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Case N, Johnston N, Nadeau J. Fluorescence Microscopy with Deep UV, Near UV, and Visible Excitation for In Situ Detection of Microorganisms. ASTROBIOLOGY 2024; 24:300-317. [PMID: 38507693 PMCID: PMC10979697 DOI: 10.1089/ast.2023.0020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 01/02/2024] [Indexed: 03/22/2024]
Abstract
We report a simple, inexpensive design of a fluorescence microscope with light-emitting diode (LED) excitation for detection of labeled and unlabeled microorganisms in mineral substrates. The use of deep UV (DUV) excitation with visible emission requires no specialized optics or slides and can be implemented easily and inexpensively using an oblique illumination geometry. DUV excitation (<280 nm) is preferable to near UV (365 nm) for avoidance of mineral autofluorescence. When excited with DUV, unpigmented bacteria show two emission peaks: one in the near UV ∼320 nm, corresponding to proteins, and another peak in the blue to green range, corresponding to flavins and/or reduced nicotinamide adenine dinucleotide (NADH). Many commonly used dyes also show secondary excitation peaks in the DUV, with identical emission spectra and quantum yields as their primary peak. However, DUV fails to excite key biosignature molecules, especially chlorophyll in cyanobacteria. Visible excitation (violet to blue) also results in less mineral autofluorescence than near UV, and most autofluorescence in the minerals seen here is green, so that red dyes and red autofluorescence of chlorophyll and porphyrins are readily distinguished. The pairing of DUV and near UV or visible excitation, with emission across the visible, represents the most thorough approach to detection of labeled and unlabeled bacteria in soil and rock.
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Affiliation(s)
- Noel Case
- Department of Physics, Portland State University, Portland, Oregon, USA
| | - Nikki Johnston
- Department of Physics, Portland State University, Portland, Oregon, USA
| | - Jay Nadeau
- Department of Physics, Portland State University, Portland, Oregon, USA
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Vucinic L, O'Connell D, Dubber D, Coxon C, Gill L. Multiple fluorescence approaches to identify rapid changes in microbial indicators at karst springs. JOURNAL OF CONTAMINANT HYDROLOGY 2023; 254:104129. [PMID: 36634484 DOI: 10.1016/j.jconhyd.2022.104129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 12/28/2022] [Accepted: 12/29/2022] [Indexed: 06/17/2023]
Abstract
Karst springs are globally important for drinking water supply but are often also exceptionally vulnerable to contamination. Such springs usually exhibit strong variation in microbial water quality in sharp response to rainfall events, thus, posing a health hazard to consumers of water supplied from these sources. The rapid detection of such changes is extremely important as well as being able to establish a link to the sources of such pollution, so that appropriate measures can be taken both in terms of immediate protection of human health and the management of karst aquifers. In this study, a fluorescence-based multi-parameter approach was trialed in order to evaluate which methods can be used to monitor rainfall-induced rapid changes in microbial water quality at karst springs, as well as determine whether such changes can be linked to sources of human effluent contamination. The results from three monitoring periods at two karst springs revealed marked responses to rainfall events for all of the microbial parameters measured. Total cell count (TCC) measurements using flow cytometry (FCM) showed very strong positive correlations with the more conventionally monitored faecal indicator bacteria (FIB) and total coliforms (TC), indicating that such a fluorescence-based and cultivation-independent technique can be very useful to indicate rapid changes in microbial water quality at karst springs. Furthermore, very strong positive correlations were also found between tryptophan-like fluorescence (TLF) measurements and concentrations of all monitored microbial parameters, again demonstrating that such a fluorescence-based approach can also be useful for detecting rapid changes in concentrations of traditional faecal indicators. Interestingly, it was found that fluorescent whitening compounds (FWCs) signals do not necessarily follow temporal variations of microbial indicators. However, the frequency of detection of positive FWCs signals may still reveal useful information about the overall magnitude of human wastewater effluent impacts on karst aquifer systems.
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Affiliation(s)
- Luka Vucinic
- Department of Civil, Structural and Environmental Engineering, University of Dublin, Trinity College, Dublin, Ireland.
| | - David O'Connell
- Department of Civil, Structural and Environmental Engineering, University of Dublin, Trinity College, Dublin, Ireland
| | - Donata Dubber
- Department of Civil, Structural and Environmental Engineering, University of Dublin, Trinity College, Dublin, Ireland
| | - Catherine Coxon
- Department of Geology, Trinity Centre for the Environment, University of Dublin, Trinity College, Dublin, Ireland
| | - Laurence Gill
- Department of Civil, Structural and Environmental Engineering, University of Dublin, Trinity College, Dublin, Ireland
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Grzesiak J, Fellner L, Grünewald K, Kölbl C, Walter A, Horlacher R, Duschek F. Fluorescence signatures of SARS-CoV-2 spike S1 proteins and a human ACE-2: excitation-emission maps and fluorescence lifetimes. JOURNAL OF BIOMEDICAL OPTICS 2022; 27:050501. [PMID: 35643871 PMCID: PMC9142794 DOI: 10.1117/1.jbo.27.5.050501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 04/12/2022] [Indexed: 06/15/2023]
Abstract
SIGNIFICANCE Fast and reliable detection of infectious SARS-CoV-2 virus loads is an important issue. Fluorescence spectroscopy is a sensitive tool to do so in clean environments. This presumes a comprehensive knowledge of fluorescence data. AIM We aim at providing fully featured information on wavelength and time-dependent data of the fluorescence of the SARS-CoV-2 spike protein S1 subunit, its receptor-binding domain (RBD), and the human angiotensin-converting enzyme 2, especially with respect to possible optical detection schemes. APPROACH Spectrally resolved excitation-emission maps of the involved proteins and measurements of fluorescence lifetimes were recorded for excitations from 220 to 295 nm. The fluorescence decay times were extracted by using a biexponential kinetic approach. The binding process in the SARS-CoV-2 RBD was likewise examined for spectroscopic changes. RESULTS Distinct spectral features for each protein are pointed out in relevant spectra extracted from the excitation-emission maps. We also identify minor spectroscopic changes under the binding process. The decay times in the biexponential model are found to be ( 2.0 ± 0.1 ) ns and ( 8.6 ± 1.4 ) ns. CONCLUSIONS Specific material data serve as an important background information for the design of optical detection and testing methods for SARS-CoV-2 loaded media.
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Affiliation(s)
- Jonas Grzesiak
- German Aerospace Center (DLR), Institute of Technical Physics, Hardthausen, Germany
| | - Lea Fellner
- German Aerospace Center (DLR), Institute of Technical Physics, Hardthausen, Germany
| | - Karin Grünewald
- German Aerospace Center (DLR), Institute of Technical Physics, Hardthausen, Germany
| | - Christoph Kölbl
- German Aerospace Center (DLR), Institute of Technical Physics, Hardthausen, Germany
| | - Arne Walter
- German Aerospace Center (DLR), Institute of Technical Physics, Hardthausen, Germany
| | | | - Frank Duschek
- German Aerospace Center (DLR), Institute of Technical Physics, Hardthausen, Germany
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Detection of invisible dental biofilm using light-induced autofluorescence in adult patients - a systematic review. Photodiagnosis Photodyn Ther 2022; 39:102916. [DOI: 10.1016/j.pdpdt.2022.102916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 05/15/2022] [Accepted: 05/17/2022] [Indexed: 11/20/2022]
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5
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Parekh JN, Soni P, Meena MK, Tandel CK, Radhakrishanan G. A New Device and Technology for Detecting Bacterial Infection and its Gram Type in Diabetic Foot Ulcer. Indian J Surg 2022. [DOI: 10.1007/s12262-021-03190-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Yuan Y, Liu X, Yin Y, Yu H, Chen J, Li M. A microbial quantity monitoring model based on 3D fluorescence data of the cucumber storeroom gas and its use in providing auxiliary early spoilage warning. Analyst 2022; 147:5347-5354. [DOI: 10.1039/d2an01121b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A microbial quality prediction model for early warning of cucumber spoilage is proposed based on the fluorescence information of the cucumber storeroom gas.
