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Yan Y, Cao M, Ma J, Suo J, Bai X, Ge W, Lv X, Zhang Q, Chen J, Cui S, Yang B. Use of proteomics to elucidate characteristics of Cronobacter sakazakii under mild heat stress. Int J Food Microbiol 2024; 425:110885. [PMID: 39178661 DOI: 10.1016/j.ijfoodmicro.2024.110885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2024] [Revised: 08/13/2024] [Accepted: 08/17/2024] [Indexed: 08/26/2024]
Abstract
Cronobacter sakazakii is an opportunistic pathogen known for causing severe diseases. Mild heat treatment is commonly used in food processing, however, the pathogenic characteristics and underlying mechanisms of Cronobacter sakazakii strains remain poorly understood. In this study, we found that mild heat stress (MHS) at 52 °C can induce several deleterious effects in Cronobacter sakazakii, including damage to the cell wall, genomic DNA breakage, and misfolding of cytoplasmic proteins. These conditions lead to a decreased survival ability under acid, desiccation, and osmotic stress; a reduction in biofilm formation; and diminished motility. Notably, surviving C. sakazakii cells retain their pathogenicity, causing significant intestinal damage in newborn mice. This damage is characterized by epithelial sloughing and disruption of the intestinal structure. Tandem mass tag (TMT)-based proteomics identified 736 proteins with differential abundance across C. sakazakii strains subjected to mild heat stress, highlighting adaptations in biofilm formation, motility, and stress tolerance. Key regulatory changes were observed in phospholipid metabolism and protein synthesis, which underpin this complex stress response. This data illustrates a sophisticated balance between environmental adaptability and pathogenic potential. The metabolic and pathogenic responses of C. sakazakii to mild heat stress are closely linked to its phospholipid metabolism and the production of secretory proteins, both crucial for its virulence and reliant on membrane transport. This complex interplay emphasizes the need to understand these mechanisms to develop effective control strategies.
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Affiliation(s)
- Yanfei Yan
- College of Food Science and Engineering, Northwest A&F University, Yangling 712100, China
| | - Mengyuan Cao
- College of Food Science and Engineering, Northwest A&F University, Yangling 712100, China
| | - Jiaqi Ma
- College of Food Science and Engineering, Northwest A&F University, Yangling 712100, China
| | - Jia Suo
- College of Food Science and Engineering, Northwest A&F University, Yangling 712100, China
| | - Xiaobao Bai
- College of Food Science and Engineering, Northwest A&F University, Yangling 712100, China
| | - Wupeng Ge
- College of Food Science and Engineering, Northwest A&F University, Yangling 712100, China; Shaanxi Engineering Research Centre of Dairy Products Quality, Safety and Health, Yangling, Shaanxi 712100, China
| | - Xin Lv
- College of Food Science and Engineering, Northwest A&F University, Yangling 712100, China; Shaanxi Engineering Research Centre of Dairy Products Quality, Safety and Health, Yangling, Shaanxi 712100, China
| | - Qiang Zhang
- College of Food Science and Engineering, Northwest A&F University, Yangling 712100, China; Shaanxi Engineering Research Centre of Dairy Products Quality, Safety and Health, Yangling, Shaanxi 712100, China.
| | - Jia Chen
- College of Chemical Technology, Shijiazhuang University, Shijiazhuang 050035, China.
| | - Shenghui Cui
- National Institutes for Food and Drug Control, Beijing 100050, China.
| | - Baowei Yang
- College of Food Science and Engineering, Northwest A&F University, Yangling 712100, China; Shaanxi Engineering Research Centre of Dairy Products Quality, Safety and Health, Yangling, Shaanxi 712100, China.
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Song Y, Mena-Aguilar D, Brown CL, Rhoads WJ, Helm RF, Pruden A, Edwards MA. Effects of Copper on Legionella pneumophila Revealed via Viability Assays and Proteomics. Pathogens 2024; 13:563. [PMID: 39057790 PMCID: PMC11279431 DOI: 10.3390/pathogens13070563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 06/22/2024] [Accepted: 06/27/2024] [Indexed: 07/28/2024] Open
Abstract
Cu is an antimicrobial that is commonly applied to premise (i.e., building) plumbing systems for Legionella control, but the precise mechanisms of inactivation are not well defined. Here, we applied a suite of viability assays and mass spectrometry-based proteomics to assess the mechanistic effects of Cu on L. pneumophila. Although a five- to six-log reduction in culturability was observed with 5 mg/L Cu2+ exposure, cell membrane integrity only indicated a <50% reduction. Whole-cell proteomic analysis revealed that AhpD, a protein related to oxidative stress, was elevated in Cu-exposed Legionella relative to culturable cells. Other proteins related to cell membrane synthesis and motility were also higher for the Cu-exposed cells relative to controls without Cu. While the proteins related to primary metabolism decreased for the Cu-exposed cells, no significant differences in the abundance of proteins related to virulence or infectivity were found, which was consistent with the ability of VBNC cells to cause infections. Whereas the cell-membrane integrity assay provided an upper-bound measurement of viability, an amoebae co-culture assay provided a lower-bound limit. The findings have important implications for assessing Legionella risk following its exposure to copper in engineered water systems.
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Affiliation(s)
- Yang Song
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA (M.A.E.)
- Utilities Department, 316 N. Academy St., Town of Cary, Cary, NC 27513, USA
| | - Didier Mena-Aguilar
- Biochemistry, Virginia Tech, 340 W Campus Dr, Blacksburg, VA 24060, USA
- Department of Biochemistry, University of Nebraska-Lincoln, N106, The Beadle Center, Lincoln, NE 68588, USA
| | - Connor L. Brown
- Genetics, Bioinformatics, and Computational Biology, Virginia Tech, Steger Hall, Blacksburg, VA 24061, USA
| | - William J. Rhoads
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA (M.A.E.)
- Black & Veatch, 8400 Ward Pkwy, Kansas City, MO 64114, USA
| | - Richard F. Helm
- Department of Biochemistry, Virginia Tech, 1015 Life Science Circle, 211B Steger Hall, Blacksburg, VA 24061, USA;
| | - Amy Pruden
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA (M.A.E.)
| | - Marc A. Edwards
- Civil and Environmental Engineering, Virginia Tech, 1145 Perry St., 418 Durham Hall, Blacksburg, VA 24061, USA (M.A.E.)
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Mermans F, De Baets H, García-Timermans C, Teughels W, Boon N. Unlocking the mechanism of action: a cost-effective flow cytometry approach for accelerating antimicrobial drug development. Microbiol Spectr 2024; 12:e0393123. [PMID: 38483479 PMCID: PMC10986550 DOI: 10.1128/spectrum.03931-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 03/04/2024] [Indexed: 04/06/2024] Open
Abstract
Antimicrobial resistance is one of the greatest challenges to global health. While the development of new antimicrobials can combat resistance, low profitability reduces the number of new compounds brought to market. Elucidating the mechanism of action is crucial for developing new antimicrobials. This can become expensive as there are no universally applicable pipelines. Phenotypic heterogeneity of microbial populations resulting from antimicrobial treatment can be captured through flow cytometric fingerprinting. Since antimicrobials are classified into limited groups, the mechanism of action of known compounds can be used for predictive modeling. We demonstrate a cost-effective flow cytometry approach for determining the mechanism of action of new compounds. Cultures of Actinomyces viscosus and Fusobacterium nucleatum were treated with different antimicrobials and measured by flow cytometry. A Gaussian mixture mask was applied over the data to construct phenotypic fingerprints. Fingerprints were used to assess statistical differences between mechanism of action groups and to train random forest classifiers. Classifiers were then used to predict the mechanism of action of cephalothin. Statistical differences were found among the different mechanisms of action groups. Pairwise comparison showed statistical differences for 35 out of 45 pairs for A. viscosus and for 32 out of 45 pairs for F. nucleatum after 3.5 h of treatment. The best-performing random forest classifier yielded a Matthews correlation coefficient of 0.92 and the mechanism of action of cephalothin could be successfully predicted. These findings suggest that flow cytometry can be a cheap and fast alternative for determining the mechanism of action of new antimicrobials.IMPORTANCEIn the context of the emerging threat of antimicrobial resistance, the development of novel antimicrobials is a commonly employed strategy to combat resistance. Elucidating the mechanism of action of novel compounds is crucial in this development but can become expensive, as no universally applicable pipelines currently exist. We present a novel flow cytometry-based approach capable of determining the mechanism of action swiftly and cost-effectively. The workflow aims to accelerate drug discovery and could help facilitate a more targeted approach for antimicrobial treatment of patients.
