451
|
He X, Yuan F, Lu F, Yin Y, Cao J. Vancomycin-induced biofilm formation by methicillin-resistant Staphylococcus aureus is associated with the secretion of membrane vesicles. Microb Pathog 2017; 110:225-231. [PMID: 28687320 DOI: 10.1016/j.micpath.2017.07.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 06/29/2017] [Accepted: 07/03/2017] [Indexed: 10/19/2022]
Abstract
Chronic burn wound infections caused by Stapyhylococcus aureus (S. aureus) are largely associated with biofilm formation. However, the mechanism by which S. aureus form biofilm in clinical environments is far less understood. In the present study we addressed the association between biofilm formation and membrane vesicle (MV) secretion of S. aureus during vancomycin treatment. A representative methicillin-resistant S. aureus (MRSA) strain BWMR22 obtained from a chronic burn wound was used in this study. Transmission electron microscope was used to observe the MV secretion. Fourier transform infrared spectroscopy was used to analyze the chemical component of MV. Biofilm formation was assayed under conditions of sub-inhibitory concentrations of vancomycin. Functional potencies of MV in surface adhesion and auto-aggregation were assayed in the presence of additional purified MVs. Biofilm formation by S. aureus BWMR22 was enhanced in the presence of sub-inhibitory concentration of vancomycin. Vancomycin treatment caused an increase in the chemical composition of protein relative to carbohydrates of secreted MVs, a property which was highly associated with bacterial hydrophobicity, surface adhesion, and intercellular aggregation. These findings suggest that MV secretion is correlated with biofilm formation by MRSA especially under clinical conditions with improper vancomycin chemotherapy. This study first demonstrates a potential role of MVs in the biofilm formation by S. aureus, stresses on the importance of avoiding low dose of antibiotic therapy in controlling of S. aureus infections, and provides further information to reveal the mechanisms behind MRSA infections.
Collapse
Affiliation(s)
- Xinlong He
- School of Medicine, Yangzhou University, Jiangsu Key Laboratory of Experimental & Translational Non-coding RNA Research, Yangzhou, 225001, Jiangsu Province, People's Republic of China; The Third People's Hospital of Wuxi (The Third Affiliated Hospital of Nantong University), Wuxi, 214041, Jiangsu Province, People's Republic of China; Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, 225001, Jiangsu Province, People's Republic of China.
| | - Fenglai Yuan
- The Third People's Hospital of Wuxi (The Third Affiliated Hospital of Nantong University), Wuxi, 214041, Jiangsu Province, People's Republic of China
| | - Feng Lu
- School of Medicine, Yangzhou University, Jiangsu Key Laboratory of Experimental & Translational Non-coding RNA Research, Yangzhou, 225001, Jiangsu Province, People's Republic of China
| | - Yinyan Yin
- School of Medicine, Yangzhou University, Jiangsu Key Laboratory of Experimental & Translational Non-coding RNA Research, Yangzhou, 225001, Jiangsu Province, People's Republic of China
| | - Jun Cao
- Jiangsu Institute of Parasitic Diseases, Key Laboratory of Parasitic Disease Control and Prevention (Ministry of Health), Jiangsu Provincial Key Laboratory of Parasite Molecular Biology, Wuxi, 214064, Jiangsu Province, People's Republic of China; Public Health Research Center, Jiangnan University, Wuxi, 214122, Jiangsu Province, People's Republic of China.
| |
Collapse
|
452
|
Eriksson S, van der Plas MJA, Mörgelin M, Sonesson A. Antibacterial and antibiofilm effects of sodium hypochlorite against Staphylococcus aureus isolates derived from patients with atopic dermatitis. Br J Dermatol 2017; 177:513-521. [PMID: 28238217 DOI: 10.1111/bjd.15410] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/21/2017] [Indexed: 12/18/2022]
Abstract
BACKGROUND Atopic dermatitis (AD) is characterized by an increased susceptibility to skin infections. Staphylococcus aureus is reported to dominate in AD lesions and reports have revealed the presence of staphylococcal biofilms. These infections contribute to aggravation of the eczema. Sodium hypochlorite is known to reduce bacterial load of skin lesions, as well as disease severity, in patients with AD, but the effect on biofilms is unknown. OBJECTIVES To investigate the antimicrobial and antibiofilm effects of sodium hypochlorite against S. aureus isolates derived from patients with AD. METHODS Skin biopsies derived from patients with infected AD were examined by scanning electron microscopy (SEM). Using radial diffusion assays, biofilm assays and confocal laser scanning microscopy, we assessed the effect of sodium hypochlorite on S. aureus isolates derived from lesional skin of patients with AD. RESULTS SEM revealed clusters of coccoid bacteria embedded in fibrin and extracellular substances at the skin of a patient with infected AD. At concentrations of 0·01-0·08%, sodium hypochlorite showed antibacterial effects against planktonic cells. Eradication of S. aureus biofilms in vitro was observed in concentrations ranging from 0·01% to 0·16%. Confocal laser scanning microscopy confirmed these results. Finally, when human AD skin was subjected to sodium hypochlorite in an ex vivo model, a dose of 0·04% reduced the bacteria derived from AD skin. CONCLUSIONS Sodium hypochlorite has antimicrobial and antibiofilm effects against clinical S. aureus isolates. Our findings suggest usage of a higher concentration than currently used in bleach baths of patients with skin-infected AD.
Collapse
Affiliation(s)
- S Eriksson
- Department of Dermatology and Venereology, Skane University Hospital, Lund University, Biomedical Center B14, 221 84, Lund, Sweden.,Division of Dermatology and Venereology, Lund University, Biomedical Center B14, 221 84, Lund, Sweden
| | - M J A van der Plas
- Division of Dermatology and Venereology, Lund University, Biomedical Center B14, 221 84, Lund, Sweden
| | - M Mörgelin
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Biomedical Center B14, 221 84, Lund, Sweden
| | - A Sonesson
- Department of Dermatology and Venereology, Skane University Hospital, Lund University, Biomedical Center B14, 221 84, Lund, Sweden.,Division of Dermatology and Venereology, Lund University, Biomedical Center B14, 221 84, Lund, Sweden
| |
Collapse
|
453
|
Yin S, Jiang B, Huang G, Gong Y, You B, Yang Z, Chen Y, Chen J, Yuan Z, Li M, Hu F, Zhao Y, Peng Y. Burn Serum Increases Staphylococcus aureus Biofilm Formation via Oxidative Stress. Front Microbiol 2017; 8:1191. [PMID: 28702016 PMCID: PMC5487419 DOI: 10.3389/fmicb.2017.01191] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 06/12/2017] [Indexed: 12/22/2022] Open
Abstract
Staphylococcus aureus is a common pathogen isolated from burn patients that can form biofilms on burn wounds and implanted deep vein catheters, which often leads to refractory infections or even biofilm-related sepsis. As biofilm formation is usually regulated by environmental conditions, we hypothesized that serum composition may be altered after burn injury, potentially affecting the ability of infecting bacteria to form biofilms. As predicted, we observed that serum from burn-injured rats increases biofilm formation by S. aureus and also induces bacterial aggregation and adherence to human fibronectin and fibrinogen. Analysis of potential regulatory factors revealed that exposure to burn serum decreases expression of the quorum-sensing agr system and increases mRNA levels of some biofilm inducers such as sarA and icaA. In addition, we also observed that burn serum imposes oxidative stress and increases expression of key oxidoreductase genes (sodA, sodM, katA, and ahpC) in S. aureus. Importantly, the ability of burn serum to enhance biofilm formation and bacterial cell aggregation can be abrogated by treatment with an antioxidant. Taken together, these findings indicate that burn serum increases S. aureus biofilm formation via elevated oxidative stress, and may lead to novel strategies to control biofilm formation and infection in burn patients.
Collapse
Affiliation(s)
- Supeng Yin
- State Key Laboratory of Trauma, Burns, and Combined Injury, Institute of Burn Research, Southwest Hospital, Third Military Medical UniversityChongqing, China
| | - Bei Jiang
- State Key Laboratory of Trauma, Burns, and Combined Injury, Institute of Burn Research, Southwest Hospital, Third Military Medical UniversityChongqing, China
| | - Guangtao Huang
- State Key Laboratory of Trauma, Burns, and Combined Injury, Institute of Burn Research, Southwest Hospital, Third Military Medical UniversityChongqing, China
| | - Yali Gong
- State Key Laboratory of Trauma, Burns, and Combined Injury, Institute of Burn Research, Southwest Hospital, Third Military Medical UniversityChongqing, China
| | - Bo You
- State Key Laboratory of Trauma, Burns, and Combined Injury, Institute of Burn Research, Southwest Hospital, Third Military Medical UniversityChongqing, China
| | - Zichen Yang
- State Key Laboratory of Trauma, Burns, and Combined Injury, Institute of Burn Research, Southwest Hospital, Third Military Medical UniversityChongqing, China
| | - Yu Chen
- State Key Laboratory of Trauma, Burns, and Combined Injury, Institute of Burn Research, Southwest Hospital, Third Military Medical UniversityChongqing, China
| | - Jing Chen
- State Key Laboratory of Trauma, Burns, and Combined Injury, Institute of Burn Research, Southwest Hospital, Third Military Medical UniversityChongqing, China
| | - Zhiqiang Yuan
- State Key Laboratory of Trauma, Burns, and Combined Injury, Institute of Burn Research, Southwest Hospital, Third Military Medical UniversityChongqing, China
| | - Ming Li
- Department of Microbiology, Third Military Medical UniversityChongqing, China
| | - Fuquan Hu
- Department of Microbiology, Third Military Medical UniversityChongqing, China
| | - Yan Zhao
- Department of Microbiology, Third Military Medical UniversityChongqing, China
| | - Yizhi Peng
- State Key Laboratory of Trauma, Burns, and Combined Injury, Institute of Burn Research, Southwest Hospital, Third Military Medical UniversityChongqing, China
| |
Collapse
|
454
|
Kapoor V, Rai R, Thiyagarajan D, Mukherjee S, Das G, Ramesh A. A Nonbactericidal Zinc-Complexing Ligand as a Biofilm Inhibitor: Structure-Guided Contrasting Effects on Staphylococcus aureus Biofilm. Chembiochem 2017; 18:1502-1509. [PMID: 28440961 DOI: 10.1002/cbic.201700139] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Indexed: 12/17/2022]
Abstract
Zinc-complexing ligands are prospective anti-biofilm agents because of the pivotal role of zinc in the formation of Staphylococcus aureus biofilm. Accordingly, the potential of a thiosemicarbazone (compound C1) and a benzothiazole-based ligand (compound C4) in the prevention of S. aureus biofilm formation was assessed. Compound C1 displayed a bimodal activity, hindering biofilm formation only at low concentrations and promoting biofilm growth at higher concentrations. In the case of C4, a dose-dependent inhibition of S. aureus biofilm growth was observed. Atomic force microscopy analysis suggested that at higher concentrations C1 formed globular aggregates, which perhaps formed a substratum that favored adhesion of cells and biofilm formation. In the case of C4, zinc supplementation experiments validated zinc complexation as a plausible mechanism of inhibition of S. aureus biofilm. Interestingly, C4 was nontoxic to cultured HeLa cells and thus has promise as a therapeutic anti-biofilm agent. The essential understanding of the structure-driven implications of zinc-complexing ligands acquired in this study might assist future screening regimes for identification of potent anti-biofilm agents.
Collapse
Affiliation(s)
- Vidushi Kapoor
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Rajanikant Rai
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Durairaj Thiyagarajan
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Sandipan Mukherjee
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Gopal Das
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Aiyagari Ramesh
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| |
Collapse
|
455
|
Maskarinec SA, Thaden JT, Cyr DD, Ruffin F, Souli M, Fowler VG. The Risk of Cardiac Device-Related Infection in Bacteremic Patients Is Species Specific: Results of a 12-Year Prospective Cohort. Open Forum Infect Dis 2017; 4:ofx132. [PMID: 28852678 PMCID: PMC5570037 DOI: 10.1093/ofid/ofx132] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 06/20/2017] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND The species-specific risk of cardiac device-related infection (CDRI) among bacteremic patients is incompletely understood. METHODS We conducted a prospective cohort study of hospitalized patients from October 2002 to December 2014 with a cardiac device (CD) and either Staphylococcus aureus bacteremia (SAB) or Gram-negative bacteremia (GNB). Cardiac devices were defined as either prosthetic heart valves (PHVs), including valvular support rings, permanent pacemakers (PPMs)/automatic implantable cardioverter defibrillators (AICDs), or left ventricular assist devices (LVADs). RESULTS During the study period, a total of 284 patients with ≥1 CD developed either SAB (n = 152 patients) or GNB (n = 132 patients). Among the 284 patients, 150 (52.8%) had PPMs/AICDs, 72 (25.4%) had PHVs, 4 (1.4%) had LVADs, and 58 (20.4%) had >1 device present. Overall, 54.6% of patients with SAB and 16.7% of patients with GNB met criteria for definite CDRI (P < .0001). Multivariable logistic regression analysis revealed that 3 bacterial species were associated with an increased risk for CDRI: Staphylococcus aureus (odds ratio [OR] = 5.57; 95% confidence interval [CI], 2.16-14.36), Pseudomonas aeruginosa (OR = 50.28; 95% CI, 4.16-606.93), and Serratia marcescens (OR = 7.75; 95% CI, 1.48-40.48). CONCLUSIONS Risk of CDRI among patients with bacteremia varies by species. Cardiac device-related infection risk is highest in patients with bacteremia due to S aureus, P aeruginosa, or S marcescens. By contrast, it is lower in patients with bacteremia due to other species of Gram-negative bacilli. Patients with a CD who develop bacteremia due to either P aeruginosa or S marcescens should be considered for diagnostic imaging to evaluate for the presence of CDRI.
