51
|
Biofilm Formation in Staphylococcus epidermidis Isolated from Hospitalized Patients. ARCHIVES OF CLINICAL INFECTIOUS DISEASES 2019. [DOI: 10.5812/archcid.64496] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
52
|
Schiffer C, Hilgarth M, Ehrmann M, Vogel RF. Bap and Cell Surface Hydrophobicity Are Important Factors in Staphylococcus xylosus Biofilm Formation. Front Microbiol 2019; 10:1387. [PMID: 31293539 PMCID: PMC6603148 DOI: 10.3389/fmicb.2019.01387] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 06/03/2019] [Indexed: 01/04/2023] Open
Abstract
Staphylococcus (S.) xylosus is a coagulase-negative Staphylococcus species naturally present in food of animal origin with a previously described potential for biofilm formation. In this study we characterized biofilm formation of five selected strains isolated from raw fermented dry sausages, upon different growth conditions. Four strains exhibited a biofilm positive phenotype with strain-dependent intensities. Biofilm formation of S. xylosus was influenced by the addition of glucose, sodium chloride and lactate to the growth medium, respectively. It was further dependent on strain-specific cell surface properties. Three strains exhibited hydrophobic and two hydrophilic cell surface properties. The biofilm positive hydrophilic strain TMW 2.1523 adhered significantly better to hydrophilic than to hydrophobic supports, whereas the differences in adherence to hydrophobic versus hydrophilic supports were not as distinct for the hydrophobic strains TMW 2.1023, TMW 2.1323, and TMW 2.1521. Comparative genomics enabled prediction of functional biofilm-related genes and link these to phenotypic variations. While a wide range of biofilm associated factors/genes previously described for S. aureus and S. epidermidis were absent in the genomes of the five strains analyzed, they all possess the gene encoding biofilm associated protein Bap. The only biofilm negative strain TMW 2.1602 showed a mutation in the bap sequence. This study demonstrates that Bap and surface hydrophobicity are important factors in S. xylosus biofilm formation with potential impact on the assertiveness of a starter strain against autochthonous staphylococci by competitive exclusion during raw sausage fermentation.
Collapse
Affiliation(s)
- Carolin Schiffer
- Lehrstuhl für Technische Mikrobiologie, Technische Universität München, Freising, Germany
| | - Maik Hilgarth
- Lehrstuhl für Technische Mikrobiologie, Technische Universität München, Freising, Germany
| | - Matthias Ehrmann
- Lehrstuhl für Technische Mikrobiologie, Technische Universität München, Freising, Germany
| | - Rudi F Vogel
- Lehrstuhl für Technische Mikrobiologie, Technische Universität München, Freising, Germany
| |
Collapse
|
53
|
The prevalence of Staphylococcus aureus with mucoid phenotype in the airways of patients with cystic fibrosis-A prospective study. Int J Med Microbiol 2019; 309:283-287. [PMID: 31122879 DOI: 10.1016/j.ijmm.2019.05.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 04/10/2019] [Accepted: 05/10/2019] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Staphylococcus aureus is one of the most frequently isolated pathogens in the respiratory tract of CF patients. Recently, we characterized peculiar mucoid S. aureus isolates, which are excessive biofilm formers and which carried a 5bp-deletion within the intergenic region of the ica operon. In this prospective study, we determined the prevalence of mucoid S. aureus-isolates in the airways of CF-patients during a 3-months period. METHODS We analyzed specimens (sputa, throat swabs) from 81 CF patients who attended two CF centers in Münster, Germany. Ten S. aureus isolates were randomly picked from every S. aureus-positive airway specimen and evaluated for mucoidy using Congo Red agar and phenotypic tests. Mucoid isolates were characterized by spa sequence typing, biofilm production and sequencing of the intergenic region of the ica operon to screen for the 5bp-deletion. RESULTS In 7 of 81 examined patients (8.6%), we detected mucoid S. aureus phenotypes (37 out of 1050 isolates; 3.5%). Twenty-five mucoid isolates carried the 5bp-deletion. Mucoid isolates produced excessive biofilm and were significantly more resistant to certain antibiotics. CONCLUSIONS In our prospective study, mucoid S. aureus was present in 8.6% of S. aureus-positive CF-patients. In 6 of 7 patients, mucoid isolates carried the 5bp-deletion, indicating that also other so far not identified mechanisms cause excessive biofilm formation. Further studies are necessary to ascertain the clinical impact of mucoid S. aureus phenotypes on the severity of the CF disease.
Collapse
|
54
|
σ B Inhibits Poly- N-Acetylglucosamine Exopolysaccharide Synthesis and Biofilm Formation in Staphylococcus aureus. J Bacteriol 2019; 201:JB.00098-19. [PMID: 30858304 DOI: 10.1128/jb.00098-19] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 03/07/2019] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus clinical strains are able to produce at least two distinct types of biofilm matrixes: biofilm matrixes made of the polysaccharide intercellular adhesin (PIA) or poly-N-acetylglucosamine (PNAG), whose synthesis is mediated by the icaADBC locus, and biofilm matrixes built of proteins (polysaccharide independent). σB is a conserved alternative sigma factor that regulates the expression of more than 100 genes in response to changes in environmental conditions. While numerous studies agree that σB is required for polysaccharide-independent biofilms, controversy persists over the role of σB in the regulation of PIA/PNAG-dependent biofilm development. Here, we show that genetically unrelated S. aureus σB-deficient strains produced stronger biofilms under both static and flow conditions and accumulated higher levels of PIA/PNAG exopolysaccharide than their corresponding wild-type strains. The increased accumulation of PIA/PNAG in the σB mutants correlated with a greater accumulation of the IcaC protein showed that it was not due to adjustments in icaADBC operon transcription and/or icaADBC mRNA stability. Overall, our results reveal that in the presence of active σB, the turnover of Ica proteins is accelerated, reducing the synthesis of PIA/PNAG exopolysaccharide and consequently the PIA/PNAG-dependent biofilm formation capacity.IMPORTANCE Due to its multifaceted lifestyle, Staphylococcus aureus needs a complex regulatory network to connect environmental signals with cellular physiology. One particular transcription factor, named σB (SigB), is involved in the general stress response and the expression of virulence factors. For many years, great confusion has existed about the role of σB in the regulation of the biofilm lifestyle in S. aureus Our study demonstrated that σB is not necessary for exopolysaccharide-dependent biofilms and, even more, that S. aureus produces stronger biofilms in the absence of σB The increased accumulation of exopolysaccharide correlates with higher stability of the proteins responsible for its synthesis. The present findings reveal an additional regulatory layer to control biofilm exopolysaccharide synthesis under stress conditions.
Collapse
|
55
|
Liu J, Li W, Zhu X, Zhao H, Lu Y, Zhang C, Lu Z. Surfactin effectively inhibits Staphylococcus aureus adhesion and biofilm formation on surfaces. Appl Microbiol Biotechnol 2019; 103:4565-4574. [PMID: 31011774 DOI: 10.1007/s00253-019-09808-w] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Revised: 03/20/2019] [Accepted: 03/26/2019] [Indexed: 11/26/2022]
Abstract
Biosurfactants are amphiphilic compounds that composed of hydrophilic and hydrophobic moieties, which possess the ability of self-organizing between phases, reducing the interfacial tension, and forming aggregates such as micelles. This spontaneous process results in significant changes in surface properties that directly influence the adherence of microorganisms. In this study, the ability of surfactin, a biosurfactant produced by Bacillus subtilis in reducing adhesion and disrupting the presence of biofilm of Staphylococcus aureus (S. aureus) on several surfaces, was investigated. Significant biofilm removal was observed on glass, polystyrene, and stainless steel surfaces. Furthermore, we explored the probable mechanism about how surfactin affected S. aureus biofilm formation. Based on our findings, surfactin had a significant effect on the polysaccharides production and especially decreased the percentage of alkali-soluble polysaccharide in biofilms. It also down-regulated the expression of icaA and icaD significantly, which are necessary for the important constituents to take shape of staphylococcal biofilm. In addition, it was found that the lipopeptide affected the quorum sensing (QS) system in S. aureus through regulating the auto inducer 2 (AI-2) activity, which has been reported to be negative for biofilm formation in S. aureus. These above properties could be applied in developing surfactin as a potential pre-coating agent on material surfaces to prevent S. aureus biofilm formation.
Collapse
Affiliation(s)
- Jin Liu
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Wei Li
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xiaoyu Zhu
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Haizhen Zhao
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yingjian Lu
- Department of Nutrition and Food Science, University of Maryland, College Park, MD, 20742, USA
- College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing, 210003, China
| | - Chong Zhang
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhaoxin Lu
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
| |
Collapse
|
56
|
Lerch MF, Schoenfelder SMK, Marincola G, Wencker FDR, Eckart M, Förstner KU, Sharma CM, Thormann KM, Kucklick M, Engelmann S, Ziebuhr W. A non-coding RNA from the intercellular adhesion (ica) locus of Staphylococcus epidermidis controls polysaccharide intercellular adhesion (PIA)-mediated biofilm formation. Mol Microbiol 2019; 111:1571-1591. [PMID: 30873665 DOI: 10.1111/mmi.14238] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/09/2019] [Indexed: 12/15/2022]
Abstract
Polysaccharide intercellular adhesin (PIA)-associated biofilm formation is mediated by the intercellular adhesin (ica) locus and represents a major pathomechanism of Staphylococcus epidermidis. Here, we report on a novel long non-coding (nc)RNA, named IcaZ, which is approximately 400 nucleotides in size. icaZ is located downstream of the ica repressor gene icaR and partially overlaps with the icaR 3' UTR. icaZ exclusively exists in ica-positive S. epidermidis, but not in S. aureus or other staphylococci. Inactivation of the gene completely abolishes PIA production. IcaZ is transcribed as a primary transcript from its own promoter during early- and mid-exponential growth and its transcription is induced by low temperature, ethanol and salt stress. IcaZ targets the icaR 5' UTR and hampers icaR mRNA translation, which alleviates repression of icaADBC operon transcription and results in PIA production. Interestingly, other than in S. aureus, posttranscriptional control of icaR mRNA in S. epidermidis does not involve icaR mRNA 5'/3' UTR base pairing. This suggests major structural and functional differences in icaADBC operon regulation between the two species that also involve the recruitment of ncRNAs. Together, the IcaZ ncRNA represents an unprecedented novel species-specific player involved in the control of PIA production in NBSP S. epidermidis.
