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Singh KV, Galloway-Peña J, Montealegre MC, Dong X, Murray BE. Genomic context as well as sequence of both psr and penicillin-binding protein 5 contributes to β-lactam resistance in Enterococcus faecium. mBio 2024; 15:e0017024. [PMID: 38564699 PMCID: PMC11077988 DOI: 10.1128/mbio.00170-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 03/04/2024] [Indexed: 04/04/2024] Open
Abstract
Penicillin-binding protein 5 (PBP5) of Enterococcus faecium (Efm) is vital for ampicillin resistance (AMP-R). We previously designated three forms of PBP5, namely, PBP5-S in Efm clade B strains [ampicillin susceptible (AMP-S)], PBP5-S/R (AMP-S or R), and PBP5-R (AMP-R) in clade A strains. Here, pbp5 deletion resulted in a marked reduction in AMP minimum inhibitory concentrations (MICs) to 0.01-0.09 µg/mL for clade B and 0.12-0.19 µg/mL for clade A strains; in situ complementation restored parental AMP MICs. Using D344SRF (lacking ftsW/psr/pbp5), constructs with ftsWA/psrA (from a clade A1 strain) cloned upstream of pbp5-S and pbp5-S/R alleles resulted in modest increases in MICs to 3-8 µg/mL, while high MICs (>64 µg/mL) were seen using pbp5 from A1 strains. Next, using ftsW ± psr from clade B and clade A/B and B/A hybrid constructs, the presence of psrB, even alone or in trans, resulted in much lower AMP MICs (3-8 µg/mL) than when psrA was present (MICs >64 µg/mL). qRT PCR showed relatively greater pbp5 expression (P = 0.007) with pbp5 cloned downstream of clade A1 ftsW/psr (MIC >128 µg/mL) vs when cloned downstream of clade B ftsW/psr (MIC 4-16 µg/mL), consistent with results in western blots. In conclusion, we report the effect of clade A vs B psr on AMP MICs as well as the impact of pbp5 alleles from different clades. While previously, Psr was not thought to contribute to AMP MICs in Efm, our results showed that the presence of psrB resulted in a major decrease in Efm AMP MICs. IMPORTANCE The findings of this study shed light on ampicillin resistance in Enterococcus faecium clade A strains. They underscore the significance of alterations in the amino acid sequence of penicillin-binding protein 5 (PBP5) and the pivotal role of the psr region in PBP5 expression and ampicillin resistance. Notably, the presence of a full-length psrB leads to reduced PBP5 expression and lower minimum inhibitory concentrations (MICs) of ampicillin compared to the presence of a shorter psrA, regardless of the pbp5 allele involved. Additionally, clade B E. faecium strains exhibit lower AMP MICs when both psr alleles from clades A and B are present, although it is important to consider other distinctions between clade A and B strains that may contribute to this effect. It is intriguing to note that the divergence between clade A and clade B E. faecium and the subsequent evolution of heightened AMP MICs in hospital-associated strains appear to coincide with changes in Pbp5 and psr. These changes in psr may have resulted in an inactive Psr, facilitating increased PBP5 expression and greater ampicillin resistance. These results raise the possibility that a mimicker of PsrB, if one could be designed, might be able to lower MICs of ampicillin-resistant E. faecium, thus potentially resorting ampicillin to our therapeutic armamentarium for this species.