Collapse
Affiliation(s)
| | - Joshua T Thaden
- Duke University, Division of Infectious Diseases, Durham, North Carolina
| | - Derek D Cyr
- Duke Clinical Research Institute, Durham, North Carolina
| | - Felicia Ruffin
- Duke University, Division of Infectious Diseases, Durham, North Carolina
| | - Maria Souli
- Duke University, Division of Infectious Diseases, Durham, North Carolina.,National and Kapodistrian University of Athens, School of Medicine, Greece
| | - Vance G Fowler
- Duke University, Division of Infectious Diseases, Durham, North Carolina.,Duke Clinical Research Institute, Durham, North Carolina
| |
Collapse
|
456
|
Abstract
Staphylococcus aureus is a serious human pathogen with remarkable adaptive powers. Antibiotic-resistant clones rapidly emerge mainly by acquisition of antibiotic-resistance genes from other S. aureus strains or even from other genera. Transfer is mediated by a diverse complement of mobile genetic elements and occurs primarily by conjugation or bacteriophage transduction, with the latter traditionally being perceived as the primary route. Recent work on conjugation and transduction suggests that transfer by these mechanisms may be more extensive than previously thought, in terms of the range of plasmids that can be transferred by conjugation and the efficiency with which transduction occurs. Here, we review the main routes of antibiotic resistance gene transfer in S. aureus in the context of its biology as a human commensal and a life-threatening pathogen.
Collapse
Affiliation(s)
- Jakob Haaber
- Department of Veterinary and Animal Sciences, Faculty of Health & Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - José R Penadés
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Hanne Ingmer
- Department of Veterinary and Animal Sciences, Faculty of Health & Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
| |
Collapse
|
457
|
Borges A, Lopez-Romero JC, Oliveira D, Giaouris E, Simões M. Prevention, removal and inactivation of Escherichia coli and Staphylococcus aureus biofilms using selected monoterpenes of essential oils. J Appl Microbiol 2017; 123:104-115. [PMID: 28497526 DOI: 10.1111/jam.13490] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 04/27/2017] [Accepted: 05/06/2017] [Indexed: 02/04/2023]
Abstract
AIMS The aim of this study was to investigate the antibiofilm potential of five essential oil (EO) components with cyclic (sabinene-SAB, carveol-C1, carvone-C2) and acyclic (citronellol-C3 and citronellal-C4) structures against Escherichia coli and Staphylococcus aureus. METHODS AND RESULTS The selected EO components prevented biofilm set-up, with C3 and C4 causing remarkable effects. When applied against pre-established biofilms, they promoted high biomass removal and inactivation of biofilm cells. Moreover, no viable E. coli biofilm cells were detected after exposure to SAB at 5 × MIC and 10 × MIC, and a significant viability decrease was observed for both bacteria with the other EO components. SAB, C3 and C4 caused the most prominent effects apparently due to their octanol-water partition coefficient (Po/w), the number of rotatable bonds (n-ROTB) and the free hydroxyl groups. CONCLUSIONS The overall results demonstrated that the selected EO components, particularly SAB, C3 and C4 are of interest as new lead molecules to both prevent biofilm set-up and to control pre-established biofilms of E. coli and S. aureus. SIGNIFICANCE AND IMPACT OF THE STUDY The tested EO components exhibited prominent antibiofilm properties against E. coli and S. aureus providing a novel and effective alternative/complementary approach to counteract chronic infections and the transmission of diseases in clinical settings.
Collapse
Affiliation(s)
- A Borges
- LEPABE, Department of Chemical Engineering, Faculty of Engineering, University of Porto, Porto, Portugal
| | - J C Lopez-Romero
- CIAD, Research Center for Food and Development, Hermosillo, Sonora, Mexico
| | - D Oliveira
- LEPABE, Department of Chemical Engineering, Faculty of Engineering, University of Porto, Porto, Portugal
| | - E Giaouris
- Department of Food Science and Nutrition, Faculty of the Environment, University of the Aegean, Myrina, Lemnos Island, Greece
| | - M Simões
- LEPABE, Department of Chemical Engineering, Faculty of Engineering, University of Porto, Porto, Portugal
| |
Collapse
|
458
|
Yang SC, Tseng CH, Wang PW, Lu PL, Weng YH, Yen FL, Fang JY. Pterostilbene, a Methoxylated Resveratrol Derivative, Efficiently Eradicates Planktonic, Biofilm, and Intracellular MRSA by Topical Application. Front Microbiol 2017; 8:1103. [PMID: 28659908 PMCID: PMC5468402 DOI: 10.3389/fmicb.2017.01103] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 05/31/2017] [Indexed: 12/23/2022] Open
Abstract
Pterostilbene is a methoxylated derivative of resveratrol originated from natural sources. We investigated the antibacterial activity of pterostilbene against drug-resistant Staphylococcus aureus and the feasibility of using it to treat cutaneous bacteria. The antimicrobial effect was evaluated using an in vitro culture model and an in vivo mouse model of cutaneous infection. The minimum inhibitory concentration (MIC) assay demonstrated a superior biocidal activity of pterostilbene compared to resveratrol (8~16-fold) against methicillin-resistant S. aureus (MRSA) and clinically isolated vancomycin-intermediate S. aureus (VISA). Pterostilbene was found to reduce MRSA biofilm thickness from 18 to 10 μm as detected by confocal microscopy. Pterostilbene showed minimal toxicity to THP-1 cells and was readily engulfed by the macrophages, facilitating the eradication of intracellular MRSA. Pterostilbene exhibited increased skin absorption over resveratrol by 6-fold. Topical pterostilbene application improved the abscess formation produced by MRSA by reducing the bacterial burden and ameliorating the skin architecture. The potent anti-MRSA capability of pterostilbene was related to bacterial membrane leakage, chaperone protein downregulation, and ribosomal protein upregulation. This mechanism of action was different from that of resveratrol according to proteomic analysis and molecular docking. Pterostilbene has the potential to serve as a novel class of topically applied agents for treating MRSA infection in the skin while demonstrating less toxicity to mammalian cells.
Collapse
Affiliation(s)
- Shih-Chun Yang
- Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung UniversityTaoyuan, Taiwan
| | - Chih-Hua Tseng
- School of Pharmacy, College of Pharmacy, Kaohsiung Medical UniversityKaohsiung, Taiwan.,Research Center for Natural Products and Drug Development, Kaohsiung Medical UniversityKaohsiung, Taiwan.,Center for Infectious Disease and Cancer Research, Kaohsiung Medical UniversityKaohsiung, Taiwan.,Department of Fragrance and Cosmetic Science, College of Pharmacy, Kaohsiung Medical UniversityKaohsiung, Taiwan
| | - Pei-Wen Wang
- Department of Medical Research, China Medical University Hospital, China Medical UniversityTaichung, Taiwan
| | - Po-Liang Lu
- Department of Internal Medicine, Kaohsiung Medical University HospitalKaohsiung, Taiwan.,College of Medicine, Kaohsiung Medical UniversityKaohsiung, Taiwan
| | - Yi-Han Weng
- Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung UniversityTaoyuan, Taiwan
| | - Feng-Lin Yen
- Department of Fragrance and Cosmetic Science, College of Pharmacy, Kaohsiung Medical UniversityKaohsiung, Taiwan.,Institute of Biomedical Sciences, National Sun Yat-Sen UniversityKaohsiung, Taiwan
| | - Jia-You Fang
- Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung UniversityTaoyuan, Taiwan.,Research Center for Food and Cosmetic Safety and Research Center for Chinese Herbal Medicine, Chang Gung University of Science and TechnologyTaoyuan, Taiwan.,Department of Anesthesiology, Chang Gung Memorial HospitalTaoyuan, Taiwan
| |
Collapse
|
459
|
Silva LN, Da Hora GCA, Soares TA, Bojer MS, Ingmer H, Macedo AJ, Trentin DS. Myricetin protects Galleria mellonella against Staphylococcus aureus infection and inhibits multiple virulence factors. Sci Rep 2017; 7:2823. [PMID: 28588273 PMCID: PMC5460262 DOI: 10.1038/s41598-017-02712-1] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 04/18/2017] [Indexed: 02/06/2023] Open
Abstract
Staphylococcus aureus is an opportunistic pathogen related to a variety of life-threatening infections but for which antimicrobial resistance is liming the treatment options. We report here that myricetin, but not its glycosylated form, can remarkably decrease the production of several S. aureus virulence factors, including adhesion, biofilm formation, hemolysis and staphyloxanthin production, without interfering with growth. Myricetin affects both surface proteins and secreted proteins which indicate that its action is unrelated to inhibition of the agr quorum sensing system. Analysis of virulence related gene expression and computational simulations of pivotal proteins involved in pathogenesis demonstrate that myricetin downregulates the saeR global regulator and interacts with sortase A and α-hemolysin. Furthermore, Myr confers a significant degree of protection against staphylococcal infection in the Galleria mellonella model. The present findings reveal the potential of Myr as an alternative multi-target antivirulence candidate to control S. aureus pathogenicity.
Collapse
Affiliation(s)
- L N Silva
- Centro de Biotecnologia do Estado do Rio Grande do Sul, Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre-RS, 91501-970, Brazil
- Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre-RS, 90610-000, Brazil
| | - G C A Da Hora
- Departmento de Química Fundamental, Universidade Federal de Pernambuco, Recife-PE, 50670-901, Brazil
| | - T A Soares
- Departmento de Química Fundamental, Universidade Federal de Pernambuco, Recife-PE, 50670-901, Brazil
- Department of Chemistry, Umeå University, 90187, Umeå, Sweden
| | - M S Bojer
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, 1870, Denmark
| | - H Ingmer
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, 1870, Denmark
| | - A J Macedo
- Centro de Biotecnologia do Estado do Rio Grande do Sul, Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre-RS, 91501-970, Brazil.
- Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre-RS, 90610-000, Brazil.
| | - D S Trentin
- Centro de Biotecnologia do Estado do Rio Grande do Sul, Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre-RS, 91501-970, Brazil
- Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre-RS, 90610-000, Brazil
- Departamento de Ciências Básicas da Saúde, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre-RS, 90050-170, Brazil
| |
Collapse
|
460
|
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
|
461
|
Fernandez S, Ledo C, Lattar S, Noto Llana M, Bertelli AM, Di Gregorio S, Sordelli DO, Gómez MI, Mollerach ME. High virulence of methicillin resistant Staphylococcus aureus ST30-SCC mec IVc- spa t019, the dominant community-associated clone in Argentina. Int J Med Microbiol 2017; 307:191-199. [DOI: 10.1016/j.ijmm.2017.05.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 05/11/2017] [Accepted: 05/14/2017] [Indexed: 10/19/2022] Open
|
462
|
Virulence factors associated with Coagulase Negative Staphylococci isolated from human infections. 3 Biotech 2017; 7:140. [PMID: 28593524 DOI: 10.1007/s13205-017-0753-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 01/23/2017] [Indexed: 10/19/2022] Open
Abstract
Infections caused by commensal organisms by changing to infectious life style generate much challenge to the current treatment strategies. Coagulase Negative Staphylococci (CoNS) are one of them, with their coexisting biofilm forming and multiple antibiotic resistance properties form important agents of nosocomial infection. To evaluate species distribution, biofilm formation, and antibiogram, CoNS isolates from various clinical samples were isolated. The presence of biofilm and associated genes icaAB, aap, atlE, embp, bhp, and fbe in CoNS was screened by PCR. The biofilm chemical composition and its correlation with the genotypes were also analysed. Staphylococcus epidermidis (59%) was found to be the most prevalent CoNS species. Most of the CoNS isolates harboring biofilm gene showed carbohydrate-protein-eDNA biofilm, whereas carbohydrate-protein biofilms were also observed. High percentage of multiple drug resistance, and biofilm gene frequency among these CoNS isolates point towards the need of periodic surveillance as CoNS are recently identified to cause difficult to treat infections.
