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Barker E, Shepherd J, Asencio IO. The Use of Cerium Compounds as Antimicrobials for Biomedical Applications. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27092678. [PMID: 35566026 PMCID: PMC9104093 DOI: 10.3390/molecules27092678] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 04/01/2022] [Accepted: 04/14/2022] [Indexed: 12/05/2022]
Abstract
Cerium and its derivatives have been used as remedies for wounds since the early 20th century. Cerium nitrate has attracted most attention in the treatment of deep burns, followed later by reports of its antimicrobial properties. Its ability to mimic and replace calcium is presumed to be a major mechanism of its beneficial action. However, despite some encouraging results, the overall data are somewhat confusing with seemingly the same compounds yielding opposing results. Despite this, cerium nitrate is currently used in wound treatment in combination with silver sulfadiazine as Flammacérium. Cerium oxide, especially in nanoparticle form (Nanoceria), has lately captured much interest due to its antibacterial properties mediated via oxidative stress, leading to an increase of published reports. The properties of Nanoceria depend on the synthesis method, their shape and size. Recently, the green synthesis route has gained a lot of interest as an alternative environmentally friendly method, resulting in production of effective antimicrobial and antifungal nanoparticles. Unfortunately, as is the case with antibiotics, emerging bacterial resistance against cerium-derived nanoparticles is a growing concern, especially in the case of bacterial biofilm. However, diverse strategies resulting from better understanding of the biology of cerium are promising. The aim of this paper is to present the progress to date in the use of cerium compounds as antimicrobials in clinical applications (in particular wound healing) and to provide an overview of the mechanisms of action of cerium at both the cellular and molecular level.
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Di Domenico EG, De Angelis B, Cavallo I, Sivori F, Orlandi F, Fernandes Lopes Morais D’Autilio M, Di Segni C, Gentile P, Scioli MG, Orlandi A, D’Agosto G, Trento E, Kovacs D, Cardinali G, Stefanile A, Koudriavtseva T, Prignano G, Pimpinelli F, Lesnoni La Parola I, Toma L, Cervelli V, Ensoli F. Silver Sulfadiazine Eradicates Antibiotic-Tolerant Staphylococcus aureus and Pseudomonas aeruginosa Biofilms in Patients with Infected Diabetic Foot Ulcers. J Clin Med 2020; 9:jcm9123807. [PMID: 33255545 PMCID: PMC7760944 DOI: 10.3390/jcm9123807] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 10/23/2020] [Accepted: 11/23/2020] [Indexed: 12/19/2022] Open
Abstract
Infections are among the most frequent and challenging events in diabetic foot ulcers (DFUs). Pathogenic bacteria growing in biofilms within host tissue are highly tolerant to environmental and chemical agents, including antibiotics. The present study was aimed at assessing the use of silver sulfadiazine (SSD) for wound healing and infection control in 16 patients with DFUs harboring biofilm-growing Staphylococcus aureus and Pseudomonas aeruginosa. All patients received a treatment based on a dressing protocol including disinfection, cleansing, application of SSD, and application of nonadherent gauze, followed by sterile gauze and tibio-breech bandage, in preparation for toilet surgery after 30 days of treatment. Clinical parameters were analyzed by the T.I.M.E. classification system. In addition, the activity of SSD against biofilm-growing S. aureus and P. aeruginosa isolates was assessed in vitro. A total of 16 patients with S. aureus and P. aeruginosa infected DFUs were included in the study. Clinical data showed a statistically significant (p < 0.002) improvement of patients’ DFUs after 30 days of treatment with SSD with significant amelioration of all the parameters analyzed. Notably, after 30 days of treatment, resolution of infection was observed in all DFUs. In vitro analysis showed that both S. aureus and P. aeruginosa isolates developed complex and highly structured biofilms. Antibiotic susceptibility profiles indicated that biofilm cultures were significantly (p ≤ 0.002) more tolerant to all tested antimicrobials than their planktonic counterparts. However, SSD was found to be effective against fully developed biofilms of both S. aureus and P. aeruginosa at concentrations below those normally used in clinical preparations (10 mg/mL). These results strongly suggest that the topical administration of SSD may represent an effective alternative to conventional antibiotics for the successful treatment of DFUs infected by biofilm-growing S. aureus and P. aeruginosa.
