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.

Inhibitory Effects of Citral, Cinnamaldehyde, and Tea Polyphenols on Mixed Biofilm Formation by Foodborne Staphylococcus aureus and Salmonella Enteritidis

2014 ◽  
Vol 77 (6) ◽  
pp. 927-933 ◽  
Author(s):  
HONGMEI ZHANG ◽  
WENYUAN ZHOU ◽  
WENYAN ZHANG ◽  
ANLIN YANG ◽  
YANLAN LIU ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Salmonella Enteritidis ◽  
Food Additives ◽  
Microtiter Plate ◽  
Tea Polyphenols ◽  
Natural Food ◽  
Inhibitory Effects ◽  
Microtiter Plate Assay ◽  
Communication Signal

Biofilms are significant hazards in the food industry. In this study, we investigated the effects of food additive such as citral, cinnamaldehyde, and tea polyphenols on mixed biofilm formation by foodborne Staphylococcus aureus and Salmonella serotype Enteritidis. The adhesion rates of mixed strains in sub-MIC of additives were determined by a microtiter plate assay and bacterial communication signal autoinducer 2 (AI-2) production via a bioluminescence reporter Vibrio harveyi BB170. The structure of mixed biofilm was analyzed using scanning electron microscopy. The effect of the disinfectants hydrogen peroxide, sodium hypochlorite, and peracetic acid was tested on the mixed biofilm. Our results demonstrated that citral, cinnamaldehyde, and tea polyphenols were able to significantly inhibit mixed biofilm formation, while citral could reduce the synthesis of AI-2. Conversely, we observed a significant increase in AI-2 mediated by cinnamaldehyde. Tea polyphenols at lower concentrations induced AI-2 synthesis; however, AI-2 synthesis was significantly inhibited at higher concentrations (300 μg/ml). Food additives inhibited the adhesion of mixed bacteria on stainless steel chips and increased the sensitivity of the mixed biofilm to disinfectants. In conclusion, citral, cinnamaldehyde, and tea polyphenols had strong inhibitory effects on mixed biofilm formation and also enhanced the effect of disinfectant on mixed biofilm formation. This study provides a scientific basis for the application of natural food additives to control biofilm formation of foodborne bacteria.

Inhibitory effect of probiotic yeast Saccharomyces cerevisiae on biofilm formation and expression of α-hemolysin and enterotoxin A genes of Staphylococcus aureus

2019 ◽  
Author(s):  
Navid Saidi ◽  
Parviz Owlia ◽  
Seyed Mahmoud Amin Marashi ◽  
Horieh Saderi
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Food Poisoning ◽  
Microtiter Plate ◽  
Inhibitory Effect ◽  
Yeast Saccharomyces Cerevisiae ◽  
Microtiter Plate Assay ◽  
Probiotic Yeast ◽  
Mrsa Strains

Background and Objectives: Staphylococcus aureus, as an opportunistic pathogen, is the cause of a variety of diseases from mild skin infections to severe invasive infections and food poisoning. Increasing antibiotic resistance in S. aureus isolates has become a major threat to public health. The use of compounds produced by probiotics can be a solution to this problem. Thus, the purpose of this study was to investigate the effect of Saccharomyces cerevisiae on some virulence factors (biofilm, α-hemolysin, and enterotoxin A) of S. aureus. Materials and Methods: Supernatant and lysate extracts were prepared from S. cerevisiae S3 culture. Sub-MIC concen- trations of both extracts were separately applied to S. aureus ATCC 29213 (methicillin-sensitive S. aureus; MSSA) and S. aureus ATCC 33591 (methicillin-resistant S. aureus; MRSA) strains. Biofilm formation of these strains was measured by microtiter plate assay and expression level of α-hemolysin and enterotoxin A genes (hla and sea, respectively) using real-time PCR technique. Results: The supernatant extract has reduced both biofilm formation and expression of sea and hla genes, while lysate ex- tract had only anti-biofilm effects. The MRSA strain showed more susceptibility to yeast extracts than MSSA strain in all tests. Conclusion: The present study exhibited favorable antagonistic effects of S. cerevisiae S3, as a probiotic yeast, on MSSA and MRSA strains. Based on the findings of this study, the compounds produced by this yeast can be used to control S. aureus infections; however, further similar studies should be conducted to confirm the findings of the present study.