Collapse
|
463
|
Deinhardt-Emmer S, Hoerr V, Löffler B. Vascular graft infection: a new model for treatment management? Future Microbiol 2017; 12:651-654. [PMID: 28541093 DOI: 10.2217/fmb-2017-0068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Stefanie Deinhardt-Emmer
- Institute of Medical Microbiology, Jena University Hospital, Am Klinikum 1, D-07747 Jena, Germany
| | - Verena Hoerr
- Institute of Medical Microbiology, Jena University Hospital, Am Klinikum 1, D-07747 Jena, Germany
| | - Bettina Löffler
- Institute of Medical Microbiology, Jena University Hospital, Am Klinikum 1, D-07747 Jena, Germany
| |
Collapse
|
464
|
Amjed S, Junaid K, Jafar J, Amjad T, Maqsood W, Mukhtar N, Tariq K, Sharif M, Awan SJ, Ansari F. Detection of antibacterial activities of Miswak, Kalonji and Aloe vera against oral pathogens & anti-proliferative activity against cancer cell line. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2017; 17:265. [PMID: 28506259 PMCID: PMC5433005 DOI: 10.1186/s12906-017-1778-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 05/08/2017] [Indexed: 11/16/2022]
Abstract
Background Emerging drug resistance and hindrance of treatment is provoking scientists to search new, less expensive medicinally active compounds. Dental diseases caused by oral pathogens are very frequent chronic infections around the world. The medical potentials of a lot of Pakistani local herbs and herbal combinations is relatively unknown, hence attempted to explore. A study was designed to investigate potential role of local medicinal herbs for example Miswak, Kalonji & Aloe vera as antimicrobial, antioxidant and anti-proliferative agents against oral pathogens and cancer cell line. Methods Medicinal extracts were prepared in solvents of different polarities. Their antimicrobial activity was determined alone and in combination against oral pathogens. Antioxidant activity was evaluated through Catalase and Superoxide dismutase assay and anti-proliferative activity was evaluated through 3-(4, 5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide) assay. Results Plant extracts alone and in combinations were found significantly effective as antimicrobial agent against standard ATCC strains of C. albicans and S. aureus (P ˂0.001). Especially Miwak extract was found highly significant against fungus. Extracts of Kalonji were found significant in inhibiting growth of HeLa cell lines. Miswak and Kalonji showed significant levels of antioxidant activity. Conclusion Medicinal herbs Miswak and Kalonji have potential to be used for therapeutic purposes. Results suggested that herbal medicinal composition can be prepared using these extracts after applying scientific standardization methods.
Collapse
|
465
|
San-Juan R, Pérez-Montarelo D, Viedma E, Lalueza A, Fortún J, Loza E, Pujol M, Ardanuy C, Morales I, de Cueto M, Resino-Foz E, Morales-Cartagena MA, Fernández-Ruiz M, Rico A, Romero MP, Fernández de Mera M, López-Medrano F, Orellana MÁ, Aguado JM, Chaves F. Pathogen-related factors affecting outcome of catheter-related bacteremia due to methicillin-susceptible Staphylococcus aureus in a Spanish multicenter study. Eur J Clin Microbiol Infect Dis 2017; 36:1757-1765. [PMID: 28477236 DOI: 10.1007/s10096-017-2989-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 04/13/2017] [Indexed: 11/24/2022]
Abstract
Even with appropriate clinical management, complicated methicillin-susceptible Staphylococcus aureus (MSSA) catheter-related bacteremia (CRB) is frequent. We investigated the influence of molecular characteristics of MSSA strains on the risk of complicated bacteremia (CB) in MSSA-CRB. A multicenter prospective study was conducted in Spain between 2011 and 2014 on MSSA-CRB. Optimized protocol-guided clinical management was required. CB included endocarditis, septic thrombophlebitis, persistent bacteremia and/or end-organ hematogenous spread. Molecular typing, agr functionality and DNA microarray analysis of virulence factors were performed in all MSSA isolates. Out of 83 MSSA-CRB episodes included, 26 (31.3%) developed CB. MSSA isolates belonged to 16 clonal complexes (CCs), with CC30 (32.5%), CC5 (15.7%) and CC45 (13.3) being the most common. Comparison between MSSA isolates in episodes with or without CB revealed no differences regarding agr type and functionality. However, our results showed that CC15 and the presence of genes like cna, chp and cap8 were associated with the development of CB. The multivariate analysis highlighted that the presence of cna (Hazard ratio 2.9; 95% CI 1.14-7.6) was associated with the development of CB. Our results suggest that particular CCs and specific genes may influence the outcome of MSSA-CRB.
Collapse
Affiliation(s)
- R San-Juan
- Unit of Infectious Diseases, University Hospital 12 de Octubre, Instituto de Investigación Hospital "12 de Octubre" (i+12), Universidad Complutense, Avenida de Córsoba, s/n, 28041, Madrid, Spain.
| | - D Pérez-Montarelo
- Department of Microbiology, University Hospital 12 de Octubre, Instituto de Investigación Hospital "12 de Octubre" (i+12), Universidad Complutense, Madrid, Spain
| | - E Viedma
- Department of Microbiology, University Hospital 12 de Octubre, Instituto de Investigación Hospital "12 de Octubre" (i+12), Universidad Complutense, Madrid, Spain
| | - A Lalueza
- Unit of Infectious Diseases, University Hospital 12 de Octubre, Instituto de Investigación Hospital "12 de Octubre" (i+12), Universidad Complutense, Avenida de Córsoba, s/n, 28041, Madrid, Spain
| | - J Fortún
- Department of Infectious Diseases, University Hospital Ramón y Cajal, Madrid, Spain
| | - E Loza
- Department of Microbiology, University Hospital Ramón y Cajal, Madrid, Spain
| | - M Pujol
- Department of Infectious Diseases, University Hospital Bellvitge, Universidad de Barcelona-IDIBELL, Barcelona, Spain
| | - C Ardanuy
- Department of Microbiology, University Hospital Bellvitge, Universidad de Barcelona-IDIBELL, Barcelona, Spain
| | - I Morales
- Department of Infectious Diseases, University Hospital Virgen de la Macarena, Seville, Spain
| | - M de Cueto
- Department of Microbiology, University Hospital Virgen de la Macarena, Seville, Spain
| | - E Resino-Foz
- Unit of Infectious Diseases, University Hospital 12 de Octubre, Instituto de Investigación Hospital "12 de Octubre" (i+12), Universidad Complutense, Avenida de Córsoba, s/n, 28041, Madrid, Spain
| | - M A Morales-Cartagena
- Unit of Infectious Diseases, University Hospital 12 de Octubre, Instituto de Investigación Hospital "12 de Octubre" (i+12), Universidad Complutense, Avenida de Córsoba, s/n, 28041, Madrid, Spain
| | - M Fernández-Ruiz
- Unit of Infectious Diseases, University Hospital 12 de Octubre, Instituto de Investigación Hospital "12 de Octubre" (i+12), Universidad Complutense, Avenida de Córsoba, s/n, 28041, Madrid, Spain
| | - A Rico
- Unit of Infectious Diseases, University Hospital La Paz, Madrid, Spain
| | - M P Romero
- Department of Microbiology, University Hospital La Paz, Madrid, Spain
| | - M Fernández de Mera
- Department of Microbiology, University Hospital 12 de Octubre, Instituto de Investigación Hospital "12 de Octubre" (i+12), Universidad Complutense, Madrid, Spain
| | - F López-Medrano
- Unit of Infectious Diseases, University Hospital 12 de Octubre, Instituto de Investigación Hospital "12 de Octubre" (i+12), Universidad Complutense, Avenida de Córsoba, s/n, 28041, Madrid, Spain
| | - M Á Orellana
- Department of Microbiology, University Hospital 12 de Octubre, Instituto de Investigación Hospital "12 de Octubre" (i+12), Universidad Complutense, Madrid, Spain
| | - J M Aguado
- Unit of Infectious Diseases, University Hospital 12 de Octubre, Instituto de Investigación Hospital "12 de Octubre" (i+12), Universidad Complutense, Avenida de Córsoba, s/n, 28041, Madrid, Spain
| | - F Chaves
- Department of Microbiology, University Hospital 12 de Octubre, Instituto de Investigación Hospital "12 de Octubre" (i+12), Universidad Complutense, Madrid, Spain
| |
Collapse
|
466
|
Palraj BR, Farid S, Sohail MR. Strategies to prevent infections associated with cardiovascular implantable electronic devices. Expert Rev Med Devices 2017; 14:371-381. [PMID: 28434261 DOI: 10.1080/17434440.2017.1322506] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
INTRODUCTION Infections involving cardiovascular implantable electronic devices (CIED) are associated with high morbidity and mortality and substantial financial cost. In the past two decades, the rate of CIED infections has increased disproportionate to the number of devices implanted, likely due to aging patient population with multiple comorbidities. Microbial contamination of the generator pocket and or leads by skin flora at the time of implantation is a major mechanism for early CIED infections. Due to resistance to host immune cells and antibiotics caused by biofilm formation, complete removal of the device generator and leads is required to achieve cure. Areas covered: In this manuscript, we review the published literature regarding epidemiology, risk factors, and pathogenesis of CIED infections with primary focus on the preventative strategies to reduce the incidence of device infections. Expert commentary: Strict adherence to infection control measures at the time of CIED implantation is critical in reducing the risk of device infection while adjunctive strategies such as use of antimicrobial envelopes might help in certain high-risk individuals. Technological advances in device manufacturing with availability of subcutaneous devices without transvenous leads and self-contained intracardiac devices without leads and generator show promise with lower risk of infection.
Collapse
Affiliation(s)
- Bharath Raj Palraj
- a Divisions of Infectious Diseases, Department of Medicine , Mayo Clinic College of Medicine and Science , Rochester , MN , USA
| | - Saira Farid
- a Divisions of Infectious Diseases, Department of Medicine , Mayo Clinic College of Medicine and Science , Rochester , MN , USA
| | - M Rizwan Sohail
- a Divisions of Infectious Diseases, Department of Medicine , Mayo Clinic College of Medicine and Science , Rochester , MN , USA.,b Department of Cardiovascular Diseases , Mayo Clinic College of Medicine and Science , Rochester , MN , USA
| |
Collapse
|
467
|
Tonoyan L, Fleming GTA, Mc Cay PH, Friel R, O'Flaherty V. Antibacterial Potential of an Antimicrobial Agent Inspired by Peroxidase-Catalyzed Systems. Front Microbiol 2017; 8:680. [PMID: 28512449 PMCID: PMC5412088 DOI: 10.3389/fmicb.2017.00680] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 04/04/2017] [Indexed: 11/13/2022] Open
Abstract
Antibiotic resistance is an increasingly serious threat to global health. Consequently, the development of non-antibiotic based therapies and disinfectants, which avoid induction of resistance, or cross-resistance, is of high priority. We report the synthesis of a biocidal complex, which is produced by the reaction between ionic oxidizable salts-iodide and thiocyanate-in the presence of hydrogen peroxide as an oxidation source. The reaction generates bactericidal reactive oxygen and iodine species. In this study, we report that the iodo-thiocyanate complex (ITC) is an effective bactericidal agent with activity against planktonic and biofilm cells of Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus and methicillin-resistant S. aureus) bacteria. The minimum bactericidal concentrations and the minimum biofilm eradication concentrations of the biocidal composite were in the range of 7.8-31.3 and 31.3-250 μg ml-1, respectively. As a result, the complex was capable to cause a rapid cell death of planktonic test cultures at between 0.5 and 2 h, and complete eradication of dual and mono-species biofilms between 30 s and 10 min. Furthermore, the test bacteria, including a MRSA strain, exposed to the cocktail failed to develop resistance after serial passages. The antimicrobial activity of the ITC appears to derive from the combinational effect of the powerful species capable of oxidizing the essential biomolecules of bacteria. The use of this composition may provide an effective and efficient method for killing potential pathogens, as well as for disinfecting and removing biofilm contamination.
