Inhibition of Escherichia coli Biofilm Formation by Self-Assembled Monolayers of Functional Alkanethiols on Gold

ABSTRACT Bacterial biofilms cause serious problems, such as antibiotic resistance and medical device-related infections. To further understand bacterium-surface interactions and to develop efficient control strategies, self-assembled monolayers (SAMs) of alkanethiols presenting different functional groups on gold films were analyzed to determine their resistance to biofilm formation. Escherichia coli was labeled with green florescence protein, and its biofilm formation on SAM-modified surfaces was monitored by confocal laser scanning microscopy. The three-dimensional structures of biofilms were analyzed with the COMSTAT software to obtain information about biofilm thickness and surface coverage. SAMs presenting methyl, l-gulonamide (a sugar alcohol tethered with an amide bond), and tri(ethylene glycol) (TEG) groups were tested. Among these, the TEG-terminated SAM was the most resistant to E. coli biofilm formation; e.g., it repressed biofilm formation by E. coli DH5α by 99.5% ± 0.1% for 1 day compared to the biofilm formation on a bare gold surface. When surfaces were patterned with regions consisting of methyl-terminated SAMs surrounded by TEG-terminated SAMs, E. coli formed biofilms only on methyl-terminated patterns. Addition of TEG as a free molecule to growth medium at concentrations of 0.1 and 1.0% also inhibited biofilm formation, while TEG at concentrations up to 1.5% did not have any noticeable effects on cell growth. The results of this study suggest that the reduction in biofilm formation on surfaces modified with TEG-terminated SAMs is a result of multiple factors, including the solvent structure at the interface, the chemorepellent nature of TEG, and the inhibitory effect of TEG on cell motility.

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The Chromosomal Toxin Gene yafQ Is a Determinant of Multidrug Tolerance for Escherichia coli Growing in a Biofilm

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00043-09 ◽

2009 ◽

Vol 53 (6) ◽

pp. 2253-2258 ◽

Cited By ~ 126

Author(s):

Joe J. Harrison ◽

William D. Wade ◽

Sarah Akierman ◽

Caterina Vacchi-Suzzi ◽

Carol A. Stremick ◽

...

Keyword(s):

Escherichia Coli ◽

Stationary Phase ◽

Cell Survival ◽

Laser Scanning ◽

Laser Scanning Microscopy ◽

Cell Counting ◽

Confocal Laser ◽

Toxin Gene ◽

Persister Cells ◽

E Coli

ABSTRACT Escherichia coli is refractory to elevated doses of antibiotics when it is growing in a biofilm, and this is potentially due to high numbers of multidrug-tolerant persister cells in the surface-adherent population. Previously, the chromosomal toxin-antitoxin loci hipBA and relBE have been linked to the frequency at which persister cells occur in E. coli populations. In the present study, we focused on the dinJ-yafQ-encoded toxin-antitoxin system and hypothesized that deletion of the toxin gene yafQ might influence cell survival in antibiotic-exposed biofilms. By using confocal laser scanning microscopy and viable cell counting, it was determined that a ΔyafQ mutant produced biofilms with a structure and a cell density equivalent to those of the parental strain. In-depth susceptibility testing identified that relative to wild-type E. coli, the ΔyafQ strain had up to a ∼2,400-fold decrease in cell survival after the biofilms were exposed to bactericidal concentrations of cefazolin or tobramycin. Corresponding to these data, controlled overexpression of yafQ from a high-copy-number plasmid resulted in up to a ∼10,000-fold increase in the number of biofilm cells surviving exposure to these bactericidal drugs. In contrast, neither the inactivation nor the overexpression of yafQ affected the tolerance of biofilms to doxycycline or rifampin (rifampicin). Furthermore, deletion of yafQ did not affect the tolerance of stationary-phase planktonic cells to any of the antibacterials tested. These results suggest that yafQ mediates the tolerance of E. coli biofilms to multiple but specific antibiotics; moreover, our data imply that this cellular pathway for persistence is likely different from that of multidrug-tolerant cells in stationary-phase planktonic cell cultures.

