scholarly journals Evaluation of the impact of adaptation of Klebsiella pneumoniae clinical isolates to benzalkonium chloride on biofilm formation

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Engy A. Elekhnawy ◽  
Fatma I. Sonbol ◽  
Tarek E. Elbanna ◽  
Ahmed A. Abdelaziz
Keyword(s):  
Klebsiella Pneumoniae ◽  
Cell Surface ◽  
Biofilm Formation ◽  
Benzalkonium Chloride ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Clinical Isolates ◽  
Transcriptional Level ◽  
The Impact ◽  
Sublethal Concentrations

Abstract Background The percentage of the multidrug resistant Klebsiella pneumoniae clinical isolates is increasing worldwide. The excessive exposure of K. pneumoniae isolates to sublethal concentrations of biocides like benzalkonium chloride (BAC) in health care settings and communities could be one of the causes contributing in the global spread of antibiotic resistance. Results We collected 50 K. pneumoniae isolates and these isolates were daily exposed to gradually increasing sublethal concentrations of BAC. The consequence of adaptation to BAC on the cell surface hydrophobicity (CSH) and biofilm formation of K. pneumoniae isolates was explored. Remarkably, 16% of the tested isolates showed an increase in the cell surface hydrophobicity and 26% displayed an enhanced biofilm formation. To evaluate whether the influence of BAC adaptation on the biofilm formation was demonstrated at the transcriptional level, the RT-PCR was employed. Noteworthy, we found that 60% of the tested isolates exhibited an overexpression of the biofilm gene (bssS). After sequencing of this gene in K. pneumoniae isolates before and after BAC adaptation and performing pairwise alignment, 100% identity was detected; a finding that means the absence of mutation after adaptation to BAC. Conclusion This study suggests that the widespread and increased use of biocides like BAC at sublethal concentrations has led to an increase biofilm formation by K. pneumoniae isolates. Enhanced biofilm formation could result in treatment failure of the infections generated by this pathogen.

Plant components affect bacterial biofilm development by altering their cell surface physicochemical properties: a predictability study using Actinomyces naeslundii

2020 ◽  
Author(s):  
Yi Wang ◽  
Lakshman P Samaranayake ◽  
Gary A Dykes
Keyword(s):  
Cell Surface ◽  
Physicochemical Properties ◽  
Biofilm Formation ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Bacterial Biofilm ◽  
Actinomyces Naeslundii ◽  
Surface Physicochemical Properties ◽  
Biofilm Development ◽  
The Impact

Abstract We hypothesized that the initial events leading to biofilm formation by bacteria, in general, are predominantly mediated by cell surface physicochemical interactions, and that natural products can impact the process by altering cell surface physicochemical properties. We exemplified this phenomenon using Actinomyces naeslundii as the model organism, and using tea products to modify its cell surface physicochemical properties. To test the hypothesis, a non-linear multiple regression model incorporating a normal distribution curve was constructed to explain the impact of tea extracts on the physiochemical processes of biofilm formation by A. naeslundii. The model utilized tea extract-induced changes in cell surface physicochemical properties as independent variables, and the corresponding biofilm formation as a dependent variable. Five different tea extracts were used to treat A. naeslundii, and their impact on the cell surface hydrophobicity, charge, auto-aggregation, attachment and biofilm formation on four different hard surfaces were measured and the data were used to construct the model. The established model was then tested in independent experiments involving other plant extracts and purified phytochemicals. Experimental results showed that the tea extracts significantly reduced cell surface hydrophobicity (by up to 21.3%), increased cell surface charge and auto-aggregation (by up to 4.5 mV and 14.9%, respectively), inhibited attachment (by 0.6–2.5 log CFU cm−2) and affected biofilm formation (by up to 0.6 log CFU cm−2). The model indicated that both cell surface hydrophobicity and charge played an important role in bacterial auto-aggregation and attachment, and that the latter two phenomena significantly correlated with subsequent biofilm development. The accuracy of the model construct was approximately 64%. This modelling approach can be employed for other microbial colonization systems to predict biofilm formation, and to study the impact of cell surface physicochemical properties in biofilm development.

scholarly journals Quercetin inhibits virulence properties of Porphyromas gingivalis in periodontal disease

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Zhiyan He ◽  
Xu Zhang ◽  
Zhongchen Song ◽  
Lu Li ◽  
Haishuang Chang ◽  
...  
Keyword(s):  
Cell Surface ◽  
Periodontal Disease ◽  
Biofilm Formation ◽  
Cell Structure ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Antimicrobial Effects ◽  
Virulence Properties

