta-lactamase-producingEscherichia coli. The present study aimed to investigate whether a shorter derivative peptide (R-thanatin) could be used as a novel antibacterial agent. We found that R-thanatin was highly potentin vitroagainst coagulase-negative staphylococci, such asS. epidermidis,S. haemolyticus, andS. hominis, and inhibited biofilm formation at subinhibitory concentrations. Properties of little toxicity to human red blood cells (hRBCs) and human umbilical vein endothelial cells, a low incidence of resistance, and relatively high stability in plasma were confirmed. Excellentin vivoprotective effects were also observed using a methicillin-resistantS. epidermidis(MRSE)-induced urinary tract infection rat model. Electron microscopy and confocal laser-scanning microscopy analyses suggested that R-thanatin disturbed cell division of MRSE severely, which might be the reason for inhibition of MRSE growth. These findings indicate that R-thanatin is active against the growth and biofilm formation of MRSEin vitroandin vivo. R-thanatin might be considered as a specific drug candidate for treating CoNS infections.

scholarly journals Amphotericin B Polymer Nanoparticles Show Efficacy against Candida Species Biofilms

Pathogens ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 73
Author(s):  
Abdughani Alakkad ◽  
Paul Stapleton ◽  
Corinna Schlosser ◽  
Sudaxshina Murdan ◽  
Uchechukwu Odunze ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Laser Scanning ◽  
Fungal Infections ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Eye Drops ◽  
Chronic Infections ◽  
Candida Biofilm ◽  
Stability Results

Purpose: Chronic infections of Candida albicans are characterised by the embedding of budding and entwined filamentous fungal cells into biofilms. The biofilms are refractory to many drugs and Candida biofilms are associated with ocular fungal infections. The objective was to test the activity of nanoparticulate amphotericin B (AmB) against Candida biofilms. Methods: AmB was encapsulated in the Molecular Envelope Technology (MET, N-palmitoyl-N-monomethyl-N,N-dimethyl-N,N,N-trimethyl-6-O-glycolchitosan) nanoparticles and tested against Candida biofilms in vitro. Confocal laser scanning microscopy (CLSM) imaging of MET nanoparticles’ penetration into experimental biofilms was carried out and a MET-AmB eye drop formulation was tested for its stability. Results: MET-AmB formulations demonstrated superior activity towards C. albicans biofilms in vitro with the EC50 being ~30 times lower than AmB alone (EC50 MET-AmB = 1.176 μg mL−1, EC50 AmB alone = 29.09 μg mL−1). A similar superior activity was found for Candida glabrata biofilms, where the EC50 was ~10× lower than AmB alone (EC50 MET-AmB = 0.0253 μg mL−1, EC50 AmB alone = 0.289 μg mL−1). CLSM imaging revealed that MET nanoparticles penetrated through the C. albicans biofilm matrix and bound to fungal cells. The activity of MET-AmB was no different from the activity of AmB alone against C. albicans cells in suspension (MET-AmB MIC90 = 0.125 μg mL−1, AmB alone MIC90 = 0.250 μg mL−1). MET-AmB eye drops were stable at room temperature for at least 28 days. Conclusions: These biofilm activity findings raise the possibility that MET-loaded nanoparticles may be used to tackle Candida biofilm infections, such as refractory ocular fungal infections.

Vacuoles Induced in Mammalian Cells by Helicobacter Cytotoxin are Acidic Organelles

1990 ◽  
Vol 48 (3) ◽  
pp. 168-169
Author(s):  
M. H. Chestnut ◽  
C. E. Catrenich
Keyword(s):  
Acridine Orange ◽  
Mammalian Cells ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Ulcer Disease ◽  
Gastroduodenal Disease ◽  
H Pylori

Helicobacter pylori is a non-invasive, Gram-negative spiral bacterium first identified in 1983, and subsequently implicated in the pathogenesis of gastroduodenal disease including gastritis and peptic ulcer disease. Cytotoxic activity, manifested by intracytoplasmic vacuolation of mammalian cells in vitro, was identified in 55% of H. pylori strains examined. The vacuoles increase in number and size during extended incubation, resulting in vacuolar and cellular degeneration after 24 h to 48 h. Vacuolation of gastric epithelial cells is also observed in vivo during infection by H. pylori. A high molecular weight, heat labile protein is believed to be responsible for vacuolation and to significantly contribute to the development of gastroduodenal disease in humans. The mechanism by which the cytotoxin exerts its effect is unknown, as is the intracellular origin of the vacuolar membrane and contents. Acridine orange is a membrane-permeant weak base that initially accumulates in low-pH compartments. We have used acridine orange accumulation in conjunction with confocal laser scanning microscopy of toxin-treated cells to begin probing the nature and origin of these vacuoles.