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Affiliation(s)
- Enea Gino Di Domenico
- Microbiology and Virology, San Gallicano Dermatological Institute IRCCS, 00144 Rome, Italy; (I.C.); (F.S.); (G.D.); (E.T.); (G.P.); (F.P.); (F.E.)
- Correspondence: ; Tel.: +39-06-5266-5564
| | - Barbara De Angelis
- Department of Plastic and Reconstructive Surgery, University of Rome Tor Vergata, 00144 Rome, Italy; (B.D.A.); (F.O.); (M.F.L.M.D.); (C.D.S.); (P.G.); (V.C.)
| | - Ilaria Cavallo
- Microbiology and Virology, San Gallicano Dermatological Institute IRCCS, 00144 Rome, Italy; (I.C.); (F.S.); (G.D.); (E.T.); (G.P.); (F.P.); (F.E.)
| | - Francesca Sivori
- Microbiology and Virology, San Gallicano Dermatological Institute IRCCS, 00144 Rome, Italy; (I.C.); (F.S.); (G.D.); (E.T.); (G.P.); (F.P.); (F.E.)
| | - Fabrizio Orlandi
- Department of Plastic and Reconstructive Surgery, University of Rome Tor Vergata, 00144 Rome, Italy; (B.D.A.); (F.O.); (M.F.L.M.D.); (C.D.S.); (P.G.); (V.C.)
| | | | - Chiara Di Segni
- Department of Plastic and Reconstructive Surgery, University of Rome Tor Vergata, 00144 Rome, Italy; (B.D.A.); (F.O.); (M.F.L.M.D.); (C.D.S.); (P.G.); (V.C.)
| | - Pietro Gentile
- Department of Plastic and Reconstructive Surgery, University of Rome Tor Vergata, 00144 Rome, Italy; (B.D.A.); (F.O.); (M.F.L.M.D.); (C.D.S.); (P.G.); (V.C.)
| | - Maria Giovanna Scioli
- Department of Anatomic Pathology, University of Rome Tor Vergata, 00144 Rome, Italy; (M.G.S.); (A.O.)
| | - Augusto Orlandi
- Department of Anatomic Pathology, University of Rome Tor Vergata, 00144 Rome, Italy; (M.G.S.); (A.O.)
| | - Giovanna D’Agosto
- Microbiology and Virology, San Gallicano Dermatological Institute IRCCS, 00144 Rome, Italy; (I.C.); (F.S.); (G.D.); (E.T.); (G.P.); (F.P.); (F.E.)
| | - Elisabetta Trento
- Microbiology and Virology, San Gallicano Dermatological Institute IRCCS, 00144 Rome, Italy; (I.C.); (F.S.); (G.D.); (E.T.); (G.P.); (F.P.); (F.E.)
| | - Daniela Kovacs
- Cutaneous Physiopathology, San Gallicano Dermatological Institute, IRCCS, 00144 Rome, Italy; (D.K.); (G.C.)
| | - Giorgia Cardinali
- Cutaneous Physiopathology, San Gallicano Dermatological Institute, IRCCS, 00144 Rome, Italy; (D.K.); (G.C.)
| | - Annunziata Stefanile
- Department of Clinical Experimental Oncology, IRCCS Regina Elena National Cancer Institute, 00144 Rome, Italy; (A.S.); (T.K.)
| | - Tatiana Koudriavtseva
- Department of Clinical Experimental Oncology, IRCCS Regina Elena National Cancer Institute, 00144 Rome, Italy; (A.S.); (T.K.)
| | - Grazia Prignano
- Microbiology and Virology, San Gallicano Dermatological Institute IRCCS, 00144 Rome, Italy; (I.C.); (F.S.); (G.D.); (E.T.); (G.P.); (F.P.); (F.E.)
