scholarly journals Essential Role for the Major Autolysin in the Fibronectin-Binding Protein-MediatedStaphylococcus aureusBiofilm Phenotype

2010 ◽  
Vol 79 (3) ◽  
pp. 1153-1165 ◽  
Author(s):  
Patrick Houston ◽  
Sarah E. Rowe ◽  
Clarissa Pozzi ◽  
Elaine M. Waters ◽  
James P. O'Gara
Keyword(s):  
Essential Role ◽  
Extracellular Dna ◽  
Protease Production ◽  
Phenylmethylsulfonyl Fluoride ◽  
Biofilm Production ◽  
Fibronectin Binding Protein ◽  
Fibronectin Binding ◽  
Primary Attachment ◽  
Biofilm Development

ABSTRACTStaphylococcus aureusclinical isolates are capable of producing at least two distinct types of biofilm mediated by the fibronectin-binding proteins (FnBPs) or theicaADBC-encoded polysaccharide intercellular adhesin (PIA). Deletion of the major autolysin geneatlreduced primary attachment rates and impaired FnBP-dependent biofilm production on hydrophilic polystyrene in 12 clinical methicillin-resistantS. aureus(MRSA) isolates but had no effect on PIA-dependent biofilm production by 9 methicillin-susceptibleS. aureus(MSSA) isolates. In contrast, Atl was required for both FnBP- and PIA-mediated biofilm development on hydrophobic polystyrene. Here we investigated the role of Atl in biofilm production on hydrophilic polystyrene. The alternative sigma factor σB, which represses RNAIII expression and extracellular protease production, was required for FnBP- but not PIA-dependent biofilm development. Furthermore, mutation of theagrlocus enhanced FnBP-dependent biofilm development, whereas asarAmutation, which increases protease production, blocked FnBP-mediated biofilm development. Mutation ofsigBin MRSA isolate BH1CC lowered primary attachment rates, in part via reducedatltranscription. Posttranslational activation or inhibition of Atl activity with phenylmethylsulfonyl fluoride and polyanethole sodium sulfonate or mutation of the Atl amidase active site interfered with lytic activity and biofilm development. Consistent with these observations, extracellular DNA was important for the early stages of Atl/FnBP-dependent biofilm development. Further analysis ofatlregulation revealed thatatlRencodes a transcriptional repressor of the major autolysin and that anatlR::Tcrmutation in BH1CC enhanced biofilm-forming capacity. These data reveal an essential role for the major autolysin in the early events of the FnBP-dependentS. aureusbiofilm phenotype.

scholarly journals Molecular Investigation of Fibronectin-Binding Protein Genes and Capacity of Biofilm Production in Staphylococcus Aureus Isolated From Clinical Samples

2021 ◽  
Author(s):  
Hossein Jafari Soghondicolaei ◽  
Mohammad Ahanjan ◽  
Mehrdad Gholami ◽  
Bahman Mirzaei ◽  
Hamid Reza Goli
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Colorimetric Assay ◽  
Binding Protein ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Biofilm Production ◽  
Fibronectin Binding Protein ◽  
Fibronectin Binding

Abstract Biofilm production increases Staphylococcus aureus resistance to antibiotics and also host defense mechanisms. The current study aims to evaluate the biofilm formation by S. aureus and to determine the prevalence of fibronectin-binding protein genes, also its correlation with drug resistance. In this study, 100 clinical isolates of S. aureus were collected. The antibiotic susceptibility pattern of the isolates was evaluated by the disk agar diffusion method. The ability of biofilm formation in the studied isolates was also determined by microplate colorimetric assay. Then, all isolates were screened by polymerase chain reaction for the fnbA and fnbB genes. Out of 100 clinical isolates of S. aureus, the highest and lowest antibiotic resistance rates were against penicillin (94%) and vancomycin (6%). Thirty-two cases were found to be multi-drug resistant (MDR) among the all strains. The ability of biofilm production was observed in 89% of the isolates. The PCR results showed that the prevalence of fnbA and fnbB genes were 91% and 17%, respectively. Moreover, 100% and 21.8% of the MDR strains harbored the fnbA and fnbB genes respectively. The ability to form biofilm in MDR isolates of S. aureus is more than non-MDR isolates, especially fnbA positive ones. As the bacteria in the biofilm are difficult to kill by antibiotics, attention to the removal or control of the biofilm production seems to be necessary.