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Affiliation(s)
- Fabian Mermans
- Center for Microbial Ecology and Technology, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
- Department of Oral Health Sciences, KU Leuven & Dentistry (Periodontology), University Hospitals Leuven, Leuven, Belgium
| | - Hanna De Baets
- Center for Microbial Ecology and Technology, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
| | - Cristina García-Timermans
- Center for Microbial Ecology and Technology, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
| | - Wim Teughels
- Department of Oral Health Sciences, KU Leuven & Dentistry (Periodontology), University Hospitals Leuven, Leuven, Belgium
| | - Nico Boon
- Center for Microbial Ecology and Technology, Faculty of Bioscience Engineering, Ghent University, Gent, Belgium
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Gupta MK, Senthilkumar S, Rangan L. 3, 5-Dihydroxy 4', 7-dimethoxyflavone-DNA interaction study for nucleic acid detection and differential cell staining. Int J Biol Macromol 2024; 261:129713. [PMID: 38281518 DOI: 10.1016/j.ijbiomac.2024.129713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 01/11/2024] [Accepted: 01/19/2024] [Indexed: 01/30/2024]
Abstract
The present study is focused on application of a natural compound, 3, 5-dihydroxy 4', 7-dimethoxyflavone (DHDM) from a medicinal plant Alpinia nigra for nucleic acid detection and differential cell staining. DHDM was found to interact with nucleic acid and forms complex, which was investigated for various applications. It was successfully utilized to visualize plasmid, genomic, and ds-linear DNA in agarose gel electrophoresis without affecting the DNA mobility in the gel. Fluorescence of DHDM increased several fold upon binding to dsDNA. Photostability of the compound was assessed and showed photobleaching effect that decreased gradually over time. Application of the compound was further extended to differential cell staining. When observed in fluorescence microscope, DHDM stained the dead cells and differentiated them from live cells in the case of bacterial, yeast, and mammalian cells. Higher concentration of the compound was found to be less cytotoxic to cancerous cells. Nucleic acid staining dyes like Ethidium bromide (EtBr), Propidium iodide (PI), etc. are carcinogens and environmental pollutants and therefore DHDM a natural compound, is a major benefit and thus can serve as an alternative to the current dyes.
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Affiliation(s)
- Manish Kumar Gupta
- Applied Biodiversity Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Assam 781039, India
| | - Sanjana Senthilkumar
- Applied Biodiversity Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Assam 781039, India
| | - Latha Rangan
- Applied Biodiversity Laboratory, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Assam 781039, India.
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Martinot PL, Guigue C, Chifflet S, Cuny P, Barani A, Didry M, Dignan C, Guyomarc'h L, Pradel N, Pringault O, Van Wambeke F, Vu CT, Mari X, Tedetti M. Assessing the bioavailability of black carbon-derived dissolved organic matter for marine heterotrophic prokaryotes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 901:165802. [PMID: 37524184 DOI: 10.1016/j.scitotenv.2023.165802] [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: 04/27/2023] [Revised: 07/01/2023] [Accepted: 07/24/2023] [Indexed: 08/02/2023]
Abstract
Here we investigated the bioavailability of black carbon (BC)-derived dissolved organic matter (DOM) for a natural mixed community of marine heterotrophic prokaryotes. We ran an in vitro biodegradation experiment that took place over 3 months and exposed a community of organisms collected in the northwestern Mediterranean Sea (Bay of Marseille, France) to three different soluble fractions of BC prepared in the laboratory from various fossil fuel combustion particulates: standard diesel (DREF), oxidized diesel (DREF-OX), and natural samples of ship soot (DSHIP). Over the course of the three months, we observed significant decreases in the concentrations of dissolved organic carbon (DOC; from 9 to 21 %), dissolved BC (DBC; from 22 to 38 %) and dissolved polycyclic aromatic hydrocarbons (d-PAH; from 24 to 64 %) along with variability in the growth dynamics and activity of the heterotrophic prokaryotic community. The heterotrophic prokaryotic community exposed to DREF-OX treatment showed the highest values of respiration and production and the highest cell abundance, associated with the highest decrease in DOC (21 %) and d-PAH (64 %) concentrations. In the DREF and DSHIP treatments, prokaryotic activity was oriented towards anabolism. DREF treatment led to the highest decrease in DBC concentration (38 %). DSHIP treatment, which presented a substantially different d-PAH and dissolved metals content to the other two treatments, showed the lowest decreases in DOC, DBC and d-PAH concentrations, as well as the lowest prokaryotic activity and biomasses. Our results indicate that BC-derived DOM, including the most condensed fraction of this material, is partly bioavailable and therefore likely to be assimilated by marine prokaryotes. The origin of BC/soot deposited at the ocean surface turns out to be a key parameter that dictates the efficiency of biodegradation of its dissolved fraction by heterotrophic prokaryotes.
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Affiliation(s)
- Pauline L Martinot
- Aix Marseille Université, Université de Toulon, CNRS, IRD, MIO, Marseille, France; Water - Environment - Oceanography (WEO) Department, University of Science and Technology of Hanoi (USTH), Vietnam Academy of Science and Technology (VAST), Hanoi, Viet Nam.