icaA Gene of Staphylococcus aureus Responds to NaCl, Leading to Increased Biofilm Formation

2018 ◽  
Vol 81 (3) ◽  
pp. 412-416 ◽  
Author(s):  
Soomin Lee ◽  
Sejeong Kim ◽  
Heeyoung Lee ◽  
Jimyeong Ha ◽  
Jeeyeon Lee ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Deletion Mutant ◽  
Microtiter Plate ◽  
Temperature Sensitive ◽  
Wild Type ◽  
Microtiter Plate Assay ◽  
Nacl Concentration ◽  
Icaa Gene

ABSTRACT The objective of this study was to elucidate the role of the icaA gene in biofilm formation of Staphylococcus aureus exposed to NaCl. The icaA-deletion mutant of S. aureus ATCC 13565 was constructed with the temperature-sensitive plasmid pIMAY. Microtiter plate assays were performed to confirm biofilm formation for both the wild type and the mutant at 0% (control), 2, 4, and 6% NaCl. The microtiter plate assay revealed that biofilm formation by the wild type increased (P < 0.05) as NaCl concentration increased, but biofilm formation of the mutant was not affected by NaCl concentration. Biofilm formation by the mutant was lower (P < 0.05) than that by the wild type. These results indicate that icaA plays an important role in biofilm formation by S. aureus when the pathogen is exposed to NaCl.

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 Anaerobic Conditions Induce Expression of Polysaccharide Intercellular Adhesin in Staphylococcus aureus and Staphylococcus epidermidis

2001 ◽  
Vol 69 (6) ◽  
pp. 4079-4085 ◽  
Author(s):  
Sarah E. Cramton ◽  
Martina Ulrich ◽  
Friedrich Götz ◽  
Gerd Döring
Keyword(s):  
Staphylococcus Aureus ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Extracellular Polysaccharide ◽  
Growth Conditions ◽  
Anaerobic Conditions ◽  
Anaerobic Environment ◽  
Specific Mrna

ABSTRACT Products of the intercellular adhesion (ica) operon in Staphylococcus aureus and Staphylococcus epidermidis synthesize a linear β-1,6-linked glucosaminylglycan. This extracellular polysaccharide mediates bacterial cell-cell adhesion and is required for biofilm formation, which is thought to increase the virulence of both pathogens in association with prosthetic biomedical implants. The environmental signal(s) that triggers ica gene product and polysaccharide expression is unknown. Here we demonstrate that anaerobic in vitro growth conditions lead to increased polysaccharide expression in both S. aureus and S. epidermidis, although the regulation is less stringent inS. epidermidis. Anaerobiosis also dramatically stimulates ica-specific mRNA expression inica- and polysaccharide-positive strains of both S. aureus and S. epidermidis.These data suggest a mechanism whereby ica gene expression and polysaccharide production may act as a virulence factor in an anaerobic environment in vivo.

scholarly journals Effect of S-PRG Eluate on Biofilm Formation and Enzyme Activity of Oral Bacteria

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Masahiro Yoneda ◽  
Nao Suzuki ◽  
Yosuke Masuo ◽  
Akie Fujimoto ◽  
Kosaku Iha ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Composite Resin ◽  
Fusobacterium Nucleatum ◽  
Microtiter Plate ◽  
Oral Bacteria ◽  
Gelatin Film ◽  
Glass Ionomer ◽  
Microtiter Plate Assay ◽  
Substrate Hydrolysis ◽  
Adherence Ability

Recently, the antibacterial activity of a composite resin containing prereacted glass ionomer (S-PRG) filler was revealed. We examined the effect of an S-PRG eluate on various biologic activities ofStreptococcus mutansandPorphyromonas gingivalis. Adherence ability ofS. mutanswas evaluated by microtiter plate assay; protease and gelatinase activities ofP. gingivaliswere examined by synthetic substrate hydrolysis and gelatin film spot assay, respectively. Coaggregation ofP. gingivaliswithFusobacterium nucleatumwas also examined. S-PRG eluate was found to suppress streptococcal adherence. S-PRG eluate inhibited the protease and gelatinase activities ofP. gingivalisand the coaggregation betweenP. gingivalisandF. nucleatum. These results indicate that S-PRG eluate suppresses streptococcal adherence and inhibits the protease and coaggregation activities ofP. gingivalis. These findings may prompt research into novel strategies for preventing caries and periodontitis.