scholarly journals Decreased expression of femXAB genes and fnbp mediated biofilm pathways in OS-MRSA clinical isolates

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Umarani Brahma ◽  
Paresh Sharma ◽  
Shweta Murthy ◽  
Savitri Sharma ◽  
Shalini Chakraborty ◽  
...  
Keyword(s):  
Antibiotic Susceptibility ◽  
Biofilm Formation ◽  
Multidrug Resistant ◽  
Agglutination Test ◽  
Clinical Isolates ◽  
Ocular Infections ◽  
Biofilm Production ◽  
Fibronectin Binding ◽  
Sequence Types

Abstract Methicillin-Resistant Staphylococcus aureus (MRSA) is a significant threat to human health. Additionally, biofilm forming bacteria becomes more tolerant to antibiotics and act as bacterial reservoir leading to chronic infection. In this study, we characterised the antibiotic susceptibility, biofilm production and sequence types (ST) of 74 randomly selected clinical isolates of S. aureus causing ocular infections. Antibiotic susceptibility revealed 74% of the isolates as resistant against one or two antibiotics, followed by 16% multidrug-resistant isolates (MDR), and 10% sensitive. The isolates were characterized as MRSA (n = 15), Methicillin-sensitive S. aureus (MSSA, n = 48) and oxacillin susceptible mecA positive S. aureus (OS-MRSA, n = 11) based on oxacillin susceptibility, mecA gene PCR and PBP2a agglutination test. All OS-MRSA would have been misclassified as MSSA on the basis of susceptibility test. Therefore, both phenotypic and genotypic tests should be included to prevent strain misrepresentation. In addition, in-depth studies for understanding the emerging OS-MRSA phenotype is required. The role of fem XAB gene family has been earlier reported in OS-MRSA phenotype. Sequence analysis of the fem XAB genes revealed mutations in fem × (K3R, H11N, N18H and I51V) and fem B (L410F) genes. The fem XAB genes were also found down-regulated in OS-MRSA isolates in comparison to MRSA. In OS-MRSA isolates, biofilm formation is regulated by fibronectin binding proteins A & B. Molecular typing of the isolates revealed genetic diversity. All the isolates produced biofilm, however, MRSA isolates with strong biofilm phenotype represent a worrisome situation and may even result in treatment failure.

scholarly journals Contribution of Autolysin and Sortase A during Enterococcus faecalis DNA-Dependent Biofilm Development

2009 ◽  
Vol 77 (9) ◽  
pp. 3626-3638 ◽  
Author(s):  
Pascale S. Guiton ◽  
Chia S. Hung ◽  
Kimberly A. Kline ◽  
Robyn Roth ◽  
Andrew L. Kau ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Laser Scanning ◽  
Developmental Stages ◽  
Extracellular Dna ◽  
Confocal Laser ◽  
Sortase A ◽  
Hydrodynamic Conditions ◽  
Biofilm Production ◽  
Dna Release ◽  
Biofilm Development

ABSTRACT Biofilm production is a major attribute of Enterococcus faecalis clinical isolates. Although some factors, such as sortases, autolysin, and extracellular DNA (eDNA), have been associated with E. faecalis biofilm production, the mechanisms underlying the contributions of these factors to this process have not been completely elucidated yet. In this study we define important roles for the major E. faecalis autolysin (Atn), eDNA, and sortase A (SrtA) during the developmental stages of biofilm formation under static and hydrodynamic conditions. Deletion of srtA affects the attachment stage and results in a deficiency in biofilm production. Atn-deficient mutants are delayed in biofilm development due to defects in primary adherence and DNA release, which we show to be particularly important during the accumulative phase for maturation and architectural stability of biofilms. Confocal laser scanning and freeze-dry electron microscopy of biofilms grown under hydrodynamic conditions revealed that E. faecalis produces a DNase I-sensitive fibrous network, which is important for biofilm stability and is absent in atn-deficient mutant biofilms. This study establishes the stage-specific requirements for SrtA and Atn and demonstrates a role for Atn in the pathway leading to DNA release during biofilm development in E. faecalis.

