scholarly journals Extracellular DNA of slow growers of mycobacteria and its contribution to biofilm formation and drug tolerance

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aleksandr Ilinov ◽  
Akihito Nishiyama ◽  
Hiroki Namba ◽  
Yukari Fukushima ◽  
Hayato Takihara ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Drug Tolerance ◽  
Extracellular Dna ◽  
Exponential Growth Phase ◽  
Human Pathogens ◽  
Pellicle Formation ◽  
Phage Dna ◽  
Physiological Impact ◽  
Slow Growing ◽  
Growth And Reproduction

AbstractDNA is basically an intracellular molecule that stores genetic information and carries instructions for growth and reproduction in all cellular organisms. However, in some bacteria, DNA has additional roles outside the cells as extracellular DNA (eDNA), which is an essential component of biofilm formation and hence antibiotic tolerance. Mycobacteria include life-threating human pathogens, most of which are slow growers. However, little is known about the nature of pathogenic mycobacteria’s eDNA. Here we found that eDNA is present in slow-growing mycobacterial pathogens, such as Mycobacterium tuberculosis, M. intracellulare, and M. avium at exponential growth phase. In contrast, eDNA is little in all tested rapid-growing mycobacteria. The physiological impact of disrupted eDNA on slow-growing mycobacteria include reduced pellicle formation, floating biofilm, and enhanced susceptibility to isoniazid and amikacin. Isolation and sequencing of eDNA revealed that it is identical to the genomic DNA in M. tuberculosis and M. intracellulare. In contrast, accumulation of phage DNA in eDNA of M. avium, suggests that the DNA released differs among mycobacterial species. Our data show important functions of eDNA necessary for biofilm formation and drug tolerance in slow-growing mycobacteria.

scholarly journals Extracellular DNA of slow growers of mycobacteria and its contribution to biofilm formation and drug tolerance

2020 ◽  
Author(s):  
Aleksandr Ilinov ◽  
Akihito Nishiyama ◽  
Hiroki Namba ◽  
Yukari Fukushima ◽  
Hayato Takihara ◽  
...  
Keyword(s):  
Genetic Information ◽  
Biofilm Formation ◽  
Drug Tolerance ◽  
Extracellular Dna ◽  
Exponential Growth Phase ◽  
Human Pathogens ◽  
Mycobacterial Species ◽  
Phage Dna ◽  
Physiological Impact ◽  
Growth And Reproduction

Abstract DNA is basically an intracellular molecule that stores genetic information and carries instructions for growth and reproduction in all cellular organisms. However, in some bacteria, DNA has additional roles on the outside as an extracellular DNA (eDNA), an essential component for the formation of antibiotic tolerance bacteria in biofilm. Mycobacteria include life-threating human pathogens, most of which are slow growers. However, little is known about the nature of pathogenic mycobacteria’s eDNA. Here we found that eDNA is present in slow growers of mycobacterial pathogens, such as Mycobacterium tuberculosis, M. intracellulare, and M. avium at exponential growth phase. In contrast, eDNA is little in all tested rapid growers of mycobacteria. The physiological impact of disrupted eDNA on slow growers of mycobacteria include reduced formation of pellicle, a floating biofilm, and enhanced susceptibility to isoniazid and amikacin. Isolation and sequencing of eDNA revealed that it is identical to the genomic DNA in M. tuberculosis and M. intracellulare. In contrast, accumulation of phage DNA in eDNA of M. avium, suggests that the DNA released differs among mycobacterial species. Our data show important functions of eDNA for biofilm formation and drug tolerance in slow growers of mycobacteria.

scholarly journals Biofilm formation in the lung contributes to virulence and drug tolerance of Mycobacterium tuberculosis