| | - Fulvia Pimpinelli
- Microbiology and Virology, San Gallicano Dermatological Institute IRCCS, 00144 Rome, Italy; (I.C.); (F.S.); (G.D.); (E.T.); (G.P.); (F.P.); (F.E.)
| | - Ilaria Lesnoni La Parola
- Lichen Sclerosus Unit, Department of Dermatology, STI, Environmental Health, Tropical and Immigration, San Gallicano Dermatological Institute, IRCCS, 00144 Rome, Italy;
| | - Luigi Toma
- Department of Research, Advanced Diagnostics, and Technological Innovation, Translational Research Area, IRCCS Regina Elena National Cancer Institute, 00144 Rome, Italy;
| | - Valerio Cervelli
- Department of Plastic and Reconstructive Surgery, University of Rome Tor Vergata, 00144 Rome, Italy; (B.D.A.); (F.O.); (M.F.L.M.D.); (C.D.S.); (P.G.); (V.C.)
| | - Fabrizio Ensoli
- Microbiology and Virology, San Gallicano Dermatological Institute IRCCS, 00144 Rome, Italy; (I.C.); (F.S.); (G.D.); (E.T.); (G.P.); (F.P.); (F.E.)
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Moyano AJ, Mas CR, Colque CA, Smania AM. Dealing with biofilms of Pseudomonas aeruginosa and Staphylococcus aureus: In vitro evaluation of a novel aerosol formulation of silver sulfadiazine. Burns 2019; 46:128-135. [PMID: 31420266 DOI: 10.1016/j.burns.2019.07.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Revised: 06/11/2019] [Accepted: 07/18/2019] [Indexed: 12/17/2022]
Abstract
The risk of infection of skin and soft tissue chronic wounds by gram-negative and gram-positive pathogens growing in biofilms is a major health-care concern. In this study we test a formulation of silver sulfadiazine, vitamin A and lidocaine (AF-SSD) for aerosol administration against biofilms of Pseudomonas aeruginosa and biofilms of methicillin-resistant (MRSA) and methicillin-sensitive (MSSA) strains of Staphylococcus aureus. The aerosol allows the administration of AF-SSD without the direct contact with the wound and avoids contamination of the product after reiterative usage. We evaluated in vitro the anti-biofilm activity of AF-SSD by carrying out different technical approaches such as resazurin assays to measure metabolic activity/viability, crystal violet staining assays to determine biofilm biomass, counting of CFUs and live/dead staining for confocal microscopy analysis. AF-SSD clearly affected biofilm viability, biomass and structure, in the three bacterial strains tested. AF-SSD displayed a strong anti-biofilm effect, showing total bactericidal activity on biofilms of P. aeruginosa at a 400-fold dilution of the product, and after a 100-fold and 10-fold dilution for MRSA and MSSA, respectively. Considering the benefits of aerosol administration, our results support this kind of formulation as a potential improvement over conventional treatments with silver sulfadiazine.
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Affiliation(s)
- Alejandro J Moyano
- Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Departamento de Química Biológica Ranwel Caputto, Córdoba, Argentina; CONICET, Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), Córdoba, Argentina.
| | - Carlos R Mas
- Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Departamento de Química Biológica Ranwel Caputto, Córdoba, Argentina; CONICET, Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), Córdoba, Argentina
| | - Claudia A Colque
- Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Departamento de Química Biológica Ranwel Caputto, Córdoba, Argentina; CONICET, Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), Córdoba, Argentina
| | - Andrea M Smania
- Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Departamento de Química Biológica Ranwel Caputto, Córdoba, Argentina; CONICET, Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), Córdoba, Argentina.