| | - Catherine Guigue
- Aix Marseille Université, Université de Toulon, CNRS, IRD, MIO, Marseille, France; Water - Environment - Oceanography (WEO) Department, University of Science and Technology of Hanoi (USTH), Vietnam Academy of Science and Technology (VAST), Hanoi, Viet Nam
| | - Sandrine Chifflet
- Aix Marseille Université, Université de Toulon, CNRS, IRD, MIO, Marseille, France
| | - Philippe Cuny
- Aix Marseille Université, Université de Toulon, CNRS, IRD, MIO, Marseille, France
| | - Aude Barani
- Aix Marseille Université, Université de Toulon, CNRS, IRD, MIO, Marseille, France
| | - Morgane Didry
- Aix Marseille Université, Université de Toulon, CNRS, IRD, MIO, Marseille, France
| | - Clara Dignan
- Université de Toulon, Aix Marseille Université, CNRS, IRD, MIO, Toulon, France
| | - Léa Guyomarc'h
- Aix Marseille Université, Université de Toulon, CNRS, IRD, MIO, Marseille, France
| | - Nathalie Pradel
- Aix Marseille Université, Université de Toulon, CNRS, IRD, MIO, Marseille, France
| | - Olivier Pringault
- Aix Marseille Université, Université de Toulon, CNRS, IRD, MIO, Marseille, France
| | - France Van Wambeke
- Aix Marseille Université, Université de Toulon, CNRS, IRD, MIO, Marseille, France
| | - Cam Tu Vu
- Water - Environment - Oceanography (WEO) Department, University of Science and Technology of Hanoi (USTH), Vietnam Academy of Science and Technology (VAST), Hanoi, Viet Nam
| | - Xavier Mari
- Aix Marseille Université, Université de Toulon, CNRS, IRD, MIO, Marseille, France; Water - Environment - Oceanography (WEO) Department, University of Science and Technology of Hanoi (USTH), Vietnam Academy of Science and Technology (VAST), Hanoi, Viet Nam
| | - Marc Tedetti
- Aix Marseille Université, Université de Toulon, CNRS, IRD, MIO, Marseille, France; Water - Environment - Oceanography (WEO) Department, University of Science and Technology of Hanoi (USTH), Vietnam Academy of Science and Technology (VAST), Hanoi, Viet Nam
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Chettri P, Ganesh KM, Mahapatra SS, Vishwanathan AS, Srivastava S. A low-cost optofluidic platform for the colorimetric assessment of bacterial activity in domestic wastewater. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2023; 15:6031-6039. [PMID: 37916527 DOI: 10.1039/d3ay01612a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
Abstract
Optofluidic chips represent a cost-effective platform for the development of miniaturized devices to perform biochemical reactions at a microscale. The dye reduction-based electron-transfer activity monitoring (DREAM) assay is a colorimetric approach that has been adopted for the rapid assessment of bacterial activity in bioreactors used in bioremediation and industrial biotechnology. A three-layered PMMA-based optofluidic chip having laser-machined microchannels coupled with a detection system comprising an LED source and a photodiode interfaced with a microcontroller for automation constituted the experimental setup. Data acquisition was executed using a user-friendly graphical user interface (GUI) that enabled real-time monitoring of bacterial activity. A performance comparison study was performed to assess the viability of replacing expensive spectrophotometers with an inexpensive photodiode for optoelectronic automation. Bacterial activity across different growth phases of a bacterial culture, initiated using untreated domestic wastewater, was assessed by the detector on the basis of voltage readings corresponding to the rate of decrease in the blue color intensity. The highest activity observed corresponded to the log phase of the growth curve. The optimal time for measurement of bacterial activity within the log phase of the growth curve was identified using different dilutions of untreated domestic wastewater. Furthermore, the device showed comparable sensitivities for samples from different time points in a bacterial growth curve and for different dilutions of untreated domestic wastewater samples. The device also demonstrated a linear response in the assessment of bacterial activity as a function of the change in strength of untreated domestic wastewater. This is the first report on colorimetric assessment of bacterial activity using a low-cost photodiode-based device at the microscale constructed using off-the-shelf components.
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Affiliation(s)
- Prajal Chettri
- FEMTO FabULLAS, CRIF, Department of Physics, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Andhra Pradesh 515134, India.
| | - Kalathur Mohan Ganesh
- STAR Laboratory, CRIF, Department of Chemistry, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Andhra Pradesh 515134, India
| | - Sahashransu Satyajeet Mahapatra
- WATER Laboratory, Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Andhra Pradesh 515134, India
| | - A S Vishwanathan
- WATER Laboratory, Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Andhra Pradesh 515134, India
| | - Shailesh Srivastava
- FEMTO FabULLAS, CRIF, Department of Physics, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Andhra Pradesh 515134, India.
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Priyadarsini M, Kushwaha J, Pandey KP, Rani J, Dhoble AS. Application of flow cytometry for rapid, high-throughput, multiparametric analysis of environmental microbiomes. J Microbiol Methods 2023; 214:106841. [PMID: 37832922 DOI: 10.1016/j.mimet.2023.106841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 10/06/2023] [Accepted: 10/08/2023] [Indexed: 10/15/2023]
Abstract
Quantification of the abundance and understanding of the dynamics of the microbial communities is essential to establish a basis for microbiome characterization. The conventional techniques used for the quantification of microbes are complicated and time-consuming. With scientific advancement, many techniques evolved and came into account. Among them, flow cytometry is a robust, high-throughput technique through which microbial dynamics, morphology, microbial distribution, physiological characteristics, and many more attributes can be studied in a high-throughput manner with comparatively less time and resources. Flow cytometry, when combined with other omics-based methods, offers a rapid and efficient platform to analyze and understand the composition of microbiome at the cellular level. The microbial diversity observed through flow cytometry will not be equivalent to that obtained by sequencing methods, but this integrated approach holds great potential for high throughput characterization of microbiomes. Flow cytometry is regarded as an established characterization tool in haematology, oncology, immunology, and medical microbiology research; however, its application in environmental microbiology is yet to be explored. This comprehensive review aims to delve into the diverse environmental applications of flow cytometry across various domains, including but not limited to bioremediation, landfills, anaerobic digestion, industrial bioprocesses, water quality regulation, and soil quality regulation. By conducting an in-depth analysis, this article seeks to shed light on the potential benefits and challenges associated with the utilization of flow cytometry in addressing environmental concerns.
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Affiliation(s)
- Madhumita Priyadarsini
- School of Biochemical Engineering, Indian Institute of Technology (BHU), Varanasi 221005, Uttar Pradesh, India
| | - Jeetesh Kushwaha
- School of Biochemical Engineering, Indian Institute of Technology (BHU), Varanasi 221005, Uttar Pradesh, India
| | - Kailash Pati Pandey
- School of Biochemical Engineering, Indian Institute of Technology (BHU), Varanasi 221005, Uttar Pradesh, India
| | - Jyoti Rani
- School of Biochemical Engineering, Indian Institute of Technology (BHU), Varanasi 221005, Uttar Pradesh, India
| | - Abhishek S Dhoble
- School of Biochemical Engineering, Indian Institute of Technology (BHU), Varanasi 221005, Uttar Pradesh, India.
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Xu Z, Li R, Zhang X, Liu J, Xu X, Wang S, Lan T, Zhang K, Gao F, He Q, Pan J, Quan F, Zhang Z. Mechanisms and effects of novel ammonifying microorganisms on nitrogen ammonification in cow manure waste composting. WASTE MANAGEMENT (NEW YORK, N.Y.) 2023; 169:167-178. [PMID: 37442037 DOI: 10.1016/j.wasman.2023.07.009] [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: 04/06/2023] [Revised: 07/01/2023] [Accepted: 07/07/2023] [Indexed: 07/15/2023]
Abstract
It is essential to reduce nitrogen losses and to improve nitrogen conversion during organic waste composting because of environmental protection and sustainable development. To reveal newly domesticated ammonifying microorganisms (AM) cultures on the ammonification and nitrogen conversion during the composting, the screened microbial agents were inoculated at 5 % concentration (in weight basis) into cow manure compost under five different treatments: sterilized distilled water (Control), Amm-1 (mesophilic fungus-F1), Amm-2 (mesophilic bacterium-Z1), Amm-3 (thermotolerant bacterium-Z2), and Amm-4 (consortium: F1, Z1, and Z2), and composted for 42 days. Compared to control, AM inoculation prolonged the thermophilic phases to 9-19 days, increased the content of NH4+-N to 1.60-1.96 g/kg in the thermophilic phase, reduced N2O and NH3 emissions by 22.85-61.13 % and 8.45-23.29 %, increased total Kjeldahl nitrogen, and improved cell count and viability by 12.09-71.33 % and 66.71-72.91 %. AM was significantly associated with different nitrogen and microbial compositions. The structural equation model (SEM) reveals NH4+-N is the preferable nitrogen for the majority of bacterial and fungal growth and that AM is closely associated with the conversion between NH3 and NH4+-N. Among the treatments, inoculation with Amm-4 was more effective, as it significantly enhanced the driving effect of the critical microbial composition on nitrogen conversion and accelerated nitrogen ammonification and sequestration. This study provided new concepts for the dynamics of microbial in the ammonification process of new AM bacterial agents in cow manure compost, and an understanding of the ecological mechanism underlying the ammonification process and its contribution to nitrogen (N) cycling from the perspective of microbial communities.