Collapse
Affiliation(s)
- Maike F Lerch
- Institute of Molecular Infection Biology, University of Wuerzburg, Josef-Schneider-Str. 2, Wuerzburg, D-97080, Germany
| | - Sonja M K Schoenfelder
- Institute of Molecular Infection Biology, University of Wuerzburg, Josef-Schneider-Str. 2, Wuerzburg, D-97080, Germany
| | - Gabriella Marincola
- Institute of Molecular Infection Biology, University of Wuerzburg, Josef-Schneider-Str. 2, Wuerzburg, D-97080, Germany
| | - Freya D R Wencker
- Institute of Molecular Infection Biology, University of Wuerzburg, Josef-Schneider-Str. 2, Wuerzburg, D-97080, Germany
| | - Martin Eckart
- Institute of Molecular Infection Biology, University of Wuerzburg, Josef-Schneider-Str. 2, Wuerzburg, D-97080, Germany
| | - Konrad U Förstner
- Institute of Molecular Infection Biology, University of Wuerzburg, Josef-Schneider-Str. 2, Wuerzburg, D-97080, Germany.,Faculty of Information Science and Communication Studies, TH Köln, Cologne, D-50678, Germany.,ZB MED-Information Centre for Life Sciences, Cologne, Germany
| | - Cynthia M Sharma
- Institute of Molecular Infection Biology, University of Wuerzburg, Josef-Schneider-Str. 2, Wuerzburg, D-97080, Germany
| | - Kai M Thormann
- Institute of Microbiology and Molecular Biology, University of Gießen, Heinrich-Buff-Ring 26, Gießen, 35392, Germany
| | - Martin Kucklick
- Helmholtz Centre for Infection Research, Microbial Proteomics, Inhoffenstraße 7, Braunschweig, 38124, Germany.,Institute of Microbiology, Technical University Braunschweig, Spielmannstr. 7, Braunschweig, 38106, Germany
| | - Susanne Engelmann
- Helmholtz Centre for Infection Research, Microbial Proteomics, Inhoffenstraße 7, Braunschweig, 38124, Germany.,Institute of Microbiology, Technical University Braunschweig, Spielmannstr. 7, Braunschweig, 38106, Germany
| | - Wilma Ziebuhr
- Institute of Molecular Infection Biology, University of Wuerzburg, Josef-Schneider-Str. 2, Wuerzburg, D-97080, Germany
| |
Collapse
|
57
|
Gómez-Sanz E, Ceballos S, Ruiz-Ripa L, Zarazaga M, Torres C. Clonally Diverse Methicillin and Multidrug Resistant Coagulase Negative Staphylococci Are Ubiquitous and Pose Transfer Ability Between Pets and Their Owners. Front Microbiol 2019; 10:485. [PMID: 30972035 PMCID: PMC6443710 DOI: 10.3389/fmicb.2019.00485] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 02/25/2019] [Indexed: 11/13/2022] Open
Abstract
Sixty-eight owners and 66 pets, from 43 unrelated pet-owning households were screened for methicillin-resistant coagulase negative staphylococci (MRCoNS), potential cases of MRCoNS interspecies transmission (IT), and persistence. MRCoNS isolates were identified by microbiological and molecular tests. MLST-based phylogenetic analysis was performed in Staphylococcus epidermidis isolates. Antimicrobial susceptibility was evaluated using phenotypic and molecular methods. SCCmec type and the presence of biofilm-related ica locus was PCR-tested. Isolates suspected for MRCoNS IT cases were subjected to SmaI-PFGE analysis and individuals from positive households were followed-up for 1 year for carriage dynamics (every 3 months, T0-T4). Nineteen MRCoNS isolates from owners (27.9%) and 12 from pets (16.7%) were detected, coming from 20 households (46.5%). S. epidermidis was predominant (90 and 67% of human and animal strains, respectively), showing high phylogenetic diversity (16 STs among 24 strains). Methicillin-resistant S. epidermidis (MRSE) strains belonged to CC5 (75%), CC11 (12.5%), singleton S556 (8.3%), and S560 (4.17%). Significant host-associated differences were observed for resistance to aminoglycosides, co-trimoxazole, chloramphenicol (higher in animal isolates) and tetracycline (higher among human strains). Multidrug resistance (MDR) was common (68.4%) and associated with human strains. Great diversity of ccr and mec complexes were detected, most strains being non-typeable, followed by SCCmecIV and V. Over one third of isolates (most from owners), carried the ica locus, all MRSE CC5. Two sporadic IT cases (T0) were identified in owners and dogs from two households (4.7%), with diverse interspecies-exchanged clones detected along the sampling year, especially in dogs. A comparative analysis of all MRCoNS, with all nasal coagulase positive staphylococci (CoPS) recovered from the same individuals at T0, revealed that CoPS alone was predominant in owners and pets, followed by co-carriage of CoPS and MRCoNS in owners but single MRCoNS in pets. Statistical analyses revealed that owners are more prone to co-carriage and that co-existence of IT cases and co-carriage are positively interrelated. MRCoNS from healthy owners and their pets are genetically heterogeneous MDR strains that are spread in the community. Therefore, pets also contribute to the dissemination of successful human clones. Owner-pet inhabitancy increases the risk for staphylococcal temporal concomitance with its subsequent risk for bacterial infection and genetic exchange.
Collapse
Affiliation(s)
- Elena Gómez-Sanz
- Institute of Food, Nutrition and Health, ETH Zürich, Zurich, Switzerland.,Área de Microbiología Molecular, Centro de Investigación Biomédica de La Rioja (CIBIR), Logroño, Spain
| | - Sara Ceballos
- Área Bioquímica y Biología Molecular, Universidad de La Rioja, Logroño, Spain
| | - Laura Ruiz-Ripa
- Área Bioquímica y Biología Molecular, Universidad de La Rioja, Logroño, Spain
| | - Myriam Zarazaga
- Área Bioquímica y Biología Molecular, Universidad de La Rioja, Logroño, Spain
| | - Carmen Torres
- Área Bioquímica y Biología Molecular, Universidad de La Rioja, Logroño, Spain
| |
Collapse
|
58
|
Luo Z, Chen M, Chen T, She P, Wu Y. Lactic Acid Produced by Glycolysis Contributed to Staphylococcus aureus Aggregation Induced by Glucose. Curr Microbiol 2019; 76:607-612. [PMID: 30895345 DOI: 10.1007/s00284-019-01666-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 03/01/2019] [Indexed: 10/27/2022]
Abstract
High concentration of glucose induces Staphylococcus aureus (S. aureus) aggregation, but the mechanism of this is still unclear. In this study, the aggregation of S. aureus strains was induced by high concentration of glucose (>7.8 mM), and which was dose- and time-dependent. In addition, the large amount of lactate acid produced during S. aureus aggregation, induced by glucose, resulted in decreased pH value. Lactic acid, the end product of glycolysis, could quickly induce S. aureus aggregation. Except for lactic acid, acetic acid and HCl also induced S. aureus aggregation. In addition, the aggregation of S. aureus strains induced by glucose or lactic acid was completely inhibited in Tris-HCl buffer (pH 7.5), and inhibition of glycolysis by 2-deoxyglucose significantly decreased S. aureus aggregation. The aggregation induced by glucose was dispersed by periodate and proteinase K. In summary, lactate acid produced by glycolysis contributed to S. aureus aggregation induced by high concentration of glucose.
Collapse
Affiliation(s)
- Zhen Luo
- Department of Clinical Laboratory, The Third Xiangya Hospital of Central South University, Changsha, China
| | - Meilin Chen
- Xiangya School of Medicine, Central South University, Changsha, China
| | - Ti Chen
- Department of Clinical Laboratory, The Third Xiangya Hospital of Central South University, Changsha, China
| | - Pengfei She
- Department of Clinical Laboratory, The Third Xiangya Hospital of Central South University, Changsha, China
| | - Yong Wu
- Department of Clinical Laboratory, The Third Xiangya Hospital of Central South University, Changsha, China.
| |
Collapse
|
59
|
Xie K, Zhou Z, Guo Y, Wang L, Li G, Zhao S, Liu X, Li J, Jiang W, Wu S, Hao Y. Long-Term Prevention of Bacterial Infection and Enhanced Osteoinductivity of a Hybrid Coating with Selective Silver Toxicity. Adv Healthc Mater 2019; 8:e1801465. [PMID: 30673161 DOI: 10.1002/adhm.201801465] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 01/12/2019] [Indexed: 11/07/2022]
Abstract
Antibacterial and osteogenic design is required for ideal orthopedic implants. The excellent antimicrobial performance of silver nanoparticles (AgNPs) has attracted interest for the treatment of implant-related infections. However, the dose-dependent cytotoxicity of silver and its negative impact on bone implants restrict the further use of AgNPs coatings. Therefore, a hybrid coating containing polydopamine (PDA), hydroxyapatite (HA), AgNPs, and chitosan (CS) is prepared. Organic chelators CS and PDA that have promising biocompatibility are used to prevent the rapid release of silver ions from the AgNPs coating. The double chelating effect of PDA and CS significantly reduces silver ion release from the hybrid coating. The coating exhibits excellent anti-biofilm efficiency of 91.7%, 89.5%, and 92.0% for Staphylococcus aureus, Staphylococcus epidermidis, and Escherichia coli, respectively. In addition, the coating can significantly stimulate osteogenic differentiation of MC3T3-E1 cells and promote bone-implant osseointegration in vivo as compared to that in the control group. The longitudinal biosafety of the coating is confirmed in vivo by histological evaluation and blood tests. The results of this study indicate that the hybrid coating exhibits antibacterial properties as well as allow bone-implant osseointegration, thereby providing insight into the design of multifunctional implants for long-term orthopedic applications.
Collapse
Affiliation(s)
- Kai Xie
- Shanghai Key Laboratory of Orthopaedic Implants; Department of Orthopaedic Surgery; Shanghai Ninth People's Hospital; Shanghai Jiao Tong University School of Medicine; Shanghai 200011 China
| | - Ziao Zhou
- Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials; Hubei Key Laboratory of Polymer Materials; School of Materials Science & Engineering; Hubei University; Wuhan 430062 China
| | - Yu Guo
- Shanghai Key Laboratory of Orthopaedic Implants; Department of Orthopaedic Surgery; Shanghai Ninth People's Hospital; Shanghai Jiao Tong University School of Medicine; Shanghai 200011 China
| | - Lei Wang
- Shanghai Key Laboratory of Orthopaedic Implants; Department of Orthopaedic Surgery; Shanghai Ninth People's Hospital; Shanghai Jiao Tong University School of Medicine; Shanghai 200011 China
| | - Guoyuan Li
- Shanghai Key Laboratory of Orthopaedic Implants; Department of Orthopaedic Surgery; Shanghai Ninth People's Hospital; Shanghai Jiao Tong University School of Medicine; Shanghai 200011 China
| | - Shuang Zhao
- Shanghai Key Laboratory of Orthopaedic Implants; Department of Orthopaedic Surgery; Shanghai Ninth People's Hospital; Shanghai Jiao Tong University School of Medicine; Shanghai 200011 China
| | - Xiangmei Liu
- Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials; Hubei Key Laboratory of Polymer Materials; School of Materials Science & Engineering; Hubei University; Wuhan 430062 China
| | - Jun Li
- School of Materials Science & Engineering; the Key Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of China; Tianjin University; Tianjin 300072 China
| | - Wenbo Jiang
- Clinical and Translational Research Center for 3D Printing Technology; Shanghai Ninth People's Hospital; Shanghai Jiao Tong University School of Medicine; Shanghai 200011 China
| | - Shuilin Wu
- Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials; Hubei Key Laboratory of Polymer Materials; School of Materials Science & Engineering; Hubei University; Wuhan 430062 China
- School of Materials Science & Engineering; the Key Laboratory of Advanced Ceramics and Machining Technology by the Ministry of Education of China; Tianjin University; Tianjin 300072 China
| | - Yongqiang Hao
- Shanghai Key Laboratory of Orthopaedic Implants; Department of Orthopaedic Surgery; Shanghai Ninth People's Hospital; Shanghai Jiao Tong University School of Medicine; Shanghai 200011 China
- Clinical and Translational Research Center for 3D Printing Technology; Shanghai Ninth People's Hospital; Shanghai Jiao Tong University School of Medicine; Shanghai 200011 China
| |
Collapse
|
60
|
Transcriptional Regulation of icaADBC by both IcaR and TcaR in Staphylococcus epidermidis. J Bacteriol 2019; 201:JB.00524-18. [PMID: 30602488 DOI: 10.1128/jb.00524-18] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 12/17/2018] [Indexed: 12/17/2022] Open
Abstract
S. epidermidis is a primary cause of biofilm-mediated infections in humans due to adherence to foreign bodies. A major staphylococcal biofilm accumulation molecule is polysaccharide intracellular adhesin (PIA), which is synthesized by enzymes encoded by the icaADBC operon. Expression of PIA is highly variable among clinical isolates, suggesting that PIA expression levels are selected in certain niches of the host. However, the mechanisms that govern enhanced icaADBC transcription and PIA synthesis in these isolates are not known. We hypothesized that enhanced PIA synthesis in these isolates was due to function of IcaR and/or TcaR. Thus, two S. epidermidis isolates (1457 and CSF41498) with different icaADBC transcription and PIA expression levels were studied. Constitutive expression of both icaR and tcaR demonstrated that both repressors are functional and can completely repress icaADBC transcription in both 1457 and CSF41498. However, it was found that IcaR was the primary repressor for CSF41498 and TcaR was the primary repressor for 1457. Further analysis demonstrated that icaR transcription was repressed in 1457 in comparison to CSF41498, suggesting that TcaR functions as a repressor only in the absence of IcaR. Indeed, DNase I footprinting suggests IcaR and TcaR may bind to the same site within the icaR-icaA intergenic region. Lastly, we found mutants expressing variable amounts of PIA could rapidly be selected from both 1457 and CSF41498. Collectively, we propose that strains producing enhanced PIA synthesis are selected within certain niches of the host through several genetic mechanisms that function to repress icaR transcription, thus increasing PIA synthesis.IMPORTANCE Staphylococcus epidermidis is a commensal bacterium that resides on our skin. As a commensal, it protects humans from bacterial pathogens through a variety of mechanisms. However, it is also a significant cause of biofilm infections due to its ability to bind to plastic. Polysaccharide intercellular adhesin is a significant component of biofilm, and we propose that the expression of this polysaccharide is beneficial in certain host niches, such as providing extra strength when the bacterium is colonizing the lumen of a catheter, and detrimental in others, such as colonization of the skin surface. We show here that fine-tuning of icaADBC transcription, and thus PIA synthesis, is mediated via two transcriptional repressors, IcaR and TcaR.
