1
|
Zhao P, Lu D, Li L, Wu X, Yan L. Molecular Engineering to Achieve AIE-active Fluorophore with Near-infrared (NIR) Emission and Temperature-sensitive Property. J Fluoresc 2024; 34:1109-1117. [PMID: 37470966 DOI: 10.1007/s10895-023-03338-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 07/06/2023] [Indexed: 07/21/2023]
Abstract
Near-infrared organic small molecule luminescent materials have the advantages of easy modification, high quantum efficiency, good biological affinity, and color adjustability; thus, have promising application prospects in the fields of photoelectric devices, sensitive detection, photodynamic therapy, and biomedical imaging. However, traditional organic luminescent molecules have the problems of short emission wavelength, aggregation-causing emission quenching, and low quantum yield. Herein, we successfully synthesized four D-π-A-D light-emitting molecules based on electron-withdrawing malonitrile group and different electron-donating arylamine groups. These compounds showed satisfactory solvatochromism, aggregation-induced emission, red and near-infrared fluorescence, high photoluminescence quantum efficiency and temperature response properties. This successful example of molecular engineering provides a valuable reference for the development of advanced NIR materials with AIE and temperature-sensitive properties.
Collapse
Affiliation(s)
- Peng Zhao
- College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, 541006, Guangxi, P.R. China
| | - Dongqing Lu
- College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, 541006, Guangxi, P.R. China
| | - Lin Li
- College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, 541006, Guangxi, P.R. China
| | - Xiongzhi Wu
- College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, 541006, Guangxi, P.R. China.
| | - Liqiang Yan
- College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, 541006, Guangxi, P.R. China.
| |
Collapse
|
2
|
Aggarwal A, Thompson S, Singh S, Newton B, Moore A, Gao R, Gu X, Mukherjee S, Drain CM. Photophysics of glycosylated derivatives of a chlorin, isobacteriochlorin and bacteriochlorin for photodynamic theragnostics: discovery of a two-photon-absorbing photosensitizer. Photochem Photobiol 2013; 90:419-30. [PMID: 24112086 DOI: 10.1111/php.12179] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Revised: 09/16/2013] [Accepted: 09/18/2013] [Indexed: 12/11/2022]
Abstract
The photophysical properties of a chlorin, isobacteriochlorin and bacteriochlorin built on a core tetrapentafluorophenylporphyrin (TPPF20 ) and the nonhydrolyzable para thioglycosylated conjugates of these chromophores are presented. The photophysical characterization of these compounds was done in three different solvents to correlate with different environments in cells and tissues. Compared with TPPF20 other dyes have greater absorption in the red region of the visible spectrum and greater fluorescence quantum yields. The excited state lifetimes are from 3 to 11 ns. The radiative and nonradiative rate constants for deactivation of the excited state were estimated from the fluorescence quantum yield and excited state lifetime. The data indicate that the bacteriochlorin has strong absorption bands near 730 nm and efficiently enters the triplet manifold. The isobacteriochlorin has a 40-70% fluorescence quantum yield depending on solvent, so it may be a good fluorescent tag. The isobacteriochlorins also display enhanced two-photon absorption, thereby allowing the use of 860 nm light to excite the compound. While the two-photon cross section of 25 GM units is not large, excitation of low chromophore concentrations can induce apoptosis. The glycosylated compounds accumulate in cancer cells and a head and neck squamous carcinoma xenograft tumor model in mice. These compounds are robust to photobleaching.