Abstract Porphyromonas gingivalis is a causative agent in the onset and progression of periodontal disease. This study aims to investigate the effects of quercetin, a natural plant product, on P. gingivalis virulence properties including gingipain, haemagglutinin and biofilm formation. Antimicrobial effects and morphological changes of quercetin on P. gingivalis were detected. The effects of quercetin on gingipains activities and hemolytic, hemagglutination activities were evaluated using chromogenic peptides and sheep erythrocytes. The biofilm biomass and metabolism with different concentrations of quercetin were assessed by the crystal violet and MTT assay. The structures and thickness of the biofilms were observed by confocal laser scanning microscopy. Bacterial cell surface properties including cell surface hydrophobicity and aggregation were also evaluated. The mRNA expression of virulence and iron/heme utilization was assessed using real time-PCR. Quercetin exhibited antimicrobial effects and damaged the cell structure. Quercetin can inhibit gingipains, hemolytic, hemagglutination activities and biofilm formation at sub-MIC concentrations. Molecular docking analysis further indicated that quercetin can interact with gingipains. The biofilm became sparser and thinner after quercetin treatment. Quercetin also modulate cell surface hydrophobicity and aggregation. Expression of the genes tested was down-regulated in the presence of quercetin. In conclusion, our study demonstrated that quercetin inhibited various virulence factors of P. gingivalis.

scholarly journals Effect of Eugenol on Cell Surface Hydrophobicity, Adhesion, and Biofilm ofCandida tropicalisandCandida dubliniensisIsolated from Oral Cavity of HIV-Infected Patients

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Suelen Balero de Paula ◽  
Thais Fernanda Bartelli ◽  
Vanessa Di Raimo ◽  
Jussevania Pereira Santos ◽  
Alexandre Tadachi Morey ◽  
...  
Keyword(s):  
Cell Surface ◽  
Oral Cavity ◽  
Biofilm Formation ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Planktonic Cells ◽  
Hydrophobic Behavior ◽  
Significant Difference ◽  
Substrate Surfaces ◽  
Sessile Cells

MostCandidaspp. infections are associated with biofilm formation on host surfaces. Cells within these communities display a phenotype resistant to antimicrobials and host defenses, so biofilm-associated infections are difficult to treat, representing a source of reinfections. The present study evaluated the effect of eugenol on the adherence properties and biofilm formation capacity ofCandida dubliniensisandCandida tropicalisisolated from the oral cavity of HIV-infected patients. All isolates were able to form biofilms on different substrate surfaces. Eugenol showed inhibitory activity against planktonic and sessile cells ofCandidaspp. No metabolic activity in biofilm was detected after 24 h of treatment. Scanning electron microscopy demonstrated that eugenol drastically reduced the number of sessile cells on denture material surfaces. MostCandidaspecies showed hydrophobic behavior and a significant difference in cell surface hydrophobicity was observed after exposure of planktonic cells to eugenol for 1 h. Eugenol also caused a significant reduction in adhesion of mostCandidaspp. to HEp-2 cells and to polystyrene. These findings corroborate the effectiveness of eugenol againstCandidaspecies other thanC. albicans, reinforcing its potential as an antifungal applied to limit both the growth of planktonic cells and biofilm formation on different surfaces.

scholarly journals Factors associated with adherence to and biofilm formation on polystyrene byStenotrophomonas maltophilia: the role of cell surface hydrophobicity and motility

2008 ◽  
Vol 287 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Arianna Pompilio ◽  
Raffaele Piccolomini ◽  
Carla Picciani ◽  
Domenico D'Antonio ◽  
Vincenzo Savini ◽  
...  
Keyword(s):  
Cell Surface ◽  
Biofilm Formation ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Factors Associated

scholarly journals Biofilm Formation and Cell Surface Properties among Pathogenic and Nonpathogenic Strains of the Bacillus cereus Group

2009 ◽  
Vol 75 (20) ◽  
pp. 6616-6618 ◽  
Author(s):  
Sandrine Auger ◽  
Nalini Ramarao ◽  
Christine Faille ◽  
Agnès Fouet ◽  
Stéphane Aymerich ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cell Surface ◽  
Bacillus Cereus ◽  
Digestive Tract ◽  
Biofilm Formation ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Bacillus Cereus Group ◽  
Cell Surface Properties ◽  
Tract Infections

ABSTRACT Biofilm formation by 102 Bacillus cereus and B. thuringiensis strains was determined. Strains isolated from soil or involved in digestive tract infections were efficient biofilm formers, whereas strains isolated from other diseases were poor biofilm formers. Cell surface hydrophobicity, the presence of an S layer, and adhesion to epithelial cells were also examined.

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