Collapse
|
61
|
Osmotic stress induces biofilm production by Staphylococcus epidermidis isolates from neonates. Diagn Microbiol Infect Dis 2019; 94:337-341. [PMID: 30885396 DOI: 10.1016/j.diagmicrobio.2019.02.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 01/30/2019] [Accepted: 02/09/2019] [Indexed: 11/23/2022]
Abstract
Staphylococcus epidermidis is one of the leading causes of bloodstream infections, particularly in premature neonates, and biofilm formation is a major virulence factor. We characterized biofilm formation by 50 S. epidermidis neonatal isolates under osmotic stress and evaluated the expression of biofilm-associated genes. Phenotypical analyses of biofilm production were performed in culture medium with or without addition of NaCl or glucose. In control medium (no additions), most isolates (84%) were nonproducers or weak biofilm producers. Growth in NaCl-containing medium increased the number of moderate/strong producers, and this increase was even greater in medium containing glucose. Most of the protein-enriched biofilms (60%) could be observed only during growth in glucose, whereas 50% of the polysaccharide-enriched biofilms were observed during growth in NaCl. Studies that evaluate the conditions used to characterize biofilm production are important to help us understand the dynamics of this important virulence factor in S. epidermidis and their impact on neonatal infections.
Collapse
|
62
|
Weiland-Bräuer N, Malek I, Schmitz RA. Metagenomic quorum quenching enzymes affect biofilm formation of Candida albicans and Staphylococcus epidermidis. PLoS One 2019; 14:e0211366. [PMID: 30689669 PMCID: PMC6349329 DOI: 10.1371/journal.pone.0211366] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 01/13/2019] [Indexed: 12/15/2022] Open
Abstract
Biofilm formation in the clinical environment is of increasing concern since a significant part of human infections is associated, and caused by biofilm establishment of (opportunistic) pathogens, for instance Candida albicans and Staphylococcus epidermidis. The rapidly increasing number of antibiotic-resistant biofilms urgently requires the development of novel and effective strategies to prevent biofilm formation ideally targeting a wide range of infectious microorganisms. Both, synthesis of extracellular polymeric substances and quorum sensing are crucial for biofilm formation, and thus potential attractive targets to combat undesirable biofilms.We evaluated the ability of numerous recently identified metagenome-derived bacterial quorum quenching (QQ) proteins to inhibit biofilm formation of C. albicans and S. epidermidis. Here, proteins QQ-5 and QQ-7 interfered with the morphogenesis of C. albicans by inhibiting the yeast-to-hyphae transition, ultimately leading to impaired biofilm formation. Moreover, QQ5 and QQ-7 inhibited biofilm formation of S. epidermidis; in case of QQ7 most likely due to induced expression of the icaR gene encoding the repressor for polysaccharide intercellular adhesin (PIA) synthesis, the main determinant for staphylococcal biofilm formation. Our results indicate that QQ-5 and QQ-7 are attractive potential anti-biofilm agents in the prevention and treatment of C. albicans and S. epidermidis mono-species biofilms, and potentially promising anti-biofilm drugs in also combating multi-species infections.
Collapse
Affiliation(s)
| | - Irene Malek
- Kiel University, Institute for General Microbiology, Kiel, Germany
| | - Ruth A. Schmitz
- Kiel University, Institute for General Microbiology, Kiel, Germany
| |
Collapse
|
63
|
Complete Genome Sequence of Staphylococcus epidermidis CSF41498. Microbiol Resour Announc 2019; 8:MRA01138-18. [PMID: 30643875 PMCID: PMC6328648 DOI: 10.1128/mra.01138-18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 11/27/2018] [Indexed: 11/29/2022] Open
Abstract
Staphylococcus epidermidis CSF41498 is amenable to genetic manipulation and has been used to study mechanisms of biofilm formation. We report here the whole-genome sequence of this strain, which contains 2,427 protein-coding genes and 82 RNAs within its 2,481,008-bp-long genome, as well as three plasmids. Staphylococcus epidermidis CSF41498 is amenable to genetic manipulation and has been used to study mechanisms of biofilm formation. We report here the whole-genome sequence of this strain, which contains 2,427 protein-coding genes and 82 RNAs within its 2,481,008-bp-long genome, as well as three plasmids.
Collapse
|
64
|
Abstract
Staphylococci, with the leading species Staphylococcus aureus and Staphylococcus epidermidis, are the most frequent causes of infections on indwelling medical devices. The biofilm phenotype that those bacteria adopt during device-associated infection facilitates increased resistance to antibiotics and host immune defenses. This review presents and discusses the molecular mechanisms contributing to staphylococcal biofilm development and their in-vivo importance. Furthermore, it summarizes current strategies for the development of therapeutics against staphylococcal biofilm-associated infection.
Collapse
|
65
|
Jin Z, Jiang Q, Fang B, Sun B. The ArlR-MgrA regulatory cascade regulates PIA-dependent and protein-mediated biofilm formation in Rbf-dependent and Rbf-independent pathways. Int J Med Microbiol 2018; 309:85-96. [PMID: 30606691 DOI: 10.1016/j.ijmm.2018.12.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 12/01/2018] [Accepted: 12/28/2018] [Indexed: 12/11/2022] Open
Abstract
The two-component system response regulator ArlR and the global regulator MgrA in Staphylococcus aureus participated in numerous biological processes including biofilm formation inhibition. Previous studies have shown that these two regulators could function as a regulatory cascade. Rbf is a positive regulator of biofilm formation enhancing the production of PIA (polysaccharide intercellular adhesin). Here we have demonstrated that both ArlR and MgrA can directly bind to the promoter of rbf and repress its expression. ArlR and MgrA can also directly bind to the promoter of ica operon and enhance the expression of icaA and PIA production, revealing that the ArlR-MgrA regulatory cascade controls PIA-dependent biofilm formation. In addition, we have found that Rbf can directly bind to the aur promoter and repress the expression of aur, which encodes a protease initiating a protease cascade to inhibit protein-mediated biofilm formation. Moreover, our data indicate that the ArlR-MgrA regulatory cascade can promote the expression of aur by directly binding to its promoter and inhibit protein-mediated biofilm formation. These findings shed light on the molecular mechanisms of both PIA-dependent and protein-mediated biofilm formation modulated by the ArlR-MgrA regulatory cascade and the new role of Rbf in protein-mediated biofilm formation, and broaden our understanding of the biofilm formation regulation in S. aureus.
Collapse
Affiliation(s)
- Zeyu Jin
- CAS Key Laboratory of Innate Immunity and Chronic Disease and School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui, 230027, China
| | - Qiu Jiang
- CAS Key Laboratory of Innate Immunity and Chronic Disease and School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui, 230027, China
| | - Bo Fang
- CAS Key Laboratory of Innate Immunity and Chronic Disease and School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui, 230027, China
| | - Baolin Sun
- CAS Key Laboratory of Innate Immunity and Chronic Disease and School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui, 230027, China; Division of Molecular Medicine, Hefei National Laboratory for Physical Sciences at Microscale, Hefei, Anhui 230027, China.
| |
Collapse
|
66
|
Akhavan B, Bakhshandeh S, Najafi-Ashtiani H, Fluit AC, Boel E, Vogely C, van der Wal BCH, Zadpoor AA, Weinans H, Hennink WE, Bilek MM, Amin Yavari S. Direct covalent attachment of silver nanoparticles on radical-rich plasma polymer films for antibacterial applications. J Mater Chem B 2018; 6:5845-5853. [PMID: 32254705 DOI: 10.1039/c8tb01363b] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Prevention and treatment of biomaterial-associated infections (BAI) are imperative requirements for the effective and long-lasting function of orthopedic implants. Surface-functionalization of these materials with antibacterial agents, such as antibiotics, nanoparticles and peptides, is a promising approach to combat BAI. The well-known silver nanoparticles (AgNPs) in particular, although benefiting from strong and broad-range antibacterial efficiency, have been frequently associated with mammalian cell toxicity when physically adsorbed on biomaterials. The majority of irreversible immobilization techniques employed to fabricate AgNP-functionalized surfaces are based on wet-chemistry methods. However, these methods are typically substrate-dependent, complex, and time-consuming. Here we present a simple and dry strategy for the development of polymeric coatings used as platforms for the direct, linker-free covalent attachment of AgNPs onto solid surfaces using ion-assisted plasma polymerization. The resulting coating not only exhibits long-term antibiofilm efficiency against adherent Staphylococcus aureus (S. aureus), but also enhances osteoblast adhesion and proliferation. High resolution X-ray photoelectron spectroscopy (XPS), before and after sodium dodecyl sulfate (SDS) washing, confirms covalent bonding. The development of such silver-functionalized surfaces through a simple, plasma-based process holds great promise for the fabrication of implantable devices with improved tissue-implant integration and reduced biomaterial associated infections.
Collapse
Affiliation(s)
- Behnam Akhavan
- School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, Sydney, NSW 2006, Australia.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
67
|
Zheng Y, He L, Asiamah TK, Otto M. Colonization of medical devices by staphylococci. Environ Microbiol 2018; 20:3141-3153. [PMID: 29633455 DOI: 10.1111/1462-2920.14129] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 03/16/2018] [Accepted: 04/03/2018] [Indexed: 12/19/2022]
Abstract
The use of medical devices in modern medicine is constantly increasing. Despite the multiple precautionary strategies that are being employed in hospitals, which include increased hygiene and sterilization measures, bacterial infections on these devices still happen frequently. Staphylococci are among the major causes of medical device infection. This is mostly due to the strong capacity of those bacteria to form device-associated biofilms, which provide resistance to chemical and physical treatments as well as attacks by the host's immune system. Biofilm development is a multistep process with specific factors participating in each step. It is tightly regulated to provide a balance between biofilm expansion and detachment. Detachment from a biofilm on a medical device can lead to severe systemic infection, such as bacteremia and sepsis. While our understanding of staphylococcal biofilm formation has increased significantly and staphylococcal biofilm formation on medical devices is among the best understood biofilm-associated infections, the extensive effort put in preclinical studies with the goal to find novel therapies against staphylococcal device-associated infections has not yet resulted in efficient, applicable therapeutic options for that difficult-to-treat type of disease.