Collapse
Affiliation(s)
- Amit Aggarwal
- Department of Chemistry, Hunter College of the City University of New York, New York, NY; Department of Science, Borough of Manhattan Community College of the City University of New York, New York, NY
| | | | | | | | | | | | | | | | | |
Collapse
|
3
|
Karton-Lifshin N, Albertazzi L, Bendikov M, Baran PS, Shabat D. “Donor–Two-Acceptor” Dye Design: A Distinct Gateway to NIR Fluorescence. J Am Chem Soc 2012. [DOI: 10.1021/ja308124q] [Citation(s) in RCA: 177] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Naama Karton-Lifshin
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv
69978, Israel
| | - Lorenzo Albertazzi
- Institute
for Complex Molecular
Systems, Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600
MB Eindhoven, The Netherlands
- NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, I-56127 Pisa,
Italy
| | - Michael Bendikov
- Department of Organic
Chemistry, The Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Phil S. Baran
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey
Pines Road, La Jolla, California 92037, United States
| | - Doron Shabat
- School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv
69978, Israel
| |
Collapse
|
4
|
Ghafari H, Parambath M, Hanley QS. Macromolecular binding and kinetic analysis with optically sectioned planar format assays. Analyst 2012; 137:4809-14. [DOI: 10.1039/c2an35134j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
5
|
Intravital three-dimensional dynamic pathology of experimental colitis in living mice using two-photon laser scanning microscopy. J Gastrointest Surg 2011; 15:1842-50. [PMID: 21796457 DOI: 10.1007/s11605-011-1632-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Accepted: 07/12/2011] [Indexed: 01/31/2023]
Abstract
BACKGROUND Intravital three-dimensional (3D) visualization of treatment efficacy in experimental colitis in living mice using two-photon laser scanning microscopy (TPLSM) has not been described. METHODS Colitis was induced with dextran sulfate sodium (DSS) in green fluorescent protein (GFP) transgenic mice. The 3D tomographic image of DSS-induced colitis with or without prednisolone was obtained intravitally using TPLSM. A serosal-approaching method was developed, by which we could observe all layers of the cecum from serosa to luminal mucosa without opening and everting the cecum. The dynamic pathology and treatment efficacy were assessed in the same mouse on several occasions. RESULTS The time-lapse 3D tomographic movie of DSS-induced colitis was obtained in living mice at a magnification of greater than ×600, which demonstrated irregularity of crypts, disappearance of crypts, inflammatory cell infiltrates in the lamina propria, and abscess formation at the bottom of crypts. Intravital TPLSM in the same mice demonstrated fewer infiltrating leukocytes and crypt abscesses on day 14 in the steroid group compared with the nonsteroid group. CONCLUSIONS Intravital 3D tomographic visualization of experimental colitis using TPLSM in combination with the serosal-approaching method can provide dynamic pathology at a high magnification, which may be useful in evaluating treatment efficacy in the same living mice.
Collapse
|
6
|
Hwang YJ, Kolettis N, Yang M, Gillard ER, Sanchez E, Sun CH, Tromberg BJ, Krasieva TB, Lyubovitsky JG. Multiphoton imaging of actin filament formation and mitochondrial energetics of human ACBT gliomas. Photochem Photobiol 2011; 87:408-17. [PMID: 21143483 DOI: 10.1111/j.1751-1097.2010.00873.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We studied the three-dimensional (3D) distribution of actin filaments and mitochondria in relation to ACBT glioblastoma cells migration. We embedded the cells in the spheroid form within collagen hydrogels and imaged them by in situ multiphoton microscopy (MPM). The static 3D overlay of the distribution of actin filaments and mitochondria provided a greater understanding of cell-to-cell and cell-to-substrate interactions and morphology. While imaging mitochondria to obtain ratiometric redox index based on cellular fluorescence from reduced nicotinamide adenine dinucleotide and oxidized flavin adenine dinucleotide we observed differential sensitivity of the migrating ACBT glioblastoma cells to femtosecond laser irradiation employed in MPM. We imaged actin-green fluorescent protein fluorescence in live ACBT glioma cells and for the first time observed dynamic modulation of the pools of actin during migration in 3D. The MPM imaging, which probes cells directly within the 3D cancer models, could potentially aid in working out a link between the functional performance of mitochondria, actin distribution and cancer invasiveness.
Collapse
Affiliation(s)
- Yu-Jer Hwang
- Cell Molecular and Developmental Biology Program, University of California, Riverside, Riverside, CA, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Jameson DM, Ross JA. Fluorescence polarization/anisotropy in diagnostics and imaging. Chem Rev 2010; 110:2685-708. [PMID: 20232898 DOI: 10.1021/cr900267p] [Citation(s) in RCA: 398] [Impact Index Per Article: 28.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- David M Jameson
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, 651 Ilalo Street, BSB222, Honolulu, Hawaii 96813, USA.
