scholarly journals Antibody response to the 45 kDa Candida albicans antigen in an animal model and potential role of the antigen in adherence

2008 ◽  
Vol 57 (12) ◽  
pp. 1466-1472 ◽  
Author(s):  
Helena Bujdáková ◽  
Ema Paulovičová ◽  
Silvia Borecká-Melkusová ◽  
Juraj Gašperík ◽  
Soňa Kucharíková ◽  
...  
Keyword(s):  
Animal Model ◽  
Candida Albicans ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Vaccine Development ◽  
Laser Scanning Microscopy ◽  
Model Systems ◽  
Confocal Laser

The Candida antigen CR3-RP (complement receptor 3-related protein) is supposed to be a ‘mimicry’ protein because of its ability to bind antibody directed against the α subunit of the mammalian CR3 (CD11b/CD18). This study aimed to (i) investigate the specific humoral isotypic response to immunization with CR3-RP in vivo in a rabbit animal model, and (ii) determine the role of CR3-RP in the adherence of Candida albicans in vitro using the model systems of buccal epithelial cells (BECs) and biofilm formation. The synthetic C. albicans peptide DINGGGATLPQ corresponding to 11 amino-acids of the CR3-RP sequence DINGGGATLPQALXQITGVIT, determined by N-terminal sequencing, was used for immunization of rabbits to obtain polyclonal anti-CR3-PR serum and for subsequent characterization of the humoral isotypic response of rabbits. A significant increase of IgG, IgA and IgM anti-CR3-RP specific antibodies was observed after the third (P<0.01) and the fourth (P<0.001) immunization doses. The elevation of IgA levels suggested peptide immunomodulation of the IgA1 subclass, presumably in coincidence with Candida epithelial adherence. Blocking CR3-RP with polyclonal anti-CR3-RP serum reduced the ability of Candida to adhere to BECs, in comparison with the control, by up to 35 % (P<0.001), and reduced biofilm formation by 28 % (P<0.001), including changes in biofilm thickness and integrity detected by confocal laser scanning microscopy. These properties of CR3-RP suggest that it has potential for future vaccine development.

scholarly journals Bacterial lipopolysaccharides variably modulate in vitro biofilm formation of Candida species

2010 ◽  
Vol 59 (10) ◽  
pp. 1225-1234 ◽  
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.

Endotracheal tubes coated with a broad-spectrum antibacterial ceragenin reduce bacterial biofilm in an in vitro bench top model

2021 ◽  
Author(s):  
María Consuelo Latorre ◽  
María Jesús Pérez-Granda ◽  
Paul B Savage ◽  
Beatriz Alonso ◽  
Pablo Martín-Rabadán ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Laser Scanning ◽  
In Vitro Study ◽  
Bacterial Biofilm ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Endotracheal Tubes ◽  
Clinical Strains ◽  
Number Of Cells

Abstract Background Ventilator-associated pneumonia is one of the most common nosocomial infections, caused mainly by bacterial/fungal biofilm. Therefore, it is necessary to develop preventive strategies to avoid biofilm formation based on new compounds. Objectives We performed an in vitro study to compare the efficacy of endotracheal tubes (ETTs) coated with the ceragenin CSA-131 and that of uncoated ETTs against the biofilm of clinical strains of Pseudomonas aeruginosa (PA), Escherichia coli (EC) and Staphylococcus aureus (SA). Methods We applied an in vitro bench top model using coated and uncoated ETTs that were treated with three different clinical strains of PA, EC and SA for 5 days. After exposure to biofilm, ETTs were analysed for cfu count by culture of sonicate and total number of cells by confocal laser scanning microscopy. Results The median (IQR) cfu/mL counts of PA, EC and SA in coated and uncoated ETTs were, respectively, as follows: 1.00 × 101 (0.0–3.3 × 102) versus 3.32 × 109 (6.6 × 108–3.8 × 109), P &lt; 0.001; 0.0 (0.0–5.4 × 103) versus 1.32 × 106 (2.3 × 103–5.0 × 107), P &lt; 0.001; and 8.1 × 105 (8.5 × 101–1.4 × 109) versus 2.7 × 108 (8.6 × 106–1.6 × 1011), P = 0.058. The median (IQR) total number of cells of PA, EC and SA in coated and non-coated ETTs were, respectively, as follows: 11.0 [5.5–not applicable (NA)] versus 87.9 (60.5–NA), P = 0.05; 9.1 (6.7–NA) versus 62.6 (42.0–NA), P = 0.05; and 97.7 (94.6–NA) versus 187.3 (43.9–NA), P = 0.827. Conclusions We demonstrated significantly reduced biofilm formation in coated ETTs. However, the difference for SA was not statistically significant. Future clinical studies are needed to support our findings.