Collapse
Affiliation(s)
- Yue Zheng
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, MD, USA
| | - Lei He
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, MD, USA
| | - Titus K Asiamah
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, MD, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, U.S. National Institutes of Health, Bethesda, MD, USA
| |
Collapse
|
68
|
Novel Treatment of Staphylococcus aureus Device-Related Infections Using Fibrinolytic Agents. Antimicrob Agents Chemother 2018; 62:AAC.02008-17. [PMID: 29203484 DOI: 10.1128/aac.02008-17] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 11/21/2017] [Indexed: 11/20/2022] Open
Abstract
Staphylococcal infections involving biofilms represent a significant challenge in the treatment of patients with device-related infections. Staphylococcus aureus biofilms have been shown to be SaeRS regulated and dependent on the coagulase-catalyzed conversion of fibrinogen into fibrin on surfaces coated with human plasma. Here we investigated the treatment of staphylococcal biofilm device-related infections by digesting the fibrin biofilm matrix with and without existing antimicrobials. The fibrinolytic agents plasmin, streptokinase, and nattokinase, and TrypLE, a recombinant trypsin-like protease, were used to digest and treat S. aureus biofilms grown in vitro using in vivo-like static biofilm assays with and without antimicrobials. Cytotoxicity, the potential to induce a cytokine response in whole human blood, and the risk of induction of tolerance to fibrinolytic agents were investigated. A rat model of intravascular catheter infection was established to investigate the efficacy of selected fibrinolytic agents in vivo Under biomimetic conditions, the fibrinolytic agents effectively dispersed established S. aureus biofilms and, in combination with common antistaphylococcal antimicrobials, effectively killed bacterial cells being released from the biofilm. These fibrinolytic agents were not cytotoxic and did not affect the host immune response. The rat model of infection successfully demonstrated the activity of the selected fibrinolytic agents alone and in combination with antimicrobials on established biofilms in vivo TrypLE and nattokinase most successfully removed adherent cells from plasma-coated surfaces and significantly improved the efficacy of existing antimicrobials against S. aureus biofilms in vitro and in vivo These biofilm dispersal agents represent a viable future treatment option for S. aureus device-related infections.
Collapse
|
69
|
Vadyvaloo V, Otto M. Molecular Genetics of Staphylococcus Epidermidis Biofilms on Indwelling Medical Devices. Int J Artif Organs 2018; 28:1069-78. [PMID: 16353113 DOI: 10.1177/039139880502801104] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Staphylococcus epidermidis is an opportunistic pathogen associated with foreign body infections and nosocomial sepsis. The pathogenicity of S. epidermidis is mostly due to its ability to colonize indwelling polymeric devices and form a thick, multilayered biofilm. Biofilm formation is a major problem in treating S. epidermidis infection as biofilms provide significant resistance to antibiotics and to components of the innate host defenses. Various cell surface associated bacterial factors play a role in adherence and accumulation of the biofilm such as the polysaccharide intercellular adhesin and the autolysin AtlE. Furthermore, recent studies have shown that global regulators such as the agr quorum sensing system, the transcriptional regulator sarA and the alternative sigma factor sigB have an important function in the regulation of biofilm formation. Understanding the many complex mechanisms involved in biofilm formation is a key factor in the search for new anti-staphylococcal therapeutics.
Collapse
Affiliation(s)
- V Vadyvaloo
- Rocky Mountain Laboratories, NIAID/NIH, Hamilton, MT, USA
| | | |
Collapse
|
70
|
JÄger S, Jonas B, Pfanzelt D, Horstkotte MA, Rohde H, Mack D, Knobloch JKM. Regulation of Biofilm Formation by σB is a Common Mechanism in Staphylococcus Epidermidis and is not Mediated by Transcriptional Regulation of sarA. Int J Artif Organs 2018; 32:584-91. [DOI: 10.1177/039139880903200907] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Biofilm formation is a major pathogenetic factor of Staphylococcus epidermidis. In S. epidermidis the alternative sigma factor σB was identified to regulate biofilm formation in S. epidermidis 1457. In S. aureus σB dependent regulation plays a minor role, whereas sarA (Staphylococcus accessory regulator) is an essential regulator. Therefore, we investigated the impact of σB on sarA transcription and biofilm formation in three independent S. epidermidis isolates. Mutants with dysfunctional σB displayed a strongly reduced biofilm formation, whereas in mutants with constitutive σB activity bio film formation was increased. Transcriptional analysis revealed that IcaA transcription was down-regulated in all σB negative mutants while icaR transcription was up-regulated. However, transcriptional differences varied between individual strains, indicating that additional σB-dependent regulators are involved in biofilm expression. Interestingly, despite the presence of a σB promoter beside two σA promoters no differences, or only minor ones, were observed in sarA transcription, indicating that σB-dependent sarA transcript has no influence on the phenotypic changes. The data observed in independent clinical S. epidermidis isolates suggests that, in contrast to S. aureus, regulation of biofilm formation by σB is a general feature in S. epidermidis. Additionally, we were able to demonstrate that the sarA- dependent regulation is not involved in this regulatory pathway.
Collapse
Affiliation(s)
- Sebastian JÄger
- Department of Cardiology and Pneumology, Charité Universitätsmedizin Berlin, Campus Benjamin Franklin, Berlin - Germany
| | - Beate Jonas
- Institute for Medical Microbiology and Hygiene, University of Lübeck, Lübeck - Germany
| | - Dorothea Pfanzelt
- Institute for Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Hamburg - Germany
| | | | - Holger Rohde
- Institute for Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Hamburg - Germany
| | - Dietrich Mack
- Chair of Medical Microbiology and Infectious Diseases, The School of Medicine, University of Wales Swansea, Swansea - United Kingdom
| | | |
Collapse
|
71
|
The Photodynamic Effect of Tetra-Substituted N-Methyl-Pyridyl-Porphine Combined with the Action of Vancomycin or Host Defense Mechanisms Disrupts Staphylococcus Epidermidis Biofilms. Int J Artif Organs 2018; 32:574-83. [DOI: 10.1177/039139880903200906] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The skin commensal and opportunistic pathogen Staphylococcus epidermidis is an important cause of nosocomial infections. Virulence is attributable to formation of biofilm, which provides a microenvironment that protects the bacterium from attack by the host immune system and by chemotherapy. In this study we extended to S. epidermidis strategies previously aimed at treatment of S. aureus bio films using photodynamic treatment (PDT) combined with chemotherapy or phagocytosis. A significant reduction in bacterial survival was observed when structurally distinct biofilms were exposed to the cationic porphyrin, tetra-substituted N-methyl-pyridyl-porphine (TMP), and simultaneously to visible light. Of note, the extent of biofilm clearance depended on its maturation stage: developing, young biofilms, were more sensitive towards PDT than mature biofilms. Furthermore, PDT-treated biofilms exposed to vancomycin or subjected to phagocytic action of whole blood were almost completely eradicated. The data we obtained establish that PDT combined with antibiotics or host defenses may also be a useful approach for the inactivation of S. epidermidis biofilms.
Collapse
|
72
|
Tandem Amplification of the Staphylococcal Cassette Chromosome mec Element Can Drive High-Level Methicillin Resistance in Methicillin-Resistant Staphylococcus aureus. Antimicrob Agents Chemother 2017; 61:AAC.00869-17. [PMID: 28717043 DOI: 10.1128/aac.00869-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 07/08/2017] [Indexed: 11/20/2022] Open
Abstract
Hospital-associated methicillin-resistant Staphylococcus aureus (MRSA) strains typically express high-level, homogeneous (HoR) β-lactam resistance, whereas community-associated MRSA (CA-MRSA) more commonly express low-level heterogeneous (HeR) resistance. Expression of the HoR phenotype typically requires both increased expression of the mecA gene, carried on the staphylococcal cassette chromosome mec element (SCCmec), and additional mutational event(s) elsewhere on the chromosome. Here the oxacillin concentration in a chemostat culture of the CA-MRSA strain USA300 was increased from 8 μg/ml to 130 μg/ml over 13 days to isolate highly oxacillin-resistant derivatives. A stable, small-colony variant, designated HoR34, which had become established in the chemostat culture was found to have acquired mutations in gdpP, clpX, guaA, and camS Closer inspection of the genome sequence data further revealed that reads covering SCCmec were ∼10 times overrepresented compared to other parts of the chromosome. Quantitative PCR (qPCR) confirmed >10-fold-higher levels of mecA DNA on the HoR34 chromosome, and MinION genome sequencing verified the presence of 10 tandem repeats of the SCCmec element. qPCR further demonstrated that subculture of HoR34 in various concentrations of oxacillin (0 to 100 μg/ml) was accompanied by accordion-like contraction and amplification of the SCCmec element. Although slower growing than strain USA300, HoR34 outcompeted the parent strain in the presence of subinhibitory oxacillin. These data identify tandem amplification of the SCCmec element as a new mechanism of high-level methicillin resistance in MRSA, which may provide a competitive advantage for MRSA under antibiotic selection.
Collapse
|
73
|
O'Gara JP. Into the storm: Chasing the opportunistic pathogen Staphylococcus aureus from skin colonisation to life-threatening infections. Environ Microbiol 2017. [PMID: 28631399 DOI: 10.1111/1462-2920.13833] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Colonisation of the human skin by Staphylococcus aureus is a precursor for a variety of infections ranging from boils to sepsis and pneumonia. The rapid emergence of methicillin-resistant S. aureus following the clinical introduction of this antimicrobial drug and reports of resistance to all currently used anti-staphylococcal drugs has added to its formidable reputation. S. aureus survival on the skin and in vivo virulence is underpinned by a remarkable environmental adaptability, made possible by highly orchestrated regulation of gene expression and a capacity to undertake genome remodelling. Depending on the ecological or infection niche, controlled expression of a variety of adhesins can be initiated to facilitate adherence to extracellular matrix proteins, survival against desiccation or biofilm accumulation on implanted medical devices and host tissue. These adherence mechanisms complement toxin and enzyme production, immune evasion strategies, and antibiotic resistance and tolerance to collectively thwart efforts to develop reliable antimicrobial drug regimens and an effective S. aureus vaccine.
Collapse
Affiliation(s)
- James P O'Gara
- Department of Microbiology, School of Natural Sciences, National University of Ireland, Galway, Ireland
| |
Collapse
|
74
|
Gupta A, Mishra S, Singh S, Mishra S. Prevention of IcaA regulated poly N-acetyl glucosamine formation in Staphylococcus aureus biofilm through new-drug like inhibitors: In silico approach and MD simulation study. Microb Pathog 2017; 110:659-669. [PMID: 28579399 DOI: 10.1016/j.micpath.2017.05.025] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 05/15/2017] [Accepted: 05/19/2017] [Indexed: 01/07/2023]
Abstract
OBJECTIVES The effectiveness of various ligands against the protein structure of IcaA of the IcaABCD gene locus of Staphylococcus aureus were examined using the approach of structure based drug designing in reference with the protein's efficiency to form biofilms. RESULTS Four compounds CID42738592, CID90468752, CID24277882, and CID6435208 were secluded from a database of 31,242 inhibitory ligands on the justification of the evaluated values falling under the four - tier structure based virtual screening. Under this principle value of least binding energy, human oral absorption and ADME properties were taken into consideration. Using the Glide module of Schrödinger, the above mentioned ligands showed an effective action against the protein IcaA which showed reduced activity as a glucosaminyl transferase. The complex of protein and ligand with best docking score was chosen for simulation studies. CONCLUSIONS Structure based drug designing for the protein IcaA has given us potential leads as anti - biofilm agents. These screened out ligands might enable the development of new therapeutic strategies aimed at disrupting Staphylococcus aureus biofilms. The complex was showing stability towards the end of time for which it has been put for simulation. Thus molecule could be considered for making of biofilms.
