scholarly journals Methicillin-ResistantStaphylococcus aureusBiofilms and Their Influence on Bacterial Adhesion and Cohesion

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Khulood Hamid Dakheel ◽  
Raha Abdul Rahim ◽  
Vasantha Kumari Neela ◽  
Jameel R. Al-Obaidi ◽  
Tan Geok Hun ◽  
...  

Twenty-five methicillin-resistantStaphylococcus aureus(MRSA) isolates were characterized by staphylococcal protein A gene typing and the ability to form biofilms. The presence of exopolysaccharides, proteins, and extracellular DNA and RNA in biofilms was assessed by a dispersal assay. In addition, cell adhesion to surfaces and cell cohesion were evaluated using the packed-bead method and mechanical disruption, respectively. The predominant genotype wasspatype t127 (22 out of 25 isolates); the majority of isolates were categorized as moderate biofilm producers. Twelve isolates displayed PIA-independent biofilm formation, while the remaining 13 isolates were PIA-dependent. Both groups showed strong dispersal in response to RNase and DNase digestion followed by proteinase K treatment. PIA-dependent biofilms showed variable dispersal after sodium metaperiodate treatment, whereas PIA-independent biofilms showed enhanced biofilm formation. There was no correlation between the extent of biofilm formation or biofilm components and the adhesion or cohesion abilities of the bacteria, but the efficiency of adherence to glass beads increased after biofilm depletion. In conclusion, nucleic acids and proteins formed the main components of the MRSA clone t127 biofilm matrix, and there seems to be an association between adhesion and cohesion in the biofilms tested.

2008 ◽  
Vol 76 (5) ◽  
pp. 2044-2050 ◽  
Author(s):  
Kati Seidl ◽  
Christiane Goerke ◽  
Christiane Wolz ◽  
Dietrich Mack ◽  
Brigitte Berger-Bächi ◽  
...  

ABSTRACT Biofilm formation in Staphylococcus aureus under in vitro growth conditions is generally promoted by high concentrations of sugar and/or salts. The addition of glucose to routinely used complex growth media triggered biofilm formation in S. aureus strain SA113. Deletion of ccpA, coding for the catabolite control protein A (CcpA), which regulates gene expression in response to the carbon source, abolished the capacity of SA113 to form a biofilm under static and flow conditions, while still allowing primary attachment to polystyrene surfaces. This suggested that CcpA mainly affects biofilm accumulation and intercellular aggregation. trans-Complementation of the mutant with the wild-type ccpA allele fully restored the biofilm formation. The biofilm produced by SA113 was susceptible to sodium metaperiodate, DNase I, and proteinase K treatment, indicating the presence of polysaccharide intercellular adhesin (PIA), protein factors, and extracellular DNA (eDNA). The investigation of several factors which were reported to influence biofilm formation in S. aureus (arlRS, mgrA, rbf, sarA, atl, ica, citZ, citB, and cidABC) showed that CcpA up-regulated the transcription of cidA, which was recently shown to contribute to eDNA production. Moreover, we showed that CcpA increased icaA expression and PIA production, presumably over the down-regulation of the tricarboxylic acid cycle genes citB and citZ.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1758
Author(s):  
Urszula Wójcik-Bojek ◽  
Joanna Rywaniak ◽  
Przemysław Bernat ◽  
Anna Podsędek ◽  
Dominika Kajszczak ◽  
...  

Staphylococcus aureus is still one of the leading causes of both hospital- and community-acquired infections. Due to the very high percentage of drug-resistant strains, the participation of drug-tolerant biofilms in pathological changes, and thus the limited number of effective antibiotics, there is an urgent need to search for alternative methods of prevention or treatment for S. aureus infections. In the present study, biochemically characterized (HPLC/UPLC–QTOF–MS) acetonic, ethanolic, and water extracts from fruits and bark of Viburnum opulus L. were tested in vitro as diet additives that potentially prevent staphylococcal infections. The impacts of V. opulus extracts on sortase A (SrtA) activity (Fluorimetric Assay), staphylococcal protein A (SpA) expression (FITC-labelled specific antibodies), the lipid composition of bacterial cell membranes (LC-MS/MS, GC/MS), and biofilm formation (LIVE/DEAD BacLight) were assessed. The cytotoxicity of V. opulus extracts to the human fibroblast line HFF-1 was also tested (MTT reduction). V. opulus extracts strongly inhibited SrtA activity and SpA expression, caused modifications of S. aureus cell membrane, limited biofilm formation by staphylococci, and were non-cytotoxic. Therefore, they have pro-health potential. Nevertheless, their usefulness as diet supplements that are beneficial for the prevention of staphylococcal infections should be confirmed in animal models in the future.


PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0245708
Author(s):  
Eun Seob Lim ◽  
Seung-Youb Baek ◽  
Taeyoung Oh ◽  
Minseon Koo ◽  
Joo Young Lee ◽  
...  

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.


2021 ◽  
Author(s):  
Eun Seob Lim ◽  
Seung-Youb Baek ◽  
Taeyoung Oh ◽  
Minseon Koo ◽  
Joo Young Lee ◽  
...  

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 and the ATCC 10987 reference strain were incubated at 30? 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 analysis 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.


Chemotherapy ◽  
2016 ◽  
Vol 62 (2) ◽  
pp. 128-133 ◽  
Author(s):  
Huale Chen ◽  
Jianming Cao ◽  
Cui Zhou ◽  
Haiyang Liu ◽  
Xiaoxiao Zhang ◽  
...  

Background: Tigecycline, one of the few therapeutic options against multidrug-resistant Acinetobacter baumannii, reaches subinhibitory serum concentrations only with cautious clinical dosing and pharmacokinetics. Subinhibitory concentrations of tigecycline might induce an A. baumannii biofilm. Methods: Biofilm formation was assessed via the crystal violet staining method. We further analyzed the main biofilm components with NaIO4, proteinase K, and DNase. Real-time RT-PCR was applied for quantitative detection of biofilm potential-associated genes. Results: In this study, A. baumannii proved to be a strong biofilm producer, and we found that proteins and extracellular DNA are crucial components of the A. baumannii biofilm. Quantitative real-time RT-PCR revealed positive correlations between biofilm formation restrained by subinhibitory concentrations of tigecycline and the expression of biofilm potential-associated genes, especially the AdeFGH efflux pump gene. Conclusion: Our results suggest that downregulation of efflux pumps, especially the AdeFGH efflux pump, is probably responsible for the decline in biofilm formation in A. baumannii treated with subinhibitory concentrations of tigecyclin.


Microbiology ◽  
2011 ◽  
Vol 157 (2) ◽  
pp. 408-418 ◽  
Author(s):  
Linda M. Holland ◽  
Brian Conlon ◽  
James P. O'Gara

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.


2015 ◽  
Vol 61 (7) ◽  
pp. 503-512 ◽  
Author(s):  
Trond Møretrø ◽  
Shahab Sharifzadeh ◽  
Solveig Langsrud ◽  
Even Heir ◽  
Alexander H. Rickard

In this study, coaggregation interactions between Rhodococcus and Acinetobacter strains isolated from food-processing surfaces were characterized. Rhodococcus sp. strain MF3727 formed intrageneric coaggregates with Rhodococcus sp. strain MF3803 and intergeneric coaggregates with 2 strains of Acinetobacter calcoaceticus (MF3293, MF3627). Stronger coaggregation between A. calcoaceticus MF3727 and Rhodococcus sp. MF3293 was observed after growth in batch culture at 30 °C than at 20 °C, after growth in tryptic soy broth than in liquid R2A medium, and between cells in exponential and early stationary phases than cells in late stationary phase. The coaggregation ability of Rhodococcus sp. MF3727 was maintained even after heat and Proteinase K treatment, suggesting its ability to coaggregate was protein independent whereas the coaggregation determinants of the other strains involved proteinaceous cell-surface-associated polymers. Coaggregation was stable at pH 5–9. The mechanisms of coaggregation among Acinetobacter and Rhodococcus strains bare similarity to those displayed by coaggregating bacteria of oral and freshwater origin, with respect to binding between proteinaceous and nonproteinaceous determinants and the effect of environmental factors on coaggregation. Coaggregation may contribute to biofilm formation on industrial food surfaces, protecting bacteria against cleaning and disinfection.


2017 ◽  
Vol 11 (1) ◽  
pp. 142-151 ◽  
Author(s):  
Agostinho Alves Lima-e-Silva ◽  
Renato Geraldo Silva-Filho ◽  
Henry Marcel Zalona Fernandes ◽  
Carmen Soares Meirelles Saramago ◽  
Alice Slotfeldt Viana ◽  
...  