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Affiliation(s)
- Kavindra V. Singh
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA
| | - Jessica Galloway-Peña
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA
| | - Maria Camila Montealegre
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA
- Department of Microbiology and Infectious Diseases, University of Texas Health Science Center, Houston, Texas, USA
| | - Xingxing Dong
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA
| | - Barbara E. Murray
- Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA
- Department of Microbiology and Infectious Diseases, University of Texas Health Science Center, Houston, Texas, USA
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Boeder AM, Spiller F, Carlstrom M, Izídio GS. Enterococcus faecalis: implications for host health. World J Microbiol Biotechnol 2024; 40:190. [PMID: 38702495 DOI: 10.1007/s11274-024-04007-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2024] [Accepted: 04/26/2024] [Indexed: 05/06/2024]
Abstract
The microbiota represents a crucial area of research in maintaining human health due to its potential for uncovering novel biomarkers, therapies, and molecular mechanisms relevant to population identification and experimental model characterization. Among these microorganisms, Enterococcus faecalis, a Gram-positive bacterium found in the gastrointestinal tract of humans and animals, holds particular significance. Strains of this bacterial species have sparked considerable debate in the literature due to their dual nature; they can either be utilized as probiotics in the food industry or demonstrate resistance to antibiotics, potentially leading to severe illness, disability, and death. Given the diverse characteristics of Enterococcus faecalis strains, this review aims to provide a comprehensive understanding of their impact on various systems within the host, including the immunological, cardiovascular, metabolic, and nervous systems. Furthermore, we summarize the bacterium-host interaction characteristics and molecular effects to highlight their targets, features, and overall impact on microbial communities and host health.
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Affiliation(s)
- Ariela Maína Boeder
- Department of Pharmacology, Federal University of Santa Catarina, Florianópolis, Brazil
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Fernando Spiller
- Department of Pharmacology, Federal University of Santa Catarina, Florianópolis, Brazil
| | - Mattias Carlstrom
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Geison Souza Izídio
- Department of Pharmacology, Federal University of Santa Catarina, Florianópolis, Brazil.
- Department of Cell Biology, Embryology and Genetics, Federal University of Santa Catarina, Florianópolis, Brazil.
- Department of Psychiatry and Legal Medicine, Autonomous University of Barcelona, Barcelona, Spain.
- Laboratório de Genética do Comportamento, Universidade Federal de Santa Catarina, Centro de Ciências Biológicas, Departamento de Biologia Celular, Embriologia e Genética, Florianopolis, SC, Brazil.
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Bapat RA, Libat R, Yuin OS, Parolia A, Ilyas MS, Khan AS, Kay MK, Pichika MR, Saxena K, Seow LL, Sidhu P, Daood U. Antimicrobial FiteBac® K21 promotes antimicrobial Potency and wound healing. Heliyon 2023; 9:e19282. [PMID: 37664740 PMCID: PMC10469996 DOI: 10.1016/j.heliyon.2023.e19282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 07/27/2023] [Accepted: 08/17/2023] [Indexed: 09/05/2023] Open
Abstract
Objectives Successful root canal therapy is dependent on the efficacy of complete instrumentation and adequate use of chemical irrigant to eliminate the biofilm from dentin surface. The aim of the study was to examine antibiofilm and antimicrobial effectiveness of newly formulated Quaternary ammonium silane (QAS/also codenamed K21; against Fusobacterium nucleatum (F. nucleatum) and Enterococcus faecalis (E. faecalis) biofilm on radicular dentin with evaluation of the anti-inflammatory consequence in vivo. Methods Fourier Transform Infrared Spectroscopy (FTIR) was performed after complete hydrolysis of K21 solution. Human teeth were inoculated with biofilms for 7-days followed by treatment with various irrigants. The irrigant groups were Sodium hypochlorite [NaOCl (6%)], Chlorhexidine [CHX (2%)], K21 (0.5%), K21 (1%) and Saline. Scanning electron microscopy (SEM) was performed for biofilm and resin-dentin penetration. Transmission Electron Microscopy (TEM) of biofilms was done to evaluate application of K21. For in vivo evaluation, Albino wistar rats were injected subcutaneously and sections were stained with haematoxylin/eosin. Macrophage, M1/M2 expression were evaluated along with molecular simulation. Raman measurements were done on dried biofilms. Results FTIR K21 specimens demonstrated presence of ethanol/silanol groups. Raman band at 1359 cm-1 resemble to -CH2- wagging displaying 29Si atoms in Nuclear Magnetic Resonance (NMR). 0.5%K21 showed cells exhibiting folded membranes. SEM showed staggering amount of resin tags with 0.5% K21 group. TEM showed membrane disruption in K21-groups. K21 groups were initially irritant, which subsided completely afterwards showing increased CD68. K21 and MMP/collagen complex was thermodynamically favourable. Conclusion K21 root canal irrigant was able to penetrate bacterial wall and can serve as a potential irrigant for therapeutic benefits. Expression of M2 polarized subsets showed K21 can serve in resolving inflammation and potentiate tissue repair.