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Affiliation(s)
- Yunxia Yuan
- College of Food & Bioengineering, Henan University of Science & Technology, Luoyang 471023, China
| | - Xueru Liu
- College of Food & Bioengineering, Henan University of Science & Technology, Luoyang 471023, China
| | - Yong Yin
- College of Food & Bioengineering, Henan University of Science & Technology, Luoyang 471023, China
| | - Huichun Yu
- College of Food & Bioengineering, Henan University of Science & Technology, Luoyang 471023, China
| | - Junliang Chen
- College of Food & Bioengineering, Henan University of Science & Technology, Luoyang 471023, China
| | - Mengli Li
- College of Food & Bioengineering, Henan University of Science & Technology, Luoyang 471023, China
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Laboratory In-Situ Production of Autochthonous and Allochthonous Fluorescent Organic Matter by Freshwater Bacteria. Microorganisms 2021; 9:microorganisms9081623. [PMID: 34442702 PMCID: PMC8400322 DOI: 10.3390/microorganisms9081623] [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: 06/14/2021] [Revised: 07/16/2021] [Accepted: 07/26/2021] [Indexed: 11/17/2022] Open
Abstract
This work investigates the origin and range of fluorescent organic matter (FOM) produced in-situ by environmentally sourced freshwater bacteria. Aquatic FOM is an essential component in global carbon cycling and is generally classified as either autochthonous, produced in-situ via microbial processes, or allochthonous, transported into aquatic systems from external sources. We have demonstrated that, within laboratory model systems, environmentally sourced mixed microbial communities and bacterial isolates can produce and/or export FOM associated with both autochthonous and allochthonous material. This study focuses on fluorescence peak B, T, M, C and C+, exploring (1) the cellular nature of FOM produced, (2) FOM exported as extracellular material into the water column and (3) the impact of physical cell lysis on FOM signature. For the laboratory model systems studied, Peak T fluorescence is retained within bacterial cells (>68%), while Peak C fluorescence is mainly observed as extracellular material (>80%). Peak M is identified as both cellular and extracellular FOM, produced by all isolated freshwater microorganisms investigated. The origin of Peak C+ is postulated to originate from functional metabolites associated with specific microorganisms, seen specifically within the Pseudomonas sp. monoculture here. This work challenges the binary classification of FOM as either allochthonous or autochthonous, suggesting that FOM processing and production occurs along a dynamic continuum. Within this study, fluorescence intensity data for the environmental bacteria isolate monocultures are presented as enumeration corrected data, for the first time providing quantitative fluorescence data per bacterial colony forming unit (cfu). From this, we are able to assess the relative contribution of different bacteria to the autochthonous FOM pool and if this material is cellular or extracellular.
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Peguda HK, Mahbub SB, Sherpa TD, Subedi D, Habibalahi A, Anwer AG, Gu Z, Willcox MDP, Goldys EM, Carnt NA. The Autofluorescence Patterns of Acanthamoeba castellanii, Pseudomonas aeruginosa and Staphylococcus aureus: Effects of Antibiotics and Tetracaine. Pathogens 2021; 10:pathogens10070894. [PMID: 34358044 PMCID: PMC8308758 DOI: 10.3390/pathogens10070894] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/10/2021] [Accepted: 07/12/2021] [Indexed: 11/28/2022] Open
Abstract
Acanthamoeba Keratitis (AK) can lead to substantial vision loss and morbidity among contact lens wearers. Misdiagnosis or delayed diagnosis is a major factor contributing to poor outcomes of AK. This study aimed to assess the effect of two antibiotics and one anaesthetic drug used in the diagnosis and nonspecific management of keratitis on the autofluorescence patterns of Acanthamoeba and two common bacteria that may also cause keratitis. Acanthamoeba castellanii ATCC 30868, Pseudomonas aeruginosa ATCC 9027, and Staphylococcus aureus ATCC 6538 were grown then diluted in either PBS (bacteria) or ¼ strength Ringer’s solution (Acanthamoeba) to give final concentrations of 0.1 OD at 660 nm or 104 cells/mL. Cells were then treated with ciprofloxacin, tetracycline, tetracaine, or no treatment (naïve). Excitation–emission matrices (EEMs) were collected for each sample with excitation at 270–500 nm with increments in 5 nm steps and emission at 280–700 nm at 2 nm steps using a Fluoromax-4 spectrometer. The data were analysed using MATLAB software to produce smoothed color-coded images of the samples tested. Acanthamoeba exhibited a distinctive fluorescence pattern compared to bacteria. The addition of antibiotics and anaesthetic had variable effects on autofluorescence. Tetracaine altered the fluorescence of all three microorganisms, whereas tetracycline did not show any effect on the fluorescence. Ciprofloxacin produced changes to the fluorescence pattern for the bacteria, but not Acanthamoeba. Fluorescence spectroscopy was able to differentiate Acanthamoeba from P. aeruginosa and S. aureus in vitro. There is a need for further assessment of the fluorescence pattern for different strains of Acanthamoeba and bacteria. Additionally, analysis of the effects of anti-amoebic drugs on the fluorescence pattern of Acanthamoeba and bacteria would be prudent before in vivo testing of the fluorescence diagnostic approach in the animal models.
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Affiliation(s)
- Hari Kumar Peguda
- School of Optometry and Vision Science, University of New South Wales, Sydney 2052, Australia; (T.D.S.); (D.S.); (M.D.P.W.); (N.A.C.)
- Correspondence:
| | - Saabah B. Mahbub
- ARC Centre of Excellence for Nanoscale Biophotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney 2052, Australia; (S.B.M.); (A.H.); (A.G.A.); (E.M.G.)
| | - Tashi Doma Sherpa
- School of Optometry and Vision Science, University of New South Wales, Sydney 2052, Australia; (T.D.S.); (D.S.); (M.D.P.W.); (N.A.C.)
| | - Dinesh Subedi
- School of Optometry and Vision Science, University of New South Wales, Sydney 2052, Australia; (T.D.S.); (D.S.); (M.D.P.W.); (N.A.C.)
- School of Biological Sciences, Monash University, Clayton 3800, Australia
| | - Abbas Habibalahi
- ARC Centre of Excellence for Nanoscale Biophotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney 2052, Australia; (S.B.M.); (A.H.); (A.G.A.); (E.M.G.)
| | - Ayad G. Anwer
- ARC Centre of Excellence for Nanoscale Biophotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney 2052, Australia; (S.B.M.); (A.H.); (A.G.A.); (E.M.G.)
| | - Zi Gu
- School of Chemical Engineering, University of New South Wales, Sydney 2052, Australia;
| | - Mark D. P. Willcox
- School of Optometry and Vision Science, University of New South Wales, Sydney 2052, Australia; (T.D.S.); (D.S.); (M.D.P.W.); (N.A.C.)
| | - Ewa M. Goldys
- ARC Centre of Excellence for Nanoscale Biophotonics, Graduate School of Biomedical Engineering, University of New South Wales, Sydney 2052, Australia; (S.B.M.); (A.H.); (A.G.A.); (E.M.G.)
| | - Nicole A. Carnt
- School of Optometry and Vision Science, University of New South Wales, Sydney 2052, Australia; (T.D.S.); (D.S.); (M.D.P.W.); (N.A.C.)
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A Mobile Device for Monitoring the Biological Purity of Air and Liquid Samples. SENSORS 2021; 21:s21103570. [PMID: 34065526 PMCID: PMC8161204 DOI: 10.3390/s21103570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/14/2021] [Accepted: 05/18/2021] [Indexed: 11/16/2022]
Abstract
A detector for identifying potential bacterial hazards in the air was designed and created in the Military Institute of Chemistry and Radiometry in the framework of the project FLORABO. The presence of fungi and bacteria in the air can affect the health of people in a given room. The need to control the amount of microorganisms, both in terms of quantity and quality, applies to both hospitals and offices. The device is based on the fluorescence spectroscopy analysis of the sample and then these results were compared to the resulting spectrogram database, which includes the standard curves obtained in the laboratory for selected bacteria. The measurements provide information about the presence, the type, and the approximate concentration of bacteria in the sample. The spectra were collected at different excitation wavelengths, and the waveforms are specific for each of the strains. It also takes under analysis the signal intensities of the different spectra (not only shape a maximum of the peak) so that the concentration of bacteria in the sample being tested can be determined. The device was tested in the laboratory with concentrations ranging from 10 to 108 cells/mL. Additionally, the detector can distinguish between the vegetative forms of spores of the bacteria.
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Owoicho O, Olwal CO, Quaye O. Potential of laser-induced fluorescence-light detection and ranging for future stand-off virus surveillance. Microb Biotechnol 2021; 14:126-135. [PMID: 33242369 PMCID: PMC7753352 DOI: 10.1111/1751-7915.13698] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 10/16/2020] [Accepted: 10/19/2020] [Indexed: 12/21/2022] Open
Abstract
Viruses remain a significant public health concern worldwide. Recently, humanity has faced deadly viral infections, including Zika, Ebola and the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The threat is associated with the ability of the viruses to mutate frequently and adapt to different hosts. Thus, there is the need for robust detection and classification of emerging virus strains to ensure that humanity is prepared in terms of vaccine and drug developments. A point or stand-off biosensor that can detect and classify viruses from indoor and outdoor environments would be suited for viral surveillance. Light detection and ranging (LiDAR) is a facile and versatile tool that has been explored for stand-off detection in different environments including atmospheric, oceans and forest sensing. Notably, laser-induced fluorescence-light detection and ranging (LIF-LiDAR) has been used to identify MS2 bacteriophage on artificially contaminated surgical equipment or released amidst other primary biological aerosol particles in laboratory-like close chamber. It has also been shown to distinguish between different picornaviruses. Currently, the potentials of the LIF-LiDAR technology for real-time stand-off surveillance of pathogenic viruses in indoor and outdoor environments have not been assessed. Considering the increasing applications of LIF-LiDAR for potential microbial pathogens detection and classification, and the need for more robust tools for viral surveillance at safe distance, we critically evaluate the prospects and challenges of LIF-LiDAR technology for real-time stand-off detection and classification of potentially pathogenic viruses in various environments.