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Vitse J, Tchero H, Meaume S, Dompmartin A, Malloizel-Delaunay J, Géri C, Faure C, Herlin C, Teot L. Silver Sulfadiazine and Cerium Nitrate in Ischemic Skin Necrosis of the Leg and Foot: Results of a Prospective Randomized Controlled Study. INT J LOW EXTR WOUND 2019; 17:151-160. [PMID: 30222081 DOI: 10.1177/1534734618795534] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Flammacerium is a topical treatment composed of silver sulfadiazine and cerium nitrate initially used in burns. The objective was to assess the effectiveness of silver sulfadiazine and cerium nitrate on ischemic necrosis wounds of the lower limb as an alternative to amputation for a period of 12 weeks. Patients were prospectively randomized to receive silver sulfadiazine and cerium nitrate or standard care. Patients included adults with an ischemic wound of the lower limb, with necrosis covering over at least 50%. Critical ischemia limb was confirmed by an ankle-brachial index <0.7 or >1.3 with radiological confirmation. Patient demographic data, amputations procedures, wound area, Visual Analogue Scale pain rating, clinical infection, and adverse events were recorded. Fifty patients, 34 males and 16 females, were recruited between January 2010 and April 2014, 25 in each group. The mean age was 75.14 years (±11.64). Nine amputations (36%) occurred in each group. Amputation-free survival was superior in the active treatment group versus the standard group (169 393 days, 95% confidence interval = 134.926-203.861, vs 169 393 days, 95% confidence interval = 134.926-203.861). It was not statistically significant (log-rank, P = .958). Wound area reduction between both groups was not statistically different ( P = .651). Less adverse events of the lower limb occurred in the active treatment group ( P = .001). Our study showed that silver sulfadiazine and cerium nitrate is not inferior to standardized care on ischemic necrotic wounds of the lower extremity. Further studies are still needed to confirm its effectiveness.
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Affiliation(s)
- Julian Vitse
- 1 Montpellier University Hospital, Montpellier, France
| | | | | | | | | | - Chloé Géri
- 1 Montpellier University Hospital, Montpellier, France
| | | | | | - Luc Teot
- 1 Montpellier University Hospital, Montpellier, France
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Silva-Dias A, Miranda IM, Branco J, Cobrado L, Monteiro-Soares M, Pina-Vaz C, Rodrigues AG. In vitro antifungal activity and in vivo antibiofilm activity of cerium nitrate against Candida species. J Antimicrob Chemother 2015; 70:1083-93. [PMID: 25558078 DOI: 10.1093/jac/dku511] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
OBJECTIVES The objective of this study was to clarify the antifungal properties of cerium, a lanthanide member, against Candida species. A comprehensive study with planktonic and sessile cells was performed. The ability of cerium nitrate (CN) to impair in vitro and in vivo biofilm formation was evaluated and its potential use in biofilm treatment was also evaluated. METHODS Forty-eight clinical isolates of different Candida species and the type strain ATCC 90028 were tested according to the protocol M27-A3. The MICs and minimum lethal concentrations were determined. A time-kill assay was performed and a cytometric kinetic study was performed using live/dead markers. Biofilm inhibition and biofilm susceptibility in the presence of cerium was evaluated by quantification of the biofilm metabolic activity and total biomass with XTT and crystal violet assays, respectively. CN in vivo efficacy as a coating for medical indwelling devices was evaluated for the first time for Candida parapsilosis, using a mouse subcutaneous foreign body model using polyurethane catheter segments. Scanning electron microscopy was used to assess biofilm architecture after CN treatment. RESULTS The MICs for planktonic cells correlated with severe cellular metabolic activity impairment and membrane damage after 3 h of incubation. Moreover, CN efficiently prevented biofilm formation both in vitro and in vivo in segments of polyurethane catheters. At higher concentrations, it was also able to disorganize and almost eradicate preformed biofilms. CONCLUSIONS Our results strongly suggest that CN application in the clinical setting might be effective in preventing the formation of biofilm-associated infections, namely through catheter coating and ultimately as an antimicrobial lock therapy.