Collapse
Affiliation(s)
- Lilit Tonoyan
- Microbiology, School of Natural Sciences and Ryan Institute, National University of Ireland GalwayGalway, Ireland
| | - Gerard T. A. Fleming
- Microbiology, School of Natural Sciences and Ryan Institute, National University of Ireland GalwayGalway, Ireland
| | - Paul H. Mc Cay
- Microbiology, School of Natural Sciences and Ryan Institute, National University of Ireland GalwayGalway, Ireland
| | - Ruairi Friel
- Westway Health Ltd., Business Innovation Centre, National University of Ireland GalwayGalway, Ireland
| | - Vincent O'Flaherty
- Microbiology, School of Natural Sciences and Ryan Institute, National University of Ireland GalwayGalway, Ireland
| |
Collapse
|
468
|
Histones from Avian Erythrocytes Exhibit Antibiofilm activity against methicillin-sensitive and methicillin-resistant Staphylococcus aureus. Sci Rep 2017; 7:45980. [PMID: 28378802 PMCID: PMC5380990 DOI: 10.1038/srep45980] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 03/07/2017] [Indexed: 12/15/2022] Open
Abstract
Staphylococcus aureus, a human pathogen associated with many illnesses and post-surgical infections, can resist treatment due to the emergence of antibiotic-resistant strains and through biofilm formation. The current treatments for chronic biofilm infections are antibiotics and/or surgical removal of the contaminated medical device. Due to higher morbidity and mortality rates associated with overuse/misuse of antibiotics, alternate treatments are essential. This study reports the antibiofilm activity of avian erythrocyte histones against methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA). Fluorescence and scanning electron microscopy revealed membrane damage to bacteria in histone-treated biofilms. Histones and indolicidin (positive control) increased the expression of apsS and apsR, which are associated with the Antimicrobial Peptide (AMP) sensor/regulator system in S. aureus. The expression of dltB, and vraF, associated with AMP resistance mechanisms, were under histone inducible control in the biofilm-embedded bacterial cells. The time kill kinetics for histones against S. aureus revealed a rapid biocidal activity (<5 min). Purified erythrocyte-specific histone H5 possessed 3-4 fold enhanced antimicrobial activity against planktonic cells compared to the histone mixture (H1, H2A, H2B, H3, H4, H5). These results demonstrate the promise of histones and histone-like derivatives as novel antibiotics against pathogens in their planktonic and biofilm forms.
Collapse
|
469
|
Searching for new strategies against biofilm infections: Colistin-AMP combinations against Pseudomonas aeruginosa and Staphylococcus aureus single- and double-species biofilms. PLoS One 2017; 12:e0174654. [PMID: 28355248 PMCID: PMC5371341 DOI: 10.1371/journal.pone.0174654] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 03/13/2017] [Indexed: 12/13/2022] Open
Abstract
Antimicrobial research is being pressured to look for more effective therapeutics for the ever-growing antibiotic-resistant infections, and antimicrobial peptides (AMP) and antimicrobial combinations are promising solutions. This work evaluates colistin-AMP combinations against two major pathogens, Pseudomonas aeruginosa and Staphylococcus aureus, encompassing non- and resistant strains. Colistin (CST) combined with the AMP temporin A (TEMP-A), citropin 1.1 (CIT-1.1) and tachyplesin I linear analogue (TP-I-L) was tested against planktonic, single- and double-species biofilm cultures. Overall synergy for planktonic P. aeruginosa and synergy/additiveness for planktonic S. aureus were observed. Biofilm growth prevention was achieved with synergy and additiveness. Pre-established 24 h-old biofilms were harder to eradicate, especially for S. aureus and double-species biofilms; still, some synergy and addictiveness was observed for higher concentrations, including for the biofilms of resistant strains. Different treatment times and growth media did not greatly influence AMP activity. CST revealed low toxicity compared with the other AMP but its combinations were toxic for high concentrations. Overall, combinations reduced effective AMP concentrations, mainly in prevention scenarios. Improvement of effectiveness and toxicity of therapeutic strategies will be further investigated.
Collapse
|
470
|
Bacterial bloodstream infections in the allogeneic hematopoietic cell transplant patient: new considerations for a persistent nemesis. Bone Marrow Transplant 2017; 52:1091-1106. [PMID: 28346417 DOI: 10.1038/bmt.2017.14] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 12/20/2016] [Accepted: 01/12/2017] [Indexed: 12/14/2022]
Abstract
Bacterial bloodstream infections (BSI) cause significant transplant-related morbidity and mortality following allogeneic hematopoietic cell transplantation (allo-HCT). This manuscript reviews the risk factors for and the bacterial pathogens causing BSIs in allo-HCT recipients in the contemporary transplant period. In addition, it offers insight into emerging resistant pathogens and reviews clinical management considerations to treat and strategies to prevent BSIs in allo-HCT patients.
Collapse
|
471
|
Miao J, Liang Y, Chen L, Wang W, Wang J, Li B, Li L, Chen D, Xu Z. Formation and development ofStaphylococcusbiofilm: With focus on food safety. J Food Saf 2017. [DOI: 10.1111/jfs.12358] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Jian Miao
- School of Food Science and Engineering; South China University of Technology; Guangzhou China
| | - Yanrui Liang
- School of Food Science and Engineering; South China University of Technology; Guangzhou China
| | - Lequn Chen
- School of Food Science and Engineering; South China University of Technology; Guangzhou China
| | - Wenxin Wang
- School of Food Science and Engineering; South China University of Technology; Guangzhou China
| | - Jingwen Wang
- School of Food Science and Engineering; South China University of Technology; Guangzhou China
| | - Bing Li
- School of Food Science and Engineering; South China University of Technology; Guangzhou China
- Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety; Guangzhou China
| | - Lin Li
- School of Food Science and Engineering; South China University of Technology; Guangzhou China
- Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety; Guangzhou China
| | - Dingqiang Chen
- Department of Laboratory Medicine; First Affiliated Hospital of Guangzhou Medical University; Guangzhou China
| | - Zhenbo Xu
- School of Food Science and Engineering; South China University of Technology; Guangzhou China
- Department of Microbial Pathogenesis; University of Maryland; Baltimore
- Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety; Guangzhou China
| |
Collapse
|
472
|
Antibiotic tolerance and the alternative lifestyles of Staphylococcus aureus. Essays Biochem 2017; 61:71-79. [PMID: 28258231 DOI: 10.1042/ebc20160061] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 11/22/2016] [Accepted: 11/25/2016] [Indexed: 12/11/2022]
Abstract
Staphylococcus aureus has an incredible ability to survive, either by adapting to environmental conditions or defending against exogenous stress. Although there are certainly important genetic traits, in part this ability is provided by the breadth of modes of growth S. aureus can adopt. It has been proposed that while within their host, S. aureus survives host-generated and therapeutic antimicrobial stress via alternative lifestyles: a persister sub-population, through biofilm growth on host tissue or by growing as small colony variants (SCVs). Key to an understanding of chronic and relapsing S. aureus infections is determining the molecular basis for its switch to these quasi-dormant lifestyles. In a multicellular biofilm, the metabolically quiescent bacterial community additionally produces a highly protective extracellular polymeric substance (EPS). Furthermore, there are bacteria within a biofilm community that have an altered physiology potentially equivalent to persister cells. Recent studies have directly linked the cellular ATP production by persister cells as their key feature and the basis for their tolerance of a range of antibiotics. In clinical settings, SCVs of S. aureus have been observed for many years; when cultured, these cells form non-pigmented colonies and are approximately ten times smaller than their counterparts. Various genotypic factors have been identified in attempts to characterize S. aureus SCVs and different environmental stresses have been implicated as important inducers.
Collapse
|
473
|
Optimizing the treatment of osteomyelitis with antimicrobial drugs: current concepts. CURRENT ORTHOPAEDIC PRACTICE 2017. [DOI: 10.1097/bco.0000000000000477] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
474
|
dos Santos Rodrigues JB, de Carvalho RJ, de Souza NT, de Sousa Oliveira K, Franco OL, Schaffner D, de Souza EL, Magnani M. Effects of oregano essential oil and carvacrol on biofilms of Staphylococcus aureus from food-contact surfaces. Food Control 2017. [DOI: 10.1016/j.foodcont.2016.10.043] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
|
475
|
Balasubramanian S, Othman EM, Kampik D, Stopper H, Hentschel U, Ziebuhr W, Oelschlaeger TA, Abdelmohsen UR. Marine Sponge-Derived Streptomyces sp. SBT343 Extract Inhibits Staphylococcal Biofilm Formation. Front Microbiol 2017; 8:236. [PMID: 28261188 PMCID: PMC5311426 DOI: 10.3389/fmicb.2017.00236] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 02/03/2017] [Indexed: 01/22/2023] Open
Abstract
Staphylococcus epidermidis and Staphylococcus aureus are opportunistic pathogens that cause nosocomial and chronic biofilm-associated infections. Indwelling medical devices and contact lenses are ideal ecological niches for formation of staphylococcal biofilms. Bacteria within biofilms are known to display reduced susceptibilities to antimicrobials and are protected from the host immune system. High rates of acquired antibiotic resistances in staphylococci and other biofilm-forming bacteria further hamper treatment options and highlight the need for new anti-biofilm strategies. Here, we aimed to evaluate the potential of marine sponge-derived actinomycetes in inhibiting biofilm formation of several strains of S. epidermidis, S. aureus, and Pseudomonas aeruginosa. Results from in vitro biofilm-formation assays, as well as scanning electron and confocal microscopy, revealed that an organic extract derived from the marine sponge-associated bacterium Streptomyces sp. SBT343 significantly inhibited staphylococcal biofilm formation on polystyrene, glass and contact lens surfaces, without affecting bacterial growth. The extract also displayed similar antagonistic effects towards the biofilm formation of other S. epidermidis and S. aureus strains tested but had no inhibitory effects towards Pseudomonas biofilms. Interestingly the extract, at lower effective concentrations, did not exhibit cytotoxic effects on mouse fibroblast, macrophage and human corneal epithelial cell lines. Chemical analysis by High Resolution Fourier Transform Mass Spectrometry (HRMS) of the Streptomyces sp. SBT343 extract proportion revealed its chemical richness and complexity. Preliminary physico-chemical characterization of the extract highlighted the heat-stable and non-proteinaceous nature of the active component(s). The combined data suggest that the Streptomyces sp. SBT343 extract selectively inhibits staphylococcal biofilm formation without interfering with bacterial cell viability. Due to absence of cell toxicity, the extract might represent a good starting material to develop a future remedy to block staphylococcal biofilm formation on contact lenses and thereby to prevent intractable contact lens-mediated ocular infections.
Collapse
Affiliation(s)
| | - Eman M Othman
- Institute of Pharmacology and Toxicology, University of WürzburgWürzburg, Germany; Department of Analytical Chemistry, Faculty of Pharmacy, Minia UniversityMinia, Egypt
| | - Daniel Kampik
- Department of Ophthalmology, University Hospital Würzburg Würzburg, Germany
| | - Helga Stopper
- Institute of Pharmacology and Toxicology, University of Würzburg Würzburg, Germany
| | - Ute Hentschel
- GEOMAR Helmholtz Centre for Ocean Research, RD3 Marine Microbiology, and Christian-Albrechts University of Kiel Kiel, Germany
| | - Wilma Ziebuhr
- Institute for Molecular Infection Biology, University of Würzburg Würzburg, Germany
| | | | - Usama R Abdelmohsen
- Department of Botany II, Julius-von-Sachs Institute for Biological Sciences, University of WürzburgWürzburg, Germany; Department of Pharmacognosy, Faculty of Pharmacy, Minia UniversityMinia, Egypt
| |
Collapse
|
476
|
Effects of nutritional and ambient oxygen condition on biofilm formation in Mycobacterium avium subsp. hominissuis via altered glycolipid expression. Sci Rep 2017; 7:41775. [PMID: 28155911 PMCID: PMC5290538 DOI: 10.1038/srep41775] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 12/28/2016] [Indexed: 11/08/2022] Open
Abstract
Mycobacterium avium subsp. hominissuis (MAH) is the major causative agent of nontuberculous mycobacteriosis, the representative case of environment-related infectious diseases the incidence of which is increasing in industrialized countries. MAH is found in biofilm in drinking water distribution system and residential environments. We investigated the effect of gaseous and nutritional conditions, and the role of glycopeptidolipids (GPLs) on biofilm-like pellicle formation in MAH. Pellicle formation was observed under 5% oxygen in Middlebrook 7H9 broth containing 0.2% glycerol and 10% albumin-dextrose-catalase enrichment but not under normoxia or in nutrient-poor media. An analysis of 17 environmental isolates revealed that hypoxia (5% oxygen) preferentially enhanced pellicle formation both in plastic plates and in glass tubes, compared with hypercapnia (5% carbon dioxide). Wild-type strains (WT) developed much thicker pellicles than GPL-deficient rough mutants (RM). WT bacterial cells distributed randomly and individually in contrast to that RM cells positioned linearly in a definite order. Exogenous supplementation of GPLs thickened the pellicles of RM, resulting in a similar morphological pattern to WT. These data suggest a significant implication of eutrophication and hypoxia in biofilm-like pellicle formation, and a functional role of GPLs on development of pellicles in MAH.