scholarly journals Characterization of Biofilm Formation by Clinically Relevant Serotypes of Group A Streptococci

2006 ◽  
Vol 72 (4) ◽  
pp. 2864-2875 ◽  
Author(s):  
Cordula Lembke ◽  
Andreas Podbielski ◽  
Carlos Hidalgo-Grass ◽  
Ludwig Jonas ◽  
Emanuel Hanski ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Laser Scanning ◽  
Group A Streptococcus ◽  
Three Dimensional ◽  
Positive Control ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Subsequent Formation ◽  
Group A

ABSTRACT Streptococcus pyogenes (group A streptococcus [GAS]) is a frequent cause of purulent infections in humans. As potentially important aspects of its pathogenicity, GAS was recently shown to aggregate, form intratissue microcolonies, and potentially participate in multispecies biofilms. In this study, we show that GAS in fact forms monospecies biofilms in vitro, and we analyze the basic parameters of S. pyogenes in vitro biofilm formation, using Streptococcus epidermidis as a biofilm-positive control. Of nine clinically important serotype strains, M2, M6, M14, and M18 were found to significantly adhere to coated and uncoated polystyrene surfaces. Fibronectin and collagen types I and IV best supported primary adherence of serotype M2 and M18 strains, respectively, whereas serotype M6 and M14 strains strongly bound to uncoated polystyrene surfaces. Absorption measurements of safranin staining, as well as electron scanning and confocal laser scanning microscopy, documented that primary adherence led to subsequent formation of three-dimensional biofilm structures consisting of up to 46 bacterial layers. Of note, GAS isolates belonging to the same serotype were found to be very heterogeneous in their biofilm-forming behavior. Biofilm formation was equally efficient under static and continuous flow conditions and consisted of the classical three steps, including partial disintegration after long-term incubation. Activity of the SilC signaling peptide as a component of a putative quorum-sensing system was found to influence the biofilm structure and density of serotype M14 and M18 strains. Based on the presented methods and results, standardized analyses of GAS biofilms and their impact on GAS pathogenicity are now feasible.

scholarly journals Spatial Arrangements and Associative Behavior of Species in an In Vitro Oral Biofilm Model

2001 ◽  
Vol 67 (3) ◽  
pp. 1343-1350 ◽  
Author(s):  
M. Guggenheim ◽  
S. Shapiro ◽  
R. Gmür ◽  
B. Guggenheim
Keyword(s):  
Biofilm Formation ◽  
Laser Scanning ◽  
Fusobacterium Nucleatum ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Streptococcus Sobrinus ◽  
Growth Phenomenon ◽  
Associative Behavior ◽  
Species Specific

ABSTRACT The spatial arrangements and associative behavior ofActinomyces naeslundii, Veillonella dispar, Fusobacterium nucleatum, Streptococcus sobrinus, and Streptococcus oralis strains in an in vitro model of supragingival plaque were determined. Using species-specific fluorescence-labeled antibodies in conjunction with confocal laser scanning microscopy, the volumes and distribution of the five strains were assessed during biofilm formation. The volume-derived cell numbers of each strain correlated well with respective culture data. Between 15 min and 64 h, populations of each strain increased in a manner reminiscent of batch growth. The microcolony morphologies of all members of the consortium and their distributions within the biofilm were characterized, as were interspecies associations. Biofilms formed 15 min after inoculation consisted principally of single nonaggregated cells. All five strains adhered strongly to the saliva-conditioned substratum, and therefore, coadhesion played no role during the initial phase of biofilm formation. This observation does not reflect the results of in vitro coaggregation of the five strains, which depended upon the nature of the suspension medium. While the possibility cannot be excluded that some interspecies associations observed at later stages of biofilm formation were initiated by coadhesion, increase in bacterial numbers appeared to be largely a growth phenomenon regulated by the prevailing cultivation conditions.