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Affiliation(s)
- Ana Silva-Dias
- Department of Microbiology, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal Cardiovascular Research & Development Unit, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal CINTESIS, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
| | - Isabel M Miranda
- Department of Microbiology, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal Cardiovascular Research & Development Unit, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal CINTESIS, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
| | - Joana Branco
- Department of Microbiology, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
| | - Luís Cobrado
- Department of Microbiology, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal Cardiovascular Research & Development Unit, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal CINTESIS, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal Burn Unit and Department of Plastic and Reconstructive Surgery, Centro Hospitalar S. João, 4200-319 Porto, Portugal
| | - Matilde Monteiro-Soares
- CIDES, Department of Information and Decision Sciences in Health, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
| | - Cidália Pina-Vaz
- Department of Microbiology, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal Cardiovascular Research & Development Unit, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal CINTESIS, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal Department of Microbiology, Centro Hospitalar S. João, 4200-319 Porto, Portugal
| | - Acácio G Rodrigues
- Department of Microbiology, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal Cardiovascular Research & Development Unit, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal CINTESIS, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal Burn Unit and Department of Plastic and Reconstructive Surgery, Centro Hospitalar S. João, 4200-319 Porto, Portugal
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Li S, Qu Y, Hu D, Shi YX. Comparison of extended spectrum β-lactamases-producing Escherichia coli with non-ESBLs-producing E.coli: drug-resistance and virulence. World J Emerg Med 2014; 3:208-12. [PMID: 25215065 DOI: 10.5847/wjem.j.issn.1920-8642.2012.03.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2012] [Accepted: 07/28/2012] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND The virulent factors of Escherichia coli (E.coli) play an important role in the process of pathopoiesis. The study aimed to compare drug-resistant genes and virulence genes between extended spectrum β-lactamases (ESBLs)-producing E.coli and non-ESBLs-producing E.coli to provide a reference for physicians in management of hospital infection. METHODS From October 2010 to August 2011, 96 drug-resistant strains of E.coli isolated were collected from the specimens in Qingdao Municipal Hospital, Qingdao, China. These bacteria strains were divided into a ESBLs-producing group and a non-ESBLs-producing group. Drug sensitivity tests were performed using the Kirby-Bauer (K-B) method. Disinfectant gene, qacEΔ1-sull and 8 virulence genes (CNF2, hlyA, eaeA, VT1, est, bfpA, elt, and CNF1) were tested by polymerase chain reaction (PCR). RESULTS Among the 96 E.coli isolates, the ESBLs-producing E.coli comprised 46 (47.9%) strains and the non-ESBLs-producing E.coli consisted of 50 (52.1%) strains. The detection rates of multiple drug-resistant strain, qacEΔ1-sull, CNF2, hlyA, eaeA,VT1, est, bfpA, elt, and CNF1 in 46 ESBLs-producing E.coli isolates were 89.1%, 76.1%, 6.5%, 69.6%, 69.6%, 89.1%, 10.9%, 26.1%, 8.7%, and 19.6%, respectively. In the non-ESBLs-producing E.coli strains, the positive rates of multiple drug-resistant strain, qacEΔ1-sull, CNF2, hlyA, eaeA, VT1, est, bfpA, elt, and CNF1 were 62.0%, 80.0%, 16.0%, 28.0%, 64.0%, 38.0%, 6.0%, 34.0%, 10.0%, and 24.0%, respectively. The difference in the detection rates of multiple drug-resistant strain, hlyA and VT1 between the ESBLs-producing E.coli strains and the non-ESBLs-producing E.coli strains was statistically significant (P<0.05). CONCLUSION The positive rate of multiple drug-resistant strains is higher in the ESBLs-producing strains than in the non-ESBLs-producing strains. The expression of some virulence genes hlyA and VT1 varies between the ESBLs-producing strains and the non-ESBLs-producing strains. Increased awareness of clinicians and enhanced testing by laboratories are required to reduce treatment failures and prevent the spread of multiple drug-resistant strains.