Adhesion of Escherichia coli, Citrobacter freundii and Klebsiella pneumoniae isolated from milk: consequence on the efficiency of sanitation procedures

2003 ◽  
Vol 47 (5) ◽  
pp. 225-231 ◽  
Author(s):  
C. Faille ◽  
F. Fontaine ◽  
C. Lelièvre ◽  
T. Bénézech
Keyword(s):  
Essential Role ◽  
Physiological State ◽  
Organic Matrix ◽  
Similar Increase ◽  
E Coli ◽  
Biofilm Development ◽  
Biofilm Structure ◽  
Cleaning And Disinfection ◽  
Strain Dependent

The effects of adhesion and of biofilm development on the efficiency of cleaning and disinfection procedures were investigated on three strains belonging to the E. coli, C. freundii and K. pneumoniae species, which were able to raise more or less complex biofilms. Resistance to a rinsing procedure was strain dependent but not related to the biofilm structure: E. coli was poorly adherent although embedded in an organic matrix. Conversely, a similar increase in the heat- and disinfectant-resistance was observed, regardless of the complexity of the biofilm (more or less significant organic matrix). These results suggested the essential role of the bacterial physiological state in resistance to sanitation procedures.

scholarly journals Biofilm Forming Potential of Escherichia coli from Various Sources

2020 ◽  
Vol 1 (2) ◽  
pp. 26-29
Author(s):  
Kome Otokunefor ◽  
Deborah Melex ◽  
Gideon Abu
Keyword(s):  
Escherichia Coli ◽  
Bacterial Communities ◽  
Essential Role ◽  
Clinical Isolates ◽  
E Coli ◽  
Biofilm Production ◽  
Port Harcourt ◽  
Adverse Environmental Conditions ◽  
High Level ◽  
Biofilm Development

Majority of bacterial communities exist as biofilms and these contribute to the survival of the bacteria. Biofilm development has been associated with protection from adverse environmental conditions and resistance to harmful agents. Generally, however data on biofilm-forming potential of bacteria in Nigeria is sparse. This study was therefore aimed at analyzing variations in biofilm-forming potential of Escherichia coli from various sources in Port Harcourt, Nigeria. Previously characterized clinical (30) and non-clinical (30) E. coli isolates were assessed for their biofilm-forming potential using the Congo Red agar method and variations in this potential determined as weak, moderate or strong. Majority of isolates (67%) had the potential to form biofilms but only 40% of isolates exhibiting biofilm-forming potential were from clinical sources. Isolates exhibited variable degrees of biofilm-forming potential, with only non-clinical isolates exhibiting strong potential. Majority of both clinical and non-clinical isolates (68.7% and 88% respectively) exhibited moderate biofilm-forming potential. The higher occurrence of E. coli exhibiting biofilm-forming potential among non-clinical isolates possibly reflects the essential role biofilms play in the survival of bacteria in nature, but not in infection cases. This study reports on a high level association between the isolates and biofilm production and highlights differences in the abilities of biofilm production between clinical and non-clinical isolates.  

scholarly journals Role of fibronectin-binding protein A in Clostridium difficile intestinal colonization

2011 ◽  
Vol 60 (8) ◽  
pp. 1155-1161 ◽  
Author(s):  
Amira Barketi-Klai ◽  
Sandra Hoys ◽  
Sylvie Lambert-Bordes ◽  
Anne Collignon ◽  
Imad Kansau
Keyword(s):  
Clostridium Difficile ◽  
Binding Protein ◽  
Protein A ◽  
Intestinal Colonization ◽  
Fibronectin Binding Protein ◽  
Fibronectin Binding

scholarly journals Mutation of tagO reveals an essential role for wall teichoic acids in Staphylococcus epidermidis biofilm development