scholarly journals Role of Exopolysaccharides in Pseudomonas aeruginosa Biofilm Formation and Architecture

2011 ◽  
Vol 77 (15) ◽  
pp. 5238-5246 ◽  
Author(s):  
Aamir Ghafoor ◽  
Iain D. Hay ◽  
Bernd H. A. Rehm
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Bacterial Biofilm ◽  
Laser Scanning Microscopy ◽  
Extracellular Dna ◽  
Confocal Laser ◽  
Content Type ◽  
Biofilm Architecture

ABSTRACTPseudomonas aeruginosais an opportunistic human pathogen and has been established as a model organism to study bacterial biofilm formation. At least three exopolysaccharides (alginate, Psl, and Pel) contribute to the formation of biofilms in this organism. Here mutants deficient in the production of one or more of these polysaccharides were generated to investigate how these polymers interactively contribute to biofilm formation. Confocal laser scanning microscopy of biofilms formed in flow chambers showed that mutants deficient in alginate biosynthesis developed biofilms with a decreased proportion of viable cells than alginate-producing strains, indicating a role of alginate in viability of cells in biofilms. Alginate-deficient mutants showed enhanced extracellular DNA (eDNA)-containing surface structures impacting the biofilm architecture. PAO1 ΔpslAΔalg8overproduced Pel, and eDNA showing meshwork-like structures presumably based on an interaction between both polymers were observed. The formation of characteristic mushroom-like structures required both Psl and alginate, whereas Pel appeared to play a role in biofilm cell density and/or the compactness of the biofilm. Mutants producing only alginate, i.e., mutants deficient in both Psl and Pel production, lost their ability to form biofilms. A lack of Psl enhanced the production of Pel, and the absence of Pel enhanced the production of alginate. The function of Psl in attachment was independent of alginate and Pel. A 30% decrease in Psl promoter activity in the alginate-overproducing MucA-negative mutant PDO300 suggested inverse regulation of both biosynthesis operons. Overall, this study demonstrated that the various exopolysaccharides and eDNA interactively contribute to the biofilm architecture ofP. aeruginosa.

scholarly journals Biocontrol of Biofilm Formation: Jamming of Sessile-Associated Rhizobial Communication by Rhodococcal Quorum-Quenching

2021 ◽  
Vol 22 (15) ◽  
pp. 8241
Author(s):  
Yvann Bourigault ◽  
Sophie Rodrigues ◽  
Alexandre Crépin ◽  
Andrea Chane ◽  
Laure Taupin ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Communication Systems ◽  
Laser Scanning ◽  
Rhodococcus Erythropolis ◽  
Quorum Quenching ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Fluorescent Biosensors ◽  
Visual Evidence

Biofilms are complex structures formed by a community of microbes adhering to a surface and/or to each other through the secretion of an adhesive and protective matrix. The establishment of these structures requires a coordination of action between microorganisms through powerful communication systems such as quorum-sensing. Therefore, auxiliary bacteria capable of interfering with these means of communication could be used to prevent biofilm formation and development. The phytopathogen Rhizobium rhizogenes, which causes hairy root disease and forms large biofilms in hydroponic crops, and the biocontrol agent Rhodococcus erythropolis R138 were used for this study. Changes in biofilm biovolume and structure, as well as interactions between rhizobia and rhodococci, were monitored by confocal laser scanning microscopy with appropriate fluorescent biosensors. We obtained direct visual evidence of an exchange of signals between rhizobia and the jamming of this communication by Rhodococcus within the biofilm. Signaling molecules were characterized as long chain (C14) N-acyl-homoserine lactones. The role of the Qsd quorum-quenching pathway in biofilm alteration was confirmed with an R. erythropolis mutant unable to produce the QsdA lactonase, and by expression of the qsdA gene in a heterologous host, Escherichia coli. Finally, Rhizobium biofilm formation was similarly inhibited by a purified extract of QsdA enzyme.