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Poushali Chakraborty ◽  
Sapna Bajeli ◽  
Deepak Kaushal ◽  
Bishan Dass Radotra ◽  
Ashwani Kumar
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Immune System ◽  
Biofilm Formation ◽  
Antimycobacterial Activity ◽  
Drug Tolerance ◽  
Host Immune System ◽  
Tissue Sections ◽  
Slow Growing

AbstractTuberculosis is a chronic disease that displays several features commonly associated with biofilm-associated infections: immune system evasion, antibiotic treatment failures, and recurrence of infection. However, although Mycobacterium tuberculosis (Mtb) can form cellulose-containing biofilms in vitro, it remains unclear whether biofilms are formed during infection in vivo. Here, we demonstrate the formation of Mtb biofilms in animal models of infection and in patients, and that biofilm formation can contribute to drug tolerance. First, we show that cellulose is also a structural component of the extracellular matrix of in vitro biofilms of fast and slow-growing nontuberculous mycobacteria. Then, we use cellulose as a biomarker to detect Mtb biofilms in the lungs of experimentally infected mice and non-human primates, as well as in lung tissue sections obtained from patients with tuberculosis. Mtb strains defective in biofilm formation are attenuated for survival in mice, suggesting that biofilms protect bacilli from the host immune system. Furthermore, the administration of nebulized cellulase enhances the antimycobacterial activity of isoniazid and rifampicin in infected mice, supporting a role for biofilms in phenotypic drug tolerance. Our findings thus indicate that Mtb biofilms are relevant to human tuberculosis.

scholarly journals SpoVG Modulates Cell Aggregation in Staphylococcus aureus by Regulating sasC Expression and Extracellular DNA Release

2020 ◽  
Vol 86 (15) ◽  
Author(s):  
Qing Zhu ◽  
Banghui Liu ◽  
Baolin Sun
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Cell Aggregation ◽  
Drug Tolerance ◽  
Negative Regulator ◽  
Extracellular Dna ◽  
Deletion Strain ◽  
Content Type ◽  
Oxacillin Resistance ◽  
Biofilm Development

ABSTRACT Biofilm formation is involved in numerous Staphylococcus aureus infections such as endocarditis, septic arthritis, osteomyelitis, and infections of indwelling medical devices. In these diseases, S. aureus forms biofilms as cell aggregates interspersed in host matrix material. Here, we have observed that the level of cell aggregation was significantly higher in the isogenic spoVG-deletion strain than in the wild-type strain. Reverse transcription-quantitative PCR data indicated that SpoVG could repress the expression of sasC, which codes for S. aureus surface protein C and is involved in cell aggregation and biofilm accumulation. Electromagnetic mobility shift assay demonstrated that SpoVG could specifically bind to the promoter region of sasC, indicating that SpoVG is a negative regulator and directly represses the expression of sasC. In addition, deletion of the SasC aggregation domain in the spoVG-deletion strain indicated that high-level expression of sasC could be the underlying cause of significantly increased cell aggregation formation. Our previous study showed that SpoVG is involved in oxacillin resistance of methicillin-resistant S. aureus by regulating the expression of genes involved in cell wall synthesis and degradation. In this study, we also found that SpoVG was able to negatively modulate the S. aureus drug tolerance under conditions of a high concentration of oxacillin treatment. These findings can broaden our understanding of the regulation of biofilm formation and drug tolerance in S. aureus. IMPORTANCE This study revealed that SpoVG can modulate cell aggregation by repressing sasC expression and extracellular DNA (eDNA) release. Furthermore, we have demonstrated the potential linkage between cell aggregation and antibiotic resistance. Our findings provide novel insights into the regulatory mechanisms of SpoVG involved in cell aggregation and in biofilm development and formation in Staphylococcus aureus.

scholarly journals Differential Roles of Poly-N-Acetylglucosamine Surface Polysaccharide and Extracellular DNA in Staphylococcus aureus and Staphylococcus epidermidis Biofilms