Evaluation of the Role of Staphylococci in the Pathomechanism of Conjunctivitis

2021 ◽  
Author(s):  
Ewa Jasińska ◽  
Agnieszka Bogut ◽  
Agnieszka Magryś ◽  
Alina Olender
Keyword(s):  
Antibiotic Resistance ◽  
Epithelial Cells ◽  
Biofilm Formation ◽  
Methicillin Resistance ◽  
Microtiter Plate ◽  
Host Cells ◽  
Diffusion Method ◽  
Microtiter Plate Assay ◽  
Low Prevalence

Abstract Purpose: Determination of the association between ica genes and phenotypic biofilm formation in staphylococcal isolates involved in conjunctivitis, their antibiotic resistance as well as detection of selected virulence characteristics: adhesion to epithelial cells and in vitro cytotoxicity.Methods: The study included 26 Staphylococcus aureus (SA) and 26 Staphylococcus epidermidis (SE) isolates. The presence of icaAD genes and ica operon was determined by the PCR assay. Phenotypic biofilm formation was verified using the microtiter plate assay. Antibiotic resistance was performed using the disc diffusion method. Staphylococcal ability to attach to host cells was assessed by flow cytometry. Cytotoxicity on epithelial cells was evaluated by LDH assay.Results: The ica genes were detected in 26.9% of SE and in 42.3% of SA isolates. Only 15.3% of isolates (SE) were positive for both the icaAD and the ica operon. Phenotypically, 19.2% of SE isolates were strong biofilm producers, among which three were both icaAD- and ica operon-positive. 26.9% of SA isolates were strong biofilm producers. Methicillin resistance (MR) was detected in 34.6% of SE and 26.9% of SA isolates. 75% of MR isolates were multidrug resistant. SA isolates adhered to host cells more extensively than SE. SA isolates released higher level of LDH than SE.Conclusions: Adherence abilities were commonly observed in staphylococci associated with conjunctivitis. However, low prevalence of isolates positive for a complete and functional ica locus and low prevalence of strong biofilm producers was detected. SA adhered to a greater extent to eukaryotic cells than SE and were more cytotoxic.

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.

scholarly journals Effect of Silver Nanoparticles on Biofilm Formation and EPS Production of Multidrug-Resistant Klebsiella pneumoniae

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Muhammad Hussnain Siddique ◽  
Bilal Aslam ◽  
Muhammad Imran ◽  
Asma Ashraf ◽  
Habibullah Nadeem ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Biofilm Formation ◽  
Extracellular Polymeric Substances ◽  
Microtiter Plate ◽  
Cellular Protein ◽  
Antibiofilm Activity ◽  
Biofilm Inhibition ◽  
Microtiter Plate Assay ◽  
Protein Leakage ◽  
Hela Cell Lines

Antibiotic resistance against present antibiotics is rising at an alarming rate with need for discovery of advanced methods to treat infections caused by resistant pathogens. Silver nanoparticles are known to exhibit satisfactory antibacterial and antibiofilm activity against different pathogens. In the present study, the AgNPs were synthesized chemically and characterized by UV-Visible spectroscopy, scanning electron microscopy, and X-ray diffraction. Antibacterial activity against MDR K. pneumoniae strains was evaluated by agar diffusion and broth microdilution assay. Cellular protein leakage was determined by the Bradford assay. The effect of AgNPs on production on extracellular polymeric substances was evaluated. Biofilm formation was assessed by tube method qualitatively and quantitatively by the microtiter plate assay. The cytotoxic potential of AgNPs on HeLa cell lines was also determined. AgNPs exhibited an MIC of 62.5 and 125 μg/ml, while their MBC is 250 and 500 μg/ml. The production of extracellular polymeric substance decreased after AgNP treatment while cellular protein leakage increased due to higher rates of cellular membrane disruption by AgNPs. The percentage biofilm inhibition was evaluated to be 64% for K. pneumoniae strain MF953600 and 86% for MF953599 at AgNP concentration of 100 μg/ml. AgNPs were evaluated to be minimally cytotoxic and safe at concentrations of 15-120 μg/ml. The data evaluated by this study provided evidence of AgNPs being safe antibacterial and antibiofilm compounds against MDR K. pneumoniae.

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