Collapse
Affiliation(s)
- Ayushi Gupta
- Applied Science Department, Indian Institute of Information Technology, Allahabad 211012, Uttar Pradesh, India
| | - Swechha Mishra
- Applied Science Department, Indian Institute of Information Technology, Allahabad 211012, Uttar Pradesh, India
| | - Sangeeta Singh
- Applied Science Department, Indian Institute of Information Technology, Allahabad 211012, Uttar Pradesh, India.
| | - Sonali Mishra
- Applied Science Department, Indian Institute of Information Technology, Allahabad 211012, Uttar Pradesh, India
| |
Collapse
|
75
|
Hogan S, Zapotoczna M, Stevens N, Humphreys H, O'Gara J, O'Neill E. Potential use of targeted enzymatic agents in the treatment of Staphylococcus aureus biofilm-related infections. J Hosp Infect 2017; 96:177-182. [DOI: 10.1016/j.jhin.2017.02.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 02/08/2017] [Indexed: 01/15/2023]
|
76
|
Ma R, Qiu S, Jiang Q, Sun H, Xue T, Cai G, Sun B. AI-2 quorum sensing negatively regulates rbf expression and biofilm formation in Staphylococcus aureus. Int J Med Microbiol 2017; 307:257-267. [PMID: 28416278 DOI: 10.1016/j.ijmm.2017.03.003] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Indexed: 12/11/2022] Open
Abstract
Staphylococcus aureus is an important pathogen that is capable of forming biofilms on biomaterial surfaces to cause biofilm-associated infections. Autoinducer 2 (AI-2), a universal language for interspecies communication, is involved in a variety of physiological activities, although its exact role in Gram-positive bacteria, especially in S. aureus, is not yet thoroughly characterized. Herein we demonstrate that inactivation of luxS, which encodes AI-2 synthase, resulted in increased biofilm formation and higher polysaccharide intercellular adhesion (PIA) production compared with the wild-type strain in S. aureus NCTC8325. The transcript level of rbf, a positive regulator of biofilm formation, was significantly increased in the luxS mutant. All of the parental phenotypes could be restored by genetic complementation and chemically synthesized 4,5-dihydroxy-2,3-pentanedione, the AI-2 precursor molecule, suggesting that AI-2 has a signaling function to regulate rbf transcription and biofilm formation in S. aureus. Phenotypic analysis revealed that the luxS rbf double mutant produced approximately the same amount of biofilms and PIA as the rbf mutant. In addition, real-time quantitative reverse transcription-PCR analysis showed that the icaA transcript level of the rbf mutant was similar to that of the luxS rbf double mutant. These findings demonstrate that the LuxS/AI-2 system regulates PIA-dependent biofilm formation via repression of rbf expression in S. aureus. Furthermore, we demonstrated that Rbf could bind to the sarX and rbf promoters to upregulate their expression.
Collapse
Affiliation(s)
- Ronghua Ma
- CAS Key Laboratory of Innate Immunity and Chronic Disease, University of Science and Technology of China, Hefei, Anhui 230027, China; School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Shuwan Qiu
- School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Qiu Jiang
- CAS Key Laboratory of Innate Immunity and Chronic Disease, University of Science and Technology of China, Hefei, Anhui 230027, China; School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Haipeng Sun
- CAS Key Laboratory of Innate Immunity and Chronic Disease, University of Science and Technology of China, Hefei, Anhui 230027, China; School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Ting Xue
- School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Gang Cai
- School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027, China; Hefei National Laboratory for Physical Sciences at Microscale, Hefei, Anhui 230027, China.
| | - Baolin Sun
- CAS Key Laboratory of Innate Immunity and Chronic Disease, University of Science and Technology of China, Hefei, Anhui 230027, China; School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui 230027, China; Hefei National Laboratory for Physical Sciences at Microscale, Hefei, Anhui 230027, China.
| |
Collapse
|
77
|
Zapotoczna M, Boksmati N, Donohue S, Bahtiar B, Boland A, Somali HA, Cox A, Humphreys H, O'Gara JP, Brennan M, O'Neill E. Novel anti-staphylococcal and anti-biofilm properties of two anti-malarial compounds: MMV665953 {1-(3-chloro-4-fluorophenyl)-3-(3,4-dichlorophenyl)urea} and MMV665807 {5-chloro-2-hydroxy-N-[3-(trifluoromethyl)phenyl]benzamide}. J Med Microbiol 2017; 66:377-387. [PMID: 28327271 DOI: 10.1099/jmm.0.000446] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
PURPOSE The treatment of device-related infections is challenging and current anti-microbial compounds have poor anti-biofilm activity. We aimed to identify and characterize novel compounds effective in the eradication of Staphylococcus aureus biofilms. METHODOLOGY Two novel compounds, MMV665953 {1-(3-chloro-4-fluorophenyl)-3-(3,4-dichlorophenyl)urea} and MMV665807{5-chloro-2-hydroxy-N-[3-(trifluoromethyl)phenyl]benzamide}, effective in killing S. aureus biofilms, were identified by screening of the open access 'malaria box' chemical library. The minimum bactericidal concentrations, half-maximal inhibition concentration (IC50) values and minimal biofilm killing concentrations effective in the killing of biofilm were determined against meticillin-resistant S. aureus and meticillin-sensitive S. aureus. Fibrin-embedded biofilms were grown under in vivo-relevant conditions, and viability was measured using a resazurin-conversion assay and confocal microscopy. The potential for the development of resistance and cytotoxicity was also assessed. RESULTS MMV665953 and MMV665807 were bactericidal against S. aureus isolates. The IC50 against S. aureus biofilms was at 0.15-0.58 mg l-1 after 24 h treatment, whereas the concentration required to eradicate all tested biofilms was 4 mg l-1, making the compounds more bactericidal than conventional antibiotics. The cytotoxicity against human keratinocytes and primary endothelial cells was determined as IC50 7.47 and 0.18 mg l-1 for MMV665953, and as 1.895 and 0.076 mg l-1 for MMV665807. Neither compound was haemolytic nor caused platelet activation. MMV665953 and MMV665807 derivatives with reduced cytotoxicity exhibited a concomitant loss in anti-staphylococcal activity. CONCLUSION MMV665953 and MMV665807 are more bactericidal against S. aureus biofilms than currently used anti-staphylococcal antibiotics and represent a valuable structural basis for further investigation in the treatment of staphylococcal biofilm-related infections.
Collapse
Affiliation(s)
- Marta Zapotoczna
- Department of Clinical Microbiology, Education and Research Centre, Beaumont Hospital, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Nabila Boksmati
- Molecular and Cellular Therapeutics, Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Sinead Donohue
- Department of Clinical Microbiology, Education and Research Centre, Beaumont Hospital, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Baizurina Bahtiar
- Molecular and Cellular Therapeutics, Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Ahmad Boland
- Molecular and Cellular Therapeutics, Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Hamzah Al Somali
- Molecular and Cellular Therapeutics, Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Alysia Cox
- Molecular and Cellular Therapeutics, Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Hilary Humphreys
- Department of Clinical Microbiology, Education and Research Centre, Beaumont Hospital, Royal College of Surgeons in Ireland, Dublin, Ireland.,Department of Microbiology, Beaumont Hospital, Dublin, Ireland
| | - James P O'Gara
- Department of Microbiology, School of Natural Sciences, National University of Ireland, Galway, Ireland
| | - Marian Brennan
- Molecular and Cellular Therapeutics, Irish Centre for Vascular Biology, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Eoghan O'Neill
- Department of Microbiology, Connolly Hospital, Dublin, Ireland.,Department of Clinical Microbiology, Education and Research Centre, Beaumont Hospital, Royal College of Surgeons in Ireland, Dublin, Ireland
| |
Collapse
|
78
|
Islam N, Hossain KG, Ross JM, Marten MR. Blood Serum Affects Polysaccharide Production and Surface Protein Expression in S. Aureus. ADVANCES IN BIOTECHNOLOGY & MICROBIOLOGY (NEWBURY, CALIF.) 2017; 2:555589. [PMID: 29863159 PMCID: PMC5983386 DOI: 10.19080/argh.2017.02.555589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
BACKGROUND S. aureus biofilm serves a major role in pathogenesis. Two of the major components of bacterial biofilm are Polysaccharides intercellular adhesions (PIA) and surface proteins. It is not known how PIA and surface proteins expressions are affected in presence of blood serum. Analyses of surface proteins expressions will provide more effective biomarker discovery that might lead to development of antimicrobial therapeutics to meet the challenges of biofilm-related infections. METHOD Secondary cultures of S. aureus Philips, a biofilm-forming bacterium, were generated by inoculating 1 ml of overnight culture into 50 ml of TSB. Bacteria were cultured at several concentrations of blood serum and found that 12.5% supplemented blood serum provide s similar growth curve as normal TSB (100%). One and 2 D SASPAGE were used to separate proteins and the differentially expressed proteins were identified by nano-LC/MS. RESULTS Polysaccharide intercellular adhesions production was significantly increased due to the addition of blood serum in the media. We also identified two serum proteins, apolipoprotein and globulin (Fc and Fab), that remained attached with the membrane fraction of bacterial proteins. CONCLUSION These results have strongly demonstrated that blood serum influences the exopolysaccharide expression in S. aureus.
Collapse
Affiliation(s)
- Nazrul Islam
- Department of Nutrition and Food Science, University of Maryland-College Park, USA
| | | | - Julia M Ross
- Department of Chemical, Biochemical and Environmental Engineering, University of Maryland Baltimore County (UMBC), USA
| | - Mark R Marten
- Department of Chemical, Biochemical and Environmental Engineering, University of Maryland Baltimore County (UMBC), USA
| |
Collapse
|
79
|
Liu M, Wu X, Li J, Liu L, Zhang R, Shao D, Du X. The specific anti-biofilm effect of gallic acid on Staphylococcus aureus by regulating the expression of the ica operon. Food Control 2017. [DOI: 10.1016/j.foodcont.2016.09.015] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
|
80
|
A Novel Repressor of the ica Locus Discovered in Clinically Isolated Super-Biofilm-Elaborating Staphylococcus aureus. mBio 2017; 8:mBio.02282-16. [PMID: 28143981 PMCID: PMC5285506 DOI: 10.1128/mbio.02282-16] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Staphylococcus aureus TF2758 is a clinical isolate from an atheroma and a super-biofilm-elaborating/polysaccharide intercellular adhesin (PIA)/poly-N-acetylglucosamine (PNAG)-overproducing strain (L. Shrestha et al., Microbiol Immunol 60:148–159, 2016, https://doi.org/10.1111/1348-0421.12359). A microarray analysis and DNA genome sequencing were performed to identify the mechanism underlying biofilm overproduction by TF2758. We found high transcriptional expression levels of a 7-gene cluster (satf2580 to satf2586) and the ica operon in TF2758. Within the 7-gene cluster, a putative transcriptional regulator gene designated rob had a nonsense mutation that caused the truncation of the protein. The complementation of TF2758 with rob from FK300, an rsbU-repaired derivative of S. aureus strain NCTC8325-4, significantly decreased biofilm elaboration, suggesting a role for rob in this process. The deletion of rob in non-biofilm-producing FK300 significantly increased biofilm elaboration and PIA/PNAG production. In the search for a gene(s) in the 7-gene cluster for biofilm elaboration controlled by rob, we identified open reading frame (ORF) SAOUHSC_2898 (satf2584). Our results suggest that ORF SAOUHSC_2898 (satf2584) and icaADBC are required for enhanced biofilm elaboration and PIA/PNAG production in the rob deletion mutant. Rob bound to a palindromic sequence within its own promoter region. Furthermore, Rob recognized the TATTT motif within the icaR-icaA intergenic region and bound to a 25-bp DNA stretch containing this motif, which is a critically important short sequence regulating biofilm elaboration in S. aureus. Our results strongly suggest that Rob is a long-sought repressor that recognizes and binds to the TATTT motif and is an important regulator of biofilm elaboration through its control of SAOUHSC_2898 (SATF2584) and Ica protein expression in S. aureus. During the search for molecular mechanisms underlying biofilm overproduction of Staphylococcus aureus TF2758, we found a putative transcriptional regulator gene designated rob within a 7-gene cluster showing a high transcriptional expression level by microarray analysis. The deletion of rob in non-biofilm-producing FK300, an rsbU-repaired derivative of NCTC8325-4, significantly increased biofilm elaboration and PIA/PNAG production. The search for a gene(s) in the 7-gene cluster for biofilm elaboration controlled by rob identified ORF SAOUHSC_2898. Besides binding to its own promoter region to control ORF SAOUHSC_2898 expression, Rob recognized the TATTT motif within the icaR-icaA intergenic region and bound to a 25-bp DNA stretch containing this motif, which is a critically important short sequence regulating biofilm elaboration in S. aureus. Our results strongly suggest that Rob is a long-sought repressor that recognizes and binds to the TATTT motif and is a new important regulator of biofilm elaboration through its control of SAOUHSC_2898 and Ica protein expression in S. aureus.
