1
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Nikolic N, Anagnostidis V, Tiwari A, Chait R, Gielen F. Droplet-based methodology for investigating bacterial population dynamics in response to phage exposure. Front Microbiol 2023; 14:1260196. [PMID: 38075890 PMCID: PMC10703435 DOI: 10.3389/fmicb.2023.1260196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 10/23/2023] [Indexed: 02/12/2024] Open
Abstract
An alarming rise in antimicrobial resistance worldwide has spurred efforts into the search for alternatives to antibiotic treatments. The use of bacteriophages, bacterial viruses harmless to humans, represents a promising approach with potential to treat bacterial infections (phage therapy). Recent advances in microscopy-based single-cell techniques have allowed researchers to develop new quantitative methodologies for assessing the interactions between bacteria and phages, especially the ability of phages to eradicate bacterial pathogen populations and to modulate growth of both commensal and pathogen populations. Here we combine droplet microfluidics with fluorescence time-lapse microscopy to characterize the growth and lysis dynamics of the bacterium Escherichia coli confined in droplets when challenged with phage. We investigated phages that promote lysis of infected E. coli cells, specifically, a phage species with DNA genome, T7 (Escherichia virus T7) and two phage species with RNA genomes, MS2 (Emesvirus zinderi) and Qβ (Qubevirus durum). Our microfluidic trapping device generated and immobilized picoliter-sized droplets, enabling stable imaging of bacterial growth and lysis in a temperature-controlled setup. Temporal information on bacterial population size was recorded for up to 25 h, allowing us to determine growth rates of bacterial populations and helping us uncover the extent and speed of phage infection. In the long-term, the development of novel microfluidic single-cell and population-level approaches will expedite research towards fundamental understanding of the genetic and molecular basis of rapid phage-induced lysis and eco-evolutionary aspects of bacteria-phage dynamics, and ultimately help identify key factors influencing the success of phage therapy.
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Affiliation(s)
- Nela Nikolic
- Living Systems Institute, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
- Department of Physics and Astronomy, Faculty of Environment, Science and Economy, University of Exeter, Exeter, United Kingdom
- Translational Research Exchange @ Exeter, University of Exeter, Exeter, United Kingdom
| | - Vasileios Anagnostidis
- Living Systems Institute, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
- Department of Physics and Astronomy, Faculty of Environment, Science and Economy, University of Exeter, Exeter, United Kingdom
| | - Anuj Tiwari
- Living Systems Institute, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
| | - Remy Chait
- Living Systems Institute, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
- Department of Biosciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
| | - Fabrice Gielen
- Living Systems Institute, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom
- Department of Physics and Astronomy, Faculty of Environment, Science and Economy, University of Exeter, Exeter, United Kingdom
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2
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Liu Y, Xu P. Quantitative and analytical tools to analyze the spatiotemporal population dynamics of microbial consortia. Curr Opin Biotechnol 2022; 76:102754. [PMID: 35809433 DOI: 10.1016/j.copbio.2022.102754] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/30/2022] [Accepted: 06/06/2022] [Indexed: 12/27/2022]
Abstract
Microorganisms occupy almost every niche on earth. They play critical roles in maintaining ecological balance, atmospheric C/N cycle, and human health. Microbes live in consortia with metabolite exchange or signal communication. Quantitative and analytical tools are becoming increasingly important to study microbial consortia dynamics. We argue that a combined reductionist and holistic approach will be important to understanding the assembly rules and spatiotemporal population dynamics of the microbial community (MICOM). Reductionism allows us to reconstruct complex MICOM from isolated or simple synthetic consortia. Holism allows us to understand microbes as a community with cooperation and competition. Here we review the recent development of quantitative and analytical tools to uncover the underlying principles in microbial communities that govern their spatiotemporal change and interaction dynamics. Mathematical models and analytical tools will continue to provide essential knowledge and expand our capability to manipulate and control microbial consortia.