Background and Objectives:Staphylococcus aureusis an important pathogen and a frequent cause of infections associated with biofilm production in implantable medical devices. Biofilm production can be induced by sub-inhibitory concentrations (sub-MICs) of certain antibiotics, but few studies have researched this occurrence inS. aureus. In this study, we investigated the effect of sub-MICs of rifampicin and minocycline on biofilm production by five clinical and five non-clinicalS. aureusisolates.Methods:Microtiter Plate assay and Congo Red Agar Test were used to analyze the biofilm production. The biofilm composition was evaluated by the detachment assay with sodium metaperiodate and proteinase K.Results:Rifampicin sub-MICs induced very high biofilm formation in seven isolates that were non-producers in Tryptic Soy Broth. In one producer isolate, the biofilm formation level was not affected by sub-MICs of this drug. Sub-MICs of minocycline did not induce biofilm production in all isolates tested and in two producer isolates, instead, MIC/2 and MIC/4 inhibited biofilm production. The results of the drugs in combination were similar to those with rifampicin alone. The biofilm matrix was identified as polysaccharide, except for one producer isolate, classified as proteinaceous. Polysaccharide biofilm producer isolates, when grown on Congo Red Agar without sucrose, but with sub-MICs of rifampicin, showed results in agreement with those obtained in Microtiter Plate Test.Conclusion:The high biofilm production induced by sub-MICs of rifampicin has potential clinical relevance, because this is one of the drugs commonly used in the impregnation of catheters. In addition, it is used adjunctively to treat certainS. aureusinfections.


2013 ◽  
Vol 62 (7) ◽  
pp. 1051-1059 ◽  
Author(s):  
Valerie S. Greco-Stewart ◽  
Hamza Ali ◽  
Dilini Kumaran ◽  
M. Kalab ◽  
Ineke G. H. Rood ◽  
...  

Bacterial contamination of platelet concentrates (PCs) poses the greatest infectious risk in modern transfusion medicine despite the implementation of measures such as improved skin disinfection and first aliquot diversion. The majority of PC contaminants are commensal skin flora introduced by venipuncture at the time of blood collection. The predominant organisms are Gram-positive coagulase-negative staphylococci such as Staphylococcus capitis. This bacterium has been implicated in numerous instances of infection and sepsis, likely for its ability to form surface-associated communities of micro-organisms encased in extracellular materials, known as biofilms. In the present study, five strains of S. capitis isolated from contaminated PCs were assessed for their ability to produce extracellular polysaccharide (slime), a canonical indicator of biofilm-formation ability, on Congo red agar plates. Biofilm formation was evaluated in both glucose-enriched trypticase soy broth (TSBg) and in PCs by using a crystal violet staining assay. The chemical nature of the biofilms was evaluated by disruption assays using sodium metaperiodate and proteinase K. In addition, biofilm architecture was observed by scanning electron microscopy. The presence of the biofilm-associated icaR and icaADBC genes was also examined by PCR. While only two out of the five S. capitis strains formed biofilms in TSBg, all strains formed biofilms in PCs. The ability of strains to produce extracellular polysaccharide and their possession of wild-type ica genes were not exclusive predictors of biofilm formation in TSBg or PCs; different profiles of biofilm markers were observed among isolates. This is likely due to the proteinaceous composition of the S. capitis biofilm matrix. Interestingly, an ica-negative, non-slime-producing isolate was capable of biofilm formation in PCs. Together, these data indicate that the platelet storage environment stimulates biofilm formation in S. capitis in the absence of extracellular polysaccharide production and that multiple bacterial factors and regulatory elements are likely involved in biofilm formation in this milieu.


2021 ◽  
Vol 6 (7) ◽  
pp. 241-253
Author(s):  
Xinyu Qi ◽  
Kimberly M. Brothers ◽  
Dongzhu Ma ◽  
Jonathan B. Mandell ◽  
Niles P. Donegan ◽  
...  

Abstract. The high antibiotic tolerance of Staphylococcus aureus biofilms is associated with challenges for treating periprosthetic joint infection. The toxin–antitoxin system, YefM–YoeB, is thought to be a regulator for antibiotic tolerance, but its physiological role is unknown. The objective of this study was to determine the biofilm and antibiotic susceptibility phenotypes associated with S. aureus yoeB homologs. We hypothesized the toxin–antitoxin yoeB homologs contribute to biofilm formation and antibiotic susceptibility. Disruption of yoeB1 and yoeB2 resulted in decreased biofilm formation in comparison to Newman and JE2 wild-type (WT) S. aureus strains. In comparison to yoeB mutants, both Newman and JE2 WT strains had higher polysaccharide intercellular adhesin (PIA) production. Treatment with sodium metaperiodate increased biofilm formation in Newman WT, indicating biofilm formation may be increased under conditions of oxidative stress. DNase I treatment decreased biofilm formation in Newman WT but not in the absence of yoeB1 or yoeB2. Additionally, WT strains had a higher extracellular DNA (eDNA) content in comparison to yoeB mutants but no differences in biofilm protein content. Moreover, loss of yoeB1 and yoeB2 decreased biofilm survival in both Newman and JE2 strains. Finally, in a neutropenic mouse abscess model, deletion of yoeB1 and yoeB2 resulted in reduced bacterial burden. In conclusion, our data suggest that yoeB1 and yoeB2 are associated with S. aureus planktonic growth, extracellular dependent biofilm formation, antibiotic tolerance, and virulence.


Sign in / Sign up

Export Citation Format

Share Document