Collapse
|
81
|
Liu J, Stone VN, Ge X, Tang M, Elrami F, Xu P. TetR Family Regulator brpT Modulates Biofilm Formation in Streptococcus sanguinis. PLoS One 2017; 12:e0169301. [PMID: 28046010 PMCID: PMC5207742 DOI: 10.1371/journal.pone.0169301] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 12/14/2016] [Indexed: 11/19/2022] Open
Abstract
Biofilms are a key component in bacterial communities providing protection and contributing to infectious diseases. However, mechanisms involved in S. sanguinis biofilm formation have not been clearly elucidated. Here, we report the identification of a novel S. sanguinis TetR repressor, brpT (Biofilm Regulatory Protein TetR), involved in biofilm formation. Deletion of brpT resulted in a significant increase in biofilm formation. Interestingly, the mutant accumulated more water soluble and water insoluble glucans in its biofilm compared to the wild-type and the complemented mutant. The brpT mutation led to an altered biofilm morphology and structure exhibiting a rougher appearance, uneven distribution with more filaments bound to the chains. RNA-sequencing revealed that gtfP, the only glucosyltransferase present in S. sanguinis, was significantly up-regulated. In agreement with these findings, we independently observed that deletion of gtfP in S. sanguinis led to reduced biofilm and low levels of water soluble and insoluble glucans. These results suggest that brpT is involved in the regulation of the gtfP-mediated exopolysaccharide synthesis and controls S. sanguinis biofilm formation. The deletion of brpT may have a potential therapeutic application in regulating S. sanguinis colonization in the oral cavity and the prevention of dental caries.
Collapse
Affiliation(s)
- Jinlin Liu
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Victoria N. Stone
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Xiuchun Ge
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Madison Tang
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Fadi Elrami
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, Virginia, United States of America
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Ping Xu
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, Virginia, United States of America
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, Virginia, United States of America
- Center for the Study of Biological Complexity of Virginia Commonwealth University, Richmond, Virginia, United States of America
- * E-mail:
| |
Collapse
|
82
|
Melo TA, Dos Santos TF, de Almeida ME, Junior LAGF, Andrade EF, Rezende RP, Marques LM, Romano CC. Inhibition of Staphylococcus aureus biofilm by Lactobacillus isolated from fine cocoa. BMC Microbiol 2016; 16:250. [PMID: 27793096 PMCID: PMC5084336 DOI: 10.1186/s12866-016-0871-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 10/26/2016] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Biofilm production represents an important virulence and pathogenesis factor for Staphylococcus aureus. The formation of biofilms on medical devices is a major concern in hospital environments, as they can become a constant source of infection. Probiotic bacteria, such as Lactobacillus fermentum and L. plantarum, have been found to inhibit biofilm formation; however little is known about the underlying mechanism. In this study, we tested the activity of supernatants produced by L. fermentum TCUESC01 and L. plantarum TCUESC02, isolated during the fermentation of fine cocoa, against S. aureus CCMB262 biofilm production. We measured inhibition of biofilm formation in vitro and analyzed biofilm structure by confocal and electronic microscopy. Additionally, we quantified the expression of S. aureus genes icaA and icaR involved in the synthesis of the biofilm matrix by real-time PCR. RESULTS Both Lactobacillus supernatants inhibited S. aureus growth. However, only L. fermentum TCUESC01 significantly reduced the thickness of the biofilm, from 14 μm to 2.83 μm (at 18 mg∙mL-1, 90 % of the minimum inhibitory concentration, MIC), 3.12 μm (at 14 mg∙mL-1, 70 % of the MIC), and 5.21 μm (at 10 mg∙mL-1, 50 % of the MIC). Additionally, L. fermentum TCUESC01 supernatant modulated the expression of icaA and icaR. CONCLUSIONS L. fermentum TCUESC01 reduces the formation of S. aureus biofilm under subinhibitory conditions. Inhibition of biofilm production probably depends on modulation of the ica operon.
Collapse
Affiliation(s)
- Tauá Alves Melo
- Department of Biological Sciences, Santa Cruz State University, Ilhéus-Itabuna Road, km 16 Salobrinho, Ilhéus, 45662-900, Bahia State, Brazil
| | - Thalis Ferreira Dos Santos
- Department of Biological Sciences, Santa Cruz State University, Ilhéus-Itabuna Road, km 16 Salobrinho, Ilhéus, 45662-900, Bahia State, Brazil
| | - Milena Evangelista de Almeida
- Department of Biological Sciences, Santa Cruz State University, Ilhéus-Itabuna Road, km 16 Salobrinho, Ilhéus, 45662-900, Bahia State, Brazil
| | - Luiz Alberto Gusmão Fontes Junior
- Department of Biological Sciences, Santa Cruz State University, Ilhéus-Itabuna Road, km 16 Salobrinho, Ilhéus, 45662-900, Bahia State, Brazil
| | - Ewerton Ferraz Andrade
- Multidisciplinary Institute for Health, Federal University of Bahia, Rio de Contas Street, Candeiasn 17,58 Block, Vitória da Conquista, 45029-094, Bahia State, Brazil
| | - Rachel Passos Rezende
- Department of Biological Sciences, Santa Cruz State University, Ilhéus-Itabuna Road, km 16 Salobrinho, Ilhéus, 45662-900, Bahia State, Brazil
| | - Lucas Miranda Marques
- Multidisciplinary Institute for Health, Federal University of Bahia, Rio de Contas Street, Candeiasn 17,58 Block, Vitória da Conquista, 45029-094, Bahia State, Brazil
| | - Carla Cristina Romano
- Department of Biological Sciences, Santa Cruz State University, Ilhéus-Itabuna Road, km 16 Salobrinho, Ilhéus, 45662-900, Bahia State, Brazil.
| |
Collapse
|
83
|
AraC-Type Regulator Rbf Controls the Staphylococcus epidermidis Biofilm Phenotype by Negatively Regulating the icaADBC Repressor SarR. J Bacteriol 2016; 198:2914-2924. [PMID: 27501984 DOI: 10.1128/jb.00374-16] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 08/04/2016] [Indexed: 11/20/2022] Open
Abstract
Regulation of icaADBC-encoded polysaccharide intercellular adhesin (PIA)/poly-N-acetylglucosasmine (PNAG) production in staphylococci plays an important role in biofilm-associated medical-device-related infections. Here, we report that the AraC-type transcriptional regulator Rbf activates icaADBC operon transcription and PIA production in Staphylococcus epidermidis Purified recombinant Rbf did not bind to the ica operon promoter region in electrophoretic mobility shift assays (EMSAs), indicating that Rbf regulates ica transcription indirectly. To identify the putative transcription factor(s) involved in Rbf-mediated icaADBC regulation, the ability of recombinant Rbf to interact with the promoter sequences of known icaADBC regulators was investigated. Recombinant Rbf bound to the sarR promoter and not the sarX, sarA, sarZ, spx, and srrA promoters. Reverse transcription (RT)-PCR demonstrated that Rbf acts as a repressor of sarR transcription. PIA expression and biofilm production were restored to wild-type levels in an rbf sarR double mutant grown in brain heart infusion (BHI) medium supplemented with NaCl, which is known to activate the ica locus, but not in BHI medium alone. RT-PCR further demonstrated that although Rbf does not bind the sarX promoter, it nevertheless exerted a negative effect on sarX expression. Apparently, direct downregulation of the SarR repressor by Rbf has a dominant effect over indirect repression of the SarX activator by Rbf in the control of S. epidermidis PIA production and biofilm formation. IMPORTANCE The importance of Staphylococcus epidermidis as an opportunistic pathogen in hospital patients with implanted medical devices derives largely from its capacity to form biofilm. Expression of the icaADBC-encoded extracellular polysaccharide is the predominant biofilm mechanism in S. epidermidis clinical isolates and is tightly regulated. Here, we report that the transcriptional regulator Rbf promotes icaADBC expression by negatively regulating expression of sarR, which encodes an ica operon repressor. Furthermore, Rbf indirectly represses the ica operon activator, SarX. The data reveal complicated interplay between Rbf and two Sar family proteins in fine-tuning regulation of the biofilm phenotype and indicate that in the hierarchy of biofilm regulators, IcaR is dominant over the Rbf-SarR-SarX axis.
Collapse
|
84
|
Wang J, Li J, Guo G, Wang Q, Tang J, Zhao Y, Qin H, Wahafu T, Shen H, Liu X, Zhang X. Silver-nanoparticles-modified biomaterial surface resistant to staphylococcus: new insight into the antimicrobial action of silver. Sci Rep 2016; 6:32699. [PMID: 27599568 PMCID: PMC5013400 DOI: 10.1038/srep32699] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 08/12/2016] [Indexed: 01/29/2023] Open
Abstract
Titanium implants are widely used clinically, but postoperative implant infection remains a potential severe complication. The purpose of this study was to investigate the antibacterial activity of nano-silver(Ag)-functionalized Ti surfaces against epidemic Staphylococcus from the perspective of the regulation of biofilm-related genes and based on a bacteria-cell co-culture study. To achieve this goal, two representative epidemic Staphylococcus strains, Staphylococcus epidermidis (S. epidermidis, RP62A) and Staphylococcus aureus (S. aureus, USA 300), were used, and it was found that an Ag-nanoparticle-modified Ti surface could regulate the expression levels of biofilm-related genes (icaA and icaR for S. epidermidis; fnbA and fnbB for S. aureus) to inhibit bacterial adhesion and biofilm formation. Moreover, a novel bacteria-fibroblast co-culture study revealed that the incorporation of Ag nanoparticles on such a surface can help mammalian cells to survive, adhere and spread more successfully than Staphylococcus. Therefore, the modified surface was demonstrated to possess a good anti-infective capability against both sessile bacteria and planktonic bacteria through synergy between the effects of Ag nanoparticles and ion release. This work provides new insight into the antimicrobial action and mechanism of Ag-nanoparticle-functionalized Ti surfaces with bacteria-killing and cell-assisting capabilities and paves the way towards better satisfying the clinical needs.
Collapse
Affiliation(s)
- Jiaxing Wang
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai Jiao Tong University, Shanghai 200233, China
| | - Jinhua Li
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Geyong Guo
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai Jiao Tong University, Shanghai 200233, China
| | - Qiaojie Wang
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai Jiao Tong University, Shanghai 200233, China
| | - Jin Tang
- Department of Clinical Laboratory, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai Jiao Tong University, Shanghai 200233, China
| | - Yaochao Zhao
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai Jiao Tong University, Shanghai 200233, China
| | - Hui Qin
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai Jiao Tong University, Shanghai 200233, China
| | - Tuerhongjiang Wahafu
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai Jiao Tong University, Shanghai 200233, China
| | - Hao Shen
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai Jiao Tong University, Shanghai 200233, China
| | - Xuanyong Liu
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - Xianlong Zhang
- Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai Jiao Tong University, Shanghai 200233, China
| |
Collapse
|
85
|
Crosby HA, Kwiecinski J, Horswill AR. Staphylococcus aureus Aggregation and Coagulation Mechanisms, and Their Function in Host-Pathogen Interactions. ADVANCES IN APPLIED MICROBIOLOGY 2016; 96:1-41. [PMID: 27565579 DOI: 10.1016/bs.aambs.2016.07.018] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The human commensal bacterium Staphylococcus aureus can cause a wide range of infections ranging from skin and soft tissue infections to invasive diseases like septicemia, endocarditis, and pneumonia. Muticellular organization almost certainly contributes to S. aureus pathogenesis mechanisms. While there has been considerable focus on biofilm formation and its role in colonizing prosthetic joints and indwelling devices, less attention has been paid to nonsurface-attached group behavior like aggregation and clumping. S. aureus is unique in its ability to coagulate blood, and it also produces multiple fibrinogen-binding proteins that facilitate clumping. Formation of clumps, which are large, tightly packed groups of cells held together by fibrin(ogen), has been demonstrated to be important for S. aureus virulence and immune evasion. Clumps of cells are able to avoid detection by the host's immune system due to a fibrin(ogen) coat that acts as a shield, and the size of the clumps facilitates evasion of phagocytosis. In addition, clumping could be an important early step in establishing infections that involve tight clusters of cells embedded in host matrix proteins, such as soft tissue abscesses and endocarditis. In this review, we discuss clumping mechanisms and regulation, as well as what is known about how clumping contributes to immune evasion.