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Affiliation(s)
- Sha Li
- Department of Nursing, Qingdao University Medical College, Qingdao 266021, China
| | - Yan Qu
- ICU, Qingdao Municipal Hospital, Qingdao 266071, China
| | - Dan Hu
- ICU, Qingdao Municipal Hospital, Qingdao 266071, China
| | - Yong-Xin Shi
- Department of Clinical Laboratory, Qingdao Municipal Hospital, Qingdao 266071, China
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Hajská M, Slobodníková L, Hupková H, Koller J. In vitro efficacy of various topical antimicrobial agents in different time periods from contamination to application against 6 multidrug-resistant bacterial strains isolated from burn patients. Burns 2014; 40:713-8. [DOI: 10.1016/j.burns.2013.09.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 09/02/2013] [Accepted: 09/03/2013] [Indexed: 11/26/2022]
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Gnanasundaram S, Ranganathan M, Das BN, Mandal AB. Surface modified and medicated polyurethane materials capable of controlling microorganisms causing foot skin infection in athletes. Colloids Surf B Biointerfaces 2013; 102:139-45. [DOI: 10.1016/j.colsurfb.2012.07.024] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 07/17/2012] [Indexed: 11/27/2022]
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Glasser JS, Guymon CH, Mende K, Wolf SE, Hospenthal DR, Murray CK. Activity of topical antimicrobial agents against multidrug-resistant bacteria recovered from burn patients. Burns 2010; 36:1172-84. [PMID: 20542641 DOI: 10.1016/j.burns.2010.05.013] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Revised: 05/10/2010] [Accepted: 05/11/2010] [Indexed: 01/22/2023]
Abstract
BACKGROUND Topical antimicrobials are employed for prophylaxis and treatment of burn wound infections despite no established susceptibility breakpoints, which are becoming vital in an era of multidrug-resistant (MDR) bacteria. We compared two methods of determining topical antimicrobial susceptibilities. METHODS Isolates of Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus (MRSA), extended spectrum beta-lactamase (ESBL) producing Klebsiella pneumoniae, and Acinetobacter baumanii-calcoaceticus (ABC) from burn patients were tested using broth microdilution and agar well diffusion to determine minimum inhibitory concentrations (MICs) and zones of inhibition (ZI). Isolates had systemic antibiotic resistance and clonality determined. MDR included resistance to antibiotics in three or more classes. RESULTS We assessed 22 ESBL-producing K. pneumoniae, 20 ABC (75% MDR), 20 P. aeruginosa (45% MDR), and 20 MRSA isolates. The most active agents were mupirocin for MRSA and mafenide acetate for the gram-negatives with moderate MICs/ZI found with silver sulfadiazene, silver nitrate, and honey. MDR and non-MDR isolates had similar topical resistance. There was no clonality associated with resistance patterns. CONCLUSION Despite several methods to test bacteria for topical susceptibility, no defined breakpoints exist and standards need to be established. We recommend continuing to use silver products for prophylaxis against gram-negatives and mafenide acetate for treatment, and mupirocin for MRSA.
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Perkas N, Amirian G, Applerot G, Efendiev E, Kaganovskii Y, Ghule AV, Chen BJ, Ling YC, Gedanken A. Depositing silver nanoparticles on/in a glass slide by the sonochemical method. NANOTECHNOLOGY 2008; 19:435604. [PMID: 21832700 DOI: 10.1088/0957-4484/19/43/435604] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A glass substrate was coated with silver by ultrasound irradiation. The structure and morphology of the nanoparticles in the deposited film were characterized using methods such as XRD, TEM, HR TEM, HRSEM, AFM, TOF-SIMS and optical spectroscopy. It was demonstrated that nucleation and the ensuing growth of the nanoparticles occurs in solution and is influenced by the concentration of the precursor, temperature and time of sonication. TOF-SIMS measurements revealed that silver nanoparticles passed through the glass interface and diffused within the glass substrate up to ∼60 nm. An analysis of the thermal effects accompanying the sonochemical cavitation of micro-bubbles in the solution near the solid surfaces shows that the collision of nanoparticles can lead to their melting and coalescence. Sonochemical deposition takes place layer by layer, so that the completion of the deposition of each layer of nanoparticles is followed by the sintering of adjacent particles and the formation of a close-packed layer. Using PVP as a stabilizing agent, a monolayer coating of silver nanoparticles on the glass surface was obtained. The coated glass demonstrated antibacterial activity.