Microbiology ◽  
2011 ◽  
Vol 157 (2) ◽  
pp. 408-418 ◽  
Author(s):  
Linda M. Holland ◽  
Brian Conlon ◽  
James P. O'Gara
Keyword(s):  
Staphylococcus Epidermidis ◽  
Cell Surface Hydrophobicity ◽  
Extracellular Dna ◽  
Proteinase K ◽  
Pellicle Formation ◽  
Sodium Metaperiodate ◽  
Teichoic Acids ◽  
Primary Attachment ◽  
Biofilm Development ◽  
Wall Teichoic Acids

The icaADBC-encoded polysaccharide intercellular adhesin (PIA) and wall teichoic acids (WTA) are structural components of Staphylococcus epidermidis biofilms. Deletion of tagO, which encodes the first enzymic step in WTA biosynthesis, had pleiotropic effects, including enhanced intercellular aggregation and autolytic activity, and impaired biofilm production. The biofilm-negative phenotype of the tagO mutant, named TAGO1, was associated with increased cell surface hydrophobicity, lower rates of primary attachment to polystyrene, and reduced icaADBC operon and PIA expression. Mild acid stress induced by growth in BHI glucose media reduced rates of stationary phase autolysis and enhanced aggregation by TAGO1, leading to formation of a pellicle, which unlike a biofilm was only loosely attached to the polystyrene surface. TAGO1 pellicles were dispersed by proteinase K and DNase I but not sodium metaperiodate, implicating protein and extracellular DNA (eDNA) and not PIA in this phenotype. Substantially increased levels of eDNA were recovered from TAGO1 culture supernatants compared with the wild-type. These data indicate that WTA are essential for the primary attachment and accumulation phases of the S. epidermidis biofilm phenotype. Furthermore, in the absence of WTA, proteins and eDNA can promote cell aggregation and pellicle formation, which also appear to limit interactions with artificial surfaces.

Biofilm formation in the life cycle of the cellulolytic actinomycete Thermobifida fusca

Biofilms ◽  
2008 ◽  
pp. 1-11 ◽  
Author(s):  
A. N. Alonso ◽  
P. J. Pomposiello ◽  
S. B. Leschine
Keyword(s):  
Life Cycle ◽  
Biofilm Formation ◽  
Cellulose Degradation ◽  
Extracellular Dna ◽  
Thermobifida Fusca ◽  
General Strategy ◽  
Dialysis Tubing ◽  
Biofilm Production ◽  
Mycelial Pellets ◽  
Biofilm Development

ABSTRACTActinomycetes have been used with enormous success in industrial processes; however, little is known about biofilm formation by these filamentous microbes, or community development on insoluble substrates such as cellulose. We hypothesized that biofilm formation is a general strategy used by actinomycetes in the degradation of cellulose, and that it may serve as a means for these microbes to secure nutrients and persist in their environments. The objective of this study was to examine biofilm production byThermobifida fusca, an actinomycete that rapidly degrades cellulose by means of a well-characterized extracellular cellulase system.Thermobifida fuscacells grew as biofilms attached to both nutritive (e.g. dialysis tubing membrane) and non-nutritive surfaces. Dialysis tubing was colonized byT. fuscaaleuriospores but not by mycelial pellets, except when mycelial pellets were disrupted by sonication. Microscopic examination of surface-attached growth revealed structures characteristic of biofilms, with cells embedded in fibrous material suggestive of an extracellular polymeric matrix. Concanavalin A bound to the extracellular polymeric substance of biofilms and mycelial pellets, indicating alpha-linkedd-mannosyl and/or alpha-linkedd-glucosyl residues. The carbohydrate content of both biofilms and mycelial pellets increased during growth. Also, DNase I inhibited biofilm production, suggesting a role for extracellular DNA inT. fuscabiofilm development. Cellulose degradation and expression ofcelE(encoding endoglucanase E5) was similar forT. fuscabiofilms and mycelial pellets. Results of this study indicate that, in the life cycle of this actinomycete, cellulose is specifically colonized by aleuriospores, which germinate, grow and degrade cellulose, ultimately developing into biofilms encased in a carbohydrate-containing exopolymeric matrix, a hallmark of biofilm production.