Collapse
Affiliation(s)
- H A Crosby
- University of Iowa, Iowa City, IA, United States
| | - J Kwiecinski
- University of Iowa, Iowa City, IA, United States
| | - A R Horswill
- University of Iowa, Iowa City, IA, United States
| |
Collapse
|
86
|
Abstract
Microbes produce a biofilm matrix consisting of proteins, extracellular DNA, and polysaccharides that is integral in the formation of bacterial communities. Historical studies of polysaccharides revealed that their overproduction often alters the colony morphology and can be diagnostic in identifying certain species. The polysaccharide component of the matrix can provide many diverse benefits to the cells in the biofilm, including adhesion, protection, and structure. Aggregative polysaccharides act as molecular glue, allowing the bacterial cells to adhere to each other as well as surfaces. Adhesion facilitates the colonization of both biotic and abiotic surfaces by allowing the bacteria to resist physical stresses imposed by fluid movement that could separate the cells from a nutrient source. Polysaccharides can also provide protection from a wide range of stresses, such as desiccation, immune effectors, and predators such as phagocytic cells and amoebae. Finally, polysaccharides can provide structure to biofilms, allowing stratification of the bacterial community and establishing gradients of nutrients and waste products. This can be advantageous for the bacteria by establishing a heterogeneous population that is prepared to endure stresses created by the rapidly changing environments that many bacteria encounter. The diverse range of polysaccharide structures, properties, and roles highlight the importance of this matrix constituent to the successful adaptation of bacteria to nearly every niche. Here, we present an overview of the current knowledge regarding the diversity and benefits that polysaccharide production provides to bacterial communities within biofilms.
Collapse
|
87
|
The Possible Role of Staphylococcus epidermidis LPxTG Surface Protein SesC in Biofilm Formation. PLoS One 2016; 11:e0146704. [PMID: 26799073 PMCID: PMC4723045 DOI: 10.1371/journal.pone.0146704] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 12/21/2015] [Indexed: 01/14/2023] Open
Abstract
Staphylococcus epidermidis is the most common cause of device-associated infections. It has been shown that active and passive immunization in an animal model against protein SesC significantly reduces S. epidermidis biofilm-associated infections. In order to elucidate its role, knock-out of sesC or isolation of S. epidermidis sesC-negative mutants were attempted, however, without success. As an alternative strategy, sesC was introduced into Staphylococcus aureus 8325–4 and its isogenic icaADBC and srtA mutants, into the clinical methicillin-sensitive S. aureus isolate MSSA4 and the MRSA S. aureus isolate BH1CC, which all lack sesC. Transformation of these strains with sesC i) changed the biofilm phenotype of strains 8325–4 and MSSA4 from PIA-dependent to proteinaceous even though PIA synthesis was not affected, ii) converted the non-biofilm-forming strain 8325–4 ica::tet to a proteinaceous biofilm-forming strain, iii) impaired PIA-dependent biofilm formation by 8325–4 srtA::tet, iv) had no impact on protein-mediated biofilm formation of BH1CC and v) increased in vivo catheter and organ colonization by strain 8325–4. Furthermore, treatment with anti-SesC antibodies significantly reduced in vitro biofilm formation and in vivo colonization by these transformants expressing sesC. These findings strongly suggest that SesC is involved in S. epidermidis attachment to and subsequent biofilm formation on a substrate.
Collapse
|
88
|
Abstract
Our studies demonstrate that sodium chloride (NaCl) induces changes in biofilm, mediated by increased production of polysaccharides intercellular adhesion (PIA). We identified 12 proteins that showed higher abundance in increased level of NaCl. This includes one important protein (IsaA) known to be associated with biofilm stability. In addition, we also found higher abundance of a cold shock protein, CspA, at higher NaCl. We have also identified several other proteins that are differentially expressed to the elevated levels of NaCl and mapped them in the regulatory pathways of PIA. The majority of proteins are involved with various aspects bacterial metabolic function. Our results demonstrated that NaCl influences gene regulatory networks controlling exopolysaccharide expression.
Collapse
Affiliation(s)
- Nazrul Islam
- Department of Chemical and Biochemical Engineering, University of Maryland Baltimore County (UMBC), 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - Julia M Ross
- Department of Chemical and Biochemical Engineering, University of Maryland Baltimore County (UMBC), 1000 Hilltop Circle, Baltimore, MD 21250, USA
| | - Mark R Marten
- Department of Chemical and Biochemical Engineering, University of Maryland Baltimore County (UMBC), 1000 Hilltop Circle, Baltimore, MD 21250, USA
| |
Collapse
|
89
|
Osman KM, Abd El-Razik KA, Marie HSH, Arafa A. Relevance of biofilm formation and virulence of different species of coagulase-negative staphylococci to public health. Eur J Clin Microbiol Infect Dis 2015; 34:2009-16. [DOI: 10.1007/s10096-015-2445-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 06/29/2015] [Indexed: 11/29/2022]
|
90
|
McCarthy H, Rudkin JK, Black NS, Gallagher L, O'Neill E, O'Gara JP. Methicillin resistance and the biofilm phenotype in Staphylococcus aureus. Front Cell Infect Microbiol 2015; 5:1. [PMID: 25674541 PMCID: PMC4309206 DOI: 10.3389/fcimb.2015.00001] [Citation(s) in RCA: 240] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 01/05/2015] [Indexed: 12/05/2022] Open
Abstract
Antibiotic resistance and biofilm-forming capacity contribute to the success of Staphylococcus aureus as a human pathogen in both healthcare and community settings. These virulence factors do not function independently of each other and the biofilm phenotype expressed by clinical isolates of S. aureus is influenced by acquisition of the methicillin resistance gene mecA. Methicillin-sensitive S. aureus (MSSA) strains commonly produce an icaADBC operon-encoded polysaccharide intercellular adhesin (PIA)-dependent biofilm. In contrast, the release of extracellular DNA (eDNA) and cell surface expression of a number of sortase-anchored proteins, and the major autolysin have been implicated in the biofilm phenotype of methicillin-resistant S. aureus (MRSA) isolates. Expression of high level methicillin resistance in a laboratory MSSA strain resulted in (i) repression of PIA-mediated biofilm production, (ii) down-regulation of the accessory gene regulator (Agr) system, and (iii) attenuation of virulence in murine sepsis and device infection models. Here we review the mechanisms of MSSA and MRSA biofilm production and the relationships between antibiotic resistance, biofilm and virulence gene regulation in S. aureus.
Collapse
Affiliation(s)
- Hannah McCarthy
- Department of Microbiology, School of Natural Sciences, National University of Ireland Galway, Ireland
| | - Justine K Rudkin
- Department of Microbiology, School of Natural Sciences, National University of Ireland Galway, Ireland
| | - Nikki S Black
- Department of Microbiology, School of Natural Sciences, National University of Ireland Galway, Ireland
| | - Laura Gallagher
- Department of Microbiology, School of Natural Sciences, National University of Ireland Galway, Ireland
| | - Eoghan O'Neill
- Department of Clinical Microbiology, Royal College of Surgeons in Ireland Dublin, Ireland
| | - James P O'Gara
- Department of Microbiology, School of Natural Sciences, National University of Ireland Galway, Ireland
| |
Collapse
|
91
|
Xue T, Ni J, Shang F, Chen X, Zhang M. Autoinducer-2 increases biofilm formation via an ica- and bhp-dependent manner in Staphylococcus epidermidis RP62A. Microbes Infect 2015; 17:345-52. [PMID: 25637952 DOI: 10.1016/j.micinf.2015.01.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 01/14/2015] [Accepted: 01/14/2015] [Indexed: 10/24/2022]
Abstract
Staphylococcus epidermidis has become the most common cause of nosocomial bacteraemia and the principal organism responsible for indwelling medical device -associated infections. Its pathogenicity is mainly due to its ability to form biofilms on the implanted medical devices. Biofilm formation is a quorum-sensing (QS)-dependent process controlled by autoinducers, which are signalling molecules. Here, we investigated the function of the autoinducer-2 (AI-2) QS system, especially the influence of AI-2 on biofilm formation in S. epidermidis RP62A. Results showed that the addition of AI-2 leads to a significant increase in biofilm formation, in contrast with previous studies which showed that AI-2 limits biofilm formation in Staphylococci. We found that AI-2 increases biofilm formation by enhancing the transcription of the ica operon, which is a known component in the AI-2-regulated biofilm pathway. In addition, we first observed that the transcript level of bhp, which encodes a biofilm-associated protein, was also increased following the addition of AI-2. Furthermore, we found that, among the known biofilm regulator genes (icaR, sigB, rbsU, sarA, sarX, sarZ, clpP, agrA, abfR, arlRS, saeRS), only icaR can be regulated by AI-2, suggesting that AI-2 may regulate biofilm formation by an icaR-dependent mechanism in S. epidermidis RP62A.
Collapse
Affiliation(s)
- Ting Xue
- School of Life Sciences, Anhui Agricultural University, Hefei, Anhui 230036, China.
| | - Jingtian Ni
- School of Life Sciences, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Fei Shang
- School of Life Sciences, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Xiaolin Chen
- School of Life Sciences, Anhui Agricultural University, Hefei, Anhui 230036, China
| | - Ming Zhang
- School of Life Sciences, Anhui Agricultural University, Hefei, Anhui 230036, China
| |
Collapse
|
92
|
Asai K, Yamada K, Yagi T, Baba H, Kawamura I, Ohta M. Effect of incubation atmosphere on the production and composition of staphylococcal biofilms. J Infect Chemother 2014; 21:55-61. [PMID: 25454214 DOI: 10.1016/j.jiac.2014.10.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 09/19/2014] [Accepted: 10/02/2014] [Indexed: 11/24/2022]
Abstract
Staphylococcus aureus and Staphylococcus epidermidis are pathogenic bacteria that often cause invasive infections in humans. In this study, we characterized the composition and growth characteristics of staphylococcal biofilms under various incubation atmospheres. We assessed the effect of incubation atmosphere (aerobic, 5% CO2, anaerobic, and microaerobic) on the biofilm production capabilities of S. aureus strains isolated from healthy volunteers and from patients with catheter-related bloodstream infection. In addition, the composition of S. aureus and S. epidermidis biofilms was determined by assessment of biofilm degradation after treatment with DNase I, proteinase K, and dispersin B. The strains obtained from healthy volunteers and patients showed similar biofilm formation capabilities. Biofilms of S. aureus were rich in proteins when developed under ambient atmospheric conditions, 5% CO2, and microaerobic condition, whereas S. epidermidis biofilms contained large amounts of poly-β (1, 6)-N-acetyl-D-glucosamine when developed under ambient atmospheric conditions and microaerobic condition. The biofilm-producing capability of S. epidermidis was considerably higher than that of S. aureus under aerobic condition. Staphylococcal isolates obtained from healthy individuals and patients with catheter-related infections have similar biofilm-forming capabilities. Under microaerobic conditions, S. aureus and S. epidermidis form protein-rich and poly-β (1, 6)-N-acetyl-D-glucosamine-rich biofilms, respectively. These components may play an important role in the development of biofilms inside the body and may be the target molecules to prevent catheter-related infections caused by these organisms.