Collapse
|
477
|
Van den Driessche F, Brackman G, Swimberghe R, Rigole P, Coenye T. Screening a repurposing library for potentiators of antibiotics against Staphylococcus aureus biofilms. Int J Antimicrob Agents 2017; 49:315-320. [PMID: 28159655 DOI: 10.1016/j.ijantimicag.2016.11.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 09/26/2016] [Accepted: 11/25/2016] [Indexed: 01/29/2023]
Abstract
Staphylococcus aureus biofilms are involved in a wide range of infections that are extremely difficult to treat with conventional antibiotic therapy. We aimed to identify potentiators of antibiotics against mature biofilms of S. aureus Mu50, a methicillin-resistant and vancomycin-intermediate-resistant strain. Over 700 off-patent drugs from a repurposing library were screened in combination with vancomycin in a microtitre plate (MTP)-based biofilm model system. This led to the identification of 25 hit compounds, including four phenothiazines among which thioridazine was the most potent. Their activity was evaluated in combination with other antibiotics both against planktonic and biofilm-grown S. aureus cells. The most promising combinations were subsequently tested in an in vitro chronic wound biofilm infection model. Although no synergistic activity was observed against planktonic cells, thioridazine potentiated the activity of tobramycin, linezolid and flucloxacillin against S. aureus biofilm cells. However, this effect was only observed in a general biofilm model and not in a chronic wound model of biofilm infection. Several drug compounds were identified that potentiated the activity of vancomycin against biofilms formed in a MTP-based biofilm model. A selected hit compound lost its potentiating activity in a model that mimics specific aspects of wound biofilms. This study provides a platform for discovering and evaluating potentiators against bacterial biofilms and highlights the necessity of using relevant in vitro biofilm model systems.
Collapse
Affiliation(s)
- Freija Van den Driessche
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ottergemsesteenweg 460, 9000 Gent, Belgium
| | - Gilles Brackman
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ottergemsesteenweg 460, 9000 Gent, Belgium
| | - Rosalie Swimberghe
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ottergemsesteenweg 460, 9000 Gent, Belgium
| | - Petra Rigole
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ottergemsesteenweg 460, 9000 Gent, Belgium
| | - Tom Coenye
- Laboratory of Pharmaceutical Microbiology, Ghent University, Ottergemsesteenweg 460, 9000 Gent, Belgium.
| |
Collapse
|
478
|
Gogoi-Tiwari J, Williams V, Waryah CB, Costantino P, Al-Salami H, Mathavan S, Wells K, Tiwari HK, Hegde N, Isloor S, Al-Sallami H, Mukkur T. Mammary Gland Pathology Subsequent to Acute Infection with Strong versus Weak Biofilm Forming Staphylococcus aureus Bovine Mastitis Isolates: A Pilot Study Using Non-Invasive Mouse Mastitis Model. PLoS One 2017; 12:e0170668. [PMID: 28129375 PMCID: PMC5271311 DOI: 10.1371/journal.pone.0170668] [Citation(s) in RCA: 25] [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: 09/07/2016] [Accepted: 01/09/2017] [Indexed: 12/30/2022] Open
Abstract
Background Biofilm formation by Staphylococcus aureus is an important virulence attribute because of its potential to induce persistent antibiotic resistance, retard phagocytosis and either attenuate or promote inflammation, depending upon the disease syndrome, in vivo. This study was undertaken to evaluate the potential significance of strength of biofilm formation by clinical bovine mastitis-associated S. aureus in mammary tissue damage by using a mouse mastitis model. Methods Two S. aureus strains of the same capsular phenotype with different biofilm forming strengths were used to non-invasively infect mammary glands of lactating mice. Biofilm forming potential of these strains were determined by tissue culture plate method, ica typing and virulence gene profile per detection by PCR. Delivery of the infectious dose of S. aureus was directly through the teat lactiferous duct without invasive scraping of the teat surface. Both bacteriological and histological methods were used for analysis of mammary gland pathology of mice post-infection. Results Histopathological analysis of the infected mammary glands revealed that mice inoculated with the strong biofilm forming S. aureus strain produced marked acute mastitic lesions, showing profuse infiltration predominantly with neutrophils, with evidence of necrosis in the affected mammary glands. In contrast, the damage was significantly less severe in mammary glands of mice infected with the weak biofilm-forming S. aureus strain. Although both IL-1β and TNF-α inflammatory biomarkers were produced in infected mice, level of TNF-α produced was significantly higher (p<0.05) in mice inoculated with strong biofilm forming S. aureus than the weak biofilm forming strain. Conclusion This finding suggests an important role of TNF-α in mammary gland pathology post-infection with strong biofilm-forming S. aureus in the acute mouse mastitis model, and offers an opportunity for the development of novel strategies for reduction of mammary tissue damage, with or without use of antimicrobials and/or anti-inflammatory compounds for the treatment of bovine mastitis.
Collapse
Affiliation(s)
- Jully Gogoi-Tiwari
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
- College of Veterinary Sciences and Animal Husbandry, Central Agricultural University, Selesih, Aizawl, Mizoram, India
| | - Vincent Williams
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
| | - Charlene Babra Waryah
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
- Department of Medicine and Cell Biology, Albert Einstein College of Medicine, Bronx, New York, United States of America
| | - Paul Costantino
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
| | - Hani Al-Salami
- School of Pharmacy, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
| | - Sangeetha Mathavan
- School of Pharmacy, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
| | - Kelsi Wells
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
| | - Harish Kumar Tiwari
- School of Veterinary and Life Sciences, Murdoch University, Perth, Western Australia, Australia
| | | | - Shrikrishna Isloor
- Veterinary College, Karnataka Veterinary, Animal and Fisheries Sciences University, Bangalore, India
| | | | - Trilochan Mukkur
- School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, Perth, Western Australia, Australia
- * E-mail:
| |
Collapse
|
479
|
Moreira CS, Silva ACJA, Novais JS, Sá Figueiredo AM, Ferreira VF, da Rocha DR, Castro HC. Searching for a potential antibacterial lead structure against bacterial biofilms among new naphthoquinone compounds. J Appl Microbiol 2017; 122:651-662. [PMID: 27930849 DOI: 10.1111/jam.13369] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 11/13/2016] [Accepted: 11/28/2016] [Indexed: 01/10/2023]
Abstract
AIMS The aims of this study were to design, synthesize and to evaluate 2-hydroxy-3-phenylsulfanylmethyl-[1,4]-naphthoquinones against Gram-negative and Gram-positive bacterial strains, including methicillin-resistant Staphylococcus aureus (MRSA) and its biofilm, to probe for potential lead structures. METHODS AND RESULTS Thirty-six new analogues were prepared with good yields using a simple, fast, operational three-procedure reaction and a thiol addition to an ο-quinone methide using microwave irradiation. All compounds were tested against Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Proteus mirabilis ATCC 15290, Serratia marcescens ATCC 14756, Klebsiella pneumoniae ATCC 4352, Enterobacter cloacae ATCC 23355, Enterococcus faecalis ATCC 29212, S. aureus ATCC 25923, Staphylococcus simulans ATCC 27851, Staphylococcus epidermidis ATCC 12228 and a hospital strain of MRSA. Their antibacterial activity was determined using the disc diffusion method, revealing the activity of 19 compounds, mainly against Gram-positive strains. Interestingly, the minimal inhibitory concentration ranges detected for the hit molecules (32-128 μg ml-1 ) were within Clinical and Laboratory Standards Institute levels. Promisingly, compound 15 affected the MRSA strain, with a reduction of up to 50% in biofilm formation, which is better than vancomycin as biofilm forms a barrier against the antibiotic that avoids its action. CONCLUSIONS After probing 36 naphthoquinones for a potential antibacterial lead structure against the bacterial biofilm, we found that compound 15 should be explored further and also should be structurally modified in the near future to test against Gram-negative strains. SIGNIFICANCE AND IMPACT OF THE STUDY Since vancomycin is one of the last treatment options currently available, and it is unable to inhibit biofilm, the research of new antimicrobials is urgent. In this context, 2-hydroxy-3-phenylsulfanylmethyl-[1,4]-naphthoquinones proved to be a promising lead structure against MRSA and bacterial biofilm.
Collapse
Affiliation(s)
- C S Moreira
- Organic Chemistry Department, Chemistry Institute, Federal Fluminense University, Niterói, Rio de Janeiro, Brazil
| | - A C J A Silva
- Molecular and Cell Biology Department, PPBI, Biology Institute, Federal Fluminense University, Niterói, Rio de Janeiro, Brazil
| | - J S Novais
- Molecular and Cell Biology Department, PPBI, Biology Institute, Federal Fluminense University, Niterói, Rio de Janeiro, Brazil
| | - A M Sá Figueiredo
- Department of Medical Microbiology, Institute of Microbiology Professor Paulo de Góes, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - V F Ferreira
- Organic Chemistry Department, Chemistry Institute, Federal Fluminense University, Niterói, Rio de Janeiro, Brazil
| | - D R da Rocha
- Organic Chemistry Department, Chemistry Institute, Federal Fluminense University, Niterói, Rio de Janeiro, Brazil
| | - H C Castro
- Molecular and Cell Biology Department, PPBI, Biology Institute, Federal Fluminense University, Niterói, Rio de Janeiro, Brazil
| |
Collapse
|
480
|
Dotto C, Lombarte Serrat A, Cattelan N, Barbagelata MS, Yantorno OM, Sordelli DO, Ehling-Schulz M, Grunert T, Buzzola FR. The Active Component of Aspirin, Salicylic Acid, Promotes Staphylococcus aureus Biofilm Formation in a PIA-dependent Manner. Front Microbiol 2017; 8:4. [PMID: 28167931 PMCID: PMC5253544 DOI: 10.3389/fmicb.2017.00004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Accepted: 01/03/2017] [Indexed: 01/10/2023] Open
Abstract
Aspirin has provided clear benefits to human health. But salicylic acid (SAL) -the main aspirin biometabolite- exerts several effects on eukaryote and prokaryote cells. SAL can affect, for instance, the expression of Staphylococcus aureus virulence factors. SAL can also form complexes with iron cations and it has been shown that different iron chelating molecules diminished the formation of S. aureus biofilm. The aim of this study was to elucidate whether the iron content limitation caused by SAL can modify the S. aureus metabolism and/or metabolic regulators thus changing the expression of the main polysaccharides involved in biofilm formation. The exposure of biofilm to 2 mM SAL induced a 27% reduction in the intracellular free Fe2+ concentration compared with the controls. In addition, SAL depleted 23% of the available free Fe2+ cation in culture media. These moderate iron-limited conditions promoted an intensification of biofilms formed by strain Newman and by S. aureus clinical isolates related to the USA300 and USA100 clones. The slight decrease in iron bioavailability generated by SAL was enough to induce the increase of PIA expression in biofilms formed by methicillin-resistant as well as methicillin-sensitive S. aureus strains. S. aureus did not produce capsular polysaccharide (CP) when it was forming biofilms under any of the experimental conditions tested. Furthermore, SAL diminished aconitase activity and stimulated the lactic fermentation pathway in bacteria forming biofilms. The polysaccharide composition of S. aureus biofilms was examined and FTIR spectroscopic analysis revealed a clear impact of SAL in a codY-dependent manner. Moreover, SAL negatively affected codY transcription in mature biofilms thus relieving the CodY repression of the ica operon. Treatment of mice with SAL induced a significant increase of S aureus colonization. It is suggested that the elevated PIA expression induced by SAL might be responsible for the high nasal colonization observed in mice. SAL-induced biofilms may contribute to S. aureus infection persistence in vegetarian individuals as well as in patients that frequently consume aspirin.