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Affiliation(s)
- Yugeng Liu
- Department of Chemical Engineering, Guangdong Technion-Israel Institute of Technology, Shantou, Guangdong 515063, China
| | - Peng Xu
- Department of Chemical Engineering, Guangdong Technion-Israel Institute of Technology, Shantou, Guangdong 515063, China; Guangdong Provincial Key Laboratory of Materials and Technologies for Energy Conversion, Guangdong Technion-Israel Institute of Technology, Shantou, Guangdong 515063, China.
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3
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Taylor D, Verdon N, Lomax P, Allen RJ, Titmuss S. Tracking the stochastic growth of bacterial populations in microfluidic droplets. Phys Biol 2022; 19. [PMID: 35042205 DOI: 10.1088/1478-3975/ac4c9b] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 01/18/2022] [Indexed: 11/11/2022]
Abstract
Bacterial growth in microfluidic droplets is relevant in biotechnology, in microbial ecology, and in understanding stochastic population dynamics in small populations. However, it has proved challenging to automate measurement of absolute bacterial numbers within droplets, forcing the use of proxy measures for population size. Here we present a microfluidic device and imaging protocol that allows high-resolution imaging of thousands of droplets, such that individual bacteria stay in the focal plane and can be counted automatically. Using this approach, we track the stochastic growth of hundreds of replicate Escherichia coli populations within droplets. {We find that, for early times, the statistics of the growth trajectories obey the predictions of the Bellman-Harris model, in which there is no inheritance of division time. Our approach should allow further testing of models for stochastic growth dynamics, as well as contributing to broader applications of droplet-based bacterial culture.
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Affiliation(s)
- Daniel Taylor
- The University of Edinburgh School of Physics and Astronomy, JCMB, Edinburgh, EH9 3FD, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
| | - Nia Verdon
- The University of Edinburgh School of Physics and Astronomy, JCMB, Edinburgh, EH9 3FD, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
| | - Peter Lomax
- School of Engineering, University of Edinburgh, The University of Edinburgh Institute for Integrated Micro and Nano Systems, Scottish Microelectronics Centre, King's Buildings, Alexander Crum Brown Road, Edinburgh, Edinburgh, EH9 3FF, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
| | - Rosalind J Allen
- Theoretical Microbial Ecology, Friedrich-Schiller-Universität Jena, Buchaer Strasse 6, Jena, Thüringen, 07749, GERMANY
| | - Simon Titmuss
- The University of Edinburgh School of Physics and Astronomy, JCMB, Edinburgh, EH9 3FD, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
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4
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Uzoukwu EU, Phandanouvong-Lozano V, Usman H, Sfeir C, Niepa THR. Droplet-based microsystems as novel assessment tools for oral microbial dynamics. Biotechnol Adv 2022; 55:107903. [PMID: 34990774 DOI: 10.1016/j.biotechadv.2021.107903] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 12/03/2021] [Accepted: 12/30/2021] [Indexed: 12/11/2022]
Abstract
The human microbiome comprises thousands of microbial species that live in and on the body and play critical roles in human health and disease. Recent findings on the interplay among members of the oral microbiome, defined by a personalized set of microorganisms, have elucidated the role of bacteria and yeasts in oral health and diseases including dental caries, halitosis, and periodontal infections. However, the majority of these studies rely on traditional culturing methods which are limited in their ability of replicating the oral microenvironment, and therefore fail to evaluate key microbial interactions in microbiome dynamics. Novel culturing methods have emerged to address this shortcoming. Here, we reviewed the potential of droplet-based microfluidics as an alternative approach for culturing microorganisms and assessing the oral microbiome dynamics. We discussed the state of the art and recent progress in the field of oral microbiology. Although at its infancy, droplet-based microtechnology presents an interesting potential for elucidating oral microbial dynamics and pathophysiology. We highlight how new findings provided by current microfluidic-based methodologies could advance the investigation of the oral microbiome. We anticipate that our work involving the droplet-based microfluidic technique with a semipermeable membrane will lay the foundations for future microbial dynamics studies and further expand the knowledge of the oral microbiome and its implication in oral health.