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Affiliation(s)
- Oloche Owoicho
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP)University of GhanaAccraGhana
- Department of Biochemistry, Cell and Molecular BiologyCollege of Basic and Applied SciencesUniversity of GhanaAccraGhana
| | - Charles Ochieng’ Olwal
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP)University of GhanaAccraGhana
- Department of Biochemistry, Cell and Molecular BiologyCollege of Basic and Applied SciencesUniversity of GhanaAccraGhana
| | - Osbourne Quaye
- West African Centre for Cell Biology of Infectious Pathogens (WACCBIP)University of GhanaAccraGhana
- Department of Biochemistry, Cell and Molecular BiologyCollege of Basic and Applied SciencesUniversity of GhanaAccraGhana
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The Real Experience and Management Strategies Analysis of Chinese Nurses Aiding COVID-19 Epidemic: A Qualitative Study. Disaster Med Public Health Prep 2020; 16:889-891. [PMID: 33726870 PMCID: PMC7985646 DOI: 10.1017/dmp.2020.477] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Emergent public health events, such as coronavirus disease 2019 (COVID-19), have been the focus of attention of researchers at home and abroad. In China, nurses are an important group contributing to the prevention and control of the COVID-19 pneumonia epidemic. METHODS Using semi-structured interviews, qualitative interviews were conducted with 23 nurses who supported the novel coronavirus pneumonia epidemic, and the data were collated and analyzed using Colaizzi analysis. RESULTS The work experience of Chinese nurses can be summarized into 4 major themes: they had different emotional experiences during aiding periods, aiding work had a double impact on the nurses, there were certain difficulties in aiding work, and there were significant age differences in aiding work experience. CONCLUSIONS It is necessary to strengthen the psychological construction of nurses. All hospitals must coordinate and manage various safety tasks, and ensure the precise, scientific, and streamlined deployment of rescue work. Humanized management, shift adjustment, performance allocation weight, and organizational care are also the top priorities of human resource management.
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Sorensen JPR, Diaw MT, Pouye A, Roffo R, Diongue DML, Faye SC, Gaye CB, Fox BG, Goodall T, Lapworth DJ, MacDonald AM, Read DS, Ciric L, Taylor RG. In-situ fluorescence spectroscopy indicates total bacterial abundance and dissolved organic carbon. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 738:139419. [PMID: 32521357 DOI: 10.1016/j.scitotenv.2020.139419] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 05/11/2020] [Accepted: 05/11/2020] [Indexed: 06/11/2023]
Abstract
We explore in-situ fluorescence spectroscopy as an instantaneous indicator of total bacterial abundance and faecal contamination in drinking water. Eighty-four samples were collected outside of the recharge season from groundwater-derived water sources in Dakar, Senegal. Samples were analysed for tryptophan-like (TLF) and humic-like (HLF) fluorescence in-situ, total bacterial cells by flow cytometry, and potential indicators of faecal contamination such as thermotolerant coliforms (TTCs), nitrate, and in a subset of 22 samples, dissolved organic carbon (DOC). Significant single-predictor linear regression models demonstrated that total bacterial cells were the most effective predictor of TLF, followed by on-site sanitation density; TTCs were not a significant predictor. An optimum multiple-predictor model of TLF incorporated total bacterial cells, nitrate, nitrite, on-site sanitation density, and sulphate (r2 0.68). HLF was similarly related to the same parameters as TLF, with total bacterial cells being the best correlated (ρs 0.64). In the subset of 22 sources, DOC clustered with TLF, HLF, and total bacterial cells, and a linear regression model demonstrated HLF was the best predictor of DOC (r2 0.84). The intergranular nature of the aquifer, timing of the study, and/or non-uniqueness of the signal to TTCs can explain the significant associations between TLF/HLF and indicators of faecal contamination such as on-site sanitation density and nutrients but not TTCs. The bacterial population that relates to TLF/HLF is likely to be a subsurface community that develops in-situ based on the availability of organic matter originating from faecal sources. In-situ fluorescence spectroscopy instantly indicates a drinking water source is impacted by faecal contamination but it remains unclear how that relates specifically to microbial risk in this setting.
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Affiliation(s)
- James P R Sorensen
- British Geological Survey, Maclean Building, Wallingford OX10 8BB, UK; Department of Geography, University College London, London WC1E 6BT, UK.
| | - Mor Talla Diaw
- Department of Geology, Université Cheikh Anta Diop, Senegal
| | | | - Raphaëlle Roffo
- Department of Geography, University College London, London WC1E 6BT, UK
| | | | | | - Cheikh B Gaye
- Department of Geology, Université Cheikh Anta Diop, Senegal
| | - Bethany G Fox
- Centre for Research in Biosciences, University of the West of England, Bristol BS16 1QY, UK
| | - Timothy Goodall
- UK Centre for Ecology & Hydrology (UKCEH), Maclean Building, Wallingford OX10 8BB, UK
| | - Daniel J Lapworth
- British Geological Survey, Maclean Building, Wallingford OX10 8BB, UK
| | - Alan M MacDonald
- British Geological Survey, Lyell Centre, Research Avenue South, Edinburgh EH14 4AP, UK
| | - Daniel S Read
- UK Centre for Ecology & Hydrology (UKCEH), Maclean Building, Wallingford OX10 8BB, UK
| | - Lena Ciric
- Department of Civil, Environmental & Geomatic Engineering, University College London, London WC1E 6BT, UK
| | - Richard G Taylor
- Department of Geography, University College London, London WC1E 6BT, UK
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Sorensen JPR, Carr AF, Nayebare J, Diongue DML, Pouye A, Roffo R, Gwengweya G, Ward JST, Kanoti J, Okotto-Okotto J, van der Marel L, Ciric L, Faye SC, Gaye CB, Goodall T, Kulabako R, Lapworth DJ, MacDonald AM, Monjerezi M, Olago D, Owor M, Read DS, Taylor RG. Tryptophan-like and humic-like fluorophores are extracellular in groundwater: implications as real-time faecal indicators. Sci Rep 2020; 10:15379. [PMID: 32958794 PMCID: PMC7505957 DOI: 10.1038/s41598-020-72258-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 06/17/2020] [Indexed: 12/17/2022] Open
Abstract
Fluorescent natural organic matter at tryptophan-like (TLF) and humic-like fluorescence (HLF) peaks is associated with the presence and enumeration of faecal indicator bacteria in groundwater. We hypothesise, however, that it is predominantly extracellular material that fluoresces at these wavelengths, not bacterial cells. We quantified total (unfiltered) and extracellular (filtered at < 0.22 µm) TLF and HLF in 140 groundwater sources across a range of urban population densities in Kenya, Malawi, Senegal, and Uganda. Where changes in fluorescence occurred following filtration they were correlated with potential controlling variables. A significant reduction in TLF following filtration (ΔTLF) was observed across the entire dataset, although the majority of the signal remained and thus considered extracellular (median 96.9%). ΔTLF was only significant in more urbanised study areas where TLF was greatest. Beneath Dakar, Senegal, ΔTLF was significantly correlated to total bacterial cells (ρs 0.51). No significant change in HLF following filtration across all data indicates these fluorophores are extracellular. Our results suggest that TLF and HLF are more mobile than faecal indicator bacteria and larger pathogens in groundwater, as the predominantly extracellular fluorophores are less prone to straining. Consequently, TLF/HLF are more precautionary indicators of microbial risks than faecal indicator bacteria in groundwater-derived drinking water.
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Affiliation(s)
- James P R Sorensen
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK.
- Department of Geography, University College London, London, WC1E 6BT, UK.