2007 ◽  
Vol 74 (2) ◽  
pp. 470-476 ◽  
Author(s):  
Era A. Izano ◽  
Matthew A. Amarante ◽  
William B. Kher ◽  
Jeffrey B. Kaplan
Keyword(s):  
Staphylococcus Aureus ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Cetylpyridinium Chloride ◽  
Microtiter Plate ◽  
Dnase I ◽  
Extracellular Dna ◽  
Human Pathogens ◽  
Microtiter Plate Assay ◽  
Surface Polysaccharide

ABSTRACT Staphylococcus aureus and Staphylococcus epidermidis are major human pathogens of increasing importance due to the dissemination of antibiotic-resistant strains. Evidence suggests that the ability to form matrix-encased biofilms contributes to the pathogenesis of S. aureus and S. epidermidis. In this study, we investigated the functions of two staphylococcal biofilm matrix polymers: poly-N-acetylglucosamine surface polysaccharide (PNAG) and extracellular DNA (ecDNA). We measured the ability of a PNAG-degrading enzyme (dispersin B) and DNase I to inhibit biofilm formation, detach preformed biofilms, and sensitize biofilms to killing by the cationic detergent cetylpyridinium chloride (CPC) in a 96-well microtiter plate assay. When added to growth medium, both dispersin B and DNase I inhibited biofilm formation by both S. aureus and S. epidermidis. Dispersin B detached preformed S. epidermidis biofilms but not S. aureus biofilms, whereas DNase I detached S. aureus biofilms but not S. epidermidis biofilms. Similarly, dispersin B sensitized S. epidermidis biofilms to CPC killing, whereas DNase I sensitized S. aureus biofilms to CPC killing. We concluded that PNAG and ecDNA play fundamentally different structural roles in S. aureus and S. epidermidis biofilms.

scholarly journals Extracellular DNA release from the genome-reduced pathogen Mycoplasma hyopneumoniae is essential for biofilm formation on abiotic surfaces

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Benjamin B. A. Raymond ◽  
Cheryl Jenkins ◽  
Lynne Turnbull ◽  
Cynthia B. Whitchurch ◽  
Steven P. Djordjevic
Keyword(s):  
Biofilm Formation ◽  
Mycoplasma Hyopneumoniae ◽  
Extracellular Dna ◽  
Abiotic Surfaces ◽  
Dna Release

scholarly journals Effects of pH on the Properties of Membrane Vesicles Including Glucosyltransferase in Streptococcus mutans

2021 ◽  
Vol 9 (11) ◽  
pp. 2308
Author(s):  
Yusuke Iwabuchi ◽  
Tomoyo Nakamura ◽  
Yasuka Kusumoto ◽  
Ryoma Nakao ◽  
Tsutomu Iwamoto ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Membrane Vesicles ◽  
Extracellular Dna ◽  
Tooth Surface ◽  
Initial Ph ◽  
Effects Of Ph ◽  
Low Levels ◽  
Quantitative Changes ◽  
Biofilm Development

Streptococcus mutans releases membrane vesicles (MVs) and induces MV-dependent biofilm formation. Glucosyltransferases (Gtfs) are bound to MVs and contribute to the adhesion and glucans-dependent biofilm formation of early adherent bacteria on the tooth surface. The biofilm formation of S. mutans may be controlled depending on whether the initial pH tends to be acidic or alkaline. In this study, the characteristics and effects of MVs extracted from various conditions {(initial pH 6.0 and 8.0 media prepared with lactic acid (LA) and acetic acid (AA), and with NaOH (NO), respectively)} on the biofilm formation of S. mutans and early adherent bacteria were investigated. The quantitative changes in glucans between primary pH 6.0 and 8.0 conditions were observed, associated with different activities affecting MV-dependent biofilm formation. The decreased amount of Gtfs on MVs under the initial pH 6.0 conditions strongly guided low levels of MV-dependent biofilm formation. However, in the initial pH 6.0 and 8.0 solutions prepared with AA and NO, the MVs in the biofilm appeared to be formed by the expression of glucans and/or extracellular DNA. These results suggest that the environmental pH conditions established by acid and alkaline factors determine the differences in the local pathogenic activities of biofilm development in the oral cavity.