| | | |
Collapse
|
8
|
Feng XJ, Wu PL, Bolze F, Leung HWC, Li KF, Mak NK, Kwong DWJ, Nicoud JF, Cheah KW, Wong MS. Cyanines as New Fluorescent Probes for DNA Detection and Two-Photon Excited Bioimaging. Org Lett 2010; 12:2194-7. [DOI: 10.1021/ol100474b] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xin Jiang Feng
- Centre for Advanced Luminescence Materials, Department of Chemistry, Department of Physics, and Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China, and Laboratoire de Biophotonique et Pharmacologie, Faculté de Pharmacie (UMR 7213), Université de Strasbourg, 74 route du Rhin, F-67401 Illkirch, France
| | - Po Lam Wu
- Centre for Advanced Luminescence Materials, Department of Chemistry, Department of Physics, and Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China, and Laboratoire de Biophotonique et Pharmacologie, Faculté de Pharmacie (UMR 7213), Université de Strasbourg, 74 route du Rhin, F-67401 Illkirch, France
| | - Frédéric Bolze
- Centre for Advanced Luminescence Materials, Department of Chemistry, Department of Physics, and Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China, and Laboratoire de Biophotonique et Pharmacologie, Faculté de Pharmacie (UMR 7213), Université de Strasbourg, 74 route du Rhin, F-67401 Illkirch, France
| | - Heidi W. C. Leung
- Centre for Advanced Luminescence Materials, Department of Chemistry, Department of Physics, and Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China, and Laboratoire de Biophotonique et Pharmacologie, Faculté de Pharmacie (UMR 7213), Université de Strasbourg, 74 route du Rhin, F-67401 Illkirch, France
| | - King Fai Li
- Centre for Advanced Luminescence Materials, Department of Chemistry, Department of Physics, and Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China, and Laboratoire de Biophotonique et Pharmacologie, Faculté de Pharmacie (UMR 7213), Université de Strasbourg, 74 route du Rhin, F-67401 Illkirch, France
| | - Nai Ki Mak
- Centre for Advanced Luminescence Materials, Department of Chemistry, Department of Physics, and Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China, and Laboratoire de Biophotonique et Pharmacologie, Faculté de Pharmacie (UMR 7213), Université de Strasbourg, 74 route du Rhin, F-67401 Illkirch, France
| | - Daniel W. J. Kwong
- Centre for Advanced Luminescence Materials, Department of Chemistry, Department of Physics, and Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China, and Laboratoire de Biophotonique et Pharmacologie, Faculté de Pharmacie (UMR 7213), Université de Strasbourg, 74 route du Rhin, F-67401 Illkirch, France
| | - Jean-François Nicoud
- Centre for Advanced Luminescence Materials, Department of Chemistry, Department of Physics, and Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China, and Laboratoire de Biophotonique et Pharmacologie, Faculté de Pharmacie (UMR 7213), Université de Strasbourg, 74 route du Rhin, F-67401 Illkirch, France
| | - Kok Wai Cheah
- Centre for Advanced Luminescence Materials, Department of Chemistry, Department of Physics, and Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China, and Laboratoire de Biophotonique et Pharmacologie, Faculté de Pharmacie (UMR 7213), Université de Strasbourg, 74 route du Rhin, F-67401 Illkirch, France
| | - Man Shing Wong
- Centre for Advanced Luminescence Materials, Department of Chemistry, Department of Physics, and Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China, and Laboratoire de Biophotonique et Pharmacologie, Faculté de Pharmacie (UMR 7213), Université de Strasbourg, 74 route du Rhin, F-67401 Illkirch, France
| |
Collapse
|
9
|
Affiliation(s)
- Jean-Claude G. Bünzli
- Laboratory of Lanthanide Supramolecular Chemistry, École Polytechnique Fédérale de Lausanne (EPFL), BCH 1402, CH-1015 Lausanne, Switzerland, and Department of Advanced Materials Chemistry, WCU Center for Next Generation Photovoltaic Systems, Korea University, Sejong Campus, 208 Seochang, Jochiwon, Chung Nam 339-700, Republic of Korea
| |
Collapse
|
10
|
Eliseeva SV, Auböck G, van Mourik F, Cannizzo A, Song B, Deiters E, Chauvin AS, Chergui M, Bünzli JCG. Multiphoton-Excited Luminescent Lanthanide Bioprobes: Two- and Three-Photon Cross Sections of Dipicolinate Derivatives and Binuclear Helicates. J Phys Chem B 2010; 114:2932-7. [DOI: 10.1021/jp9090206] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Svetlana V. Eliseeva