Collapse
Affiliation(s)
- Kentaro Asai
- Department of Bacteriology, Nagoya University Graduate School of Medicine, Japan
| | - Keiko Yamada
- Department of Bacteriology, Nagoya University Graduate School of Medicine, Japan.
| | - Tetsuya Yagi
- Department of Infectious Diseases, Centre of National University Hospital for Infection Control, Nagoya University Hospital, Japan
| | - Hisashi Baba
- Department of Infectious Diseases, Kanazawa Medical University, Japan
| | - Ichiro Kawamura
- Division of Infectious Diseases, Shizuoka Cancer Center, Japan
| | - Michio Ohta
- Department of Nursing, School of Nursing, Sugiyama Jogakuen University, Japan
| |
Collapse
|
93
|
Abstract
The definition of the heterogeneous group of coagulase-negative staphylococci (CoNS) is still based on diagnostic procedures that fulfill the clinical need to differentiate between Staphylococcus aureus and those staphylococci classified historically as being less or nonpathogenic. Due to patient- and procedure-related changes, CoNS now represent one of the major nosocomial pathogens, with S. epidermidis and S. haemolyticus being the most significant species. They account substantially for foreign body-related infections and infections in preterm newborns. While S. saprophyticus has been associated with acute urethritis, S. lugdunensis has a unique status, in some aspects resembling S. aureus in causing infectious endocarditis. In addition to CoNS found as food-associated saprophytes, many other CoNS species colonize the skin and mucous membranes of humans and animals and are less frequently involved in clinically manifested infections. This blurred gradation in terms of pathogenicity is reflected by species- and strain-specific virulence factors and the development of different host-defending strategies. Clearly, CoNS possess fewer virulence properties than S. aureus, with a respectively different disease spectrum. In this regard, host susceptibility is much more important. Therapeutically, CoNS are challenging due to the large proportion of methicillin-resistant strains and increasing numbers of isolates with less susceptibility to glycopeptides.
Collapse
Affiliation(s)
- Karsten Becker
- Institute of Medical Microbiology, University Hospital Münster, Münster, Germany
| | - Christine Heilmann
- Institute of Medical Microbiology, University Hospital Münster, Münster, Germany
| | - Georg Peters
- Institute of Medical Microbiology, University Hospital Münster, Münster, Germany
| |
Collapse
|
94
|
Extracellular DNA impedes the transport of vancomycin in Staphylococcus epidermidis biofilms preexposed to subinhibitory concentrations of vancomycin. Antimicrob Agents Chemother 2014; 58:7273-82. [PMID: 25267673 DOI: 10.1128/aac.03132-14] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Staphylococcus epidermidis biofilm formation is responsible for the persistence of orthopedic implant infections. Previous studies have shown that exposure of S. epidermidis biofilms to sub-MICs of antibiotics induced an increased level of biofilm persistence. BODIPY FL-vancomycin (a fluorescent vancomycin conjugate) and confocal microscopy were used to show that the penetration of vancomycin through sub-MIC-vancomycin-treated S. epidermidis biofilms was impeded compared to that of control, untreated biofilms. Further experiments showed an increase in the extracellular DNA (eDNA) concentration in biofilms preexposed to sub-MIC vancomycin, suggesting a potential role for eDNA in the hindrance of vancomycin activity. Exogenously added, S. epidermidis DNA increased the planktonic vancomycin MIC and protected biofilm cells from lethal vancomycin concentrations. Finally, isothermal titration calorimetry (ITC) revealed that the binding constant of DNA and vancomycin was 100-fold higher than the previously reported binding constant of vancomycin and its intended cellular d-Ala-d-Ala peptide target. This study provides an explanation of the eDNA-based mechanism of antibiotic tolerance in sub-MIC-vancomycin-treated S. epidermidis biofilms, which might be an important factor for the persistence of biofilm infections.
Collapse
|
95
|
Role for the A domain of unprocessed accumulation-associated protein (Aap) in the attachment phase of the Staphylococcus epidermidis biofilm phenotype. J Bacteriol 2014; 196:4268-75. [PMID: 25266380 DOI: 10.1128/jb.01946-14] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The polysaccharide intercellular adhesin or the cell wall-anchored accumulation-associated protein (Aap) mediates cellular accumulation during Staphylococcus epidermidis biofilm maturation. Mutation of sortase, which anchors up to 11 proteins (including Aap) to the cell wall, blocked biofilm development by the cerebrospinal fluid isolate CSF41498. Aap was implicated in this phenotype when Western blots and two-dimensional (2D) electrophoresis revealed increased levels of the protein in culture supernatants. Unexpectedly, reduced levels of primary attachment were associated with impaired biofilm formation by CSF41498 srtA and aap mutants. In contrast to previous studies, which implicated Aap proteolytic cleavage and, specifically, the Aap B domains in biofilm accumulation, the CSF41498 Aap protein was unprocessed. Furthermore, aap appeared to play a less important role in the biofilm phenotype of S. epidermidis 1457, in which the Aap protein is processed. Anti-Aap A-domain IgG inhibited primary attachment and biofilm formation in strain CSF41498 but not in strain 1457. The nucleotide sequences of the aap gene A-domain region and cleavage site in strains CSF41498 and 1457 were identical, implicating altered protease activity in the differential Aap processing results in the two strains. These data reveal a new role for the A domain of unprocessed Aap in the attachment phase of biofilm formation and suggest that extracellular protease activity can influence whether Aap contributes to the attachment or accumulation phases of the S. epidermidis biofilm phenotype.
Collapse
|
96
|
Qin H, Cao H, Zhao Y, Zhu C, Cheng T, Wang Q, Peng X, Cheng M, Wang J, Jin G, Jiang Y, Zhang X, Liu X, Chu PK. In vitro and in vivo anti-biofilm effects of silver nanoparticles immobilized on titanium. Biomaterials 2014; 35:9114-25. [PMID: 25112937 DOI: 10.1016/j.biomaterials.2014.07.040] [Citation(s) in RCA: 185] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 07/23/2014] [Indexed: 01/09/2023]
Abstract
Prevention of periprosthetic infection (PPI) by inhibiting biofilm formation on prostheses is crucial to orthopedic surgery. In this work, silver nanoparticles (Ag NPs) are fabricated in situ and immobilized on titanium by silver plasma immersion ion implantation (PIII). The anti-biofilm activity rendered by the immobilized Ag NPs is assessed using Staphylococcus epidermidis, a biofilm producing strain, in vitro and in vivo. The immobilized Ag NPs show no apparent cytotoxicity but reduce biofilm formation in vitro by inhibiting bacteria adhesion and icaAD transcription. The immobilized Ag NPs offer a good defense against multiple cycles of bacteria attack in vitro, and the mechanism is independent of silver release. Radiographic assessment, microbiological cultures, and histopathological results demonstrate the ability of the functionalized surface against bacterial infection to reduce the risk of implant-associated PPI.
Collapse
Affiliation(s)
- Hui Qin
- Department of Orthopedics, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai 200233, China
| | - Huiliang Cao
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - Yaochao Zhao
- Department of Orthopedics, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai 200233, China
| | - Cheng Zhu
- Department of Orthopedics, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai 200233, China
| | - Tao Cheng
- Department of Orthopedics, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai 200233, China
| | - Qiaojie Wang
- Department of Orthopedics, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai 200233, China
| | - Xiaochun Peng
- Department of Orthopedics, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai 200233, China
| | - Mengqi Cheng
- Department of Orthopedics, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai 200233, China
| | - Jiaxin Wang
- Department of Orthopedics, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai 200233, China
| | - Guodong Jin
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China
| | - Yao Jiang
- Department of Orthopedics, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai 200233, China
| | - Xianlong Zhang
- Department of Orthopedics, Shanghai Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai 200233, China.
| | - Xuanyong Liu
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China.
| | - Paul K Chu
- Department of Physics & Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China
| |
Collapse
|
97
|
Kwon KH, Hwang SY, Park YK, Yoon JW, Kim S, Hong J. A Quantitative Real-Time Immuno-PCR Assay for Detection of S
taphylococcus Aureus
Enterotoxin H. J Food Saf 2014. [DOI: 10.1111/jfs.12120] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ka Hee Kwon
- Department of Veterinary Microbiology; College of Veterinary Medicine; Seoul National University; Seoul 151-742 South Korea
- Research Institute for Veterinary Science; College of Veterinary Medicine; Seoul National University; Seoul 151-742 South Korea
| | - Sun Young Hwang
- Department of Veterinary Microbiology; College of Veterinary Medicine; Seoul National University; Seoul 151-742 South Korea
- Research Institute for Veterinary Science; College of Veterinary Medicine; Seoul National University; Seoul 151-742 South Korea
| | - Young Kyung Park
- Department of Veterinary Microbiology; College of Veterinary Medicine; Seoul National University; Seoul 151-742 South Korea
| | - Jang Won Yoon
- College of Veterinary Medicine; Kangwon National University; Chuncheon 200-701 South Korea
| | - Sangphil Kim
- Food Safety Department; Health Care Business; Seoul 150-705 South Korea
| | - Joonbae Hong
- Food Microbiology Team; Test & Research Department; Consumer Safety Center; Korea Consumer Agency; Seoul 137-700 South Korea
| |
Collapse
|
98
|
Bekir K, Noumi E, Abid NBS, Bakhrouf A. Adhesive properties to materials used in unit care by Staphylococcus aureus strains incubated in seawater microcosms. J IND ENG CHEM 2014. [DOI: 10.1016/j.jiec.2013.10.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
99
|
You Y, Xue T, Cao L, Zhao L, Sun H, Sun B. Staphylococcus aureus glucose-induced biofilm accessory proteins, GbaAB, influence biofilm formation in a PIA-dependent manner. Int J Med Microbiol 2014; 304:603-12. [PMID: 24836943 DOI: 10.1016/j.ijmm.2014.04.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Revised: 03/28/2014] [Accepted: 04/19/2014] [Indexed: 10/25/2022] Open
Abstract
The Gram-positive bacteria Staphylococcus aureus and Staphylococcus epidermidis are capable of attaching to a biomaterial surface and forming resistant biofilms. The identification of biomolecular and regulatory factors involved in staphylococcal adhesion and biofilm formation is needed to understand biofilm-associated infection in humans. Here, we have identified a new operon, gbaAB (glucose induced biofilm accessory gene), that affects biofilm formation in S. aureus NCTC8325. Real-time reverse transcription PCR (RT-PCR) and electrophoretic mobility shift assay showed that GbaA and GbaB are transcribed from the same transcript, and GbaA directly inhibits the transcription of the gbaAB operon through self-repression. Our results indicated that the gbaA mutant displayed enhanced biofilm formation compared with the wild type. However, the gbaB and the gbaAB double mutant displayed reduced biofilm formation, suggesting that the gbaAB operon is involved in biofilm formation and that gbaB might be the key gene in biofilm regulation. Phenotypic analysis suggested that the gbaAB operon mediated biofilm formation of S. aureus at the multicellular aggregation stage rather than during initial attachment. In addition, real-time RT-PCR analysis showed that icaA was upregulated in the gbaA mutant and downregulated in the gbaB and gbaAB mutants compared with the wild type. In addition, the gbaA and the gbaB mutants affected the induction of biofilm formation by glucose. Our results suggest that the gbaAB operon is involved in the regulation of the multicellular aggregation step of S. aureus biofilm formation in response to glucose and that this regulation may be mediated through the ica operon.
Collapse
Affiliation(s)
- Yibo You
- Department of Microbiology and Immunology, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Ting Xue
- Department of Microbiology and Immunology, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Linyan Cao
- Department of Microbiology and Immunology, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Liping Zhao
- Department of Microbiology and Immunology, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Haipeng Sun
- Department of Microbiology and Immunology, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Baolin Sun
- Department of Microbiology and Immunology, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China.
| |
Collapse
|
100
|
A different path: revealing the function of staphylococcal proteins in biofilm formation. FEBS Lett 2014; 588:1869-72. [PMID: 24735724 DOI: 10.1016/j.febslet.2014.04.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 04/02/2014] [Accepted: 04/03/2014] [Indexed: 11/17/2022]
Abstract
Staphylococcus aureus and Staphylococcus epidermidis cause dangerous and difficult to treat medical device-related infections through their ability to form biofilms. Extracellular poly-N-acetylglucosamine (PNAG) facilitates biofilm formation and is a vaccination target, yet details of its biosynthesis by the icaADBC gene products is limited. IcaC is the proposed transporter for PNAG export, however a comparison of the Ica proteins to homologous exo-polysaccharide synthases suggests that the common IcaAD protein components both synthesise and transport the PNAG. The limited distribution of icaC to the Staphylococcaceae and its membership of a family of membrane-bound acyltransferases, leads us to suggest that IcaC is responsible for the known O-succinylation of PNAG that occurs in staphylococci, identifying a potentially new therapeutic target specific for these bacteria.
Collapse
|