| | - Andrew F Carr
- Department of Geography, University College London, London, WC1E 6BT, UK
| | - Jacintha Nayebare
- Department of Geology and Petroleum Studies, Makerere University, Kampala, Uganda
| | - Djim M L Diongue
- Department of Geology, Universite Cheikh Anta Diop, Dakar, Senegal
| | - Abdoulaye Pouye
- Department of Geology, Universite Cheikh Anta Diop, Dakar, Senegal
| | - Raphaëlle Roffo
- Department of Geography, University College London, London, WC1E 6BT, UK
| | - Gloria Gwengweya
- Chancellor College, University of Malawi, P.O. Box 280, Zomba, Malawi
| | - Jade S T Ward
- British Geological Survey, Keyworth, NG12 5GG, UK
- Department of Civil and Environmental Engineering, University of Surrey, Guildford, GU2 7XH, UK
| | - Japhet Kanoti
- Department of Geology, University of Nairobi, Nairobi, Kenya
| | - Joseph Okotto-Okotto
- Victoria Institute for Research on Environment and Development (VIRED) International, Rabuour Environment and Development Centre, Kisumu-Nairobi Road, P.O. Box, Kisumu, 6423-40103, Kenya
| | | | - Lena Ciric
- Department of Civil, Environmental and Geomatic Engineering, University College London, London, WC1E 6BT, UK
| | - Seynabou C Faye
- Department of Geology, Universite Cheikh Anta Diop, Dakar, Senegal
| | - Cheikh B Gaye
- Department of Geology, Universite Cheikh Anta Diop, Dakar, Senegal
| | - Timothy Goodall
- Centre for Ecology and Hydrology, Maclean Building, Wallingford, OX10 8BB, UK
| | - Robinah Kulabako
- Department of Civil and Environmental Engineering, Makerere University, Kampala, Uganda
| | - Daniel J Lapworth
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK
| | - Alan M MacDonald
- British Geological Survey, Lyell Centre, Research Avenue South, Edinburgh, EH14 4AP, UK
| | - Maurice Monjerezi
- Chancellor College, University of Malawi, P.O. Box 280, Zomba, Malawi
| | - Daniel Olago
- Department of Geology, University of Nairobi, Nairobi, Kenya
| | - Michael Owor
- Department of Geology and Petroleum Studies, Makerere University, Kampala, Uganda
| | - Daniel S Read
- Centre for Ecology and Hydrology, Maclean Building, Wallingford, OX10 8BB, UK
| | - Richard G Taylor
- Department of Geography, University College London, London, WC1E 6BT, UK
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14
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Parbhoo T, Sampson SL, Mouton JM. Recent Developments in the Application of Flow Cytometry to Advance our Understanding of Mycobacterium tuberculosis Physiology and Pathogenesis. Cytometry A 2020; 97:683-693. [PMID: 32437069 PMCID: PMC7496436 DOI: 10.1002/cyto.a.24030] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 04/18/2020] [Accepted: 04/21/2020] [Indexed: 12/16/2022]
Abstract
The ability of the bacterial pathogen Mycobacterium tuberculosis to adapt and survive within human cells to disseminate to other individuals and cause active disease is poorly understood. Research supports that as M. tuberculosis adapts to stressors encountered in the host, it exhibits variable physiological and metabolic states that are time and niche-dependent. Challenges associated with effective treatment and eradication of tuberculosis (TB) are in part attributed to our lack of understanding of these different mycobacterial phenotypes. This is mainly due to a lack of suitable tools to effectively identify/detect heterogeneous bacterial populations, which may include small, difficult-to-culture subpopulations. Importantly, flow cytometry allows rapid and affordable multiparametric measurements of physical and chemical characteristics of single cells, without the need to preculture cells. Here, we summarize current knowledge of flow cytometry applications that have advanced our understanding of the physiology of M. tuberculosis during TB disease. Specifically, we review how host-associated stressors influence bacterial characteristics such as metabolic activity, membrane potential, redox status and the mycobacterial cell wall. Further, we highlight that flow cytometry offers unprecedented opportunities for insight into bacterial population heterogeneity, which is increasingly appreciated as an important determinant of disease outcome. © 2020 The Authors. Cytometry Part A published by Wiley Periodicals, Inc. on behalf of International Society for Advancement of Cytometry.
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Affiliation(s)
- Trisha Parbhoo
- NRF‐DST Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health SciencesStellenbosch UniversityCape TownSouth Africa
| | - Samantha L. Sampson
- NRF‐DST Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health SciencesStellenbosch UniversityCape TownSouth Africa
| | - Jacoba M. Mouton
- NRF‐DST Centre of Excellence for Biomedical Tuberculosis Research, South African Medical Research Council Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health SciencesStellenbosch UniversityCape TownSouth Africa
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15
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Saygin H, Baysal A. Similarities and Discrepancies Between Bio-Based and Conventional Submicron-Sized Plastics: In Relation to Clinically Important Bacteria. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2020; 105:26-35. [PMID: 32556685 DOI: 10.1007/s00128-020-02908-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Accepted: 06/10/2020] [Indexed: 06/11/2023]
Abstract
In recent years, many studies have reported the harmful effects of plastic debris both on the environment and on human health. Therefore, the attempt has increased for the replacement of conventional plastics with bioplastics. On the other hand, not only the studies on the effects of bioplastics and conventional plastics in the field of micro-, submicron- and nano-sized are still very limited, but also knowledge of their relationship with clinically important bacteria. In this study, the effect of two end products made from bioplastics and their equivalent end products from conventional plastics were evaluated using clinically important gram-positive and gram-negative bacteria. To evaluate the effect of the submicron-sized bioplastics and conventional plastics on the bacteria, their viability and activation and/or inhibition mechanism were performed towards the main biochemical (protein, carbohydrate, lipid and antioxidant) and physicochemical (particle size, zeta potential, chemical composition, and surface chemistry) phenomenon. This work highlights the similarities and discrepancies between bio-based and conventional submicron-sized plastics in relation to bacteria.
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Affiliation(s)
- Hasan Saygin
- Application and Research Center for Advanced Studies, T.C. Istanbul Aydin University, Sefakoy Kucukcekmece, 34295, Istanbul, Turkey
| | - Asli Baysal
- Health Services Vocational School of Higher Education, T.C. Istanbul Aydin University, Sefakoy Kucukcekmece, 34295, Istanbul, Turkey.
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16
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Satpathy G, Chandra GK, Manikandan E, Mahapatra DR, Umapathy S. Pathogenic Escherichia coli (E. coli) detection through tuned nanoparticles enhancement study. Biotechnol Lett 2020; 42:853-863. [PMID: 32040672 DOI: 10.1007/s10529-020-02835-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 02/04/2020] [Indexed: 01/25/2023]
Abstract
OBJECTIVE This study aims to detect pathogenic Escherichia coli (E. coli) bacteria using non-destructive fluorescence microscopy and micro-Raman spectroscopy. RESULTS Raman vibrational spectroscopy provides additional information regarding biochemical changes at the cellular level. We have used two nanomaterials zinc oxide nanoparticles (ZnO-NPs) and gold nanoparticles (Au-NPs) to detect pathogenic E. coli. The scanning electron microscope (SEM) with energy dispersive X-ray (EDAX) spectroscopy exhibit surface morphology and the elemental composition of the synthesized NPs. The metal NPs are useful contrast agents due to the surface plasmon resonance (SPR) to detect the signal intensity and hence the bacterial cells. The changes due to the interaction between cells and NPs are further correlated to the change in the surface charge and stiffness of the cell surface with the help of the fluorescence microscopic assay. CONCLUSIONS We conclude that when two E. coli strains (MTCC723 and MTCC443) and NPs are respectively mixed and kept overnight, the growth of bacteria are inhibited by ZnO-NPs due to changes in cell membrane permeability and intracellular metabolic system under fluorescence microscopy. However, SPR possessed Au-NPs result in enhanced fluorescence of both pathogens. In addition, with the help of Raman microscopy and element analysis, significant changes are observed when Au-NPs are added with the two strains as compared to ZnO-NPs due to protein, lipid and DNA/RNA induced conformational changes.
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Affiliation(s)
- Gargibala Satpathy
- Central Research Laboratory, Sree Balaji Medical College & Hospital (SBMCH), Bharath Institute for Higher Education & Research (BIHER), Bharath University, Chennai, Tamil Nadu, 600073, India.,Laboratory of Integrative Multiscale Engineering Materials and Systems, Department of Aerospace Engineering, Indian Institute of Science, Bangalore, 560012, India
| | | | - E Manikandan
- Central Research Laboratory, Sree Balaji Medical College & Hospital (SBMCH), Bharath Institute for Higher Education & Research (BIHER), Bharath University, Chennai, Tamil Nadu, 600073, India. .,Solid-State Nanoscale Laboratory, Department of Physics, TUCAS Campus, Thiruvalluvar University, Thennangur, Vellore, 604408, India.
| | - D Roy Mahapatra
- Laboratory of Integrative Multiscale Engineering Materials and Systems, Department of Aerospace Engineering, Indian Institute of Science, Bangalore, 560012, India.
| | - Siva Umapathy
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore, 560012, India. .,Indian Institute of Science Education and Research, Bhopal, Madhya Pradesh, 462066, India.
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17
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Inkinen J, Ahonen M, Iakovleva E, Karppinen P, Mielonen E, Mäkinen R, Mannonen K, Koivisto J. Contamination detection by optical measurements in a real-life environment: A hospital case study. JOURNAL OF BIOPHOTONICS 2020; 13:e201960069. [PMID: 31613045 PMCID: PMC7065611 DOI: 10.1002/jbio.201960069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 09/30/2019] [Accepted: 10/06/2019] [Indexed: 05/05/2023]
Abstract
Organic dirt on touch surfaces can be biological contaminants (microbes) or nutrients for those but is often invisible by the human eye causing challenges for evaluating the need for cleaning. Using hyperspectral scanning algorithm, touch surface cleanliness monitoring by optical imaging was studied in a real-life hospital environment. As the highlight, a human eye invisible stain from a dirty chair armrest was revealed manually with algorithms including threshold levels for intensity and clustering analysis with two excitation lights (green and red) and one bandpass filter (wavelength λ = 500 nm). The same result was confirmed by automatic k-means clustering analysis from the entire dirty data of visible light (red, green and blue) and filters 420 to 720 nm with 20 nm increments. Overall, the collected touch surface samples (N = 156) indicated the need for cleaning in some locations by the high culturable bacteria and adenosine triphosphate counts despite the lack of visible dirt. Examples of such locations were toilet door lock knobs and busy registration desk armchairs. Thus, the studied optical imaging system utilizing the safe visible light area shows a promising method for touch surface cleanliness evaluation in real-life environments.