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Effect of Lactobacillus plantarum Biofilms on the Adhesion of Escherichia coli to Urinary Tract Devices

Antibiotics ◽

10.3390/antibiotics10080966 ◽

2021 ◽

Vol 10 (8) ◽

pp. 966

Author(s):

Fábio M. Carvalho ◽

Rita Teixeira-Santos ◽

Filipe J. M. Mergulhão ◽

Luciana C. Gomes

Keyword(s):

Escherichia Coli ◽

Urinary Tract ◽

Lactobacillus Plantarum ◽

Laser Scanning ◽

Optimal Growth ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Novel Technologies ◽

E Coli ◽

Static Conditions

Novel technologies to prevent biofilm formation on urinary tract devices (UTDs) are continually being developed, with the ultimate purpose of reducing the incidence of urinary infections. Probiotics have been described as having the ability to displace adhering uropathogens and inhibit microbial adhesion to UTD materials. This work aimed to evaluate the effect of pre-established Lactobacillus plantarum biofilms on the adhesion of Escherichia coli to medical-grade silicone. The optimal growth conditions of lactobacilli biofilms on silicone were first assessed in 12-well plates. Then, biofilms of L. plantarum were placed in contact with E. coli suspensions for up to 24 h under quasi-static conditions. Biofilm monitoring was performed by determining the number of culturable cells and by confocal laser scanning microscopy (CLSM). Results showed significant reductions of 76%, 77% and 99% in E. coli culturability after exposure to L. plantarum biofilms for 3, 6 and 12 h, respectively, corroborating the CLSM analysis. The interactions between microbial cell surfaces and the silicone surface with and without L. plantarum biofilms were also characterized using contact angle measurements, where E. coli was shown to be thermodynamically less prone to adhere to L. plantarum biofilms than to silicone. Thus, this study suggests the use of probiotic cells as potential antibiofilm agents for urinary tract applications.

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Specific Electromagnetic Effects of Microwave Radiation on Escherichia coli

Applied and Environmental Microbiology ◽

10.1128/aem.01899-10 ◽

2011 ◽

Vol 77 (9) ◽

pp. 3017-3022 ◽

Cited By ~ 44

Author(s):

Yury Shamis ◽

Alex Taube ◽

Natasa Mitik-Dineva ◽

Rodney Croft ◽

Russell J. Crawford ◽

...

Keyword(s):

Escherichia Coli ◽

Cell Membrane ◽

Cell Morphology ◽

Laser Scanning ◽

Simulation Software ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Bacterial Cells ◽

Content Type ◽

E Coli

ABSTRACTThe present study investigated the effects of microwave (MW) radiation applied under a sublethal temperature onEscherichia coli. The experiments were conducted at a frequency of 18 GHz and at a temperature below 40°C to avoid the thermal degradation of bacterial cells during exposure. The absorbed power was calculated to be 1,500 kW/m3, and the electric field was determined to be 300 V/m. Both values were theoretically confirmed using CST Microwave Studio 3D Electromagnetic Simulation Software. As a negative control,E. colicells were also thermally heated to temperatures up to 40°C using Peltier plate heating. Scanning electron microscopy (SEM) analysis performed immediately after MW exposure revealed that theE. colicells exhibited a cell morphology significantly different from that of the negative controls. This MW effect, however, appeared to be temporary, as following a further 10-min elapsed period, the cell morphology appeared to revert to a state that was identical to that of the untreated controls. Confocal laser scanning microscopy (CLSM) revealed that fluorescein isothiocyanate (FITC)-conjugated dextran (150 kDa) was taken up by the MW-treated cells, suggesting that pores had formed within the cell membrane. Cell viability experiments revealed that the MW treatment was not bactericidal, since 88% of the cells were recovered after radiation. It is proposed that one of the effects of exposingE. colicells to MW radiation under sublethal temperature conditions is that the cell surface undergoes a modification that is electrokinetic in nature, resulting in a reversible MW-induced poration of the cell membrane.

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Effects of lipid emulsions on the formation of Escherichia coli–Candida albicans mixed-species biofilms on PVC

Scientific Reports ◽

10.1038/s41598-021-96385-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Shanshan Li ◽

Wanshi Duan ◽

Yujie Lei ◽

Zhonghui Wang ◽

Chaojiang Fu ◽

...