Collapse
Affiliation(s)
- Cristian Dotto
- Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, Instituto de Investigaciones en Microbiología y Parasitología Médica, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires Buenos Aires, Argentina
| | - Andrea Lombarte Serrat
- Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, Instituto de Investigaciones en Microbiología y Parasitología Médica, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires Buenos Aires, Argentina
| | - Natalia Cattelan
- Facultad de Ciencias Exactas, Centro de Investigación y Desarrollo de Fermentaciones Industriales (CINDEFI), Centro Científico Technológico Consejo Nacional de Investigaciones Científicas y Tócnicas (CTT CONICET La Plata), Universidad Nacional de La Plata La Plata, Argentina
| | - María S Barbagelata
- Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, Instituto de Investigaciones en Microbiología y Parasitología Médica, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires Buenos Aires, Argentina
| | - Osvaldo M Yantorno
- Facultad de Ciencias Exactas, Centro de Investigación y Desarrollo de Fermentaciones Industriales (CINDEFI), Centro Científico Technológico Consejo Nacional de Investigaciones Científicas y Tócnicas (CTT CONICET La Plata), Universidad Nacional de La Plata La Plata, Argentina
| | - Daniel O Sordelli
- Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, Instituto de Investigaciones en Microbiología y Parasitología Médica, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires Buenos Aires, Argentina
| | - Monika Ehling-Schulz
- Functional Microbiology, Institute for Microbiology, University of Veterinary Medicine Vienna, Austria
| | - Tom Grunert
- Functional Microbiology, Institute for Microbiology, University of Veterinary Medicine Vienna, Austria
| | - Fernanda R Buzzola
- Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, Instituto de Investigaciones en Microbiología y Parasitología Médica, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires Buenos Aires, Argentina
| |
Collapse
|
481
|
Abstract
Biofilm-associated bacteria are less sensitive to antibiotics than free-living (planktonic) cells. Furthermore, with variations in the concentration of antibiotics throughout a biofilm, microbial cells are often exposed to levels below inhibitory concentrations and may develop resistance. This, as well as the irresponsible use of antibiotics, leads to the selection of pathogens that are difficult to eradicate. The Centers for Disease Control and Prevention use the terms "antibiotic" and "antimicrobial agent" interchangeably. However, a clear distinction between these two terms is required for the purpose of this assessment. Therefore, we define "antibiotics" as pharmaceutically formulated and medically administered substances and "antimicrobials" as a broad category of substances which are not regulated as drugs. This comprehensive minireview evaluates the effect of natural antimicrobials on pathogens in biofilms when used instead of, or in combination with, commonly prescribed antibiotics.
Collapse
|
482
|
Van de Vyver H, Bovenkamp PR, Hoerr V, Schwegmann K, Tuchscherr L, Niemann S, Kursawe L, Grosse C, Moter A, Hansen U, Neugebauer U, Kuhlmann MT, Peters G, Hermann S, Löffler B. A Novel Mouse Model of Staphylococcus aureus Vascular Graft Infection: Noninvasive Imaging of Biofilm Development in Vivo. THE AMERICAN JOURNAL OF PATHOLOGY 2017; 187:268-279. [PMID: 28088288 DOI: 10.1016/j.ajpath.2016.10.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 09/20/2016] [Accepted: 10/04/2016] [Indexed: 10/20/2022]
Abstract
Staphylococcus aureus causes very serious infections of vascular grafts. Knowledge of the molecular mechanisms of this disease is largely lacking because of the absence of representable models. Therefore, the aim of this study was to set up a mouse model of vascular graft infections that closely mimics the human situation. A catheter was inserted into the right carotid artery of mice, which acted as a vascular graft. Mice were infected i.v. using 8 different S. aureus strains, and development of the infection was followed up. Although all strains had varying abilities to form biofilm in vitro and different levels of virulence in mice, they all caused biofilm formation on the grafts. This graft infection was monitored using magnetic resonance imaging (MRI) and 18F-fluordeoxyglucose positron emission tomography (FDG-PET). MRI allowed the quantification of blood flow through the arteries, which was decreased in the catheter after infection. FDG-PET revealed high inflammation levels at the site of the catheter after infection. This model closely resembles the situation in patients, which is characterized by a tight interplay between pathogen and host, and can therefore be used for the testing of novel treatment, diagnosis, and prevention strategies. In addition, combining MRI and PET with microscopic techniques provides an appropriate way to characterize the course of these infections and to precisely analyze biofilm development.
Collapse
Affiliation(s)
- Hélène Van de Vyver
- Institute of Medical Microbiology, University Hospital Muenster, Muenster, Germany.
| | - Philipp R Bovenkamp
- Department of Clinical Radiology, University Hospital Muenster, Muenster, Germany
| | - Verena Hoerr
- Department of Clinical Radiology, University Hospital Muenster, Muenster, Germany; Institute of Medical Microbiology, Jena University Hospital, Jena, Germany
| | - Katrin Schwegmann
- European Institute for Molecular Imaging, University Hospital Muenster, Muenster, Germany
| | - Lorena Tuchscherr
- Institute of Medical Microbiology, Jena University Hospital, Jena, Germany
| | - Silke Niemann
- Institute of Medical Microbiology, University Hospital Muenster, Muenster, Germany
| | - Laura Kursawe
- Biofilmcenter, German Heart Institute Berlin, Berlin, Germany
| | - Christina Grosse
- Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany; Leibniz Institute of Photonic Technology, Jena, Germany
| | - Annette Moter
- Biofilmcenter, German Heart Institute Berlin, Berlin, Germany
| | - Uwe Hansen
- Institute of Experimental Musculoskeletal Medicine, University Hospital Muenster, Muenster, Germany
| | - Ute Neugebauer
- Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany; Leibniz Institute of Photonic Technology, Jena, Germany; Institute of Physical Chemistry, University of Jena, Jena, Germany
| | - Michael T Kuhlmann
- European Institute for Molecular Imaging, University Hospital Muenster, Muenster, Germany
| | - Georg Peters
- Institute of Medical Microbiology, University Hospital Muenster, Muenster, Germany; Cells-in-Motion Cluster of Excellence (EXC 1003 - CiM), University of Münster, Münster, Germany
| | - Sven Hermann
- European Institute for Molecular Imaging, University Hospital Muenster, Muenster, Germany
| | - Bettina Löffler
- Institute of Medical Microbiology, Jena University Hospital, Jena, Germany
| |
Collapse
|
483
|
Shrestha L, Kayama S, Sasaki M, Kato F, Hisatsune J, Tsuruda K, Koizumi K, Tatsukawa N, Yu L, Takeda K, Sugai M. Inhibitory effects of antibiofilm compound 1 against Staphylococcus aureus biofilms. Microbiol Immunol 2017; 60:148-59. [PMID: 26786482 DOI: 10.1111/1348-0421.12359] [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: 11/19/2015] [Revised: 01/04/2016] [Accepted: 01/12/2016] [Indexed: 01/01/2023]
Abstract
A novel benzimidazole molecule that was identified in a small-molecule screen and is known as antibiofilm compound 1 (ABC-1) has been found to prevent bacterial biofilm formation by multiple bacterial pathogens, including Staphylococcus aureus, without affecting bacterial growth. Here, the biofilm inhibiting ability of 156 μM ABC-1 was tested in various biofilm-forming strains of S. aureus. It was demonstrated that ABC-1 inhibits biofilm formation by these strains at micromolar concentrations regardless of the strains' dependence on Polysaccharide Intercellular Adhesin (PIA), cell wall-associated protein dependent or cell wall- associated extracellular DNA (eDNA). Of note, ABC-1 treatment primarily inhibited Protein A (SpA) expression in all strains tested. spa gene disruption showed decreased biofilm formation; however, the mutants still produced more biofilm than ABC-1 treated strains, implying that ABC-1 affects not only SpA but also other factors. Indeed, ABC-1 also attenuated the accumulation of PIA and eDNA on cell surface. Our results suggest that ABC-1 has pleotropic effects on several biofilm components and thus inhibits biofilm formation by S. aureus.
Collapse
Affiliation(s)
- Looniva Shrestha
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical Sciences
| | - Shizuo Kayama
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical Sciences.,Project Research Center for Nosocomial Infectious Disease, Hiroshima University
| | - Michiko Sasaki
- Department of Synthetic Organic Chemistry, Hiroshima University Graduate School of Biomedical Sciences, 1-2-3 Kasumi Minami-ku Hiroshima 734-8551, Japan
| | - Fuminori Kato
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical Sciences.,Project Research Center for Nosocomial Infectious Disease, Hiroshima University
| | - Junzo Hisatsune
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical Sciences.,Project Research Center for Nosocomial Infectious Disease, Hiroshima University
| | - Keiko Tsuruda
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical Sciences
| | - Kazuhisa Koizumi
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical Sciences.,Project Research Center for Nosocomial Infectious Disease, Hiroshima University
| | - Nobuyuki Tatsukawa
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical Sciences
| | - Liansheng Yu
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical Sciences
| | - Kei Takeda
- Department of Synthetic Organic Chemistry, Hiroshima University Graduate School of Biomedical Sciences, 1-2-3 Kasumi Minami-ku Hiroshima 734-8551, Japan
| | - Motoyuki Sugai
- Department of Bacteriology, Hiroshima University Graduate School of Biomedical Sciences.,Project Research Center for Nosocomial Infectious Disease, Hiroshima University
| |
Collapse
|
484
|
Singh AK, Prakash P, Achra A, Singh GP, Das A, Singh RK. Standardization and Classification of In vitro Biofilm Formation by Clinical Isolates of Staphylococcus aureus. J Glob Infect Dis 2017; 9:93-101. [PMID: 28878520 PMCID: PMC5572203 DOI: 10.4103/jgid.jgid_91_16] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Staphylococcus aureus is Gram-positive bacterium commonly associated with nosocomial infections. The development of biofilm exhibiting drug resistance especially in foreign body associated infections has enabled the bacterium to draw considerable attention. However, till date, consensus guidelines for in vitro biofilm quantitation and categorization criterion for the bacterial isolates based on biofilm-forming capacity are lacking. Therefore, it was intended to standardize in vitro biofilm formation by clinical isolates of S. aureus and then to classify them on the basis of their biofilm-forming capacity. MATERIALS AND METHODS A study was conducted for biofilm quantitation by tissue culture plate (TCP) assay employing 61 strains of S. aureus isolated from clinical samples during May 2015- December 2015 wherein several factors influencing the biofilm formation were optimized. Therefore, it was intended to propose a biofilm classification criteria based on the standard deviation multiples of the control differentiating them into non, low, medium, and high biofilm formers. RESULTS Brain-heart infusion broth was found to be more effective in biofilm formation compared to trypticase soy broth. Heat fixation was more effective than chemical fixation. Although, individually, glucose, sucrose, and sodium chloride (NaCl) had no significant effect on biofilm formation, a statistically significant increase in absorbance was observed after using the supplement mix consisting of 222.2 mM glucose, 116.9 mM sucrose, and 1000 mM NaCl (P= 0.037). CONCLUSIONS The present study puts forth a standardized in vitro TCP assay for biofilm biomass quantitation and categorization criteria for clinical isolates of S. aureus based on their biofilm-forming capacity. The proposed in vitro technique may be further evaluated for its usefulness in the management of persistent infections caused by the bacterium.
Collapse
Affiliation(s)
- Ashish Kumar Singh
- Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Pradyot Prakash
- Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Arvind Achra
- Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Gyan Prakash Singh
- Department of Community Medicine, Division of Biostatistics, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Arghya Das
- Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Rakesh Kumar Singh
- Department of Biochemistry, Institute of Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| |
Collapse
|
485
|
Doulgeraki AI, Di Ciccio P, Ianieri A, Nychas GJE. Methicillin-resistant food-related Staphylococcus aureus: a review of current knowledge and biofilm formation for future studies and applications. Res Microbiol 2017; 168:1-15. [DOI: 10.1016/j.resmic.2016.08.001] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 07/18/2016] [Accepted: 08/05/2016] [Indexed: 12/18/2022]
|
486
|
The ω Subunit Governs RNA Polymerase Stability and Transcriptional Specificity in Staphylococcus aureus. J Bacteriol 2016; 199:JB.00459-16. [PMID: 27799328 DOI: 10.1128/jb.00459-16] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 10/26/2016] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus is a major human pathogen that causes infection in a wide variety of sites within the human body. Its ability to adapt to the human host and to produce a successful infection requires precise orchestration of gene expression. While DNA-dependent RNA polymerase (RNAP) is generally well characterized, the roles of several small accessory subunits within the complex have yet to be fully explored. This is particularly true for the omega (ω or RpoZ) subunit, which has been extensively studied in Gram-negative bacteria but largely neglected in Gram-positive counterparts. In Escherichia coli, it has been shown that ppGpp binding, and thus control of the stringent response, is facilitated by ω. Interestingly, key residues that facilitate ppGpp binding by ω are not conserved in S. aureus, and consequently, survival under starvation conditions is unaffected by rpoZ deletion. Further to this, ω-lacking strains of S. aureus display structural changes in the RNAP complex, which result from increased degradation and misfolding of the β' subunit, alterations in δ and σ factor abundance, and a general dissociation of RNAP in the absence of ω. Through RNA sequencing analysis we detected a variety of transcriptional changes in the rpoZ-deficient strain, presumably as a response to the negative effects of ω depletion on the transcription machinery. These transcriptional changes translated to an impaired ability of the rpoZ mutant to resist stress and to fully form a biofilm. Collectively, our data underline, for the first time, the importance of ω for RNAP stability, function, and cellular physiology in S. aureus IMPORTANCE: In order for bacteria to adjust to changing environments, such as within the host, the transcriptional process must be tightly controlled. Transcription is carried out by DNA-dependent RNA polymerase (RNAP). In addition to its major subunits (α2ββ') a fifth, smaller subunit, ω, is present in all forms of life. Although this small subunit is well studied in eukaryotes and Gram-negative bacteria, only limited information is available for Gram-positive and pathogenic species. In this study, we investigated the structural and functional importance of ω, revealing key roles in subunit folding/stability, complex assembly, and maintenance of transcriptional integrity. Collectively, our data underline, for the first time, the importance of ω for RNAP function and cellular harmony in S. aureus.