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Affiliation(s)
- Ranjeet Ajit Bapat
- Restorative Division, School of Dentistry, International Medical University Kuala Lumpur, 126, Jalan Jalil Perkasa 19, Bukit Jalil, 57000, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Rikan Libat
- Restorative Division, School of Dentistry, International Medical University Kuala Lumpur, 126, Jalan Jalil Perkasa 19, Bukit Jalil, 57000, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Ong Shu Yuin
- Restorative Division, School of Dentistry, International Medical University Kuala Lumpur, 126, Jalan Jalil Perkasa 19, Bukit Jalil, 57000, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Abhishek Parolia
- Restorative Division, School of Dentistry, International Medical University Kuala Lumpur, 126, Jalan Jalil Perkasa 19, Bukit Jalil, 57000, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | | | - Abdul Samad Khan
- Department of Restorative Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University; Dammam, Saudi Arabia
| | - Mak Kit Kay
- Pharmaceutical Chemistry, School of Pharmacy, International Medical University, Kuala Lumpur, Malaysia
| | - Mallikarjuna Rao Pichika
- Pharmaceutical Chemistry, School of Pharmacy, International Medical University, Kuala Lumpur, Malaysia
| | - Kirti Saxena
- Clinical Oral Health Sciences Division, School of Dentistry, International Medical University Kuala Lumpur, 126, Jalan Jalil Perkasa 19, Bukit Jalil, 57000, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Liang Lin Seow
- Restorative Division, School of Dentistry, International Medical University Kuala Lumpur, 126, Jalan Jalil Perkasa 19, Bukit Jalil, 57000, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Preena Sidhu
- Restorative Division, School of Dentistry, International Medical University Kuala Lumpur, 126, Jalan Jalil Perkasa 19, Bukit Jalil, 57000, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Umer Daood
- Restorative Division, School of Dentistry, International Medical University Kuala Lumpur, 126, Jalan Jalil Perkasa 19, Bukit Jalil, 57000, Wilayah Persekutuan Kuala Lumpur, Malaysia
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Șchiopu P, Toc DA, Colosi IA, Costache C, Ruospo G, Berar G, Gălbău ȘG, Ghilea AC, Botan A, Pană AG, Neculicioiu VS, Todea DA. An Overview of the Factors Involved in Biofilm Production by the Enterococcus Genus. Int J Mol Sci 2023; 24:11577. [PMID: 37511337 PMCID: PMC10380289 DOI: 10.3390/ijms241411577] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 07/08/2023] [Accepted: 07/14/2023] [Indexed: 07/30/2023] Open
Abstract
Enterococcus species are known for their ability to form biofilms, which contributes to their survival in extreme environments and involvement in persistent bacterial infections, especially in the case of multi-drug-resistant strains. This review aims to provide a comprehensive understanding of the mechanisms underlying biofilm formation in clinically important species such as Enterococcus faecalis and the less studied but increasingly multi-drug-resistant Enterococcus faecium, and explores potential strategies for their eradication. Biofilm formation in Enterococcus involves a complex interplay of genes and virulence factors, including gelatinase, cytolysin, Secreted antigen A, pili, microbial surface components that recognize adhesive matrix molecules (MSCRAMMs), and DNA release. Quorum sensing, a process of intercellular communication, mediated by peptide pheromones such as Cob, Ccf, and Cpd, plays a crucial role in coordinating biofilm development by targeting gene expression and regulation. Additionally, the regulation of extracellular DNA (eDNA) release has emerged as a fundamental component in biofilm formation. In E. faecalis, the autolysin N-acetylglucosaminidase and proteases such as gelatinase and serin protease are key players in this process, influencing biofilm development and virulence. Targeting eDNA may offer a promising avenue for intervention in biofilm-producing E. faecalis infections. Overall, gaining insights into the intricate mechanisms of biofilm formation in Enterococcus may provide directions for anti-biofilm therapeutic research, with the purpose of reducing the burden of Enterococcus-associated infections.