scholarly journals Strain variation in Bacillus cereus biofilms and their susceptibility to extracellular matrix-degrading enzymes

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0245708
Author(s):  
Eun Seob Lim ◽  
Seung-Youb Baek ◽  
Taeyoung Oh ◽  
Minseon Koo ◽  
Joo Young Lee ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Bacillus Cereus ◽  
Biofilm Formation ◽  
Dnase I ◽  
Extracellular Dna ◽  
Proteinase K ◽  
Strain Variation ◽  
Protein Ratio ◽  
Degrading Enzymes ◽  
Matrix Degrading Enzymes

Bacillus cereus is a foodborne pathogen and can form biofilms on food contact surfaces, which causes food hygiene problems. While it is necessary to understand strain-dependent variation to effectively control these biofilms, strain-to-strain variation in the structure of B. cereus biofilms is poorly understood. In this study, B. cereus strains from tatsoi (BC4, BC10, and BC72) and the ATCC 10987 reference strain were incubated at 30°C to form biofilms in the presence of the extracellular matrix-degrading enzymes DNase I, proteinase K, dispase II, cellulase, amyloglucosidase, and α-amylase to assess the susceptibility to these enzymes. The four strains exhibited four different patterns in terms of biofilm susceptibility to the enzymes as well as morphology of surface-attached biofilms or suspended cell aggregates. DNase I inhibited the biofilm formation of strains ATCC 10987 and BC4 but not of strains BC10 and BC72. This result suggests that some strains may not have extracellular DNA, or their extracellular DNA may be protected in their biofilms. In addition, the strains exhibited different patterns of susceptibility to protein- and carbohydrate-degrading enzymes. While other strains were resistant, strains ATCC 10987 and BC4 were susceptible to cellulase, suggesting that cellulose or its similar polysaccharides may exist and play an essential role in their biofilm formation. Our compositional and imaging analyses of strains ATCC 10987 and BC4 suggested that the physicochemical properties of their biofilms are distinct, as calculated by the carbohydrate to protein ratio. Taken together, our study suggests that the extracellular matrix of B. cereus biofilms may be highly diverse and provides insight into the diverse mechanisms of biofilm formation among B. cereus strains.

Transcriptional activity of icaADBC is not correlated to the degree of biofilm formation in clinical ica-positive Staphylococcus epidermidis strains

Biofilms ◽  
2004 ◽  
Vol 1 (2) ◽  
pp. 101-106 ◽  
Author(s):  
S. Dobinsky ◽  
H. Rohde ◽  
J. K.-M. Knobloch ◽  
M. A. Horstkotte ◽  
D. Mack
Keyword(s):  
Sequence Analysis ◽  
Growth Phase ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Promoter Region ◽  
Transcriptional Activity ◽  
Exponential Growth Phase ◽  
Polysaccharide Intercellular Adhesin ◽  
Different Strains ◽  
Negative Phenotype

Biofilm-formation in Staphylococcus epidermidis depends on the expression of the icaADBC operon encoding the enzymes required for the synthesis of polysaccharide intercellular adhesin (PIA). Different S. epidermidis strains vary widely in the degree of PIA and biofilm that they produce. In 11 clinical S. epidermidis strains we analyzed the biofilm-forming capacity in relation to the amount of ica expressed in static biofilm cultures. In mid-exponential growth phase no correlation could be detected between the level of ica transcription and the biofilm-forming phenotype. When the different strains were grown under conditions leading to a biofilm-negative phenotype, ica-expression was highly upregulated. Sequence analysis demonstrated that the observed differences were not due to major mutations in the ica promoter region but apparently to other strain-specific regulators.

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