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Affiliation(s)
- Zhiming Xu
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi Province 712100, China
| | - Ronghua Li
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Xiu Zhang
- North Minzu University Ningxia Key Laboratory for the Development and Application of Microbial Resources in Extreme Environments, Yinchuan 750021, China
| | - Jun Liu
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi Province 712100, China
| | - Xuerui Xu
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi Province 712100, China
| | - Shaowen Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi Province 712100, China
| | - Tianyang Lan
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi Province 712100, China
| | - Kang Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi Province 712100, China
| | - Feng Gao
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi Province 712100, China
| | - Qifu He
- North Minzu University Ningxia Key Laboratory for the Development and Application of Microbial Resources in Extreme Environments, Yinchuan 750021, China
| | - Junting Pan
- Key Laboratory of Non-point Source Pollution of Ministry of Agricultural and Rural Affairs, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Fusheng Quan
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi Province 712100, China.
| | - Zengqiang Zhang
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi 712100, China
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Shen Y, Haig SJ, Prussin AJ, LiPuma JJ, Marr LC, Raskin L. Shower water contributes viable nontuberculous mycobacteria to indoor air. PNAS NEXUS 2022; 1:pgac145. [PMID: 36712351 PMCID: PMC9802317 DOI: 10.1093/pnasnexus/pgac145] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 11/07/2022] [Indexed: 11/11/2022]
Abstract
Nontuberculous mycobacteria (NTM) are frequently present in municipal drinking water and building plumbing, and some are believed to cause respiratory tract infections through inhalation of NTM-containing aerosols generated during showering. However, the present understanding of NTM transfer from water to air is insufficient to develop NTM risk mitigation strategies. This study aimed to characterize the contribution of shower water to the abundance of viable NTM in indoor air. Shower water and indoor air samples were collected, and 16S rRNA and rpoB genes were sequenced. The sequencing results showed that running the shower impacted the bacterial community structure and NTM species composition in indoor air by transferring certain bacteria from water to air. A mass balance model combined with NTM quantification results revealed that on average 1/132 and 1/254 of NTM cells in water were transferred to air during 1 hour of showering using a rain and massage showerhead, respectively. A large fraction of the bacteria transferred from water to air were membrane-damaged, i.e. they had compromised membranes based on analysis by live/dead staining and flow cytometry. However, the damaged NTM in air were recoverable as shown by growth in a culture medium mimicking the respiratory secretions of people with cystic fibrosis, implying a potential infection risk by NTM introduced to indoor air during shower running. Among the recovered NTM, Mycobacterium mucogenicum was the dominant species as determined by rpoB gene sequencing. Overall, this study lays the groundwork for future pathogen risk management and public health protection in the built environment.
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Affiliation(s)
| | | | - Aaron J Prussin
- Department of Civil and Environmental Engineering, Virginia Tech, 418 Durham Hall, Blacksburg, VA 24061, USA
| | - John J LiPuma
- Department of Pediatrics, University of Michigan Medical School, 1500 E. Medical Center Dr., Ann Arbor, MI 48109, USA
| | - Linsey C Marr
- Department of Civil and Environmental Engineering, Virginia Tech, 418 Durham Hall, Blacksburg, VA 24061, USA
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Trinh KTL, Lee NY. Recent Methods for the Viability Assessment of Bacterial Pathogens: Advances, Challenges, and Future Perspectives. Pathogens 2022; 11:pathogens11091057. [PMID: 36145489 PMCID: PMC9500772 DOI: 10.3390/pathogens11091057] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/14/2022] [Accepted: 09/15/2022] [Indexed: 11/28/2022] Open
Abstract
Viability assessment is a critical step in evaluating bacterial pathogens to determine infectious risks to public health. Based on three accepted viable criteria (culturability, metabolic activity, and membrane integrity), current viability assessments are categorized into three main strategies. The first strategy relies on the culturability of bacteria. The major limitation of this strategy is that it cannot detect viable but nonculturable (VBNC) bacteria. As the second strategy, based on the metabolic activity of bacteria, VBNC bacteria can be detected. However, VBNC bacteria sometimes can enter a dormant state that allows them to silence reproduction and metabolism; therefore, they cannot be detected based on culturability and metabolic activity. In order to overcome this drawback, viability assessments based on membrane integrity (third strategy) have been developed. However, these techniques generally require multiple steps, bulky machines, and laboratory technicians to conduct the tests, making them less attractive and popular applications. With significant advances in microfluidic technology, these limitations of current technologies for viability assessment can be improved. This review summarized and discussed the advances, challenges, and future perspectives of current methods for the viability assessment of bacterial pathogens.
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Affiliation(s)
- Kieu The Loan Trinh
- Department of Industrial Environmental Engineering, Gachon University, 1342 Seongnam-daero, Sujeong-gu, Seongnam-si 13120, Korea
| | - Nae Yoon Lee
- Department of BioNano Technology, Gachon University, 1342 Seongnam-daero, Sujeong-gu, Seongnam-si 13120, Korea
- Correspondence:
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11
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Chen Z, Yin L, Zhang W, Peng A, Sallach JB, Luo Y, Li H. NaCl salinity enhances tetracycline bioavailability to Escherichia coli on agar surfaces. CHEMOSPHERE 2022; 302:134921. [PMID: 35568221 DOI: 10.1016/j.chemosphere.2022.134921] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 04/10/2022] [Accepted: 05/07/2022] [Indexed: 06/15/2023]
Abstract
Soil salinity is a worldwide problem and is damaging soil functions. Meanwhile, increasing amounts of anthropogenic antibiotics are discharged to agricultural soils. Little is known about how soil salinity (e.g., NaCl) could influence the bioavailability of antibiotics to bacteria. In this study, a tetracycline-responsive Escherichia coli bioreporter grew on the surfaces of agar microcosms at the same tetracycline concentration (200 μg/L), but various NaCl concentrations (0.5-19.2 g/L) with estimated osmotic potential of -0.18 to -1.80 MPa, and agar content (0.3%-5%) with estimated intrinsic permeability of 38 to 32,928 nm2. These agar microcosms mimicked very fine textured soils with a range of NaCl salinity. Increasing agar content lowered the intrinsic permeability hence decreasing tetracycline bioavailability to E. coli, due likely to the reduced mass transfer of tetracycline via water flow. Intriguingly, tetracycline bioavailability increased with increasing NaCl concentration which caused the increase in osmotic stress. This is contradictory to the notion that osmotic stress reduces bacterial chemical uptake. Further analysis of E. coli membrane integrity demonstrated that the enhanced tetracycline bioavailability to bacteria could result from the compromised cell membranes and enhanced membrane permeability at higher NaCl salinity. Overall, this study suggests that high soil salinity (NaCl) may enhance the selection pressure exerted by antibiotics on bacteria.
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Affiliation(s)
- Zeyou Chen
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin, 300071, China; Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, 48824, United States
| | - Lichun Yin
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin, 300071, China
| | - Wei Zhang
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, 48824, United States
| | - Anping Peng
- School of Environmental and Municipal Engineering, Tianjin Chengjian University, Tianjin, 300384, China
| | - J Brett Sallach
- Department of Environment and Geography, University of York, Heslington, York, YO10 5NG, United Kingdom
| | - Yi Luo
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin, 300071, China
| | - Hui Li
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, 48824, United States.