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Affiliation(s)
| | | | - Huda Usman
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, PA, USA
| | - Charles Sfeir
- Department of Bioengineering, University of Pittsburgh, PA, USA; Department of Periodontics and Preventive Dentistry, University of Pittsburgh, PA, USA; Department of Oral Biology, University of Pittsburgh, PA, USA; The Center for Craniofacial Regeneration, University of Pittsburgh, PA, USA; The McGowan Institute for Regenerative Medicine, University of Pittsburgh, PA, USA
| | - Tagbo H R Niepa
- Department of Chemical and Petroleum Engineering, University of Pittsburgh, PA, USA; Department of Bioengineering, University of Pittsburgh, PA, USA; Department of Civil and Environmental Engineering, University of Pittsburgh, PA, USA; Department of Mechanical Engineering and Materials Science, University of Pittsburgh, PA, USA; Center for Medicine and the Microbiome, University of Pittsburgh, PA, USA; The McGowan Institute for Regenerative Medicine, University of Pittsburgh, PA, USA.
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5
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Hengoju S, Tovar M, Man DKW, Buchheim S, Rosenbaum MA. Droplet Microfluidics for Microbial Biotechnology. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2020; 179:129-157. [PMID: 32888037 DOI: 10.1007/10_2020_140] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Droplet microfluidics has recently evolved as a prominent platform for high-throughput experimentation for various research fields including microbiology. Key features of droplet microfluidics, like compartmentalization, miniaturization, and parallelization, have enabled many possibilities for microbiology including cultivation of microorganisms at a single-cell level, study of microbial interactions in a community, detection and analysis of microbial products, and screening of extensive microbial libraries with ultrahigh-throughput and minimal reagent consumptions. In this book chapter, we present several aspects and applications of droplet microfluidics for its implementation in various fields of microbial biotechnology. Recent advances in the cultivation of microorganisms in droplets including methods for isolation and domestication of rare microbes are reviewed. Similarly, a comparison of different detection and analysis techniques for microbial activities is summarized. Finally, several microbial applications are discussed with a focus on exploring new antimicrobials and high-throughput enzyme activity screening. We aim to highlight the advantages, limitations, and current developments in droplet microfluidics for microbial biotechnology while envisioning its enormous potential applications in the future.
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Affiliation(s)
- Sundar Hengoju
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Jena, Germany.,Faculty of Biological Sciences, Friedrich Schiller University (FSU), Jena, Germany
| | - Miguel Tovar
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Jena, Germany
| | - DeDe Kwun Wai Man
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Jena, Germany
| | - Stefanie Buchheim
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Jena, Germany.,Faculty of Biological Sciences, Friedrich Schiller University (FSU), Jena, Germany
| | - Miriam A Rosenbaum
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute (HKI), Jena, Germany. .,Faculty of Biological Sciences, Friedrich Schiller University (FSU), Jena, Germany.