Keyword(s):

Escherichia Coli ◽

Candida Albicans ◽

Laser Scanning ◽

Bloodstream Infections ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Lipid Emulsions ◽

Mixed Species ◽

E Coli ◽

Increased Risk

AbstractPatients receiving lipid emulsions are at increased risk of contracting catheter-related bloodstream infections (CRBSIs) in the clinic. More than 15% of CRBSIs are polymicrobial. The objective of this study was to explore the effects of lipid emulsions on the formation of Escherichia coli (E. coli)–Candida albicans (C. albicans) mixed-species biofilms (BFs) on polyvinyl chloride (PVC) surfaces and the underlying mechanism. Mixed-species BFs were produced by coculturing E. coli and C. albicans with PVC in various concentrations of lipid emulsions. Crystal violet staining and XTT assays were performed to test the mixed-species BF biomass and the viability of microbes in the BFs. The microstructures of the BFs were observed by an approach that combined confocal laser scanning microscopy, fluorescence in situ hybridization, and scanning electron microscopy. The study found that lipid emulsions could promote the formation of E. coli–C. albicans mixed-species BFs, especially with 10% lipid emulsions. The mechanism by which lipid emulsions promote mixed-species BF formation may involve significant upregulation of the expression of the flhDC, iha, HTA1, and HWP1 genes, which are associated with bacterial motility, adhesion, and BF formation. The results derived from this study necessitate strict aseptic precautions when handling lipid emulsions and avoiding the use of high concentrations of lipid emulsions for as long as possible.

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Exposure of Escherichia coli ATCC 12806 to Sublethal Concentrations of Food-Grade Biocides Influences Its Ability To Form Biofilm, Resistance to Antimicrobials, and Ultrastructure

Applied and Environmental Microbiology ◽

10.1128/aem.02283-13 ◽

2013 ◽

Vol 80 (4) ◽

pp. 1268-1280 ◽

Cited By ~ 62

Author(s):

Rosa Capita ◽

Félix Riesco-Peláez ◽

Alicia Alonso-Hernando ◽

Carlos Alonso-Calleja

Keyword(s):

Electron Microscopy ◽

Escherichia Coli ◽

Laser Scanning ◽

Cell Surface Hydrophobicity ◽

Culture Broth ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Content Type ◽

E Coli ◽

Subinhibitory Concentrations

ABSTRACTEscherichia coliATCC 12806 was exposed to increasing subinhibitory concentrations of three biocides widely used in food industry facilities: trisodium phosphate (TSP), sodium nitrite (SNI), and sodium hypochlorite (SHY). The cultures exhibited an acquired tolerance to biocides (especially to SNI and SHY) after exposure to such compounds.E. coliproduced biofilms (as observed by confocal laser scanning microscopy) on polystyrene microtiter plates. Previous adaptation to SNI or SHY enhanced the formation of biofilms (with an increase in biovolume and surface coverage) both in the absence and in the presence (MIC/2) of such compounds. TSP reduced the ability ofE. colito produce biofilms. The concentration of suspended cells in the culture broth in contact with the polystyrene surfaces did not influence the biofilm structure. The increase in cell surface hydrophobicity (assessed by a test of microbial adhesion to solvents) after contact with SNI or SHY appeared to be associated with a strong capacity to form biofilms. Cultures exposed to biocides displayed a stable reduced susceptibility to a range of antibiotics (mainly aminoglycosides, cephalosporins, and quinolones) compared with cultures that were not exposed. SNI caused the greatest increase in resistances (14 antibiotics [48.3% of the total tested]) compared with TSP (1 antibiotic [3.4%]) and SHY (3 antibiotics [10.3%]). Adaptation to SHY involved changes in cell morphology (as observed by scanning electron microscopy) and ultrastructure (as observed by transmission electron microscopy) which allowed this bacterium to persist in the presence of severe SHY challenges. The findings of the present study suggest that the use of biocides at subinhibitory concentrations could represent a public health risk.