- Laboratory of Lanthanide Supramolecular Chemistry, Swiss Federal Institute of Technology, Lausanne (EPFL), BCH 1402, CH-1015, Lausanne, Switzerland, Laboratory of Ultrafast Spectroscopy, EPFL, CH H1 625, CH-1015, Lausanne, Switzerland, and Department of Advanced Materials Chemistry, WCU Center for Next Generation Photovoltaic Systems, Korea University, Sejong Campus, Jochiwon, ChungNam 339−700, South Korea
| | - Gerald Auböck
- Laboratory of Lanthanide Supramolecular Chemistry, Swiss Federal Institute of Technology, Lausanne (EPFL), BCH 1402, CH-1015, Lausanne, Switzerland, Laboratory of Ultrafast Spectroscopy, EPFL, CH H1 625, CH-1015, Lausanne, Switzerland, and Department of Advanced Materials Chemistry, WCU Center for Next Generation Photovoltaic Systems, Korea University, Sejong Campus, Jochiwon, ChungNam 339−700, South Korea
| | - Frank van Mourik
- Laboratory of Lanthanide Supramolecular Chemistry, Swiss Federal Institute of Technology, Lausanne (EPFL), BCH 1402, CH-1015, Lausanne, Switzerland, Laboratory of Ultrafast Spectroscopy, EPFL, CH H1 625, CH-1015, Lausanne, Switzerland, and Department of Advanced Materials Chemistry, WCU Center for Next Generation Photovoltaic Systems, Korea University, Sejong Campus, Jochiwon, ChungNam 339−700, South Korea
| | - Andrea Cannizzo
- Laboratory of Lanthanide Supramolecular Chemistry, Swiss Federal Institute of Technology, Lausanne (EPFL), BCH 1402, CH-1015, Lausanne, Switzerland, Laboratory of Ultrafast Spectroscopy, EPFL, CH H1 625, CH-1015, Lausanne, Switzerland, and Department of Advanced Materials Chemistry, WCU Center for Next Generation Photovoltaic Systems, Korea University, Sejong Campus, Jochiwon, ChungNam 339−700, South Korea
| | - Bo Song
- Laboratory of Lanthanide Supramolecular Chemistry, Swiss Federal Institute of Technology, Lausanne (EPFL), BCH 1402, CH-1015, Lausanne, Switzerland, Laboratory of Ultrafast Spectroscopy, EPFL, CH H1 625, CH-1015, Lausanne, Switzerland, and Department of Advanced Materials Chemistry, WCU Center for Next Generation Photovoltaic Systems, Korea University, Sejong Campus, Jochiwon, ChungNam 339−700, South Korea
| | - Emmanuel Deiters
- Laboratory of Lanthanide Supramolecular Chemistry, Swiss Federal Institute of Technology, Lausanne (EPFL), BCH 1402, CH-1015, Lausanne, Switzerland, Laboratory of Ultrafast Spectroscopy, EPFL, CH H1 625, CH-1015, Lausanne, Switzerland, and Department of Advanced Materials Chemistry, WCU Center for Next Generation Photovoltaic Systems, Korea University, Sejong Campus, Jochiwon, ChungNam 339−700, South Korea
| | - Anne-Sophie Chauvin
- Laboratory of Lanthanide Supramolecular Chemistry, Swiss Federal Institute of Technology, Lausanne (EPFL), BCH 1402, CH-1015, Lausanne, Switzerland, Laboratory of Ultrafast Spectroscopy, EPFL, CH H1 625, CH-1015, Lausanne, Switzerland, and Department of Advanced Materials Chemistry, WCU Center for Next Generation Photovoltaic Systems, Korea University, Sejong Campus, Jochiwon, ChungNam 339−700, South Korea
| | - Majed Chergui
- Laboratory of Lanthanide Supramolecular Chemistry, Swiss Federal Institute of Technology, Lausanne (EPFL), BCH 1402, CH-1015, Lausanne, Switzerland, Laboratory of Ultrafast Spectroscopy, EPFL, CH H1 625, CH-1015, Lausanne, Switzerland, and Department of Advanced Materials Chemistry, WCU Center for Next Generation Photovoltaic Systems, Korea University, Sejong Campus, Jochiwon, ChungNam 339−700, South Korea
| | - Jean-Claude G. Bünzli
- Laboratory of Lanthanide Supramolecular Chemistry, Swiss Federal Institute of Technology, Lausanne (EPFL), BCH 1402, CH-1015, Lausanne, Switzerland, Laboratory of Ultrafast Spectroscopy, EPFL, CH H1 625, CH-1015, Lausanne, Switzerland, and Department of Advanced Materials Chemistry, WCU Center for Next Generation Photovoltaic Systems, Korea University, Sejong Campus, Jochiwon, ChungNam 339−700, South Korea
| |
Collapse
|
11
|