scholarly journals SrrAB Modulates Staphylococcus aureus Cell Death through Regulation ofcidABCTranscription

2016 ◽  
Vol 198 (7) ◽  
pp. 1114-1122 ◽  
Author(s):  
Ian H. Windham ◽  
Sujata S. Chaudhari ◽  
Jeffrey L. Bose ◽  
Vinai C. Thomas ◽  
Kenneth W. Bayles
Keyword(s):  
Reactive Oxygen Species ◽  
Staphylococcus Aureus ◽  
Cell Death ◽  
Reactive Oxygen ◽  
Extracellular Dna ◽  
Death Process ◽  
Oxygen Species ◽  
Content Type ◽  
Biofilm Development

ABSTRACTThe death and lysis of a subpopulation inStaphylococcus aureusbiofilm cells are thought to benefit the surviving population by releasing extracellular DNA, a critical component of the biofilm extracellular matrix. Although the means by whichS. aureuscontrols cell death and lysis is not understood, studies implicate the role of thecidABCandlrgABoperons in this process. Recently, disruption of thesrrABregulatory locus was found to cause increased cell death during biofilm development, likely as a result of the sensitivity of this mutant to hypoxic growth. In the current study, we extended these findings by demonstrating that cell death in the ΔsrrABmutant is dependent on expression of thecidABCoperon. The effect ofcidABCexpression resulted in the generation of increased reactive oxygen species (ROS) accumulation and was independent of acetate production. Interestingly, consistently with previous studies,cidC-encoded pyruvate oxidase was found to be important for the generation of acetic acid, which initiates the cell death process. However, these studies also revealed for the first time an important role of thecidBgene in cell death, as disruption ofcidBin the ΔsrrABmutant background decreased ROS generation and cell death in acidC-independent manner. ThecidBmutation also caused decreased sensitivity to hydrogen peroxide, which suggests a complex role for this system in ROS metabolism. Overall, the results of this study provide further insight into the function of thecidABCoperon in cell death and reveal its contribution to the oxidative stress response.IMPORTANCEThe manuscript focuses on cell death mechanisms inStaphylococcus aureusand provides important new insights into the genes involved in this ill-defined process. By exploring the cause of increased stationary-phase death in anS. aureusΔsrrABregulatory mutant, we found that the decreased viability of this mutant was a consequence of the overexpression of thecidABCoperon, previously shown to be a key mediator of cell death. These investigations highlight the role of thecidBgene in the death process and the accumulation of reactive oxygen species. Overall, the results of this study are the first to demonstrate a positive role for CidB in cell death and to provide an important paradigm for understanding this process in all bacteria.

scholarly journals Staphylococcus aureus Fibronectin Binding Protein A Mediates Biofilm Development and Infection

2020 ◽  
Vol 88 (5) ◽  
Author(s):  
Casey M. Gries ◽  
Trevor Biddle ◽  
Jeffrey L. Bose ◽  
Tammy Kielian ◽  
David D. Lo
Keyword(s):  
Staphylococcus Aureus ◽  
Binding Protein ◽  
Protein A ◽  
Bacterial Biofilm ◽  
Innate Immune Responses ◽  
Surface Adhesion ◽  
Content Type ◽  
Fibronectin Binding Protein ◽  
Fibronectin Binding ◽  
Biofilm Development

ABSTRACT Implanted medical device-associated infections pose significant health risks, as they are often the result of bacterial biofilm formation. Staphylococcus aureus is a leading cause of biofilm-associated infections which persist due to mechanisms of device surface adhesion, biofilm accumulation, and reprogramming of host innate immune responses. We found that the S. aureus fibronectin binding protein A (FnBPA) is required for normal biofilm development in mammalian serum and that the SaeRS two-component system is required for functional FnBPA activity in serum. Furthermore, serum-developed biofilms deficient in FnBPA were more susceptible to macrophage invasion, and in a model of biofilm-associated implant infection, we found that FnBPA is crucial for the establishment of infection. Together, these findings show that S. aureus FnBPA plays an important role in physical biofilm development and represents a potential therapeutic target for the prevention and treatment of device-associated infections.

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