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Ota S, Fuchida S, Yamaguchi H, Yamagishi T, Yamamoto H, Koshikawa H, Kawachi M. Propidium Iodide Staining and Flow Cytometry-Based Assessment of Heavy Metal Impact on Marine Phytoplankton. CYTOLOGIA 2022. [DOI: 10.1508/cytologia.87.177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Shuhei Ota
- Biodiversity Division, National Institute for Environmental Studies
| | | | - Haruyo Yamaguchi
- Biodiversity Division, National Institute for Environmental Studies
| | - Takahiro Yamagishi
- Health and Environmental Risk Division, National Institute for Environmental Studies
| | - Hiroshi Yamamoto
- Health and Environmental Risk Division, National Institute for Environmental Studies
| | - Hiroshi Koshikawa
- Regional Environment Conservation Division, National Institute for Environmental Studies
| | - Masanobu Kawachi
- Biodiversity Division, National Institute for Environmental Studies
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13
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Zhang A, Gao C, Chen T, Xie Y, Wang X. Treatment of fracturing wastewater by anaerobic granular sludge: The short-term effect of salinity and its mechanism. BIORESOURCE TECHNOLOGY 2022; 345:126538. [PMID: 34902487 DOI: 10.1016/j.biortech.2021.126538] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/04/2021] [Accepted: 12/06/2021] [Indexed: 06/14/2023]
Abstract
The effects of salinity shock on the anaerobic treatment of fracturing wastewater regarding chemical oxygen demand (COD) removal performance, sludge characteristics and microbial community were investigated. Results showed COD removal efficiency decreased from 76.0% to 69.1%, 65.6%, 33.7% and 21.9% with the increase of salinity from 2.5 g/L to 10, 15, 25 and 45 g/L, respectively. The cumulative biogas production decreased by 13.8%-81.1% when salinity increased to 15-85 g/L. The increase of salinity led to the decline in particle size of granular sludge, and the activity of granular sludge, including SMA, coenzyme F420 and dehydrogenase, was inhibited significantly. Flow cytometry indicated the percentage of damaged cells in granular sludge gradually increased with the increase of salinity. Sequence analysis illustrated that microbial community structure in anaerobic digestion reactor was influenced by the salinity, high salinity reduced the diversity of archaea and decreased the abundance of methanogens, especially Methanosaeta.
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Affiliation(s)
- Anlong Zhang
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, Shaanxi Province 710021, PR China; China Light Industry Water Pollution Control Engineering Center, Xi'an, Shaanxi Province 710021, PR China
| | - Chuyue Gao
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, Shaanxi Province 710021, PR China
| | - Tiantian Chen
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, Shaanxi Province 710021, PR China
| | - Yili Xie
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, Shaanxi Province 710021, PR China
| | - Xianbao Wang
- School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an, Shaanxi Province 710021, PR China; China Light Industry Water Pollution Control Engineering Center, Xi'an, Shaanxi Province 710021, PR China.
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Pereira AC, Tenreiro A, Cunha MV. When FLOW-FISH met FACS: Combining multiparametric, dynamic approaches for microbial single-cell research in the total environment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:150682. [PMID: 34600998 DOI: 10.1016/j.scitotenv.2021.150682] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 09/22/2021] [Accepted: 09/26/2021] [Indexed: 06/13/2023]
Abstract
In environmental microbiology, the ability to assess, in a high-throughput way, single-cells within microbial communities is key to understand their heterogeneity. Fluorescence in situ hybridization (FISH) uses fluorescently labeled oligonucleotide probes to detect, identify, and quantify single cells of specific taxonomic groups. The combination of Flow Cytometry (FLOW) with FISH (FLOW-FISH) enables high-throughput quantification of complex whole cell populations, which when associated with fluorescence-activated cell sorting (FACS) enables sorting of target microorganisms. These sorted cells may be investigated in many ways, for instance opening new avenues for cytomics at a single-cell scale. In this review, an overview of FISH and FLOW methodologies is provided, addressing conventional methods, signal amplification approaches, common fluorophores for cell physiology parameters evaluation, and model variation techniques as well. The coupling of FLOW-FISH-FACS is explored in the context of different downstream applications of sorted cells. Current and emerging applications in environmental microbiology to outline the interactions and processes of complex microbial communities within soil, water, animal microbiota, polymicrobial biofilms, and food samples, are described.
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Affiliation(s)
- André C Pereira
- Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculdade de Ciências da Universidade de Lisboa, Lisboa, Portugal; Biosystems & Integrative Sciences Institute (BioISI), Faculdade de Ciências da Universidade de Lisboa, Lisboa, Portugal
| | - Ana Tenreiro
- Biosystems & Integrative Sciences Institute (BioISI), Faculdade de Ciências da Universidade de Lisboa, Lisboa, Portugal
| | - Mónica V Cunha
- Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculdade de Ciências da Universidade de Lisboa, Lisboa, Portugal; Biosystems & Integrative Sciences Institute (BioISI), Faculdade de Ciências da Universidade de Lisboa, Lisboa, Portugal.
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Silva L, Calleja ML, Huete-Stauffer TM, Ivetic S, Ansari MI, Viegas M, Morán XAG. Heterotrophic Bacterioplankton Growth and Physiological Properties in Red Sea Tropical Shallow Ecosystems With Different Dissolved Organic Matter Sources. Front Microbiol 2022; 12:784325. [PMID: 35046913 PMCID: PMC8762102 DOI: 10.3389/fmicb.2021.784325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Accepted: 12/06/2021] [Indexed: 11/21/2022] Open
Abstract
Despite the key role of heterotrophic bacterioplankton in the biogeochemistry of tropical coastal waters, their dynamics have been poorly investigated in relation to the different dissolved organic matter (DOM) pools usually available. In this study we conducted four seasonal incubations of unfiltered and predator-free seawater (Community and Filtered treatment, respectively) at three Red Sea coastal sites characterized by different dominant DOM sources: Seagrass, Mangrove, and Phytoplankton. Bacterial abundance, growth and physiological status were assessed by flow cytometry and community composition by 16S rRNA gene amplicons. The Seagrass site showed the highest initial abundances (6.93 ± 0.30 × 105 cells mL-1), coincident with maximum DOC concentrations (>100 μmol C L-1), while growth rates peaked at the Mangrove site (1.11 ± 0.09 d-1) and were consistently higher in the Filtered treatment. The ratio between the Filtered and Community maximum bacterial abundance (a proxy for top-down control by protistan grazers) showed minimum values at the Seagrass site (1.05 ± 0.05) and maximum at the Phytoplankton site (1.24 ± 0.30), suggesting protistan grazing was higher in open waters, especially in the first half of the year. Since the Mangrove and Seagrass sites shared a similar bacterial diversity, the unexpected lack of bacterial response to predators removal at the latter site should be explained by differences in DOM characteristics. Nitrogen-rich DOM and fluorescent protein-like components were significantly associated with enhanced specific growth rates along the inshore-offshore gradient. Our study confirms the hypotheses that top-down factors control bacterial standing stocks while specific growth rates are bottom-up controlled in representative Red Sea shallow, oligotrophic ecosystems.