Chaudhary A, Raina M, Harma H, Hanninen P, McShane MJ, Srivastava R. Evaluation of glucose sensitive affinity binding assay entrapped in fluorescent dissolved-core alginate microspheres. Biotechnol Bioeng 2010; 104:1075-85. [PMID: 19655392 DOI: 10.1002/bit.22500] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The feasibility of dissolved-core alginate-templated fluorescent microspheres as "smart tattoo" glucose biosensors was investigated in simulated interstitial fluid (SIF). The sensor works on the principle of competitive binding and fluorescence resonance energy transfer. The sensor consists of multilayer thin film coated alginate microspheres incorporating dye-labeled glucose receptor and competing ligand within the partially dissolved alginate core. In this study, different approaches for the sensing and detection chemistry were studied, and the response of encapsulated reagents was compared with the solution-phase counterparts. The glucose sensitivity of the encapsulated TRITC-Con A/FITC-dextran (500 kDa) assay in DI water was estimated to be 0.26%/mM glucose while that in SIF was observed to be 0.3%/mM glucose. The glucose sensitivity of TRITC-apo-GOx/FITC-dextran (500 kDa) assay was estimated to be 0.33%/mM glucose in DI water and 0.5%/mM glucose in SIF and both demonstrated a response in the range of 0-50 mM glucose. Therefore, it is hypothesized that the calcium ion concentration outside the microsphere (in the SIF) does not interfere with the response sensitivity. The sensor response was observed to exhibit a maximum response time of 120 s. The system further exhibited a sensitivity of 0.94%/mM glucose with a response in range of 0-50 mM glucose, using near-infrared dyes (Alexa Fluor-647-labeled dextran as donor and QSY-21-conjugated apo-GOx as acceptor), thereby making the sensor more amenable to in vivo use, when implanted in scattering tissue.
Collapse
|
12
|
Mathis G, Bazin H. Stable Luminescent Chelates and Macrocyclic Compounds. LANTHANIDE LUMINESCENCE 2010. [DOI: 10.1007/4243_2010_5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
13
|
Eliseeva SV, Bünzli JCG. Lanthanide luminescence for functional materials and bio-sciences. Chem Soc Rev 2010; 39:189-227. [PMID: 20023849 DOI: 10.1039/b905604c] [Citation(s) in RCA: 2140] [Impact Index Per Article: 152.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Svetlana V Eliseeva
- Laboratory of Lanthanide Supramolecular Chemistry, Swiss Federal Institute of Technology, Lausanne (EPFL)
| | | |
Collapse
|
14
|
Methicillin-resistant Staphylococcus aureus screening by online immunometric monitoring of bacterial growth under selective pressure. Antimicrob Agents Chemother 2009; 53:5088-94. [PMID: 19752281 DOI: 10.1128/aac.00518-09] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Rapid, high-throughput screening tools are needed to contain the spread of hospital-acquired methicillin (meticillin)-resistant Staphylococcus aureus (MRSA) strains. Most techniques used in current clinical practice still require time-consuming culture for primary isolation of the microbe. We present a new phenotypic assay for MRSA screening. The technique employs a two-photon excited fluorescence (TPX) detection technology with S. aureus-specific antibodies that allows the online monitoring of bacterial growth in a single separation-free process. Different progressions of fluorescence signals are recorded for methicillin-susceptible and -resistant strains when the growth of S. aureus is monitored in the presence of cefoxitin. The performance of the new technique was evaluated with 20 MRSA strains, 6 methicillin-susceptible S. aureus strains, and 7 coagulase-negative staphylococcal strains and two different monoclonal S. aureus-specific antibodies. When either of these antibodies was used, the sensitivity and the specificity of the TPX assay were 100%. All strains were correctly classified within 8 to 12 h, and up to 70 samples were simultaneously analyzed on a single 96-well microtiter plate. As a phenotypic method, the TPX assay is suited for screening purposes. The final definition of methicillin resistance in any S. aureus strain should be based on the presence of the mecA gene. The main benefit afforded by the initial use of the TPX methodology lies in its low cost and applicability to high-throughput analysis.
Collapse
|