Collapse
|
487
|
Nair S, Desai S, Poonacha N, Vipra A, Sharma U. Antibiofilm Activity and Synergistic Inhibition of Staphylococcus aureus Biofilms by Bactericidal Protein P128 in Combination with Antibiotics. Antimicrob Agents Chemother 2016; 60:7280-7289. [PMID: 27671070 PMCID: PMC5119008 DOI: 10.1128/aac.01118-16] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 09/18/2016] [Indexed: 12/29/2022] Open
Abstract
P128 is an antistaphylococcal protein, comprising a cell wall-degrading enzymatic region and a Staphylococcus-specific binding region, which possesses specific and potent bactericidal activity against sensitive and drug-resistant strains of Staphylococcus aureus To explore P128's ability to kill S. aureus in a range of environments relevant to clinical infection, we investigated the anti-S. aureus activity of P128 alone and in combination with standard-of-care antibiotics on planktonic and biofilm-embedded cells. P128 was found to have potent antibiofilm activity on preformed S. aureus biofilms as detected by CFU reduction and a colorimetric minimum biofilm inhibitory concentration (MBIC) assay. Scanning electron microscopic images of biofilms formed on the surfaces of microtiter plates and on catheters showed that P128 at low concentrations could destroy the biofilm structure and lyse the cells. When it was tested in combination with antibiotics which are known to be poor inhibitors of S. aureus in biofilms, such as vancomycin, gentamicin, ciprofloxacin, linezolid, and daptomycin, P128 showed highly synergistic antibiofilm activity that resulted in much reduced MBIC values for P128 and the individual antibiotics. The synergistic effect was seen for both sensitive and resistant isolates of S. aureus Additionally, in an in vitro mixed-biofilm model mimicking the wound infection environment, P128 was able to prevent biofilm formation by virtue of its anti-Staphylococcus activity. The potent S. aureus biofilm-inhibiting activity of P128 both alone and in combination with antibiotics is an encouraging sign for the development of P128 for treatment of complicated S. aureus infections involving biofilms.
Collapse
Affiliation(s)
- Sandhya Nair
- GangaGen Biotechnologies Pvt. Ltd., Yeshwantpur, Bangalore, India
| | - Srividya Desai
- GangaGen Biotechnologies Pvt. Ltd., Yeshwantpur, Bangalore, India
| | | | - Aradhana Vipra
- GangaGen Biotechnologies Pvt. Ltd., Yeshwantpur, Bangalore, India
| | - Umender Sharma
- GangaGen Biotechnologies Pvt. Ltd., Yeshwantpur, Bangalore, India
| |
Collapse
|
488
|
Detection of Biofilm Production Capability and icaA/D Genes Among Staphylococci Isolates from Shiraz, Iran. Jundishapur J Microbiol 2016. [DOI: 10.5812/jjm.41431] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
489
|
Brandwein M, Steinberg D, Meshner S. Microbial biofilms and the human skin microbiome. NPJ Biofilms Microbiomes 2016; 2:3. [PMID: 28649397 PMCID: PMC5460139 DOI: 10.1038/s41522-016-0004-z] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 07/22/2016] [Accepted: 08/08/2016] [Indexed: 12/14/2022] Open
Abstract
The human skin microbiome plays an important role in both health and disease. Microbial biofilms are a well-characterized mode of surface-associated growth, which present community-like behaviors. Additionally, biofilms are a critical element in certain skin diseases. We review how the perception of the resident skin microbiota has evolved from the early linkages of certain microbes to disease states, to a more comprehensive and intricate understanding brought on by biofilm and microbiome revelations. Rapidly expanding arsenals of experimental methods are opening new horizons in the study of human-microbe and microbe-microbe interactions. Microbial community profiling has largely remained a separate discipline from that of biofilm research, yet the introduction of metatranscriptomics, metabolomics, and the ability to distinguish between dormant and active members of a community have all paved the road toward a convergent cognizance of the encounter between these two microbial disciplines.
Collapse
Affiliation(s)
- Michael Brandwein
- Faculty of Dental Medicine, The Hebrew University of Jerusalem, Hadassah Ein Kerem, Jerusalem, Israel
- Dead Sea and Arava Science Center, The Dead Sea Microbiology lab, Ein Gedi, Israel
| | - Doron Steinberg
- Faculty of Dental Medicine, The Hebrew University of Jerusalem, Hadassah Ein Kerem, Jerusalem, Israel
| | - Shiri Meshner
- Dead Sea and Arava Science Center, The Dead Sea Microbiology lab, Ein Gedi, Israel
| |
Collapse
|
490
|
Comparative evaluation of aggressiveness traits in staphylococcal strains from severe infections versus nasopharyngeal carriage. Microb Pathog 2016; 102:45-53. [PMID: 27856272 DOI: 10.1016/j.micpath.2016.11.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Revised: 11/08/2016] [Accepted: 11/08/2016] [Indexed: 01/09/2023]
Abstract
Despite their commensal status, staphylococci can become problematic pathogens expressing multiple and redundant virulence factors. This study aimed to evaluate aggressiveness markers comparatively in staphylococcal strains isolated from severe infections versus asymptomatic carriage in order to identify clinically relevant bacterial traits that could easily be detected in clinical practice and could be suggestive for particular host-pathogen interactions such as cyto-adhesion or biofilm formation, ultimately orienting the clinical decision-making process. We have used in vitro phenotypic methods to assess adhesion to and invasion of eukaryotic cells, biofilm development, and expression of soluble virulence factors in 92 Staphylococcus spp. strains. The adhesion index, invasion capacity, biofilm formation and expression of soluble factors did not differ significantly between clinical and commensal strains. The major bacterial traits we found to be significantly more prevalent in clinical staphylococci were the aggregative adhesion pattern (P = 0.012), cluster adhesion (P = 0.001) and tetrad morphology (P = 0.018). The aggregative adhesion pattern was correlated with higher cyto-adhesion (P < 0.001), higher invasion capacity (P = 0.003) and lower Carmeli scores (P = 0.002). Three major bacterial traits, namely tetrad morphology, aggregative adhesion pattern, and resistance to methicillin (acronym: TAM), can be used to compute an aggressiveness score (SAS) predictive of the staphylococcal strain's virulence and capacity to initiate and develop a biofilm-driven chronic infectious process versus a fulminant acute infection, in a susceptible host.
Collapse
|
491
|
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
|
492
|
Clinical Significance and Pathogenesis of Staphylococcal Small Colony Variants in Persistent Infections. Clin Microbiol Rev 2016; 29:401-27. [PMID: 26960941 DOI: 10.1128/cmr.00069-15] [Citation(s) in RCA: 212] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Small colony variants (SCVs) were first described more than 100 years ago for Staphylococcus aureus and various coagulase-negative staphylococci. Two decades ago, an association between chronic staphylococcal infections and the presence of SCVs was observed. Since then, many clinical studies and observations have been published which tie recurrent, persistent staphylococcal infections, including device-associated infections, bone and tissue infections, and airway infections of cystic fibrosis patients, to this special phenotype. By their intracellular lifestyle, SCVs exhibit so-called phenotypic (or functional) resistance beyond the classical resistance mechanisms, and they can often be retrieved from therapy-refractory courses of infection. In this review, the various clinical infections where SCVs can be expected and isolated, diagnostic procedures for optimized species confirmation, and the pathogenesis of SCVs, including defined underlying molecular mechanisms and the phenotype switch phenomenon, are presented. Moreover, relevant animal models and suggested treatment regimens, as well as the requirements for future research areas, are highlighted.
Collapse
|
493
|
Iyamba JML, Okombe DT, Zakanda FN, Malongo TK, Unya JW, Lukukula CM, Kikuni NZBT. Adherence of staphylococcus aureus to catheter tubing inhibition by quaternary ammonium compounds. Pan Afr Med J 2016; 25:50. [PMID: 28250874 PMCID: PMC5321151 DOI: 10.11604/pamj.2016.25.50.8134] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 07/26/2016] [Indexed: 01/09/2023] Open
Abstract
INTRODUCTION S. aureus is a Gram positive bacterium which is responsible for a wide range of infections. This pathogen has also the ability to adhere to biotic or abiotic surface such as central venous catheter (CVC) and to produce a biofilm. The aim of this study was to evaluate the effect of hexadecyltrimethyl ammonium bromide (HTAB) and Hexadecylbetainate chloride (HBC) on Staphylococcus aureus adherence to the catheter tubing and on bacteria growth. METHODS Broth microdilution method was used to determine the Minimal Inhibitory Concentration (MIC). The detection of slime production was done by Congo Red Agar method, and the adherence of bacteria to the catheter tubing was evaluated by the enumeration of bacteria on plate counts. RESULTS The results of this study showed that the MICs of HTAB were ranged from 0.125 to 0.5 µg/mL, and those of HBC fluctuated between 2 to 8 µg/mL. HTAB and HBC inhibited bacteria adhesion on the surface of the catheter tubing. CONCLUSION This study showed that HTAB and HBC can prevent the adherence of S. aureus strains to the surface of catheter tubing, suggesting that they could be used to prevent the risk of catheter related bloodstream infections.
Collapse
Affiliation(s)
- Jean-Marie Liesse Iyamba
- Laboratory of Experimental and Pharmaceutical Microbiology, Faculty of Pharmaceutical Sciences, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Daniel Tassa Okombe
- Laboratory of Experimental and Pharmaceutical Microbiology, Faculty of Pharmaceutical Sciences, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Francis Nsimba Zakanda
- Laboratory of Biochemistry, Faculty of Medicine, University of Kinshasa, Democratic Republic of Congo
| | - Trésor Kimbeni Malongo
- Laboratory of Instrumental and Bioelectrochemical analysis, Faculty of Pharmaceutical Sciences, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Joseph Welo Unya
- Laboratory of Experimental and Pharmaceutical Microbiology, Faculty of Pharmaceutical Sciences, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Cyprien Mbundu Lukukula
- Laboratory of Experimental and Pharmaceutical Microbiology, Faculty of Pharmaceutical Sciences, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Ntondo Za Balega Takaisi Kikuni
- Laboratory of Experimental and Pharmaceutical Microbiology, Faculty of Pharmaceutical Sciences, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| |
Collapse
|
494
|
Niska K, Knap N, Kędzia A, Jaskiewicz M, Kamysz W, Inkielewicz-Stepniak I. Capping Agent-Dependent Toxicity and Antimicrobial Activity of Silver Nanoparticles: An In Vitro Study. Concerns about Potential Application in Dental Practice. Int J Med Sci 2016; 13:772-782. [PMID: 27766027 PMCID: PMC5069413 DOI: 10.7150/ijms.16011] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 07/27/2016] [Indexed: 11/21/2022] Open
Abstract
Objectives: In dentistry, silver nanoparticles (AgNPs) have drawn particular attention because of their wide antimicrobial activity spectrum. However, controversial information on AgNPs toxicity limited their use in oral infections. Therefore, the aim of the present study was to evaluate the antibacterial activities against a panel of oral pathogenic bacteria and bacterial biofilms together with potential cytotoxic effects on human gingival fibroblasts of 10 nm AgNPs: non-functionalized - uncapped (AgNPs-UC) as well as surface-functionalized with capping agent: lipoic acid (AgNPs-LA), polyethylene glycol (AgNPs-PEG) or tannic acid (AgNPs-TA) using silver nitrate (AgNO3) as control. Methods: The interaction of AgNPs with human gingival fibroblast cells (HGF-1) was evaluated using the mitochondrial metabolic potential assay (MTT). Antimicrobial activity of AgNPs was tested against anaerobic Gram-positive and Gram-negative bacteria isolated from patients with oral cavity and respiratory tract infections, and selected aerobic Staphylococci strains. Minimal inhibitory concentration (MIC) values were determined by the agar dilution method for anaerobic bacteria or broth microdilution method for reference Staphylococci strains and Streptococcus mutans. These strains were also used for antibiofilm activity of AgNPs. Results: The highest antimicrobial activities at nontoxic concentrations were observed for the uncapped AgNPs and the AgNPs capped with LA. It was found that AgNPs-LA and AgNPs-PEG demonstrated lower cytotoxicity as compared with the AgNPs-TA or AgNPs-UC in the gingival fibroblast model. All of the tested nanoparticles proved less toxic and demonstrated wider spectrum of antimicrobial activities than AgNO3 solution. Additionally, AgNPs-LA eradicated Staphylococcus epidermidis and Streptococcus mutans 1-day biofilm at concentration nontoxic to oral cells. Conclusions: Our results proved that a capping agent had significant influence on the antibacterial, antibiofilm activity and cytotoxicity of AgNPs. Clinical significance: This study highlighted potential usefulness of AgNPs against oral anaerobic Gram-positive and Gram-negative bacterial infections and aerobic Staphylococci strains provided that pharmacological activity and risk assessment are carefully performed.
