Characterization of biofilm matrix, degradation by DNase treatment and evidence of capsule downregulation in Streptococcus pneumoniae clinical isolates

Hall-Stoodley, Luanne; Nistico, Laura; Sambanthamoorthy, Karthik; Dice, Bethany; Nguyen, Duc Quang; Mershon, William J; Johnson, Carrie; Hu, Fang; Stoodley, Paul; Ehrlich, Garth D.; Post, J. Christopher

doi:10.1186/1471-2180-8-173

Cited by 216 publications

(244 citation statements)

References 45 publications

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“…Although we could not determine the MIC of the bacteria present in the tissue, since MIC is measured on planktonic cells, we know from Thornsberry et al (64) that the MIC 90 for H. influenzae is 2 g/ml (1,032 isolates tested), that for S. pneumoniae is 16 g/ml (1,275 isolates tested), and that for M. catarrhalis is 0.12 g/ml (444 isolates tested). However, bacteria in biofilms are often over 100 times more resistant to antibiotics (14,23,29,65). We therefore used 2 mg/ml because it is Ͼ125 times the MIC 90 of the most common respiratory pathogens and should sufficiently test whether biofilm bacteria demonstrated increased recalcitrance to antibiotic.…”

Section: Patientmentioning

confidence: 99%

Adenoid Reservoir for Pathogenic Biofilm Bacteria

et al. 2011

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Biofilms of pathogenic bacteria are present on the middle ear mucosa of children with chronic otitis media (COM) and may contribute to the persistence of pathogens and the recalcitrance of COM to antibiotic treatment. Controlled studies indicate that adenoidectomy is effective in the treatment of COM, suggesting that the adenoids may act as a reservoir for COM pathogens. To investigate the bacterial community in the adenoid, samples were obtained from 35 children undergoing adenoidectomy for chronic OM or obstructive sleep apnea. We used a novel, culture-independent molecular diagnostic methodology, followed by confocal microscopy, to investigate the in situ distribution and organization of pathogens in the adenoids to determine whether pathogenic bacteria exhibited criteria characteristic of biofilms. The Ibis T5000 Universal Biosensor System was used to interrogate the extent of the microbial diversity within adenoid biopsy specimens. Using a suite of 16 broad-range bacterial primers, we demonstrated that adenoids from both diagnostic groups were colonized with polymicrobial biofilms. Haemophilus influenzae was present in more adenoids from the COM group (P ‫؍‬ 0.005), but there was no significant difference between the two patient groups for Streptococcus pneumoniae or Staphylococcus aureus. Fluorescence in situ hybridization, lectin binding, and the use of antibodies specific for host epithelial cells demonstrated that pathogens were aggregated, surrounded by a carbohydrate matrix, and localized on and within the epithelial cell surface, which is consistent with criteria for bacterial biofilms.

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Section: Patientmentioning

confidence: 99%

Adenoid Reservoir for Pathogenic Biofilm Bacteria

et al. 2011

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“…Therefore, the employment of PE-depolymerising agents such as gelsolin and thymosin beta 4 or DNase 1 used for dissolution of biofilm-stimulating F-actin and DNA, respectively, might constitute an interesting approach in the eradication of microbial communities [62][63][64]. The statement that the presence of eDNA is crucial for the biofilm formation and structural integrity is additionally established by the reports demonstrating that the treatment with DNase 1 reduces the attachment of microbial cells to the surface, inhibits the biofilm development, and reduces the mass of mature biofilm [65], which is determined by the impairment of cell-to-cell adhesion and joining elements in microbial aggregates [66,67]. Importantly, the co-administration of antimicrobial agents with factors that have the ability to disassemble the biofilm polyelectrolyte network, including DNase 1, considerably improves their antibacterial efficiency [5,68].…”

Section: Dna and F-actin In Bacterial Biofilm Developmentmentioning

confidence: 98%

Neutrophil extracellular traps as the main source of eDNA

Cieśluk¹,

Piktel²,

Wątek³

et al. 2017

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Neutrophil extracellular traps (NETs) are web-like structures consisting of decondensed DNA together with accompanying proteins, including histones and antimicrobial peptides released from activated neutrophils as part of the first-line defence against pathogens. Despite the protective role of neutrophils, a number of studies indicate that overproduction of NETs followed by accumulation of extracellular DNA (eDNA) and other negatively-charged polyelectrolytes (PE) such as F-actin, contribute to the pathogenesis of some diseases. Neutrophil extracellular traps are also recognised as the structural and functional support of microbial biofilms and should thus be considered as therapeutic targets. Importantly, the chemical nature of PE permits aggregate formation induced by a number of polycations occurring naturally in the human body, including cationic antimicrobial peptides. This review summarises recent reports focused on the clinical significance of NET-derived eDNA and PE and discusses the potential therapeutic strategies to limit the negative consequences of eDNA accumulation.

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“…e authors revealed that the average bio�lm thickness was reduced by 85%-97%, indicating that, within the bio�lm, areas composed of lower amounts of extracellular DNA in comparison to adherent cells exist [80].…”

Section: Deoxyribonuclease Imentioning

confidence: 99%

“…Furthermore, Hall-Stoodley et al [80] reported that DNase I induced bio�lm degradation by 66.7%-95% for six clinical isolates of Streptococcus pneumoniae, even though the bio�lms were grown for six days. e authors revealed that the average bio�lm thickness was reduced by 85%-97%, indicating that, within the bio�lm, areas composed of lower amounts of extracellular DNA in comparison to adherent cells exist [80].…”

Section: Deoxyribonuclease Imentioning

confidence: 99%

Antimicrobial, Antimycobacterial and Antibiofi lm Properties of Couroupita guianensis Aubl. Fruit Extract

Sayen¹

2014

Biofilm Control and Antimicrobial Agents

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We review the recent literature concerning the efficiency of antimicrobial photodynamic inactivation toward various microbial species in planktonic and bio�lm cultures. e review is mainly focused on bio�lm-growing microrganisms because this form of growth poses a threat to chronically infected or immunocompromised patients and is difficult to eradicate from medical devices. We discuss the bio�lm formation process and mechanisms of its increased resistance to various antimicrobials. We present, based on data in the literature, strategies for overcoming the problem of bio�lm resistance. �actors that have potential for use in increasing the efficiency of the killing of bio�lm-forming bacteria include plant extracts, enzymes that disturb the bio�lm structure, and other nonenzymatic molecules. We propose combining antimicrobial photodynamic therapy with various antimicrobial and antibio�lm approaches to obtain a synergistic effect to permit efficient microbial growth control at low photosensitizer doses.

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Characterization of biofilm matrix, degradation by DNase treatment and evidence of capsule downregulation in Streptococcus pneumoniae clinical isolates

Cited by 216 publications

References 45 publications

Adenoid Reservoir for Pathogenic Biofilm Bacteria

Adenoid Reservoir for Pathogenic Biofilm Bacteria

Neutrophil extracellular traps as the main source of eDNA

Antimicrobial, Antimycobacterial and Antibiofi lm Properties of Couroupita guianensis Aubl. Fruit Extract

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