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Affiliation(s)
- Pavel Șchiopu
- Department of Microbiology, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
- Department of Pneumology, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400332 Cluj-Napoca, Romania
| | - Dan Alexandru Toc
- Department of Microbiology, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Ioana Alina Colosi
- Department of Microbiology, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Carmen Costache
- Department of Microbiology, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Giuseppe Ruospo
- Faculty of Medicine, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - George Berar
- Faculty of Medicine, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Ștefan-Gabriel Gălbău
- Faculty of Medicine, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Alexandra Cristina Ghilea
- Faculty of Medicine, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Alexandru Botan
- Faculty of Medicine, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Adrian-Gabriel Pană
- Department of Microbiology, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Vlad Sever Neculicioiu
- Department of Microbiology, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania
| | - Doina Adina Todea
- Department of Pneumology, "Iuliu Hațieganu" University of Medicine and Pharmacy, 400332 Cluj-Napoca, Romania
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Rao Tatta E, Paul S, Kumavath R. Transcriptome Analysis revealed the Synergism of Novel Rhodethrin inhibition on Biofilm architecture, Antibiotic Resistance and Quorum sensing inEnterococcus faecalis. Gene 2023; 871:147436. [PMID: 37075926 DOI: 10.1016/j.gene.2023.147436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 03/31/2023] [Accepted: 04/13/2023] [Indexed: 04/21/2023]
Abstract
Enterococcus sp. emerged as an opportunistic nosocomial pathogen with the highest antibiotic resistance and mortality rate. Biofilm is problematic primarily since it is regulated by the global bacterial cell to cell communication mediated by the quorum sensing system. sing system. Thus, potential natural antagonists in a novel drug formulation against biofilm-forming Enterococcus faecalis is critical. We used RNA-Seq to evaluate the effects of the novel molecule rhodethrin with chloramphenicol induced on Enterococcus faecalis and DEGs were identified. In transcriptome sequence analysis, a total of 448 with control Vs rhodethrin, 1591 were in control Vs chloramphenicol, 379 genes were DEGs from control Vs synergies, in rhodethrin with chloramphenicol, 379 genes were differentially expressed, whereas 264 genes were significantly downregulated, indicating that 69.69% ofE. faecaliswas altered. The transcriptional sequence data further expression analysis qRT-PCR, and the results shed that the expression profiles of five significant biofilm formation responsible genes such as, Ace, AtpB, lepA, bopD, and typA, 3 genes involved in quorum sensing are sylA, fsrC and camE, and 4 genes involved in resistance were among including liaX, typA, EfrA, and lepA, were significantly suppressed expressions of the biofilm, quorum sensing, and resistance that are supported by transcriptome analysis.
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Affiliation(s)
- Eswar Rao Tatta
- Department of Genomic Science, School of Biological Sciences, Central University of Kerala, Tejaswini Hills, Periya (PO), Kasaragod, Kerala 671320, India
| | - Sayan Paul
- Department of Biochemistry & Molecular Biology, the University of Texas Medical Branch at Galveston, Galveston, Texas 77555, USA
| | - Ranjith Kumavath
- Department of Genomic Science, School of Biological Sciences, Central University of Kerala, Tejaswini Hills, Periya (PO), Kasaragod, Kerala 671320, India; Department of Biotechnology, School of Life Sciences, Pondicherry University, Puducherry 605014, India.