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6
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Interindividual Variation in Dietary Carbohydrate Metabolism by Gut Bacteria Revealed with Droplet Microfluidic Culture. mSystems 2020; 5:5/3/e00864-19. [PMID: 32606031 PMCID: PMC7329328 DOI: 10.1128/msystems.00864-19] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Bacterial culture and assay are components of basic microbiological research, drug development, and diagnostic screening. However, community diversity can make it challenging to comprehensively perform experiments involving individual microbiota members. Here, we present a new microfluidic culture platform that makes it feasible to measure the growth and function of microbiota constituents in a single set of experiments. As a proof of concept, we demonstrate how the platform can be used to measure how hundreds of gut bacterial taxa drawn from different people metabolize dietary carbohydrates. Going forward, we expect this microfluidic technique to be adaptable to a range of other microbial assay needs. Culture and screening of gut bacteria enable testing of microbial function and therapeutic potential. However, the diversity of human gut microbial communities (microbiota) impedes comprehensive experimental studies of individual bacterial taxa. Here, we combine advances in droplet microfluidics and high-throughput DNA sequencing to develop a platform for separating and assaying growth of microbiota members in picoliter droplets (MicDrop). MicDrop enabled us to cultivate 2.8 times more bacterial taxa than typical batch culture methods. We then used MicDrop to test whether individuals possess similar abundances of carbohydrate-degrading gut bacteria, using an approach which had previously not been possible due to throughput limitations of traditional bacterial culture techniques. Single MicDrop experiments allowed us to characterize carbohydrate utilization among dozens of gut bacterial taxa from distinct human stool samples. Our aggregate data across nine healthy stool donors revealed that all of the individuals harbored gut bacterial species capable of degrading common dietary polysaccharides. However, the levels of richness and abundance of polysaccharide-degrading species relative to monosaccharide-consuming taxa differed by up to 2.6-fold and 24.7-fold, respectively. Additionally, our unique dataset suggested that gut bacterial taxa may be broadly categorized by whether they can grow on single or multiple polysaccharides, and we found that this lifestyle trait is correlated with how broadly bacterial taxa can be found across individuals. This demonstration shows that it is feasible to measure the function of hundreds of bacterial taxa across multiple fecal samples from different people, which should in turn enable future efforts to design microbiota-directed therapies and yield new insights into microbiota ecology and evolution. IMPORTANCE Bacterial culture and assay are components of basic microbiological research, drug development, and diagnostic screening. However, community diversity can make it challenging to comprehensively perform experiments involving individual microbiota members. Here, we present a new microfluidic culture platform that makes it feasible to measure the growth and function of microbiota constituents in a single set of experiments. As a proof of concept, we demonstrate how the platform can be used to measure how hundreds of gut bacterial taxa drawn from different people metabolize dietary carbohydrates. Going forward, we expect this microfluidic technique to be adaptable to a range of other microbial assay needs.
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7
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Azarmanesh M, Dejam M, Azizian P, Yesiloz G, Mohamad AA, Sanati-Nezhad A. Passive microinjection within high-throughput microfluidics for controlled actuation of droplets and cells. Sci Rep 2019; 9:6723. [PMID: 31040307 PMCID: PMC6491429 DOI: 10.1038/s41598-019-43056-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 04/10/2019] [Indexed: 01/30/2023] Open
Abstract
Microinjection is an effective actuation technique used for precise delivery of molecules and cells into droplets or controlled delivery of genes, molecules, proteins, and viruses into single cells. Several microinjection techniques have been developed for actuating droplets and cells. However, they are still time-consuming, have shown limited success, and are not compatible with the needs of high-throughput (HT) serial microinjection. We present a new passive microinjection technique relying on pressure-driven fluid flow and pulsative flow patterns within an HT droplet microfluidic system to produce serial droplets and manage rapid and highly controlled microinjection into droplets. A microneedle is secured within the injection station to confine droplets during the microinjection. The confinement of droplets on the injection station prevents their movement or deformation during the injection process. Three-dimensional (3D) computational analysis is developed and validated to model the dynamics of multiphase flows during the emulsion generation. We investigate the influence of pulsative flows, microneedle parameters and synchronization on the efficacy of microinjection. Finally, the feasibility of implementing our microinjection model is examined experimentally. This technique can be used for tissue engineering, cells actuation and drug discovery as well as developing new strategies for drug delivery.
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Affiliation(s)
- Milad Azarmanesh
- Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Alberta, T2N 1N4, Canada.,Center for Bioengineering Research and Education, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Morteza Dejam
- Department of Petroleum Engineering, College of Engineering and Applied Science, University of Wyoming, 1000 E. University Avenue, Laramie, Wyoming, 82071-2000, USA
| | - Pooya Azizian
- Department of Mechanical Engineering, Babol Noshirvani University of Technology, Shariati St., Babol, 4714871167, Iran
| | - Gurkan Yesiloz
- Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Alberta, T2N 1N4, Canada.,Center for Bioengineering Research and Education, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Abdulmajeed A Mohamad
- Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Alberta, T2N 1N4, Canada.
| | - Amir Sanati-Nezhad
- Department of Mechanical and Manufacturing Engineering, University of Calgary, Calgary, Alberta, T2N 1N4, Canada. .,Center for Bioengineering Research and Education, University of Calgary, Calgary, Alberta, T2N 1N4, Canada.