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Affiliation(s)
- Jenni Inkinen
- Aalto University, School of Science, Department of Applied PhysicsComplex Systems and MaterialsAaltoFinland
| | - Merja Ahonen
- Satakunta University of Applied Sciences, Faculty of TechnologyWANDER Nordic Water and Materials InstituteRaumaFinland
| | - Evgenia Iakovleva
- Aalto University, School of Science, Department of Applied PhysicsComplex Systems and MaterialsAaltoFinland
| | - Pasi Karppinen
- Aalto University, School of Science, Department of Applied PhysicsComplex Systems and MaterialsAaltoFinland
| | - Eelis Mielonen
- Aalto University, School of Science, Department of Applied PhysicsComplex Systems and MaterialsAaltoFinland
| | - Riika Mäkinen
- Satakunta University of Applied Sciences, Faculty of TechnologyWANDER Nordic Water and Materials InstituteRaumaFinland
| | - Katriina Mannonen
- Satakunta University of Applied Sciences, Faculty of TechnologyWANDER Nordic Water and Materials InstituteRaumaFinland
| | - Juha Koivisto
- Aalto University, School of Science, Department of Applied PhysicsComplex Systems and MaterialsAaltoFinland
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18
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Kang SM, de Josselin de Jong E, Higham SM, Hope CK, Kim BI. Fluorescence fingerprints of oral bacteria. JOURNAL OF BIOPHOTONICS 2020; 13:e201900190. [PMID: 31654475 DOI: 10.1002/jbio.201900190] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 09/30/2019] [Accepted: 10/02/2019] [Indexed: 06/10/2023]
Abstract
The rapid detection and identification of microorganisms is one of the most important factors in many cases of ill health. The purpose of this study was to determine the fluorescence characteristics of seven oral bacteria using emission spectra with the aim of distinguishing between the bacteria, and to compare fluorescence imaging methods for the direct assessment of oral bacteria. Fluorescence images of each bacterium were obtained under a 405-nm light source using a two-filter system. The emissions of all samples were measured with a fluorescence spectrometer. The complete fluorescence data set collected for each sample employed a three-dimensional data cube. The differences in the autofluorescence characteristics of the seven oral bacteria were determined by principal components analysis (PCA). The fluorescence images of the oral bacteria varied with the genus and the filter system. The three-dimensional excitation-emission matrix fluorescence spectra exhibited distinctive fluorescence features associated with intracellular fluorophores. The seven bacteria could be clearly differentiated on the PCA score plot. The findings of this study indicate that oral bacteria can be identified based on their autofluorescence characteristics. Fluorescence spectroscopy coupled with PCA can be used to detect and classify oral bacteria.
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Affiliation(s)
- Si-Mook Kang
- Department of Preventive Dentistry and Public Oral Health, BK21 PLUS Project, Yonsei University College of Dentistry, Seoul, Republic of Korea
| | - Elbert de Josselin de Jong
- Department of Preventive Dentistry and Public Oral Health, BK21 PLUS Project, Yonsei University College of Dentistry, Seoul, Republic of Korea
- Department of Health Services Research, University of Liverpool, Liverpool, UK
- Inspektor Research Systems BV, Amsterdam, the Netherlands
| | - Susan M Higham
- Department of Health Services Research, University of Liverpool, Liverpool, UK
| | - Christopher K Hope
- Department of Health Services Research, University of Liverpool, Liverpool, UK
| | - Baek-Il Kim
- Department of Preventive Dentistry and Public Oral Health, BK21 PLUS Project, Yonsei University College of Dentistry, Seoul, Republic of Korea
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19
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Ho HJ, Cao JW, Kao CM, Lai WL. Characterization of released metabolic organics during AOC analyses by P17 and NOX strains using 3-D fluorescent signals. CHEMOSPHERE 2019; 222:205-213. [PMID: 30708154 DOI: 10.1016/j.chemosphere.2019.01.115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 01/03/2019] [Accepted: 01/20/2019] [Indexed: 06/09/2023]
Abstract
Assimilable organic carbon (AOC) serves as an indicator of the biostability of drinking water distribution systems; however, the properties of the released organic metabolites by Pseudomonas fluorescens (P17) and Spirillum (NOX) used in AOC bioassays are seldom discussed. In this study, fluorescence excitation emission matrix (FEEM) was selected to characterize organic metabolites after substrate biotransformation and their divergences at different growth stages of both strains in AOC bioassay. Excellent correlation between ATP and colony-forming units (CFUs) was observed for both strains. The concentration of ATP per colony was six times higher in the P17 strain than in the NOX strain. A retarding phenomenon was observed for the NOX strain in the presence of high acetate-C content (100-150 μg acetate-C/L). The fluorescence wavelength peaks were wider for the protein-like substance released by the P17 strain than for those released by the NOX strain. However, fluorescent fulvic-like substances only existed in the NOX strain. Relative humus accumulation (RHA), the ratio of protein-like fluorescence intensity to humus-like fluorescence intensity, decreased in the P17 strain but substantially increased in the NOX strain in the logarithmic growth phase. RHA showed a descending trend for the P17 strain as compared to that of the NOX strain during the progress from logarithmic to stationary growth phase at three different acetate-C concentrations; however, the opposite was observed at 100 μg acetate-C/L, indicating that high acetate-C content may affect the properties of released organic matter from both strains.
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Affiliation(s)
- Hsiao-Jung Ho
- Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan
| | - Jing-Wen Cao
- Graduate School of Environmental Management, Tajen University, Pingtung, Taiwan
| | - Chih-Ming Kao
- Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan
| | - Wen-Liang Lai
- Graduate School of Environmental Management, Tajen University, Pingtung, Taiwan.
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20
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Sibilo R, Pérez JM, Hurth C, Pruneri V. Surface cytometer for fluorescent detection and growth monitoring of bacteria over a large field-of-view. BIOMEDICAL OPTICS EXPRESS 2019; 10:2101-2116. [PMID: 31061773 PMCID: PMC6484973 DOI: 10.1364/boe.10.002101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 03/15/2019] [Accepted: 03/17/2019] [Indexed: 06/09/2023]
Abstract
Monitoring the early onset of bacterial film formation is critical in many clinical, environmental, and food quality control applications. We built a small inexpensive optical surface cytometer, in contrast with bulk spectroscopic methods, around a light-emitting diode (LED) and a complementary metal-oxide-semiconductor (CMOS) image sensor. It is designed to offer a large field-of-view of 200 mm2 and a large depth-of-field of 2-3 mm to overcome the limitations of routine methods like spectrophotometry and fluorescence microscopy. It provides a direct measurement without the need for complex image post-processing with a limit-of-detection around 104 cells/mm2, which is competitive with other similar yet more complex devices already available.
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Affiliation(s)
- Rafaël Sibilo
- ICFO- Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Juan Miguel Pérez
- ICFO- Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Cedric Hurth
- ICFO- Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
| | - Valerio Pruneri
- ICFO- Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain
- ICREA- Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain
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21
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Buzalewicz I, Suchwałko A, Trzciński P, Sas-Paszt L, Sumorok B, Kowal K, Kozera R, Wieliczko A, Podbielska H. Integrated multi-channel optical system for bacteria characterization and its potential use for monitoring of environmental bacteria. BIOMEDICAL OPTICS EXPRESS 2019; 10:1165-1183. [PMID: 30891337 PMCID: PMC6420290 DOI: 10.1364/boe.10.001165] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 12/28/2018] [Accepted: 01/21/2019] [Indexed: 06/09/2023]
Abstract
The potential use of a novel multichannel optical system towards fast and non-destructive bacteria identification and its application for environmental bacteria characterisation on the strain level is presented. It is the first attempt to use the proposed optical method to study various bacteria species (Gram-negative, Gram-positive) commonly present in the environment. The novel configuration of the optical system enables multichannel examination of bacterial colonies and provides additional functionality such as registration of two-dimensional (2D) distribution of monochromatic transmission coefficient of examined colonies, what can be used as a novel optical signature for bacteria characterization. Performed statistical analysis indicates that it is possible to identify representatives of environmental soil bacteria on the species level with the 98.51% accuracy and in case of two strains of Rahnella aquatilis bacteria on the strain level with the 98.8% accuracy. The proposed method is an alternative to the currently used preliminary bacteria examination in environment safety control with the advantage of being fast, reliable, non-destructive and requiring minimal sample preparation.