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Venkateswaran P, Lakshmanan PM, Muthukrishnan S, Bhagavathi H, Vasudevan S, Neelakantan P, Solomon AP. Hidden agenda of Enterococcus faecalis lifestyle transition: planktonic to sessile state. Future Microbiol 2022; 17:1051-1069. [PMID: 35899477 DOI: 10.2217/fmb-2021-0212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Enterococcus faecalis, a human gastrointestinal tract commensal, is known to cause nosocomial infections. Interestingly, the pathogen's host colonization and persistent infections are possibly linked to its lifestyle changes from planktonic to sessile state. Also, the multidrug resistance and survival fitness acquired in the sessile stage of E. faecalis has challenged treatment regimes. This situation exists because of the critical role played by several root genes and their molecular branches, which are part of quorum sensing, aggregation substance, surface adhesions, stress-related response and sex pheromones in the sessile state. It is therefore imperative to decode the hidden agenda of E. faecalis and understand the significant factors influencing biofilm formation. This would, in turn, augment the development of novel strategies to tackle E. faecalis infections.
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Affiliation(s)
- Parvathy Venkateswaran
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
| | - Priya M Lakshmanan
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
| | - Sudhiksha Muthukrishnan
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
| | - Hema Bhagavathi
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
| | - Sahana Vasudevan
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
| | | | - Adline P Solomon
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
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Daood U, Parolia A, Matinlinna J, Yiu C, Ahmed HMA, Fawzy A. Properties of a modified quaternary ammonium silane formulation as a potential root canal irrigant in endodontics. Dent Mater 2020; 36:e386-e402. [PMID: 33010944 DOI: 10.1016/j.dental.2020.09.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 06/28/2020] [Accepted: 09/09/2020] [Indexed: 12/20/2022]
Abstract
OBJECTIVES Evaluate a new modified quaternary ammonium silane irrigant solution for its antimicrobial, cytotoxic and mechanical properties of dentine substrate. METHODS Root canal preparation was performed using stainless steel K-files™ and F4 size protaper with irrigation protocols of 6% NaOCl + 2% CHX; 3.5% QIS; 2% QIS and sterile saline. Biofilms were prepared using E. faecalis adjusted and allowed to grow for 3 days, treated with irrigants, and allowed to grow for 7 days. AFM was performed and surface free energy calculated. MC3T3 cells were infected with endo irrigant treated E. faecalis biofilms. Raman spectroscopy of biofilms were performed after bacterial re-growth on root dentine and exposed to different irrigation protocols and collagen fibers analysed collagen fibers using TEM. Antimicrobial potency against E. faecalis biofilms and cytoxicity against 3T3 NIH cells were also. Resin penetration and MitoTracker green were also evaluated for sealer penetration and mitochondrial viability. Data were analysed using One-way ANOVA, principal component analysis and post-hoc Fisher's least-significant difference. RESULTS Elastic moduli were maintained amongst control (5.5 ± 0.9) and 3.5% QIS (4.4 ± 1.1) specimens with surface free energy higher in QIS specimens. MC3T3 cells showed reduced viability in 6%NaOCl+2%CHX specimens compared to QIS specimens. DNA/purine were expressed in increased intensities in control and 6% NaOCl + 2% CHX specimens with bands around 480-490 cm-1 reduced in QIS specimens. 3.5% QIS specimens showed intact collagen fibrillar network and predominantly dead bacterial cells in confocal microscopy. 3.5% QIS irrigant formed a thin crust-type surface layer with cytoplasmic extensions of 3T3NIH spread over root dentine. Experiments confirmed MitoTracker accumulation in 3.5% treated cells. SIGNIFICANCE Novel QIS root canal irrigant achieved optimum antimicrobial protection inside the root canals facilitating a toxic effect against the Enterococcus faecalis biofilm. Root dentine substrates exhibited optimum mechanical properties and there was viability of fibroblastic mitochondria.