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8
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Duarte LC, Figueredo F, Ribeiro LEB, Cortón E, Coltro WKT. Label-free counting of Escherichia coli cells in nanoliter droplets using 3D printed microfluidic devices with integrated contactless conductivity detection. Anal Chim Acta 2019; 1071:36-43. [PMID: 31128753 DOI: 10.1016/j.aca.2019.04.045] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 03/27/2019] [Accepted: 04/17/2019] [Indexed: 01/21/2023]
Abstract
This study describes for the first time the development of 3D printed microfluidic devices with integrated electrodes for label-free counting of E. coli cells incorporated inside droplets based on capacitively coupled contactless conductivity detection (C4D). Microfluidic devices were fully fabricated by 3D printing in the T-junction shape containing two channels for disperse and continuous phases and two sensing electrodes for C4D measurements. The disperse phase containing E. coli K12 cells and the continuous phase containing oil and 1% Span® 80 were pumped through flow rates fixed at 5 and 60 μL min-1, respectively. The droplets with incorporated cells were monitored in the C4D system applying a 500-kHz sinusoidal wave with 1 Vpp amplitude. The generated droplets exhibited a spherical shape with average diameter of 321 ± 9 μm and presented volume of 17.3 ± 0.5 nL. The proposed approach demonstrated ability to detect E. coli cells in the concentration range between 86.5 and 8650 CFU droplet-1. The number of cells per droplet was quantified through the plate counting method and revealed a good agreement with the Poisson distribution. The limit of detection achieved for counting E. coli cells was 63.66 CFU droplet-1. The label-free counting method has offered instrumental simplicity, low cost, high sensitivity and compatibility to be integrated on single microfluidic platforms entirely fabricated by 3D printing, thus opening new possibilities of applications in microbiology.
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Affiliation(s)
- Lucas C Duarte
- Instituto de Química, Universidade Federal de Goiás, Campus Samambaia, 74690-900, Goiânia, GO, Brazil
| | - Federico Figueredo
- Laboratorio de Biosensores y Bioanalisis (LABB), Departamento de Química Biológica e IQUIBICEN-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, CABA, Argentina
| | - Luiz E B Ribeiro
- Instituto de Química, Universidade Federal de Goiás, Campus Samambaia, 74690-900, Goiânia, GO, Brazil; Instituto Federal de Goiás - Campus Senador Canedo, 75250-000, Senador Canedo, GO, Brazil
| | - Eduardo Cortón
- Laboratorio de Biosensores y Bioanalisis (LABB), Departamento de Química Biológica e IQUIBICEN-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, CABA, Argentina
| | - Wendell K T Coltro
- Instituto de Química, Universidade Federal de Goiás, Campus Samambaia, 74690-900, Goiânia, GO, Brazil; Instituto Nacional de Ciência e Tecnologia de Bioanalítica, 13084-971, Campinas, SP, Brazil.