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Affiliation(s)
- Igor Buzalewicz
- Bio-Optics Group, Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 27 Wybrzeże S. Wyspiańskiego Street, Wroclaw, Poland
| | | | - Paweł Trzciński
- Rhizosphere Laboratory, Agrotechnical Department, Research Institute of Horticulture, 1/3 Konstytucji 3 Maja Street, Skierniewice, Poland
| | - Lidia Sas-Paszt
- Rhizosphere Laboratory, Agrotechnical Department, Research Institute of Horticulture, 1/3 Konstytucji 3 Maja Street, Skierniewice, Poland
| | - Beata Sumorok
- Rhizosphere Laboratory, Agrotechnical Department, Research Institute of Horticulture, 1/3 Konstytucji 3 Maja Street, Skierniewice, Poland
| | | | - Ryszard Kozera
- Faculty of Applied Informatics and Mathematics, Warsaw University of Life Sciences SGGW, 159 Nowoursynowska Street, Warsaw, Poland
- School of Computer Science and Software Engineering, University of Western Australia, 35 Stirling Highway, WA 6009 Crawley, Perth, Australia
| | - Alina Wieliczko
- Department of Epizootiology and Veterinary Administration with Clinic of Infectious Diseases, Wroclaw University of Environmental and Life Science, 45 Grunwaldzki Square, Wroclaw, Poland
| | - Halina Podbielska
- Bio-Optics Group, Department of Biomedical Engineering, Faculty of Fundamental Problems of Technology, Wroclaw University of Science and Technology, 27 Wybrzeże S. Wyspiańskiego Street, Wroclaw, Poland
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22
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Rennie MY, Dunham D, Lindvere-Teene L, Raizman R, Hill R, Linden R. Understanding Real-Time Fluorescence Signals from Bacteria and Wound Tissues Observed with the MolecuLight i:X TM. Diagnostics (Basel) 2019; 9:E22. [PMID: 30813551 PMCID: PMC6468690 DOI: 10.3390/diagnostics9010022] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 02/20/2019] [Accepted: 02/20/2019] [Indexed: 11/16/2022] Open
Abstract
The persistent presence of pathogenic bacteria is one of the main obstacles to wound healing. Detection of wound bacteria relies on sampling methods, which delay confirmation by several days. However, a novel handheld fluorescence imaging device has recently enabled real-time detection of bacteria in wounds based on their intrinsic fluorescence characteristics, which differ from those of background tissues. This device illuminates the wound with violet (405 nm) light, causing tissues and bacteria to produce endogenous, characteristic fluorescence signals that are filtered and displayed on the device screen in real-time. The resulting images allow for rapid assessment and documentation of the presence, location, and extent of fluorescent bacteria at moderate-to-heavy loads. This information has been shown to assist in wound assessment and guide patient-specific treatment plans. However, proper image interpretation is essential to assessing this information. To properly identify regions of bacterial fluorescence, users must understand: (1) Fluorescence signals from tissues (e.g., wound tissues, tendon, bone) and fluids (e.g., blood, pus); (2) fluorescence signals from bacteria (red or cyan); (3) the rationale for varying hues of both tissue and bacterial fluorescence; (4) image artifacts that can occur; and (5) some potentially confounding signals from non-biological materials (e.g., fluorescent cleansing solutions). Therefore, this tutorial provides clinicians with a rationale for identifying common wound fluorescence characteristics. Clinical examples are intended to help clinicians with image interpretation-with a focus on image artifacts and potential confounders of image interpretation-and suggestions of how to overcome such challenges when imaging wounds in clinical practice.
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Affiliation(s)
| | | | | | - Rose Raizman
- Department of Professional Practice, Scarborough and Rouge Hospital, Toronto, ON M1E 4B9, Canada.
| | - Rosemary Hill
- Department of Ambulatory Care, Lions Gate Hospital, Vancouver Coastal Health, North Vancouver, BC V7L 2L7, Canada.
| | - Ron Linden
- Judy Dan Research and Treatment Centre, North York, ON M2R 1N5, Canada.
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23
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Ayala OD, Wakeman CA, Pence IJ, Gaddy JA, Slaughter JC, Skaar EP, Mahadevan-Jansen A. Drug-Resistant Staphylococcus aureus Strains Reveal Distinct Biochemical Features with Raman Microspectroscopy. ACS Infect Dis 2018; 4:1197-1210. [PMID: 29845863 PMCID: PMC6476553 DOI: 10.1021/acsinfecdis.8b00029] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Staphylococcus aureus ( S. aureus) is a leading cause of hospital-acquired infections, such as bacteremia, pneumonia, and endocarditis. Treatment of these infections can be challenging since strains of S. aureus, such as methicillin-resistant S. aureus (MRSA), have evolved resistance to antimicrobials. Current methods to identify infectious agents in hospital environments often rely on time-consuming, multistep culturing techniques to distinguish problematic strains (i.e., antimicrobial resistant variants) of a particular bacterial species. Therefore, a need exists for a rapid, label-free technique to identify drug-resistant bacterial strains to guide proper antibiotic treatment. Here, our findings demonstrate the ability to characterize and identify microbes at the subspecies level using Raman microspectroscopy, which probes the vibrational modes of molecules to provide a biochemical "fingerprint". This technique can distinguish between different isolates of species such as Streptococcus agalactiae and S. aureus. To determine the ability of this analytical approach to detect drug-resistant bacteria, isogenic variants of S. aureus including the comparison of strains lacking or expressing antibiotic resistance determinants were evaluated. Spectral variations observed may be associated with biochemical components such as amino acids, carotenoids, and lipids. Mutants lacking carotenoid production were distinguished from wild-type S. aureus and other strain variants. Furthermore, spectral biomarkers of S. aureus isogenic bacterial strains were identified. These results demonstrate the feasibility of Raman microspectroscopy for distinguishing between various genetically distinct forms of a single bacterial species in situ. This is important for detecting antibiotic-resistant strains of bacteria and indicates the potential for future identification of other multidrug resistant pathogens with this technique.
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Affiliation(s)
- Oscar D. Ayala
- Biophotonics Center, Vanderbilt University, 410 24th Avenue South, Nashville, Tennessee 37235, United States
- Department of Biomedical Engineering, Vanderbilt University, 5824 Stevenson Center, Nashville, Tennessee 37232, United States
| | - Catherine A. Wakeman
- Department of Biological Sciences, Texas Tech University, 2901 Main Street, Lubbock, Texas 79409, United States
| | - Isaac J. Pence
- Biophotonics Center, Vanderbilt University, 410 24th Avenue South, Nashville, Tennessee 37235, United States
- Department of Biomedical Engineering, Vanderbilt University, 5824 Stevenson Center, Nashville, Tennessee 37232, United States
| | - Jennifer A. Gaddy
- Department of Medicine, Division of Infectious Diseases, Vanderbilt University Medical Center, 1161 21st Avenue South, Medical Center North, Nashville, Tennessee 37232, United States
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, 1161 21st Avenue South, Medical Center North, Nashville, Tennessee 37232, United States
- Tennessee Valley Healthcare Systems, Department of Veterans Affairs, 1310 24th Avenue South, Nashville, Tennessee 37212, United States
| | - James C. Slaughter
- Department of Biostatistics, Vanderbilt University School of Medicine, 2525 West End Avenue, Suite 11000, Nashville, Tennessee 37203, United States
| | - Eric P. Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, 1161 21st Avenue South, Medical Center North, Nashville, Tennessee 37232, United States
| | - Anita Mahadevan-Jansen
- Biophotonics Center, Vanderbilt University, 410 24th Avenue South, Nashville, Tennessee 37235, United States
- Department of Biomedical Engineering, Vanderbilt University, 5824 Stevenson Center, Nashville, Tennessee 37232, United States
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24
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Abstract
A variety of direct and indirect methods have been used to quantify planktonic and biofilm bacterial cells. Direct counting methods to determine the total number of cells include plate counts, microscopic cell counts, Coulter cell counting, flow cytometry, and fluorescence microscopy. However, indirect methods are often used to supplement direct cell counting, as they are often more convenient, less time-consuming, and require less material, while providing a number that can be related to the direct cell count. Herein, an indirect method is presented that uses fluorescence emission intensity as a proxy marker for studying bacterial accumulation. A clinical strain of Pseudomonas aeruginosa was genetically modified to express a green fluorescent protein (PA14/EGFP). The fluorescence intensity of EGFP in live cells was used as an indirect measure of live cell density, and was compared with the traditional cell counting methods of optical density (OD600) and plate counting (colony-forming units (CFUs)). While both OD600 and CFUs are well-established methods, the use of fluorescence spectroscopy to quantify bacteria is less common. This study demonstrates that EGFP intensity is a convenient reporter for bacterial quantification. In addition, we demonstrate the potential for fluorescence spectroscopy to be used to measure the quantity of PA14/EGFP biofilms, which have important human health implications due to their antimicrobial resistance. Therefore, fluorescence spectroscopy could serve as an alternative or complementary quick assay to quantify bacteria in planktonic cultures and biofilms.