Collapse
Affiliation(s)
- Karolina Niska
- Department of Medical Chemistry, Medical University Gdansk, Poland
| | - Narcyz Knap
- Department of Medical Chemistry, Medical University Gdansk, Poland
| | - Anna Kędzia
- Department of Oral Microbiology, Medical University Gdansk, Poland
| | - Maciej Jaskiewicz
- Department of Inorganic Chemistry, Medical University Gdansk, Poland
| | - Wojciech Kamysz
- Department of Inorganic Chemistry, Medical University Gdansk, Poland
| | | |
Collapse
|
495
|
Modulation of Staphylococcus aureus Biofilm Matrix by Subinhibitory Concentrations of Clindamycin. Antimicrob Agents Chemother 2016; 60:5957-67. [PMID: 27458233 DOI: 10.1128/aac.00463-16] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 07/13/2016] [Indexed: 12/31/2022] Open
Abstract
Staphylococcus aureus biofilms are extremely difficult to treat. They provide a protected niche for the bacteria, rendering them highly recalcitrant toward host defenses as well as antibiotic treatment. Bacteria within a biofilm are shielded from the immune system by the formation of an extracellular polymeric matrix, composed of polysaccharides, extracellular DNA (eDNA), and proteins. Many antibiotics do not readily penetrate biofilms, resulting in the presence of subinhibitory concentrations of antibiotics. Here, we show that subinhibitory concentrations of clindamycin triggered a transcriptional stress response in S. aureus via the alternative sigma factor B (σ(B)) and upregulated the expression of the major biofilm-associated genes atlA, lrgA, agrA, the psm genes, fnbA, and fnbB Our data suggest that subinhibitory concentrations of clindamycin alter the ability of S. aureus to form biofilms and shift the composition of the biofilm matrix toward higher eDNA content. An understanding of the molecular mechanisms underlying biofilm assembly and dispersal in response to subinhibitory concentrations of clinically relevant antibiotics such as clindamycin is critical to further optimize antibiotic treatment strategies of biofilm-associated S. aureus infections.
Collapse
|
496
|
Streptokinase Treatment Reverses Biofilm-Associated Antibiotic Resistance in Staphylococcus aureus. Microorganisms 2016; 4:microorganisms4030036. [PMID: 27681928 PMCID: PMC5039596 DOI: 10.3390/microorganisms4030036] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Revised: 09/07/2016] [Accepted: 09/14/2016] [Indexed: 11/24/2022] Open
Abstract
Biofilms formed by Staphylococcus aureus is a serious complication to the use of medical implants. A central part of the pathogenesis relies on S. aureus’ ability to adhere to host extracellular matrix proteins, which adsorb to medical implants and stimulate biofilm formation. Being coagulase positive, S. aureus furthermore induces formation of fibrin fibers from fibrinogen in the blood. Consequently, we hypothesized that fibrin is a key component of the extracellular matrix of S. aureus biofilms under in vivo conditions, and that the recalcitrance of biofilm infections can be overcome by combining antibiotic treatment with a fibrinolytic drug. We quantified S. aureus USA300 biofilms grown on peg-lids in brain heart infusion (BHI) broth with 0%–50% human plasma. Young (2 h) and mature (24 h) biofilms were then treated with streptokinase to determine if this lead to dispersal. Then, the minimal biofilm eradication concentration (MBEC) of 24 h old biofilms was measured for vancomycin and daptomycin alone or in combination with 10 µg/mL rifampicin in the presence or absence of streptokinase in the antibiotic treatment step. Finally, biofilms were visualized by confocal laser scanning microscopy. Addition of human plasma stimulated biofilm formation in BHI in a dose-dependent manner, and biofilms could be partially dispersed by streptokinase. The biofilms could be eradicated with physiologically relevant concentrations of streptokinase in combination with rifampicin and vancomycin or daptomycin, which are commonly used antibiotics for treatment of S. aureus infections. Fibronolytic drugs have been used to treat thromboembolic events for decades, and our findings suggest that their use against biofilm infections has the potential to improve the efficacy of antibiotics in treatment of S. aureus biofilm infections.
Collapse
|
497
|
Combining in vitro protein detection and in vivo antibody detection identifies potential vaccine targets against Staphylococcus aureus during osteomyelitis. Med Microbiol Immunol 2016; 206:11-22. [PMID: 27629411 PMCID: PMC5263195 DOI: 10.1007/s00430-016-0476-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 09/03/2016] [Indexed: 12/31/2022]
Abstract
Currently, little is known about the in vivo human immune response against Staphylococcus aureus during a biofilm-associated infection, such as osteomyelitis, and how this relates to protein production in biofilms in vitro. Therefore, we characterized IgG responses in 10 patients with chronic osteomyelitis against 50 proteins of S. aureus, analyzed the presence of these proteins in biofilms of the infecting isolates on polystyrene (PS) and human bone in vitro, and explored the relation between in vivo and in vitro data. IgG levels against 15 different proteins were significantly increased in patients compared to healthy controls. Using a novel competitive Luminex-based assay, eight of these proteins [alpha toxin, Staphylococcus aureus formyl peptide receptor-like 1 inhibitor (FlipR), glucosaminidase, iron-responsive surface determinants A and H, the putative ABC transporter SACOL0688, staphylococcal complement inhibitor (SCIN), and serine-aspartate repeat-containing protein E (SdrE)] were also detected in a majority of the infecting isolates during biofilm formation in vitro. However, 4 other proteins were detected in only a minority of isolates in vitro while, vice versa, 7 proteins were detected in multiple isolates in vitro but not associated with significantly increased IgG levels in patients. Detection of proteins was largely confirmed using a transcriptomic approach. Our data provide further insights into potential therapeutic targets, such as for vaccination, to reduce S. aureus virulence and biofilm formation. At the same time, our data suggest that either in vitro or immunological in vivo data alone should be interpreted cautiously and that combined studies are necessary to identify potential targets.
Collapse
|
498
|
Gándara L, Mamone L, Dotto C, Buzzola F, Casas A. Sae regulator factor impairs the response to photodynamic inactivation mediated by Toluidine blue in Staphylococcus aureus. Photodiagnosis Photodyn Ther 2016; 16:136-141. [PMID: 27619533 DOI: 10.1016/j.pdpdt.2016.09.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Revised: 09/06/2016] [Accepted: 09/08/2016] [Indexed: 10/21/2022]
Abstract
Photodynamic inactivation (PDI) involves the combined use of light and a photosensitizer, which, in the presence of oxygen, originates cytotoxic species capable of inactivating bacteria. Since the emergence of multi-resistant bacterial strains is becoming an increasing public health concern, PDI becomes an attractive choice. The aim of this work was to study the differential susceptibility to Toluidine blue (TB) mediated PDI (TB-PDI) of S. aureus mutants (RN6390 and Newman backgrounds) for different key regulators of virulence factors related to some extent to oxidative stress. Complete bacteria eradication of planktonic cultures of RN6390 S. aureus photosensitized with 13μM TB was obtained upon illumination with a low light dose of 4.2J/cm2 from a non-coherent light source. Similarly, complete cell death was achieved applying 1.3μM TB and 19J/cm2 light dose, showing that higher light doses can lead to equal cell death employing low photosensitizer concentrations. Interestingly, RN6390 in planktonic culture responded significantly better to TB-PDI than the Newman strain. We showed that deficiencies in rsbU, mgrA (transcription factors related to stress response) or agr (quorum sensing system involved in copper resistance to oxidative stress) did not modify the response of planktonic S. aureus to PDI. On the other hand, the two component system sae impaired the response to TB-PDI through a mechanism not related to the Eap adhesin. More severe conditions were needed to inactivate S. aureus biofilms (0.5mM TB, 157J/cm2 laser light). In mutant sae biofilms, strain dependant differential susceptibilities are not noticed.
Collapse
Affiliation(s)
- Lautaro Gándara
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, University of Buenos Aires, Córdoba 2351 1er subsuelo, Ciudad de Buenos Aires, CP1120AAF, Argentina
| | - Leandro Mamone
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, University of Buenos Aires, Córdoba 2351 1er subsuelo, Ciudad de Buenos Aires, CP1120AAF, Argentina
| | - Cristian Dotto
- Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM), CONICET-UBA, Argentina
| | - Fernanda Buzzola
- Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM), CONICET-UBA, Argentina
| | - Adriana Casas
- Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP), CONICET and Hospital de Clínicas José de San Martín, University of Buenos Aires, Córdoba 2351 1er subsuelo, Ciudad de Buenos Aires, CP1120AAF, Argentina.
| |
Collapse
|
499
|
Sarkar P, Acharyya S, Banerjee A, Patra A, Thankamani K, Koley H, Bag PK. Intracellular, biofilm-inhibitory and membrane-damaging activities of nimbolide isolated from Azadirachta indica A. Juss (Meliaceae) against meticillin-resistant Staphylococcus aureus. J Med Microbiol 2016; 65:1205-1214. [PMID: 27553840 DOI: 10.1099/jmm.0.000343] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Staphylococcus aureus is a leading aetiologic agent of nosocomial- and community-acquired infectious diseases worldwide. The public health concern regarding staphylococcal infections is inflated by the increasing occurrence of multidrug-resistant strains, e.g. multidrug- and meticillin-resistant S.aureus (MDR MRSA). This study was designed to evaluate the intracellular killing, membrane-damaging and biofilm-inhibitory activities of nimbolide isolated from Azadirachta indica against MDR MRSA. In vitro antibacterial activity of nimbolide was determined by performing MIC, minimal bactericidal concentration (MBC) and time-kill kinetic studies. Bacterial membrane-damaging activity was determined by membrane perturbation and scanning electron microscopy (SEM) examination. Biofilm-inhibitory activities were determined by SEM. Cellular drug accumulation and assessments of intracellular activities were performed using Vero cell culture. SEM revealed that nimbolide caused significant membrane damage and lysis of the S. aureus cells. The biofilm structure was disrupted, and the biofilm formation was greatly reduced in the presence of nimbolide as examined by SEM. The level of accumulation of nimbolide in Vero cells incubated for 24 h is relatively higher than that of ciprofloxacin and nalidixic acid (Cc/Ce for nimbolide > ciprofloxacin and nalidixic acid). The viable number of intracellular S. aureus was decreased [reduction of ~2 log10 c.f.u. (mg Vero cell protein)-1] in a time-dependent manner in the presence of nimbolide (4× MBC) that was comparable to that of tetracycline and nalidixic acid. The significant intracellular, biofilm-inhibitory and bacterial membrane-damaging activities of nimbolide demonstrated here suggested that it has potential as an effective antibacterial agent for the treatment of severe infections caused by MDR MRSA.
Collapse
Affiliation(s)
- Prodipta Sarkar
- Department of Biochemistry, University of Calcutta, 35 Ballygunge, Circular Road, Kolkata 700019, India
| | - Saurabh Acharyya
- Department of Biochemistry, University of Calcutta, 35 Ballygunge, Circular Road, Kolkata 700019, India
| | - Anirban Banerjee
- Department of Biochemistry, University of Calcutta, 35 Ballygunge, Circular Road, Kolkata 700019, India
| | - Amarendra Patra
- Department of Chemistry, University of Calcutta, 92 Acharya Prafulla Chandra Road, Kolkata 700009, India
| | - Karthika Thankamani
- Department of Biochemistry, University of Calcutta, 35 Ballygunge, Circular Road, Kolkata 700019, India
| | - Hemanta Koley
- National Institute of Cholera and Enteric Diseases, P-33 C.I.T. Road, Scheme-XM, Beliaghata, Kolkata 700010, India
| | - Prasanta K Bag
- Department of Biochemistry, University of Calcutta, 35 Ballygunge, Circular Road, Kolkata 700019, India
| |
Collapse
|
500
|
Meeker DG, Chen J, Smeltzer MS. Could targeted, antibiotic-loaded gold nanoconstructs be a new magic bullet to fight infection? Nanomedicine (Lond) 2016; 11:2379-82. [PMID: 27529572 DOI: 10.2217/nnm-2016-0260] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Daniel G Meeker
- Department of Microbiology & Immunology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Jingyi Chen
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA
| | - Mark S Smeltzer
- Department of Microbiology & Immunology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| |
Collapse
|