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Affiliation(s)
- Umer Daood
- Division of Clinical Dentistry, School of Dentistry, International Medical University Kuala Lumpur, 126, Jalan Jalil Perkasa 19, Bukit Jalil, 57000 Bukit Jalil, Wilayah Persekutuan Kuala Lumpur, Malaysia.
| | - Abhishek Parolia
- Division of Clinical Dentistry, School of Dentistry, International Medical University Kuala Lumpur, 126, Jalan Jalil Perkasa 19, Bukit Jalil, 57000 Bukit Jalil, Wilayah Persekutuan Kuala Lumpur, Malaysia
| | - Jukka Matinlinna
- Dental Materials Science, Applied Oral Sciences, Faculty of Dentistry, The University of Hong Kong, 34 Hospital Road, Sai Ying Pun, Hong Kong SAR, China
| | - Cynthia Yiu
- Pediatric Dentistry and Orthodontics, Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, 34 Hospital Road, Pokfulam, Hong Kong, China Hong Kong Special Administrative Region
| | - Hany Mohamed Aly Ahmed
- Department of Restorative Dentistry, Faculty of Dentistry, University of Malaya, 50603, Kuala Lumpur, Malaysia
| | - Amr Fawzy
- UWA Dental School, University of Western Australia, Nedlands, WA 6009, Australia
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Li Y, Tong Z, Ling J. Effect of the three
Enterococcus faecalis
strains on apoptosis in
MC
3T3 cells. Oral Dis 2018; 25:309-318. [DOI: 10.1111/odi.12883] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 03/27/2018] [Accepted: 04/10/2018] [Indexed: 01/09/2023]
Affiliation(s)
- Yang Li
- Department of Operative Dentistry and EndodonticsGuanghua School of StomatologyHospital of StomatologySun Yat‐sen University Guangzhou China
- Guangdong Province Key Laboratory of Stomatology Guangzhou China
| | - Zhongchun Tong
- Department of Operative Dentistry and EndodonticsGuanghua School of StomatologyHospital of StomatologySun Yat‐sen University Guangzhou China
- Guangdong Province Key Laboratory of Stomatology Guangzhou China
| | - Junqi Ling
- Department of Operative Dentistry and EndodonticsGuanghua School of StomatologyHospital of StomatologySun Yat‐sen University Guangzhou China
- Guangdong Province Key Laboratory of Stomatology Guangzhou China
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Expression of Adhesive Pili and the Collagen-Binding Adhesin Ace Is Activated by ArgR Family Transcription Factors in Enterococcus faecalis. J Bacteriol 2018; 200:JB.00269-18. [PMID: 29986940 DOI: 10.1128/jb.00269-18] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 06/29/2018] [Indexed: 12/15/2022] Open
Abstract
It was shown previously that the disruption of the ahrC gene encoding a predicted ArgR family transcription factor results in a severe defect in biofilm formation in vitro, as well as a significant attenuation of virulence of Enterococcus faecalis strain OG1RF in multiple experimental infection models. Using transcriptome sequencing (RNA-seq), we observed ahrC-dependent changes in the expression of more than 20 genes. AhrC-repressed genes included predicted determinants of arginine catabolism and several other metabolic genes and predicted transporters, while AhrC-activated genes included determinants involved in the production of surface protein adhesins. Most notably, the structural and regulatory genes of the ebp locus encoding adhesive pili were positively regulated, as well as the ace gene, encoding a collagen-binding adhesin. Using lacZ transcription reporter fusions, we determined that ahrC and a second argR transcription factor gene, argR2, both function to activate the expression of ebpR, which directly activates the transcription of the pilus structural genes. Our data suggest that in the wild-type E. faecalis, the low levels of EbpR limit the expression of pili and that biofilm biomass is also limited by the amount of pili expressed by the bacteria. The expression of ace is similarly enhanced by AhrC and ArgR2, but ace expression is not dependent on EbpR. Our results demonstrate the existence of novel regulatory cascades controlled by a pair of ArgR family transcription factors that might function as a heteromeric protein complex.IMPORTANCE Cell surface adhesins play critical roles in the formation of biofilms, host colonization, and the pathogenesis of opportunistic infections by Enterococcus faecalis Here, we present new results showing that the expression of two major enterococcal surface adhesins, ebp pili, and the collagen-binding protein Ace is positively regulated at the transcription level by two argR family transcription factors, AhrC and ArgR2. In the case of pili, the direct target of regulation is the ebpR gene, previously shown to activate the transcription of the pilus structural genes, while the activation of ace transcription appears to be directly impacted by the two ArgR proteins. These transcription factors may represent new targets for blocking enterococcal infections.