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Affiliation(s)
- Luis Silva
- Division of Biological and Environmental Sciences and Engineering, Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Maria Ll. Calleja
- Division of Biological and Environmental Sciences and Engineering, Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
- Department of Climate Geochemistry, Max Planck Institute for Chemistry, Mainz, Germany
| | - Tamara M. Huete-Stauffer
- Division of Biological and Environmental Sciences and Engineering, Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Snjezana Ivetic
- Division of Biological and Environmental Sciences and Engineering, Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Mohd I. Ansari
- Division of Biological and Environmental Sciences and Engineering, Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
- Department of Biosciences, Integral University, Lucknow, India
| | - Miguel Viegas
- Division of Biological and Environmental Sciences and Engineering, Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Xosé Anxelu G. Morán
- Division of Biological and Environmental Sciences and Engineering, Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
- Centro Oceanográfico de Gijón/Xixón (IEO, CSIC), Gijón, Spain
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Taguer M, Darbinian E, Wark K, Ter-Cheam A, Stephens DA, Maurice CF. Changes in Gut Bacterial Translation Occur before Symptom Onset and Dysbiosis in Dextran Sodium Sulfate-Induced Murine Colitis. mSystems 2021; 6:e0050721. [PMID: 34874778 PMCID: PMC8651081 DOI: 10.1128/msystems.00507-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 10/20/2021] [Indexed: 11/30/2022] Open
Abstract
Longitudinal studies on the gut microbiome that follow the effect of a perturbation are critical in understanding the microbiome's response and succession to disease. Here, we use a dextran sodium sulfate (DSS) mouse model of colitis as a tractable perturbation to study how gut bacteria change their physiology over the course of a perturbation. Using single-cell methods such as flow cytometry, bioorthogonal noncanonical amino acid tagging (BONCAT), and population-based cell sorting combined with 16S rRNA sequencing, we determine the diversity of physiologically distinct fractions of the gut microbiota and how they respond to a controlled perturbation. The physiological markers of bacterial activity studied here include relative nucleic acid content, membrane damage, and protein production. There is a distinct and reproducible succession in bacterial physiology, with an increase in bacteria with membrane damage and diversity changes in the translationally active fraction, both, critically, occurring before symptom onset. Large increases in the relative abundance of Akkermansia were seen in all physiological fractions, most notably in the translationally active bacteria. Performing these analyses within a detailed, longitudinal framework determines which bacteria change their physiology early on, focusing therapeutic efforts in the future to predict or even mitigate relapse in diseases like inflammatory bowel diseases. IMPORTANCE Most studies on the gut microbiome focus on the composition of this community and how it changes in disease. However, how the community transitions from a healthy state to one associated with disease is currently unknown. Additionally, common diversity metrics do not provide functional information on bacterial activity. We begin to address these two unknowns by following bacterial activity over the course of disease progression, using a tractable mouse model of colitis. We find reproducible changes in gut bacterial physiology that occur before symptom onset, with increases in the proportion of bacteria with membrane damage, and changes in community composition of the translationally active bacteria. Our data provide a framework to identify possible windows of intervention and which bacteria to target in microbiome-based therapeutics.
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Affiliation(s)
- M. Taguer
- Department of Microbiology & Immunology, Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec, Canada
| | - E. Darbinian
- Department of Microbiology & Immunology, Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec, Canada
| | - K. Wark
- Department of Microbiology & Immunology, Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec, Canada
| | - A. Ter-Cheam
- Department of Mathematics and Statistics, Faculty of Science, McGill University, Montreal, Quebec, Canada
| | - D. A. Stephens
- Department of Mathematics and Statistics, Faculty of Science, McGill University, Montreal, Quebec, Canada
| | - C. F. Maurice
- Department of Microbiology & Immunology, Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec, Canada
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Klasinc R, Reiter M, Digruber A, Tschulenk W, Walter I, Kirschner A, Spittler A, Stockinger H. A Novel Flow Cytometric Approach for the Quantification and Quality Control of Chlamydia trachomatis Preparations. Pathogens 2021; 10:1617. [PMID: 34959572 PMCID: PMC8706156 DOI: 10.3390/pathogens10121617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/07/2021] [Accepted: 12/09/2021] [Indexed: 11/27/2022] Open
Abstract
Chlamydia trachomatis is an obligate intracellular pathogenic bacterium with a biphasic developmental cycle manifesting two distinct morphological forms: infectious elementary bodies (EBs) and replicative intracellular reticulate bodies (RBs). Current standard protocols for quantification of the isolates assess infectious particles by titering inclusion-forming units, using permissive cell lines, and analyzing via immunofluorescence. Enumeration of total particle counts is achieved by counting labeled EBs/RBs using a fluorescence microscope. Both methods are time-consuming with a high risk of observer bias. For a better assessment of C. trachomatis preparations, we developed a simple and time-saving flow cytometry-based workflow for quantifying small particles, such as EBs with a size of 300 nm. This included optimization of gain and threshold settings with the addition of a neutral density filter for small-particle discrimination. The nucleic acid dye SYBR® Green I (SGI) was used together with propidium iodide and 5(6)-carboxyfluorescein diacetate to enumerate and discriminate between live and dead bacteria. We found no significant differences between the direct particle count of SGI-stained C. trachomatis preparations measured by microscopy or flow cytometry (p > 0.05). Furthermore, we completed our results by introducing a cell culture-independent viability assay. Our measurements showed very good reproducibility and comparability to the existing state-of-the-art methods, indicating that the evaluation of C. trachomatis preparations by flow cytometry is a fast and reliable method. Thus, our method facilitates an improved assessment of the quality of C. trachomatis preparations for downstream applications.
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Affiliation(s)
- Romana Klasinc
- Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, 1090 Vienna, Austria; (M.R.); (A.K.); (H.S.)
| | - Michael Reiter
- Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, 1090 Vienna, Austria; (M.R.); (A.K.); (H.S.)
| | - Astrid Digruber
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria;
| | - Waltraud Tschulenk
- Institute of Morphology, Department of Pathobiology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria; (W.T.); (I.W.)
| | - Ingrid Walter
- Institute of Morphology, Department of Pathobiology, University of Veterinary Medicine Vienna, 1210 Vienna, Austria; (W.T.); (I.W.)
| | - Alexander Kirschner
- Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, 1090 Vienna, Austria; (M.R.); (A.K.); (H.S.)
- Division Water Quality & Health, Department Pharmacology, Physiology and Microbiology, Karl Landsteiner University of Health Sciences, 3500 Krems, Austria
| | - Andreas Spittler
- Core Facility Flow Cytometry and Department of Surgery, Research Laboratories, Medical University of Vienna, 1090 Vienna, Austria;
| | - Hannes Stockinger
- Institute for Hygiene and Applied Immunology, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, 1090 Vienna, Austria; (M.R.); (A.K.); (H.S.)
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Scott LC, Wilson MJ, Esser SM, Lee NL, Wheeler ME, Aubee A, Aw TG. Assessing visitor use impact on antibiotic resistant bacteria and antibiotic resistance genes in soil and water environments of Rocky Mountain National Park. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 785:147122. [PMID: 33932658 DOI: 10.1016/j.scitotenv.2021.147122] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 04/08/2021] [Accepted: 04/09/2021] [Indexed: 06/12/2023]
Abstract
Antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) have been detected in soil and water in close proximity to anthropogenic sources, but the extent to which human impact plays into ARB and ARGs entering the environment is not well described. This study aimed to determine the impact of visitor use on ARB and ARGs in a national park environment. Soil (n = 240) and water (n = 210) samples were collected across a gradient of human activity in Rocky Mountain National Park and analyzed for bacteria resistant to doxycycline, levofloxacin, and vancomycin. Amount of physical effort required to access a sampling site was used as a metric for the likelihood of human presence. A subset of samples was analyzed for the presence and abundance of six ARGs using quantitative polymerase chain reaction. Linear regression analysis demonstrated that anthropogenic factors including hiking effort and proximity to a toilet significantly contributed to the variance of the abundance of ARB for multiple antibiotics in soil and water. Additionally, ecological factors such as water movement, soil texture, and season may play a role in the detection of ARB and ARGs. Predictive analysis suggests that both human presence and human activities, such as waste elimination, significantly contributed to the abundance of ARB in soil and water. The results of this work evidence that the ecology of antibiotic resistance in remote environments is more complex than anthropogenic impact alone, necessitating further environmental characterization of ARB and ARGs.