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9
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Guo X, Silva KPT, Boedicker JQ. Single-cell variability of growth interactions within a two-species bacterial community. Phys Biol 2019; 16:036001. [DOI: 10.1088/1478-3975/ab005f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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10
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Cui X, Ren L, Shan Y, Wang X, Yang Z, Li C, Xu J, Ma B. Smartphone-based rapid quantification of viable bacteria by single-cell microdroplet turbidity imaging. Analyst 2019; 143:3309-3316. [PMID: 29774899 DOI: 10.1039/c8an00456k] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Standard plate count (SPC) has been recognized as the golden standard for the quantification of viable bacteria. However, SPC usually takes one to several days to grow individual cells into a visible colony, which greatly hampers its application in rapid bacteria enumeration. Here we present a microdroplet turbidity imaging based digital standard plate count (dSPC) method to overcome this hurdle. Instead of cultivating on agar plates, bacteria are encapsulated in monodisperse microdroplets for single-cell cultivation. Proliferation of the encapsulated bacterial cell produced a detectable change in microdroplet turbidity, which allowed, after just a few bacterial doubling cycles (i.e., a few hours), enumeration of viable bacteria by visible-light imaging. Furthermore, a dSPC platform integrating a power-free droplet generator with smartphone-based turbidity imaging was established. As proof-of-concept demonstrations, a series of Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Bacillus subtilis) samples were quantified via the smartphone dSPC accurately within 6 hours, representing a detection sensitivity of 100 CFU ml-1 and at least 3 times faster. In addition, Enterobacter sakazakii (E. sakazakii) in infant milk powder as a real sample was enumerated within 6 hours, in contrast to the 24 hours needed in traditional SPC. Results with high accuracy and reproducibility were achieved, with no difference in counts found between dSPC and SPC. By enabling label-free, rapid, portable and low-cost enumeration and cultivation of viable bacteria onsite, smartphone dSPC forms the basis for a temporally and geographically trackable network for surveying live microbes globally where every citizen with a cellphone can contribute anytime and anywhere.
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Affiliation(s)
- Xiaonan Cui
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China.
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11
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Huys GR, Raes J. Go with the flow or solitary confinement: a look inside the single-cell toolbox for isolation of rare and uncultured microbes. Curr Opin Microbiol 2018; 44:1-8. [PMID: 29908491 DOI: 10.1016/j.mib.2018.05.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 05/24/2018] [Indexed: 01/01/2023]
Abstract
With the vast majority of the microbial world still considered unculturable or undiscovered, microbiologists not only require more fundamental insights concerning microbial growth requirements but also need to implement miniaturized, versatile and high-throughput technologies to upscale current microbial isolation strategies. In this respect, single-cell-based approaches are increasingly finding their way to the microbiology lab. A number of recent studies have demonstrated that analysis and separation of free microbial cells by flow-based sorting as well as physical stochastic confinement of individual cells in microenvironment compartments can facilitate the isolation of previously uncultured species and the discovery of novel microbial taxa. Still, while most of these methods give immediate access to downstream whole genome sequencing, upscaling to higher cell densities as required for metabolic readouts and preservation purposes can remain challenging. Provided that these and other technological challenges are addressed in future innovation rounds, integration of single-cell tools in commercially available benchtop instruments and service platforms is expected to trigger more targeted explorations in the microbial dark matter at a depth comparable to metagenomics.
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Affiliation(s)
- Geert Rb Huys
- Department of Microbiology and Immunology, Rega Institute, KU Leuven, Leuven, Belgium; VIB, Center for Microbiology, Leuven, Belgium
| | - Jeroen Raes
- Department of Microbiology and Immunology, Rega Institute, KU Leuven, Leuven, Belgium; VIB, Center for Microbiology, Leuven, Belgium.