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Djorić D, Kristich CJ. Extracellular SalB Contributes to Intrinsic Cephalosporin Resistance and Cell Envelope Integrity in Enterococcus faecalis. J Bacteriol 2017; 199:e00392-17. [PMID: 28874409 PMCID: PMC5686589 DOI: 10.1128/jb.00392-17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 08/30/2017] [Indexed: 11/20/2022] Open
Abstract
Enterococci are major causes of hospital-acquired infections. Intrinsic resistance to cephalosporins is a universal trait among clinically relevant enterococci. Cephalosporin resistance enables enterococci to proliferate to high densities in the intestines of patients undergoing cephalosporin treatment, a precursor to the emergence of infection. However, the genetic and biochemical mechanisms of intrinsic cephalosporin resistance in enterococci are not well understood. A two-component signal transduction system, CroR/S, is required for cephalosporin resistance in enterococci. Although the CroR/S regulon is not well defined, one gene reported to be CroR dependent in Enterococcus faecalis JH2-2 encodes an extracellular putative peptidoglycan hydrolase, SalB. To test the hypothesis that SalB is responsible for CroR-dependent cephalosporin resistance, we examined ΔsalB mutants in multiple genetic lineages of E. faecalis, revealing that SalB is required not only for intrinsic cephalosporin resistance but also for maintenance of cell envelope integrity in the absence of antibiotic stress. The N-terminal signal sequence is necessary for SalB secretion, and secretion is required for SalB to promote cephalosporin resistance. Functional dissection revealed that the C-terminal SCP domain of SalB is essential for biological activity and identified three residues within the SCP domain that are required for the stability and function of SalB. Additionally, we found that in contrast to what is seen in E. faecalis JH2-2, SalB is not regulated by the CroR/S two-component system in E. faecalis OG1, suggesting diversity in the CroR/S regulon among distinct lineages of E. faecalis IMPORTANCE Resistance to cephalosporins is universal among clinically relevant enterococci, enabling enterococcal proliferation to high densities in the intestines of patients undergoing cephalosporin treatment, a precursor to the emergence of infection. Disabling cephalosporin resistance could therefore reduce the incidence of enterococcal infections. However, the genetic and biochemical mechanisms of cephalosporin resistance are not well understood. The significance of this work is the identification of a novel extracellular factor (SalB) that promotes cephalosporin resistance in E. faecalis, which could potentially serve as a target for therapeutics that impair enterococcal cephalosporin resistance. Additionally, our work highlights the importance of the C-terminal SCP domain of SalB, including several conserved residues within the SCP domain, for the ability of SalB to promote cephalosporin resistance.
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Affiliation(s)
- Dušanka Djorić
- Department of Microbiology and Immunology, Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Christopher J Kristich
- Department of Microbiology and Immunology, Center for Infectious Disease Research, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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Differential Penicillin-Binding Protein 5 (PBP5) Levels in the Enterococcus faecium Clades with Different Levels of Ampicillin Resistance. Antimicrob Agents Chemother 2016; 61:AAC.02034-16. [PMID: 27821450 DOI: 10.1128/aac.02034-16] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 11/01/2016] [Indexed: 12/20/2022] Open
Abstract
Ampicillin resistance in Enterococcus faecium is a serious concern worldwide, complicating the treatment of E. faecium infections. Penicillin-binding protein 5 (PBP5) is considered the main ampicillin resistance determinant in E. faecium The three known E. faecium clades showed sequence variations in the pbp5 gene that are associated with their ampicillin resistance phenotype; however, these changes alone do not explain the array of resistance levels observed among E. faecium clinical strains. We aimed to determine if the levels of PBP5 are differentially regulated between the E. faecium clades, with the hypothesis that variations in PBP5 levels could help account for the spectrum of ampicillin MICs seen in E. faecium We studied pbp5 mRNA levels and PBP5 protein levels as well as the genetic environment upstream of pbp5 in 16 E. faecium strains that belong to the different E. faecium clades and for which the ampicillin MICs covered a wide range. Our results found that pbp5 and PBP5 levels are increased in subclade A1 and A2 ampicillin-resistant strains compared to those in clade B and subclade A2 ampicillin-susceptible strains. Furthermore, we found evidence of major clade-associated rearrangements in the region upstream of pbp5, including large DNA fragment insertions, deletions, and single nucleotide polymorphisms, that may be associated with the differential regulation of PBP5 levels between the E. faecium clades. Overall, these findings highlight the contribution of the clade background to the regulation of PBP5 abundance and point to differences in the region upstream of pbp5 as likely contributors to the differential expression of ampicillin resistance.