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25
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Sorensen JPR, Baker A, Cumberland SA, Lapworth DJ, MacDonald AM, Pedley S, Taylor RG, Ward JST. Real-time detection of faecally contaminated drinking water with tryptophan-like fluorescence: defining threshold values. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 622-623:1250-1257. [PMID: 29890592 DOI: 10.1016/j.scitotenv.2017.11.162] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 11/14/2017] [Accepted: 11/15/2017] [Indexed: 06/08/2023]
Abstract
We assess the use of fluorescent dissolved organic matter at excitation-emission wavelengths of 280nm and 360nm, termed tryptophan-like fluorescence (TLF), as an indicator of faecally contaminated drinking water. A significant logistic regression model was developed using TLF as a predictor of thermotolerant coliforms (TTCs) using data from groundwater- and surface water-derived drinking water sources in India, Malawi, South Africa and Zambia. A TLF threshold of 1.3ppb dissolved tryptophan was selected to classify TTC contamination. Validation of the TLF threshold indicated a false-negative error rate of 15% and a false-positive error rate of 18%. The threshold was unsuccessful at classifying contaminated sources containing <10 TTC cfu per 100mL, which we consider the current limit of detection. If only sources above this limit were classified, the false-negative error rate was very low at 4%. TLF intensity was very strongly correlated with TTC concentration (ρs=0.80). A higher threshold of 6.9ppb dissolved tryptophan is proposed to indicate heavily contaminated sources (≥100 TTC cfu per 100mL). Current commercially available fluorimeters are easy-to-use, suitable for use online and in remote environments, require neither reagents nor consumables, and crucially provide an instantaneous reading. TLF measurements are not appreciably impaired by common intereferents, such as pH, turbidity and temperature, within typical natural ranges. The technology is a viable option for the real-time screening of faecally contaminated drinking water globally.
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Affiliation(s)
| | - Andy Baker
- Connected Waters Initiative Research Centre, UNSW Australia, Sydney, New South Wales 2052, Australia
| | | | - Dan J Lapworth
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK
| | | | - Steve Pedley
- Department of Civil and Environmental Engineering, University of Surrey, Guildford GU2 7XH, UK
| | - Richard G Taylor
- Department of Geography, University College London, London WC1E 6BT, UK
| | - Jade S T Ward
- British Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK; Department of Civil and Environmental Engineering, University of Surrey, Guildford GU2 7XH, UK
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26
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Kumar G, Roy A, McMullen RS, Kutagulla S, Bradforth SE. The influence of aqueous solvent on the electronic structure and non-adiabatic dynamics of indole explored by liquid-jet photoelectron spectroscopy. Faraday Discuss 2018; 212:359-381. [DOI: 10.1039/c8fd00123e] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Time-resolved photoelectron spectroscopy (TRPES) in a liquid micro-jet is implemented here to investigate the influence of water on the electronic structure and dynamics of indole, the chromophore of the amino acid tryptophan.
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Affiliation(s)
- Gaurav Kumar
- Department of Chemistry
- University of Southern California
- Los Angeles
- USA
| | - Anirban Roy
- Department of Chemistry
- University of Southern California
- Los Angeles
- USA
| | - Ryan S. McMullen
- Department of Chemistry
- University of Southern California
- Los Angeles
- USA
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27
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Fox BG, Thorn RMS, Anesio AM, Reynolds DM. The in situ bacterial production of fluorescent organic matter; an investigation at a species level. WATER RESEARCH 2017; 125:350-359. [PMID: 28881211 DOI: 10.1016/j.watres.2017.08.040] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 07/31/2017] [Accepted: 08/17/2017] [Indexed: 06/07/2023]
Abstract
Aquatic dissolved organic matter (DOM) plays an essential role in biogeochemical cycling and transport of organic matter throughout the hydrological continuum. To characterise microbially-derived organic matter (OM) from common environmental microorganisms (Escherichia coli, Bacillus subtilis and Pseudomonas aeruginosa), excitation-emission matrix (EEM) fluorescence spectroscopy was employed. This work shows that bacterial organisms can produce fluorescent organic matter (FOM) in situ and, furthermore, that the production of FOM differs at a bacterial species level. This production can be attributed to structural biological compounds, specific functional proteins (e.g. pyoverdine production by P. aeruginosa), and/or metabolic by-products. Bacterial growth curve data demonstrates that the production of FOM is fundamentally related to microbial metabolism. For example, the majority of Peak T fluorescence (> 75%) is shown to be intracellular in origin, as a result of the building of proteins for growth and metabolism. This underpins the use of Peak T as a measure of microbial activity, as opposed to bacterial enumeration as has been previously suggested. This study shows that different bacterial species produce a range of FOM that has historically been attributed to high molecular weight allochthonous material or the degradation of terrestrial FOM. We provide definitive evidence that, in fact, it can be produced by microbes within a model system (autochthonous), providing new insights into the possible origin of allochthonous and autochthonous organic material present in aquatic systems.
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Affiliation(s)
- B G Fox
- Centre for Research in Biosciences, University of the West of England, Bristol, BS16 1QY, UK
| | - R M S Thorn
- Centre for Research in Biosciences, University of the West of England, Bristol, BS16 1QY, UK
| | - A M Anesio
- School of Geographical Sciences, University of Bristol, Bristol, BS8 1SS, UK
| | - D M Reynolds
- Centre for Research in Biosciences, University of the West of England, Bristol, BS16 1QY, UK.
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28
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Li R, Goswami U, Walck M, Khan K, Chen J, Cesario TC, Rentzepis PM. Hand-held synchronous scan spectrometer for in situ and immediate detection of live/dead bacteria ratio. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:114301. [PMID: 29195411 DOI: 10.1063/1.4991351] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The design, construction, and operation of a hand-held synchronously scanned, excitation-emission, double monochromator spectrometer is described. Data show that it is possible to record and display within minutes the fluorescence spectra and ratio of live/dead bacteria in situ. Excitation emission matrix contour plots display clearly bacteria fluorescence spectra before and after UV inactivation, respectively. The separation of the fluorescence band maxima of molecular components, such as tryptophan, tyrosine, and DNA, may be distinguished in the diffused fluorescence spectra of bacteria and mixtures.
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Affiliation(s)
- Runze Li
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, USA
| | - Umang Goswami
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, USA
| | - Matthew Walck
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, USA
| | - Kasfia Khan
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, USA
| | - Jie Chen
- Center for Ultrafast Science and Technology, Key Laboratory for Laser Plasmas (Ministry of Education), School of Physics and Astronomy, and Collaborative Innovation Center of Inertial Fusion Sciences and Applications (CICIFSA), Shanghai Jiao Tong University, Shanghai 200240, China
| | - Thomas C Cesario
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, USA
| | - Peter M Rentzepis
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, USA
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29
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Albright V, Zhuk I, Wang Y, Selin V, van de Belt-Gritter B, Busscher HJ, van der Mei HC, Sukhishvili SA. Self-defensive antibiotic-loaded layer-by-layer coatings: Imaging of localized bacterial acidification and pH-triggering of antibiotic release. Acta Biomater 2017; 61:66-74. [PMID: 28803214 DOI: 10.1016/j.actbio.2017.08.012] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 07/22/2017] [Accepted: 08/08/2017] [Indexed: 10/19/2022]
Abstract
Self-defensive antibiotic-loaded coatings have shown promise in inhibiting growth of pathogenic bacteria adhering to biomaterial implants and devices, but direct proof that their antibacterial release is triggered by bacterially-induced acidification of the immediate environment under buffered conditions remained elusive. Here, we demonstrate that Staphylococcus aureus and Escherichia coli adhering to such coatings generate highly localized acidification, even in buffered conditions, to activate pH-triggered, self-defensive antibiotic release. To this end, we utilized chemically crosslinked layer-by-layer hydrogel coatings of poly(methacrylic acid) with a covalently attached pH-sensitive SNARF-1 fluorescent label for imaging, and unlabeled-antibiotic (gentamicin or polymyxin B) loaded coatings for antibacterial studies. Local acidification of the coatings induced by S. aureus and E. coli adhering to the coatings was demonstrated by confocal-laser-scanning-microscopy via wavelength-resolved imaging. pH-triggered antibiotic release under static, small volume conditions yielded high bacterial killing efficiencies for S. aureus and E. coli. Gentamicin-loaded films retained their antibacterial activity against S. aureus under fluid flow in buffered conditions. Antibacterial activity increased with the number of polymer layers in the films. Altogether, pH-triggered, self-defensive antibiotic-loaded coatings become activated by highly localized acidification in the immediate environment of an adhering bacterium, offering potential for clinical application with minimized side-effects. STATEMENT OF SIGNIFICANCE Polymeric coatings were created that are able to uptake and selectively release antibiotics upon stimulus by adhering bacteria in order to understand the fundamental mechanisms behind pH-triggered antibiotic release as a potential way to prevent biomaterial-associated infections. Through fluorescent imaging studies, this work importantly shows that adhering bacteria produce highly localized pH changes even in buffer. Accordingly such coatings only demonstrate antibacterial activity by antibiotic release in the presence of adhering bacteria. This is clinically important, because ad libitum releasing antibiotic coatings usually show a burst release and have often lost their antibiotic content when bacteria adhere.