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Escherichia coli and its lipopolysaccharide modulate in vitro Candida biofilm formation

Journal of Medical Microbiology ◽

10.1099/jmm.0.012989-0 ◽

2009 ◽

Vol 58 (12) ◽

pp. 1623-1631 ◽

Cited By ~ 47

Author(s):

H. M. H. N. Bandara ◽

J. Y. Y. Yau ◽

R. M. Watt ◽

L. J. Jin ◽

L. P. Samaranayake

Keyword(s):

Escherichia Coli ◽

Biofilm Formation ◽

Cell Activity ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

E Coli ◽

Cell Numbers ◽

Cell Counts ◽

Biofilm Development

Demystification of microbial behaviour in mixed biofilms could have a major impact on our understanding of infectious diseases. The objectives of this study were to evaluate in vitro the interactions of six different Candida species and a Gram-negative coliform, Escherichia coli, in dual-species biofilms, and to assess the effect of E. coli LPS on Candida biofilm formation. A single isolate of E. coli ATCC 25922 and six different species of Candida, Candida albicans ATCC 90028, Candida glabrata ATCC 90030, Candida krusei ATCC 6258, Candida tropicalis ATCC 13803, Candida parapsilosis ATCC 22019 and Candida dubliniensis MYA-646, were studied using a standard biofilm assay. Each Candida species was co-cultured with E. coli on a polystyrene surface and biofilm formation was quantified by a c.f.u. assay. The biofilm was then analysed by Live/Dead staining and fluorescence microscopy (confocal laser-scanning microscopy, CLSM), whilst scanning electron microscopy (SEM) was employed to visualize the biofilm architecture. The effect of E. coli LPS on Candida biofilm cell activity at defined time intervals was assessed with an XTT reduction assay. A significant quantitative reduction in c.f.u. counts of C. tropicalis (after 90 min), C. parapsilosis (after 90 min and 24 h), C. krusei (after 24 h) and C. dubliniensis (after 24 and 48 h) was noted on incubation with E. coli in comparison with their monospecies biofilm counterparts (P <0.05). On the other hand, a simultaneous and significant reduction in E. coli cell numbers occurred on co-culture with C. albicans (after 90 min), and an elevation of E. coli cell numbers followed co-culture with C. tropicalis (after 24 h) and C. dubliniensis (after 24 h and 48 h) (P <0.05). All quantitative findings were confirmed by SEM and CLSM analyses. By SEM observation, dual-species biofilms demonstrated scanty architecture with reduced visible cell counts at all stages of biofilm development, despite profuse growth and dense colonization in their single-species counterparts. Significantly elevated metabolic activity, as assessed by XTT readings, was observed in E. coli LPS-treated C. tropicalis and C. parapsilosis biofilms (after 48 h), whilst this had the opposite effect for C. dubliniensis (after 24 h) (P <0.05). These data indicate that E. coli and Candida species in a mixed-species environment mutually modulate biofilm development, both quantitatively and qualitatively, and that E. coli LPS appears to be a key component in mediating these outcomes.

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Antibacterial Activity of Positively and Negatively Charged Hematite (α-Fe2O3) Nanoparticles to Escherichia coli, Staphylococcus aureus and Vibrio fischeri

Nanomaterials ◽

10.3390/nano11030652 ◽

2021 ◽

Vol 11 (3) ◽

pp. 652

Author(s):

Svetlana Vihodceva ◽

Andris Šutka ◽

Mariliis Sihtmäe ◽

Merilin Rosenberg ◽

Maarja Otsus ◽

...

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Antibacterial Activity ◽

Laser Scanning ◽

Vibrio Fischeri ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Fe2o3 Nanoparticles ◽