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12
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Nai C, Meyer V. From Axenic to Mixed Cultures: Technological Advances Accelerating a Paradigm Shift in Microbiology. Trends Microbiol 2018; 26:538-554. [DOI: 10.1016/j.tim.2017.11.004] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 10/25/2017] [Accepted: 11/08/2017] [Indexed: 02/07/2023]
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13
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Shams Khorrami A, Rezai P. Oscillating dispersed-phase co-flow microfluidic droplet generation: Multi-droplet size effect. BIOMICROFLUIDICS 2018; 12:034113. [PMID: 29983838 PMCID: PMC6005787 DOI: 10.1063/1.5034473] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 05/31/2018] [Indexed: 06/08/2023]
Abstract
Controllable generation of microdroplets at desired sizes and throughputs is important in many applications. Many biological assays require size-optimized droplets for effective encapsulation of analytes and reagents. To perform size optimization, different-size droplets must be generated from identical sources of samples to prevent potential cross-sample variations or other sources of error. In this paper, we introduce a novel alteration of the co-flow droplet generation technique to achieve multi-size generation of monodispersed droplets. Using a custom-made mechanism, we oscillate the disperse-phase (d-phase) flow nozzle perpendicular to the continuous phase (c-phase) flow in a co-flow channel. Oscillation of the d-phase nozzle introduces an additional lateral drag force to the growing droplets while exposing them to various levels of axial drag owing to the parabolic velocity distribution of the c-phase flow. Superimposing both effects results in simultaneous and repeatable generation of monodispersed droplets with different sizes. The effect of nozzle oscillation frequency (f = 0-15 Hz) on droplet generation at different d-phase (Qd = 0.05, 0.10, and 0.50 ml/min) and c-phase (Qc = 2, 5, and 10 ml/min) flow rates was studied. A wide range of monodispersed droplets (4nl-4 μl) were generated using this method. Droplet sizes were directly proportional to the We number and inversely proportional to the Ca number and oscillation frequency. Our technique is promising for applications such as aqueous two-phase systems, where due to inherently low interfacial tension, the d-phase flow forms a long stable jet which can be broken into droplets using the additional oscillatory drag in our device.
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Affiliation(s)
- Amin Shams Khorrami
- Department of Mechanical Engineering, York University, Toronto, Ontario M3J 1P3, Canada
| | - Pouya Rezai
- Department of Mechanical Engineering, York University, Toronto, Ontario M3J 1P3, Canada
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14
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Geng T, Smallwood CR, Bredeweg EL, Pomraning KR, Plymale AE, Baker SE, Evans JE, Kelly RT. Multimodal microfluidic platform for controlled culture and analysis of unicellular organisms. BIOMICROFLUIDICS 2017; 11:054104. [PMID: 28966700 PMCID: PMC5608609 DOI: 10.1063/1.4986533] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 09/06/2017] [Indexed: 06/07/2023]
Abstract
Modern live-cell imaging approaches permit real-time visualization of biological processes, yet limitations exist for unicellular organism isolation, culturing, and long-term imaging that preclude fully understanding how cells sense and respond to environmental perturbations and the link between single-cell variability and whole-population dynamics. Here, we present a microfluidic platform that provides fine control over the local environment with the capacity to replace media components at any experimental time point, and provides both perfused and compartmentalized cultivation conditions depending on the valve configuration. The functionality and flexibility of the platform were validated using both bacteria and yeast having different sizes, motility, and growth media. The demonstrated ability to track the growth and dynamics of both motile and non-motile prokaryotic and eukaryotic organisms emphasizes the versatility of the devices, which should enable studies in bioenergy and environmental research.
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Affiliation(s)
- Tao Geng
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory Richland, Washington 99354, USA
| | - Chuck R Smallwood
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory Richland, Washington 99354, USA
| | - Erin L Bredeweg
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory Richland, Washington 99354, USA
| | - Kyle R Pomraning
- Energy Processes and Materials Division, Pacific Northwest National Laboratory Richland, Washington 99354, USA
| | - Andrew E Plymale
- Biological Sciences Division, Pacific Northwest National Laboratory Richland, Washington 99354, USA
| | - Scott E Baker
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory Richland, Washington 99354, USA
| | - James E Evans
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory Richland, Washington 99354, USA
| | - Ryan T Kelly
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory Richland, Washington 99354, USA
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15
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Liu Y, Lu H. Microfluidics in systems biology-hype or truly useful? Curr Opin Biotechnol 2017; 39:215-220. [PMID: 27267565 DOI: 10.1016/j.copbio.2016.04.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 04/20/2016] [Accepted: 04/21/2016] [Indexed: 12/13/2022]
Abstract
Systems biology often relies on large-scale measurements and model-building to understand how complex biological systems function. Microfluidic technology has been touted as a tool for high-throughput experiments and has been a valuable tool to some systems biology research. This review focuses on applications where microfluidics can enhance experimental sensitivity and throughput, particularly in recent development in single-cell analyses and analyses on multi-cellular or complex biological entities. We conclude that microfluidics is not necessarily always useful for systems biology, but when used appropriately can greatly enhance experimentalists' ability to measure and control, and thereby enhance the understanding of and expand the utility of biological systems.