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Wojnicz D, Tichaczek-Goska D, Korzekwa K, Kicia M, Hendrich AB. Study of the impact of cranberry extract on the virulence factors and biofilm formation by Enterococcus faecalis strains isolated from urinary tract infections. Int J Food Sci Nutr 2016; 67:1005-16. [PMID: 27456160 DOI: 10.1080/09637486.2016.1211996] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Drinking of cranberry fruit juice and application of commercial preparations containing the cranberry extracts are recommended in the prevention and treatment of urinary tract infections (UTIs), especially in women with recurrent UTIs. Many studies focus on the activity of cranberries against uropathogenic Escherichia coli (E. coli) strains. However, the knowledge of the cranberry effect on Gram-positive Enterococcus faecalis (E. faecalis) is limited. Therefore, the aim of our study was to establish the activity of commercial concentrated cranberry extract on the growth, virulence factors and biofilm formation of E. faecalis strains isolated from urine. Minimal inhibitory concentrations (MICs) of cranberry extract were determined by the broth microdilution method. Disc diffusion method was used to determine antimicrobial susceptibility. The impact of cranberry extract on bacterial survival, hydrophobicity, synthesis of lipase, lecithinase, DNase, hemolysin, gelatinase and biofilm mass was determined. Results show that cranberry extract inhibits the growth, enzymatic activities of bacteria and limits biofilm formation. The antibacterial activities of the studied cranberry extract confirm that it could be successfully used in prevention of UTIs caused by E. faecalis.
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Affiliation(s)
- Dorota Wojnicz
- a Department of Biology and Medical Parasitology , Wroclaw Medical University , Wroclaw , Poland
| | - Dorota Tichaczek-Goska
- a Department of Biology and Medical Parasitology , Wroclaw Medical University , Wroclaw , Poland
| | - Kamila Korzekwa
- b Department of Microbiology , Institute of Genetics and Microbiology, University of Wroclaw , Wroclaw , Poland
| | - Marta Kicia
- a Department of Biology and Medical Parasitology , Wroclaw Medical University , Wroclaw , Poland
| | - Andrzej B Hendrich
- a Department of Biology and Medical Parasitology , Wroclaw Medical University , Wroclaw , Poland
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The two-component system GrvRS (EtaRS) regulates ace expression in Enterococcus faecalis OG1RF. Infect Immun 2014; 83:389-95. [PMID: 25385790 DOI: 10.1128/iai.02587-14] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Expression of ace (adhesin to collagen of Enterococcus faecalis), encoding a virulence factor in endocarditis and urinary tract infection models, has been shown to increase under certain conditions, such as in the presence of serum, bile salts, urine, and collagen and at 46 °C. However, the mechanism of ace/Ace regulation under different conditions is still unknown. In this study, we identified a two-component regulatory system GrvRS as the main regulator of ace expression under these stress conditions. Using Northern hybridization and β-galactosidase assays of an ace promoter-lacZ fusion, we found transcription of ace to be virtually absent in a grvR deletion mutant under the conditions that increase ace expression in wild-type OG1RF and in the complemented strain. Moreover, a grvR mutant revealed decreased collagen binding and biofilm formation as well as attenuation in a murine urinary tract infection model. Here we show that GrvR plays a major role in control of ace expression and E. faecalis virulence.
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