E Coli ◽

Positively Charged

In the current study, the antibacterial activity of positively and negatively charged spherical hematite (α-Fe2O3) nanoparticles (NPs) with primary size of 45 and 70 nm was evaluated against clinically relevant bacteria Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive) as well as against naturally bioluminescent bacteria Vibrio fischeri (an ecotoxicological model organism). α-Fe2O3 NPs were synthesized using a simple green hydrothermal method and the surface charge was altered via citrate coating. To minimize the interference of testing environment with NP’s physic-chemical properties, E. coli and S. aureus were exposed to NPs in deionized water for 30 min and 24 h, covering concentrations from 1 to 1000 mg/L. The growth inhibition was evaluated following the postexposure colony-forming ability of bacteria on toxicant-free agar plates. The positively charged α-Fe2O3 at concentrations from 100 mg/L upwards showed inhibitory activity towards E. coli already after 30 min of contact. Extending the exposure to 24 h caused total inhibition of growth at 100 mg/L. Bactericidal activity of positively charged hematite NPs against S. aureus was not observed up to 1000 mg/L. Differently from positively charged hematite NPs, negatively charged citrate-coated α-Fe2O3 NPs did not exhibit any antibacterial activity against E. coli and S. aureus even at 1000 mg/L. Confocal laser scanning microscopy and flow cytometer analysis showed that bacteria were more tightly associated with positively charged α-Fe2O3 NPs than with negatively charged citrate-coated α-Fe2O3 NPs. Moreover, the observed associations were more evident in the case of E. coli than S. aureus, being coherent with the toxicity results. Vibrio fischeri bioluminescence inhibition assays (exposure medium 2% NaCl) and colony forming ability on agar plates showed no (eco)toxicity of α-Fe2O3 (EC50 and MBC > 1000 mg/L).

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Berberine Chloride Dihydrate Enthused Nanovesicles for the Management of Dermatitis

Nanoscience &Nanotechnology-Asia ◽

10.2174/2210681210666200313123550 ◽

2020 ◽

Vol 10 ◽

Author(s):

Nimisha Srivastava ◽

Zeeshan Fatima ◽

Chanchal Deep Kaur ◽

Dilshad Ali Rizvi

Keyword(s):

Laser Scanning ◽

Skin Irritation ◽

Research Work ◽

Slight Modification ◽

Entrapment Efficiency ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Chloride Dihydrate ◽

E Coli ◽

Berberine Chloride

Background: Dermatitis is a common inflammatory skin disease that is affecting up to 25% of children and 1%-3% of adults worldwide. Paucity of exact cure for dermatitis and untoward side effects of topical immunosuppressive steroids has resulted into a great need for making use of complementary medicine to treat dermatitis. Objective: The present research work involved the development of Berberine chloride dihydrate (BCD) enthused nanovesicles i.e. ethosomes for the management of dermatitis. Method: Ethosomes were prepared by slight modification of cold method using varying concentrations of SPC (1-3%) and ethanol (10-40%) Optimized batch BCD 12 was further added to Carbopol 934P for gel formation. GEL BCD 12 was subjected to “anti-bacterial, dermatitis and skin irritation study. Result: The vesicles were in size range 142.42-398.31 nm while polydispersity index (PDI) ranges from 0.114-1.56 and for zeta potential it was from-18.8 to -39.4. Entrapment efficiency was from 46.05-88.79 %. Confocal laser scanning microscopy showed penetration depth of rhodamine enthused ethosome across rat skin upto 110 µm which was significantly higher than rhodamine solution (10 µm). In the anti-bacterial study, BCD loaded ethosomal gel (EG) showed maximum zone of inhibition of 18.5 mm against E. coli, 14.5 mm against P. aeruginosa and 23.0 mm against S. aureus. In dinitrochlorobenzene (DNCB) induced mice dermatitis model histopathology study showed marked decrease in amount of inflammatory cell nucleus in mice treated with BCD loaded ethosomal gel followed by 56% and 50 % increase in ear swelling and ear mass respectively in morphology study. Conventional marketed formulation showed nominal decrease in epidermal thickness, 66.67 % increase in ear thickness and 63.64 % increase in ear mass. Further Primary irritation index was less than 0.4 indicating negligible irritation in all the groups. Conclusion: It can be concluded that ethosomal gel is not only an efficient carrier for BCD but also proves its potential for the management of dermatitis.

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Confocal and SEM imaging to demonstrate food pathogen- biofilm biocontrol by pyocyanin from Pseudomonas aeruginosa BTRY1

International Journal of Bioassays ◽

10.21746/ijbio.2017.01.007 ◽

2016 ◽

Vol 6 (01) ◽

pp. 5218

Author(s):

Laxmi Mohandas ◽

Anju T. R. ◽

Sarita G. Bhat*

Keyword(s):

Pseudomonas Aeruginosa ◽

Biofilm Formation ◽

Laser Scanning ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Antibiofilm Activity ◽