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 Beneficial Effects of Ethyl-Cyanoacrylate Coating Against Candida Albicans Biofilm Formation

2019 ◽  
Vol 30 (3) ◽  
pp. 266-271 ◽  
Author(s):  
Flora Freitas Fernandes Távora ◽  
Ana Paula Chappuis Chocano ◽  
Denise Gusmão de Oliveira ◽  
Jefferson Ricardo Pereira ◽  
Ricardo Sergio Almeida ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Calculated Data ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Control Group ◽  
Beneficial Effects ◽  
Ethyl Cyanoacrylate ◽  
Number Of Cells

Abstract The aim of this study was to verify whether modifications made in a hard chairside reline resin by an ethyl-cyanoacrylate adhesive, ECA (Super Bonder®, Loctite, Itapevi, SP, Brazil) would be able to inhibit or reduce Candida albicans biofilm formation on its surface, comparing to a commercial surface sealant (BisCover®, Bisco, Schaumburg, USA). Reline resin specimens were fabricated and randomly divided into 6 groups (n=8): CG (control group), no surface treatment; ECA1, ECA coating on the surface before sterilization; ECA2, ECA coating after sterilization; ECA3, ECA incorporated in the resin bulk; DPE1, BisCover® coating before sterilization; DPE2, BisCover® coating after sterilization. Specimens were inoculated with C. albicans SC5314 (1x107 cells/mL) and incubated for 24 h. Then, the biofilm were stained with LIVE/DEAD® BaclightTM L7007 Kit and analyzed by Confocal Laser Scanning Microscopy. The images were evaluated by bioImageL® v.2.0 software and total biovolume (µm3), viable cells (%), and covered area (%) were calculated. Data were statistically analyzed by Kruskal-Wallis and Dunn tests (p<0.05). Results showed that ECA-coated groups presented better results, reducing C. albicans biofilm formation. Acquired images revealed that these groups (ECA1 and ECA2) presented a reduced number of cells, mostly in yeast form (less pathogenic), while the other groups presented higher number of cells, mostly in hyphae form (more pathogenic). Based on these findings, a beneficial effect of Super Bonder® coating reline resins surface could be demonstrated, suggesting a promising way to prevent fungal biofilm formation on dentures.

Activity of Synthetic Antimicrobial Peptide GH12 against Oral Streptococci

2016 ◽  
Vol 50 (1) ◽  
pp. 48-61 ◽  
Author(s):  
Huanxin Tu ◽  
Yingying Fan ◽  
Xueping Lv ◽  
Sili Han ◽  
Xuedong Zhou ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Peptide ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Reversed Phase ◽  
Laser Scanning Microscopy ◽  
Helical Conformation ◽  
Confocal Laser ◽  
Oral Streptococci

Controlling the growth of cariogenic microorganisms such as oral streptococci is an adjunct therapy for caries-active individuals to prevent and treat caries. Here we investigated the antimicrobial activity of the synthetic amphipathic α- helical antimicrobial peptide GH12 (GLLWHLLHHLLH-NH2) against oral streptococci in vitro. Circular dichroism studies showed that GH12 takes on an α-helical conformation in the presence of membrane-mimicking solvents, and reversed-phase high-performance liquid chromatography studies showed that GH12 remains stable in saliva. The peptide showed bactericidal activity against oral streptococci, with minimum inhibitory concentrations ranging from 6.7 to 32.0 μg/ml. GH12 concentrations 4-fold higher than the minimum bactericidal concentration completely killed oral streptococci within 20 min. Treating oral streptococci with GH12 caused noticeable changes in bacterial viability and morphology based on confocal laser scanning microscopy and scanning electron microscopy. Effects of GH12 on biofilm formation and on viability of mature biofilm were quantified by crystal violet staining and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. GH12 effectively inhibited biofilm formation and metabolic activity in biofilms of oral streptococci, especially S. mutans, S. sobrinus and S. salivarius. These results suggest that GH12 shows rapid and strong antimicrobial activity against oral streptococci in vitro, opening the door to preclinical and clinical studies to explore its potential for caries prevention and treatment.

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