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30
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Bhattacharjee A, Datta R, Gratton E, Hochbaum AI. Metabolic fingerprinting of bacteria by fluorescence lifetime imaging microscopy. Sci Rep 2017; 7:3743. [PMID: 28623341 PMCID: PMC5473825 DOI: 10.1038/s41598-017-04032-w] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 05/22/2017] [Indexed: 12/21/2022] Open
Abstract
Bacterial populations exhibit a range of metabolic states influenced by their environment, intra- and interspecies interactions. The identification of bacterial metabolic states and transitions between them in their native environment promises to elucidate community behavior and stochastic processes, such as antibiotic resistance acquisition. In this work, we employ two-photon fluorescence lifetime imaging microscopy (FLIM) to create a metabolic fingerprint of individual bacteria and populations. FLIM of autofluorescent reduced nicotinamide adenine dinucleotide (phosphate), NAD(P)H, has been previously exploited for label-free metabolic imaging of mammalian cells. However, NAD(P)H FLIM has not been established as a metabolic proxy in bacteria. Applying the phasor approach, we create FLIM-phasor maps of Escherichia coli, Salmonella enterica serovar Typhimurium, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus epidermidis at the single cell and population levels. The bacterial phasor is sensitive to environmental conditions such as antibiotic exposure and growth phase, suggesting that observed shifts in the phasor are representative of metabolic changes within the cells. The FLIM-phasor approach represents a powerful, non-invasive imaging technique to study bacterial metabolism in situ and could provide unique insights into bacterial community behavior, pathology and antibiotic resistance with sub-cellular resolution.
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Affiliation(s)
- Arunima Bhattacharjee
- Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, CA, 92697, USA
| | - Rupsa Datta
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, 92697, USA
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, 92697, USA
| | - Allon I Hochbaum
- Department of Chemical Engineering and Materials Science, University of California, Irvine, Irvine, CA, 92697, USA.
- Department of Chemistry, University of California, Irvine, Irvine, CA, 92697, USA.
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31
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Silva AS, Quintelas C, Ferreira EC, Lopes JA, Sousa C. Exploiting intrinsic fluorescence spectroscopy to discriminate between Acinetobacter calcoaceticus–Acinetobacter baumannii complex species. RSC Adv 2017. [DOI: 10.1039/c6ra27531a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Spectroscopy for bacterial typing purposes. Instrisinc fluorescence versus FTIR-ATR and MALDI-TOF MS.
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Affiliation(s)
- Ana Sofia Silva
- CEB-Centre of Biological Engineering
- University of Minho
- Braga
- Portugal
| | | | | | - João A. Lopes
- Research Institute for Medicines (iMed.ULisboa)
- Faculdade de Farmácia
- Universidade de Lisboa
- Lisboa
- Portugal
| | - Clara Sousa
- LAQV/REQUIMTE
- Departamento de Ciências Químicas
- Faculdade de Farmácia
- Universidade do Porto
- 4050-313 Porto
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32
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Buzalewicz I, Kujawińska M, Krauze W, Podbielska H. Novel Perspectives on the Characterization of Species-Dependent Optical Signatures of Bacterial Colonies by Digital Holography. PLoS One 2016; 11:e0150449. [PMID: 26943121 PMCID: PMC4778909 DOI: 10.1371/journal.pone.0150449] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 02/14/2016] [Indexed: 11/19/2022] Open
Abstract
The use of light diffraction for the microbiological diagnosis of bacterial colonies was a significant breakthrough with widespread implications for the food industry and clinical practice. We previously confirmed that optical sensors for bacterial colony light diffraction can be used for bacterial identification. This paper is focused on the novel perspectives of this method based on digital in-line holography (DIH), which is able to reconstruct the amplitude and phase properties of examined objects, as well as the amplitude and phase patterns of the optical field scattered/diffracted by the bacterial colony in any chosen observation plane behind the object from single digital hologram. Analysis of the amplitude and phase patterns inside a colony revealed its unique optical properties, which are associated with the internal structure and geometry of the bacterial colony. Moreover, on a computational level, it is possible to select the desired scattered/diffracted pattern within the entire observation volume that exhibits the largest amount of unique, differentiating bacterial features. These properties distinguish this method from the already proposed sensing techniques based on light diffraction/scattering of bacterial colonies. The reconstructed diffraction patterns have a similar spatial distribution as the recorded Fresnel patterns, previously applied for bacterial identification with over 98% accuracy, but they are characterized by both intensity and phase distributions. Our results using digital holography provide new optical discriminators of bacterial species revealed in one single step in form of new optical signatures of bacterial colonies: digital holograms, reconstructed amplitude and phase patterns, as well as diffraction patterns from all observation space, which exhibit species-dependent features. To the best of our knowledge, this is the first report on bacterial colony analysis via digital holography and our study represents an innovative approach to the subject.
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Affiliation(s)
- Igor Buzalewicz
- Faculty of Fundamental Problems of Technology, Department of Biomedical Engineering, Bio-Optics Group, Wrocław University of Technology, Wrocław, Poland
| | - Małgorzata Kujawińska
- Department of Mechatronics, Institute of Micromechanics and Photonics, Warsaw University of Technology, Warsaw, Poland
| | - Wojciech Krauze
- Department of Mechatronics, Institute of Micromechanics and Photonics, Warsaw University of Technology, Warsaw, Poland
| | - Halina Podbielska
- Faculty of Fundamental Problems of Technology, Department of Biomedical Engineering, Bio-Optics Group, Wrocław University of Technology, Wrocław, Poland
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33
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Suppi S, Kasemets K, Ivask A, Künnis-Beres K, Sihtmäe M, Kurvet I, Aruoja V, Kahru A. A novel method for comparison of biocidal properties of nanomaterials to bacteria, yeasts and algae. JOURNAL OF HAZARDOUS MATERIALS 2015; 286:75-84. [PMID: 25559861 DOI: 10.1016/j.jhazmat.2014.12.027] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 12/01/2014] [Accepted: 12/15/2014] [Indexed: 05/29/2023]
Abstract
Toxicity testing of nanomaterials (NMs) is experimentally challenging because NMs may interfere with test environment and assay components. In this work we propose a simple and reliable method--a 'spot test' to compare biocidal potency of NMs to unicellular microorganisms such as bacteria, yeasts and algae. The assay is straightforward: cells are incubated in deionized water suspensions of NMs for up to 24h and then pipetted as a 'spot' on agarized medium. Altogether seven bacterial strains, yeast and a microalga were tested. CuO, TiO2 and two different Ag NPs, multi-wall C-nanotubes (MWCNTs), AgNO3, CuSO4, 3,5-dichlorophenol, triclosan and H2O2 were analyzed. The biocidal potency of tested substances ranged from 0.1mg/L to >1000 mg/L; whereas, the least potent NMs toward all test species were TiO2 NPs and MWCNTs and most potent Ag and CuO NPs. Based on the similar toxicity pattern of the tested chemicals on the nine unicellular organisms in deionized water we conclude that toxicity mechanism of biocidal chemicals seems to be similar, whatever the organism (bacteria, yeast, alga). Therefore, when the organisms are not 'protected' by their environment that usually includes various organic and inorganic supplements their tolerance to toxicants is chemical- rather than organism-dependent.
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Affiliation(s)
- Sandra Suppi
- Laboratory of Environmental Toxicology, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618, Estonia; Faculty of Chemical and Materials Technology, Tallinn University of Technology, Ehitajate tee 5, Tallinn 19086, Estonia.
| | - Kaja Kasemets
- Laboratory of Environmental Toxicology, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618, Estonia.
| | - Angela Ivask
- Laboratory of Environmental Toxicology, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618, Estonia.
| | - Kai Künnis-Beres
- Laboratory of Environmental Toxicology, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618, Estonia.
| | - Mariliis Sihtmäe
- Laboratory of Environmental Toxicology, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618, Estonia.
| | - Imbi Kurvet
- Laboratory of Environmental Toxicology, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618, Estonia.
| | - Villem Aruoja
- Laboratory of Environmental Toxicology, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618, Estonia.
| | - Anne Kahru
- Laboratory of Environmental Toxicology, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn 12618, Estonia.
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34
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Awad F, Ramprasath C, Mathivanan N, Aruna PR, Ganesan S. Optical Fiber-Based Steady State and Fluorescence Lifetime Spectroscopy for Rapid Identification and Classification of Bacterial Pathogens Directly from Colonies on Agar Plates. INTERNATIONAL SCHOLARLY RESEARCH NOTICES 2014; 2014:430412. [PMID: 27379265 PMCID: PMC4897486 DOI: 10.1155/2014/430412] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 07/09/2014] [Indexed: 11/17/2022]
Abstract
Fluorescence spectroscopy was examined as a potential technique for identification and classification of bacterial pathogens. Colonies of Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhi, and Klebsiella pneumoniae on agar plates were measured directly using a laboratory spectrofluorimeter coupled with optical fiber. Steady state fluorescence spectra were collected following excitation at 280 nm (tryptophan) and 380 nm (NADH). Results showed that fluorescence lifetime decays of tryptophan at 280 nm excitation from the four organisms were best described with triexponential fit and it reveals the existence of different protein conformation. The emission spectroscopy of the four bacteria at 380 nm excitation (NADH) provided better classification (100% of original grouped cases correctly classified and 98.1% of cross-validated grouped cases correctly classified) than that of 280 nm excitation (tryptophan). Our results demonstrated that optical fiber-based fluorescence identification and classification of bacteria is rapid, easy to perform, and of low cost compared to standard methods.
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Affiliation(s)
- Fathi Awad
- Department of Medical Physics, Anna University, Chennai 600025, India; Department of Medical Physics, Red Sea University, P.O. Box 24, Port Sudan, Sudan
| | | | | | - Prakasa Rao Aruna
- Department of Medical Physics, Anna University, Chennai 600025, India
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