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Affiliation(s)
- Laura C Scott
- Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, USA
| | - Mark J Wilson
- Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, USA
| | - Scott M Esser
- Continental Divide Research Learning Center, Rocky Mountain National Park. Estes Park, CO, USA
| | - Nicholas L Lee
- Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, USA
| | - Michael E Wheeler
- School of Renewable Natural Resources, Louisiana State University, Baton Rouge, LA, USA
| | - Alexandra Aubee
- Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, USA
| | - Tiong Gim Aw
- Department of Environmental Health Sciences, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, USA.
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Wnuk M, Lewinska A. Imaging flow cytometry-based analysis of bacterial profiles in milk samples. FOOD AND BIOPRODUCTS PROCESSING 2021. [DOI: 10.1016/j.fbp.2021.04.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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20
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Bhat VJ, Vegesna SV, Kiani M, Zhao X, Blaschke D, Du N, Vogel M, Kluge S, Raff J, Hübner U, Skorupa I, Rebohle L, Schmidt H. Detecting Bacterial Cell Viability in Few µL Solutions from Impedance Measurements on Silicon-Based Biochips. Int J Mol Sci 2021; 22:ijms22073541. [PMID: 33805483 PMCID: PMC8037661 DOI: 10.3390/ijms22073541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 03/25/2021] [Accepted: 03/26/2021] [Indexed: 11/20/2022] Open
Abstract
Using two different types of impedance biochips (PS5 and BS5) with ring top electrodes, a distinct change of measured impedance has been detected after adding 1–5 µL (with dead or live Gram-positive Lysinibacillus sphaericus JG-A12 cells to 20 µL DI water inside the ring top electrode. We relate observed change of measured impedance to change of membrane potential of L. sphaericus JG-A12 cells. In contrast to impedance measurements, optical density (OD) measurements cannot be used to distinguish between dead and live cells. Dead L. sphaericus JG-A12 cells have been obtained by adding 0.02 mg/mL of the antibiotics tetracycline and 0.1 mg/mL chloramphenicol to a batch with OD0.5 and by incubation for 24 h, 30 °C, 120 rpm in the dark. For impedance measurements, we have used batches with a cell density of 25.5 × 108 cells/mL (OD8.5) and 270.0 × 108 cells/mL (OD90.0). The impedance biochip PS5 can be used to detect the more resistive and less capacitive live L. sphaericus JG-A12 cells. Also, the impedance biochip BS5 can be used to detect the less resistive and more capacitive dead L. sphaericus JG-A12 cells. An outlook on the application of the impedance biochips for high-throughput drug screening, e.g., against multi-drug-resistant Gram-positive bacteria, is given.
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Affiliation(s)
- Vinayak J. Bhat
- Leibniz Institute of Photonic Technology, Albert-Einstein-Str. 9, 07745 Jena, Germany; (V.J.B.); (D.B.); (U.H.)
| | - Sahitya V. Vegesna
- Leibniz Institute of Photonic Technology, Albert-Einstein-Str. 9, 07745 Jena, Germany; (V.J.B.); (D.B.); (U.H.)
- Correspondence: (S.V.V.); (N.D.); (H.S.)
| | - Mahdi Kiani
- Center for Microtechnologies, Chemnitz University of Technology, 09126 Chemnitz, Germany; (M.K.); (X.Z.)
| | - Xianyue Zhao
- Center for Microtechnologies, Chemnitz University of Technology, 09126 Chemnitz, Germany; (M.K.); (X.Z.)
| | - Daniel Blaschke
- Leibniz Institute of Photonic Technology, Albert-Einstein-Str. 9, 07745 Jena, Germany; (V.J.B.); (D.B.); (U.H.)
| | - Nan Du
- Leibniz Institute of Photonic Technology, Albert-Einstein-Str. 9, 07745 Jena, Germany; (V.J.B.); (D.B.); (U.H.)
- Institute for Solid State Physics, Friedrich Schiller University Jena, Helmholtzweg 3, 07743 Jena, Germany
- Correspondence: (S.V.V.); (N.D.); (H.S.)
| | - Manja Vogel
- Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany; (M.V.); (S.K.); (J.R.); (I.S.); (L.R.)
| | - Sindy Kluge
- Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany; (M.V.); (S.K.); (J.R.); (I.S.); (L.R.)
| | - Johannes Raff
- Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany; (M.V.); (S.K.); (J.R.); (I.S.); (L.R.)
| | - Uwe Hübner
- Leibniz Institute of Photonic Technology, Albert-Einstein-Str. 9, 07745 Jena, Germany; (V.J.B.); (D.B.); (U.H.)
| | - Ilona Skorupa
- Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany; (M.V.); (S.K.); (J.R.); (I.S.); (L.R.)
| | - Lars Rebohle
- Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany; (M.V.); (S.K.); (J.R.); (I.S.); (L.R.)
| | - Heidemarie Schmidt
- Leibniz Institute of Photonic Technology, Albert-Einstein-Str. 9, 07745 Jena, Germany; (V.J.B.); (D.B.); (U.H.)
- Institute for Solid State Physics, Friedrich Schiller University Jena, Helmholtzweg 3, 07743 Jena, Germany
- Correspondence: (S.V.V.); (N.D.); (H.S.)
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Ruiz-González C, Rodellas V, Garcia-Orellana J. The microbial dimension of submarine groundwater discharge: current challenges and future directions. FEMS Microbiol Rev 2021; 45:6128669. [PMID: 33538813 PMCID: PMC8498565 DOI: 10.1093/femsre/fuab010] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 01/28/2021] [Indexed: 12/22/2022] Open
Abstract
Despite the relevance of submarine groundwater discharge (SGD) for ocean biogeochemistry, the microbial dimension of SGD remains poorly understood. SGD can influence marine microbial communities through supplying chemical compounds and microorganisms, and in turn, microbes at the land–ocean transition zone determine the chemistry of the groundwater reaching the ocean. However, compared with inland groundwater, little is known about microbial communities in coastal aquifers. Here, we review the state of the art of the microbial dimension of SGD, with emphasis on prokaryotes, and identify current challenges and future directions. Main challenges include improving the diversity description of groundwater microbiota, characterized by ultrasmall, inactive and novel taxa, and by high ratios of sediment-attached versus free-living cells. Studies should explore microbial dynamics and their role in chemical cycles in coastal aquifers, the bidirectional dispersal of groundwater and seawater microorganisms, and marine bacterioplankton responses to SGD. This will require not only combining sequencing methods, visualization and linking taxonomy to activity but also considering the entire groundwater–marine continuum. Interactions between traditionally independent disciplines (e.g. hydrogeology, microbial ecology) are needed to frame the study of terrestrial and aquatic microorganisms beyond the limits of their presumed habitats, and to foster our understanding of SGD processes and their influence in coastal biogeochemical cycles.
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Affiliation(s)
- Clara Ruiz-González
- Institut de Ciències del Mar (ICM-CSIC). Passeig Marítim de la Barceloneta 37-49, E08003 Barcelona, Spain
| | - Valentí Rodellas
- Institut de Ciència i Tecnologia Ambientals (ICTA-UAB), Universitat Autònoma de Barcelona, E08193 Bellaterra, Spain
| | - Jordi Garcia-Orellana
- Institut de Ciència i Tecnologia Ambientals (ICTA-UAB), Universitat Autònoma de Barcelona, E08193 Bellaterra, Spain.,Departament de Física, Universitat Autònoma de Barcelona, E08193 Bellaterra, Spain
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22
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Salcedo-Sora JE, Jindal S, O'Hagan S, Kell DB. A palette of fluorophores that are differentially accumulated by wild-type and mutant strains of Escherichia coli: surrogate ligands for profiling bacterial membrane transporters. MICROBIOLOGY (READING, ENGLAND) 2021; 167:001016. [PMID: 33406033 PMCID: PMC8131027 DOI: 10.1099/mic.0.001016] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 12/15/2020] [Indexed: 12/12/2022]
Abstract
Our previous work demonstrated that two commonly used fluorescent dyes that were accumulated by wild-type Escherichia coli MG1655 were differentially transported in single-gene knockout strains, and also that they might be used as surrogates in flow cytometric transporter assays. We summarize the desirable properties of such stains, and here survey 143 candidate dyes. We eventually triage them (on the basis of signal, accumulation levels and cost) to a palette of 39 commercially available and affordable fluorophores that are accumulated significantly by wild-type cells of the 'Keio' strain BW25113, as measured flow cytometrically. Cheminformatic analyses indicate both their similarities and their (much more considerable) structural differences. We describe the effects of pH and of the efflux pump inhibitor chlorpromazine on the accumulation of the dyes. Even the 'wild-type' MG1655 and BW25113 strains can differ significantly in their ability to take up such dyes. We illustrate the highly differential uptake of our dyes into strains with particular lesions in, or overexpressed levels of, three particular transporters or transporter components (yhjV, yihN and tolC). The relatively small collection of dyes described offers a rapid, inexpensive, convenient and informative approach to the assessment of microbial physiology and phenotyping of membrane transporter function.