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Affiliation(s)
- Yi Liu
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0100, United States
| | - Hang Lu
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0100, United States.
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16
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Scheler O, Pacocha N, Debski PR, Ruszczak A, Kaminski TS, Garstecki P. Optimized droplet digital CFU assay (ddCFU) provides precise quantification of bacteria over a dynamic range of 6 logs and beyond. LAB ON A CHIP 2017; 17:1980-1987. [PMID: 28480460 DOI: 10.1039/c7lc00206h] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Standard digital assays need a large number of compartments for precise quantification of a sample over a broad dynamic range. We address this issue with an optimized droplet digital approach that uses a drastically reduced number of compartments for quantification. We generate serial logarithmic dilutions of an initial bacterial sample as an array of microliter-sized droplet plugs. In a subsequent step, these droplets are split into libraries of nanoliter droplets and pooled together for incubation and analysis. We show that our technology is at par with traditional dilution plate count for quantification of bacteria, but has the advantage of simplifying the experimental setup and reducing the manual workload. The method also has the potential to reduce the assay time significantly.
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Affiliation(s)
- O Scheler
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland. and Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia
| | - N Pacocha
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
| | - P R Debski
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
| | - A Ruszczak
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
| | - T S Kaminski
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
| | - P Garstecki
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
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17
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Yusufaly TI, Boedicker JQ. Spatial dispersal of bacterial colonies induces a dynamical transition from local to global quorum sensing. Phys Rev E 2016; 94:062410. [PMID: 28085443 DOI: 10.1103/physreve.94.062410] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Indexed: 06/06/2023]
Abstract
Bacteria communicate using external chemical signals called autoinducers (AI) in a process known as quorum sensing (QS). QS efficiency is reduced by both limitations of AI diffusion and potential interference from neighboring strains. There is thus a need for predictive theories of how spatial community structure shapes information processing in complex microbial ecosystems. As a step in this direction, we apply a reaction-diffusion model to study autoinducer signaling dynamics in a single-species community as a function of the spatial distribution of colonies in the system. We predict a dynamical transition between a local quorum sensing (LQS) regime, with the AI signaling dynamics primarily controlled by the local population densities of individual colonies, and a global quorum sensing (GQS) regime, with the dynamics being dependent on collective intercolony diffusive interactions. The crossover between LQS to GQS is intimately connected to a trade-off between the signaling network's latency, or speed of activation, and its throughput, or the total spatial range over which all the components of the system communicate.
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Affiliation(s)
- Tahir I Yusufaly
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089, USA
| | - James Q Boedicker
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089, USA
- Department of Biological Sciences, University of Southern California, Los Angeles, California 90089, USA
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18
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Kaminski TS, Scheler O, Garstecki P. Droplet microfluidics for microbiology: techniques, applications and challenges. LAB ON A CHIP 2016; 16:2168-87. [PMID: 27212581 DOI: 10.1039/c6lc00367b] [Citation(s) in RCA: 241] [Impact Index Per Article: 30.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Droplet microfluidics has rapidly emerged as one of the key technologies opening up new experimental possibilities in microbiology. The ability to generate, manipulate and monitor droplets carrying single cells or small populations of bacteria in a highly parallel and high throughput manner creates new approaches for solving problems in diagnostics and for research on bacterial evolution. This review presents applications of droplet microfluidics in various fields of microbiology: i) detection and identification of pathogens, ii) antibiotic susceptibility testing, iii) studies of microbial physiology and iv) biotechnological selection and improvement of strains. We also list the challenges in the dynamically developing field and new potential uses of droplets in microbiology.
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Affiliation(s)
- Tomasz S Kaminski
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
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