scholarly journals Effect of dissolution rate and subsequent ion release on cytocompatibility properties of borophosphate glasses

2019 ◽  
Vol 5 (1) ◽  
pp. 85-97
Author(s):  
Nusrat Sharmin ◽  
Mohammad S. Hasan ◽  
Md. Towhidul Islam ◽  
Chengheng Pang ◽  
Fu Gu ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Ion Release ◽  
Scanning Calorimetry ◽  
Cell Culture Study ◽  
Borophosphate Glasses ◽  
Mg63 Cells

AbstractPresent work explores the relationship between the composition, dissolution rate, ion release and cytocompatibility of a series of borophosphate glasses. While, the base glass was selected to be 40mol%P2O5-16mol%CaO-24mol%MgO-20mol%Na2O, three B2O3 modified glass compositions were formulated by replacing Na2O with 1, 5 and 10 mol% B2O3. Ion release study was conducted using inductively coupled plasma atomic emission spectroscopy (ICP-AES). The thermal scans of the glasses as determined by differential scanning calorimetry (DSC) revealed an increment in the thermal properties with increasing B2O3 content in the glasses. On the other hand, the dissolution rate of the glasses decreased with increasing B2O3 content. To identify the effect of boron ion release on the cytocompatibility properties of the glasses, MG63 cells were cultured on the surface of the glass discs. The in vitro cell culture study suggested that glasses with 5 mol% B2O3 (P40B5) showed better cell proliferation and metabolic activity as compares to the glasses with 10 mol% (P40B10) or with no B2O3 (P40B0). The confocal laser scanning microscopy (CLSM) images of live/dead stained MG63 cells attached to the surface of the glasses also revealed that the number of dead cells attached to P40B5 glasses were significantly lower than both P40B0 and P40B10 glasses.

scholarly journals Cephalosporin nitric oxide-donor prodrug DEA-C3D disperses biofilms formed by clinical cystic fibrosis isolates of Pseudomonas aeruginosa

2019 ◽  
Vol 75 (1) ◽  
pp. 117-125 ◽  
Author(s):  
Odel Soren ◽  
Ardeshir Rineh ◽  
Diogo G Silva ◽  
Yuming Cai ◽  
Robert P Howlin ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Clinical Isolates ◽  
Nitric Oxide Donor ◽  
Confocal Laser ◽  
Broth Microdilution Method

Abstract Objectives The cephalosporin nitric oxide (NO)-donor prodrug DEA-C3D (‘DiEthylAmin-Cephalosporin-3′-Diazeniumdiolate’) has been shown to initiate the dispersal of biofilms formed by the Pseudomonas aeruginosa laboratory strain PAO1. In this study, we investigated whether DEA-C3D disperses biofilms formed by clinical cystic fibrosis (CF) isolates of P. aeruginosa and its effect in combination with two antipseudomonal antibiotics, tobramycin and colistin, in vitro. Methods β-Lactamase-triggered release of NO from DEA-C3D was confirmed using a gas-phase chemiluminescence detector. MICs for P. aeruginosa clinical isolates were determined using the broth microdilution method. A crystal violet staining technique and confocal laser scanning microscopy were used to evaluate the effects of DEA-C3D on P. aeruginosa biofilms alone and in combination with tobramycin and colistin. Results DEA-C3D was confirmed to selectively release NO in response to contact with bacterial β-lactamase. Despite lacking direct, cephalosporin/β-lactam-based antibacterial activity, DEA-C3D was able to disperse biofilms formed by three P. aeruginosa clinical isolates. Confocal microscopy revealed that DEA-C3D in combination with tobramycin produces similar reductions in biofilm to DEA-C3D alone, whereas the combination with colistin causes near complete eradication of P. aeruginosa biofilms in vitro. Conclusions DEA-C3D is effective in dispersing biofilms formed by multiple clinical isolates of P. aeruginosa and could hold promise as a new adjunctive therapy to patients with CF.

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