Opportunistic Pathogens ◽

Redox Active ◽

Sem Imaging ◽

The Impact

An assortment of redox-active phenazine compounds like pyocyanin with their characteristic blue-green colour are synthesized by Pseudomonas aeruginosa, Gram-negative opportunistic pathogens, which are also considered one of the most commercially valuable microorganisms. In this study, pyocyanin from Pseudomonas aeruginosa BTRY1 from food sample was assessed for its antibiofilm activity by micro titer plate assay against strong biofilm producers belonging to the genera Bacillus, Staphylococcus, Brevibacterium and Micrococcus. Pyocyanin inhibited biofilm activity in very minute concentrations. This was also confirmed by Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM). Both SEM and CLSM helped to visualize the biocontrol of biofilm formation by eight pathogens. The imaging and quantification by CLSM also established the impact of pyocyanin on biofilm-biocontrol mainly in the food industry.

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Bacterial lipopolysaccharides variably modulate in vitro biofilm formation of Candida species

Journal of Medical Microbiology ◽

10.1099/jmm.0.021832-0 ◽

2010 ◽

Vol 59 (10) ◽

pp. 1225-1234 ◽

Cited By ~ 51

Author(s):

H. M. H. N. Bandara ◽

O. L. T. Lam ◽

R. M. Watt ◽

L. J. Jin ◽

L. P. Samaranayake

Keyword(s):

Biofilm Formation ◽

Laser Scanning ◽

Significant Inhibition ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Dependent Manner ◽

Bacterial Lipopolysaccharides ◽

Species Specific ◽

Biofilm Development

The objective of this study was to evaluate the effect of the bacterial endotoxin LPS on Candida biofilm formation in vitro. The effect of the LPS of Pseudomonas aeruginosa, Klebsiella pneumoniae, Serratia marcescens and Salmonella typhimurium on six different species of Candida, comprising Candida albicans ATCC 90028, Candida glabrata ATCC 90030, Candida krusei ATCC 6258, Candida tropicalis ATCC 13803, Candida parapsilosis ATCC 22019 and Candida dubliniensis MYA 646, was studied using a standard biofilm assay. The metabolic activity of in vitro Candida biofilms treated with LPS at 90 min, 24 h and 48 h was quantified by XTT reduction assay. Viable biofilm-forming cells were qualitatively analysed using confocal laser scanning microscopy (CLSM), while scanning electron microscopy (SEM) was employed to visualize the biofilm structure. Initially, adhesion of C. albicans was significantly stimulated by Pseudomonas and Klebsiella LPS. A significant inhibition of Candida adhesion was noted for the following combinations: C. glabrata with Pseudomonas LPS, C. tropicalis with Serratia LPS, and C. glabrata, C. parapsilosis or C. dubliniensis with Salmonella LPS (P<0.05). After 24 h of incubation, a significant stimulation of initial colonization was noted for the following combinations: C. albicans/C. glabrata with Klebsiella LPS, C. glabrata/C. tropicalis/C. krusei with Salmonella LPS. In contrast, a significant inhibition of biofilm formation was observed in C. glabrata/C. dubliniensis/C. krusei with Pseudomonas LPS, C. krusei with Serratia LPS, C. dubliniensis with Klebsiella LPS and C. parapsilosis/C. dubliniensis /C. krusei with Salmonella LPS (P<0.05). On further incubation for 48 h, a significant enhancement of biofilm maturation was noted for the following combinations: C. glabrata/C. tropicalis with Serratia LPS, C. dubliniensis with Klebsiella LPS and C. glabrata with Salmonella LPS, and a significant retardation was noted for C. parapsilosis/C. dubliniensis/C. krusei with Pseudomonas LPS, C. tropicalis with Serratia LPS, C. glabrata/C. parapsilosis/C. dubliniensis with Klebsiella LPS and C. dubliniensis with Salmonella LPS (P<0.05). These findings were confirmed by SEM and CLSM analyses. In general, the inhibition of the biofilm development of LPS-treated Candida spp. was accompanied by a scanty architecture with a reduced numbers of cells compared with the profuse and densely colonized control biofilms. These data are indicative that bacterial LPSs modulate in vitro Candida biofilm formation in a species-specific and time-dependent manner. The clinical and the biological relevance of these findings have yet to be explored.

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