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Affiliation(s)
- Nina Perkas
- Department of Chemistry, Kanbar Laboratory for Nanomaterials, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel
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Ertam I, Biyikli SEY, Yazkan FA, Aytimur D, Alper S. The frequency of nasal carriage in chronic urticaria patients. J Eur Acad Dermatol Venereol 2007; 21:777-80. [PMID: 17567307 DOI: 10.1111/j.1468-3083.2006.02083.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
OBJECTIVE Chronic urticaria is characterized by oedema of the skin and mucous membranes. Although many agents have been implicated, aetiology is unknown in 70 to 75% of patients. Infections and foci of chronic infections are most commonly held responsible for chronic urticaria. In this study, the frequency of nasal carriage as the occult focus of infection and sensitivity to antimicrobials are explored in patients with chronic urticaria. MATERIAL AND METHOD Ninety-four patients with chronic urticaria and 30 controls participated in the study, which was carried out at the Ege university medical faculty, department of dermatology between January 2004 and January 2005. Nasal swab specimens were taken from the patients and controls and incubated at 37 degrees C degrees for 48 h, and inoculated on standard bacterial medium (blood agar). Antimicrobial susceptibility of a growth from isolates of the nasal swab specimens was conducted. Data were analysed statistically using chi-square and Mann-Whitney U-tests. RESULTS Ninety-four patients with chronic urticaria (72.3% female and 27.7% male) and 30 controls (63.3% female and 36.7% male) comprised the study group. Mean age of the patients and controls were 42.6 and 33.8 years, respectively. Staphylococcus aureus was detected in swab specimens from the nasal cavity in 50 of the 94 patients (53.2%) with chronic urticaria and four of the 30 controls (13.3%). Testing revealed that the most susceptible antibiotics were cefaclor, ceftriaxone, amoxycillin-clavulanic acid, amikacin, netilmicin, and fucidic acid. CONCLUSION Growth on cultures prepared from nasal swab specimens of chronic urticaria patients was statistically higher than the control group. We detected resistance to growth against mupirocin, an antibiotic frequently used in nasal carriage. High nasal carriage of Staphylococcus aureus in patients with chronic urticaria compared to controls suggests that nasal carriage as a focus of infection should be kept in mind as aetiology.
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Affiliation(s)
- I Ertam
- Ege University Medical Faculty, Department of Dermatology, Bornova-Izmir, Turkey.
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Ochsner UA, Young CL, Stone KC, Dean FB, Janjic N, Critchley IA. Mode of action and biochemical characterization of REP8839, a novel inhibitor of methionyl-tRNA synthetase. Antimicrob Agents Chemother 2006; 49:4253-62. [PMID: 16189106 PMCID: PMC1251548 DOI: 10.1128/aac.49.10.4253-4262.2005] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Aminoacyl-tRNA synthetases have attracted interest as essential and novel targets involved in bacterial protein synthesis. REP8839 is a potent inhibitor of MetS, the methionyl-tRNA synthetase in Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), and in Streptococcus pyogenes. The biochemical activity of REP8839 was shown by specific inhibition of purified S. aureus MetS (50% inhibitory concentration, <1.9 nM). Target specificity was confirmed by overexpression of the metS gene in S. aureus, resulting in an eightfold increase in the MIC for REP8839. Macromolecular synthesis assays in the presence of REP8839 demonstrated a dose-dependent inhibition of protein synthesis and RNA synthesis in S. pneumoniae R6, but only protein synthesis was affected in an isogenic rel mutant deficient in the stringent response. Strains with reduced susceptibility to REP8839 were generated by selection of strains with spontaneous mutations and through serial passages. Point mutations within the metS gene were mapped, leading to a total of 23 different amino acid substitutions within MetS that were located around the modeled active site. The most frequent MetS mutations were I57N, leading to a shift in the MIC from 0.06 microg/ml to 4 microg/ml, and G54S, resulting in a MIC of 32 microg/ml that was associated with a reduced growth rate. The mutation prevention concentration was 32 microg/ml in four S. aureus strains (methicillin-sensitive S. aureus and MRSA), which is well below the drug concentration of 2% (20,000 microg/ml) in a topical formulation. In conclusion, we demonstrate by biochemical, physiologic, and genetic mode-of-action studies that REP8839 exerts its antibacterial activity through specific inhibition of MetS, a novel target.
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