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Affiliation(s)
- Jesus Enrique Salcedo-Sora
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown St, Liverpool L69 7ZB, UK
| | - Srijan Jindal
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown St, Liverpool L69 7ZB, UK
| | - Steve O'Hagan
- Department of Chemistry and Manchester Institute of Biotechnology, The University of Manchester, 131 Princess St, Manchester M1 7DN, UK
| | - Douglas B. Kell
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown St, Liverpool L69 7ZB, UK
- Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Building 220, Kemitorvet, 2800 Kgs Lyngby, Denmark
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23
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Silva L, Calleja ML, Ivetic S, Huete-Stauffer T, Roth F, Carvalho S, Morán XAG. Heterotrophic bacterioplankton responses in coral- and algae-dominated Red Sea reefs show they might benefit from future regime shift. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 751:141628. [PMID: 32896805 DOI: 10.1016/j.scitotenv.2020.141628] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 08/06/2020] [Accepted: 08/09/2020] [Indexed: 06/11/2023]
Abstract
In coral reefs, dissolved organic matter (DOM) cycling is a critical process for sustaining ecosystem functioning. However, global and local stressors have caused persistent shifts from coral- to algae-dominated benthic communities. The influence of such phase shifts on DOM nature and its utilization by heterotrophic bacterioplankton remains poorly studied. Every second month for one year, we retrieved seawater samples enriched in DOM produced by coral- and algae-dominated benthic communities in a central Red Sea reef during a full annual cycle. Seawater incubations were conducted in the laboratory under in situ temperature and light conditions by inoculating enriched DOM samples with bacterial assemblages collected in the surrounding waters. Dissolved organic carbon (DOC) concentrations were higher in the warmer months (May-September) in both communities, resulting in higher specific growth rates and bacterial growth efficiencies (BGE). However, these high summer values were significantly enhanced in algal-DOM relative to coral-DOM, suggesting the potential for bacterioplankton biomass increase in reefs with algae replacing healthy coral cover under warmer conditions. The potential exacerbation of heterotrophic bacterial activity in the ongoing widespread regime shift from coral- to algae-dominated communities may have detrimental consequences for the overall health of tropical coral reefs.
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Affiliation(s)
- Luis Silva
- King Abdullah University of Science and Technology (KAUST), Red Sea Research Center, Thuwal 23955-6900, Saudi Arabia.
| | - Maria Ll Calleja
- King Abdullah University of Science and Technology (KAUST), Red Sea Research Center, Thuwal 23955-6900, Saudi Arabia; Department of Climate Geochemistry, Max Planck Institute for Chemistry (MPIC), Hahn-Meitner-Weg 1, 55128 Mainz, Germany
| | | | - Tamara Huete-Stauffer
- King Abdullah University of Science and Technology (KAUST), Red Sea Research Center, Thuwal 23955-6900, Saudi Arabia
| | - Florian Roth
- King Abdullah University of Science and Technology (KAUST), Red Sea Research Center, Thuwal 23955-6900, Saudi Arabia; Baltic Sea Centre, Stockholm University, 11418 Stockholm, Sweden; Tvärminne Zoological Station, University of Helsinki, 00100 Helsinki, Finland
| | - Susana Carvalho
- King Abdullah University of Science and Technology (KAUST), Red Sea Research Center, Thuwal 23955-6900, Saudi Arabia
| | - Xosé Anxelu G Morán
- King Abdullah University of Science and Technology (KAUST), Red Sea Research Center, Thuwal 23955-6900, Saudi Arabia
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24
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Chitosan decoration improves the rapid and long-term antibacterial activities of cinnamaldehyde-loaded liposomes. Int J Biol Macromol 2020; 168:59-66. [PMID: 33279567 DOI: 10.1016/j.ijbiomac.2020.12.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 11/21/2020] [Accepted: 12/01/2020] [Indexed: 12/16/2022]
Abstract
In this work, cinnamaldehyde-loaded liposomes decorated with different concentrations of chitosan (0, 0.25, 0.5, 1, 2, 3, and 4 mg/mL) were prepared and their physical and antibacterial properties were evaluated. The results showed that the physical decoration of chitosan improved the encapsulation efficiency and storage stability of the liposomes. Liposomes decorated with chitosan at the concentration of 0.25 to 4 mg/mL were able to achieve an obvious antibacterial efficiency against Staphylococcus aureus after only 10 min of incubation. The antibacterial efficiency of chitosan-decorated liposomes was still higher than 90% after being stored for 28 d when the chitosan concentration was greater than 1 mg/mL. Besides, increasing the chitosan concentration significantly decreased the minimum inhibitory concentration of the liposomes. The comparison of the antibacterial activities and mechanisms of cinnamaldehyde-loaded liposomes decorated with chitosan at a concentration of 4 mg/mL (CH-CL), cinnamaldehyde-loaded liposomes (CL), cinnamaldehyde, and chitosan revealed that chitosan and cinnamaldehyde exerted a cumulative and synergistic bacteriostatic effect in the liposomes. This led to damage to the cell membrane integrity, causing cell death by inducing leakage of intracellular components. These results can potentially provide guidance for the preparation and application of natural preservatives with rapid and long-term bacteriostatic effects.
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25
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Sabbagh EI, Huete-Stauffer TM, Calleja MLL, Silva L, Viegas M, Morán XAG. Weekly variations of viruses and heterotrophic nanoflagellates and their potential impact on bacterioplankton in shallow waters of the central Red Sea. FEMS Microbiol Ecol 2020; 96:5800985. [PMID: 32149360 PMCID: PMC7104677 DOI: 10.1093/femsec/fiaa033] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 03/08/2020] [Indexed: 11/14/2022] Open
Abstract
Bacterioplankton play a pivotal role in marine ecosystems. However, their temporal dynamics and underlying control mechanisms are poorly understood in tropical regions such as the Red Sea. Here, we assessed the impact of bottom-up (resource availability) and top-down (viruses and heterotrophic nanoflagellates) controls on bacterioplankton abundances by weekly sampling a coastal central Red Sea site in 2017. We monitored microbial abundances by flow cytometry together with a set of environmental variables including temperature, salinity, dissolved organic and inorganic nutrients and chlorophyll a. We distinguished five groups of heterotrophic bacteria depending on their physiological properties relative nucleic acid content, membrane integrity and cell-specific respiratory activity, two groups of Synechococcus cyanobacteria and three groups of viruses. Viruses controlled heterotrophic bacteria for most of the year, as supported by a negative correlation between their respective abundances and a positive one between bacterial mortality rates and mean viral abundances. On the contrary, heterotrophic nanoflagellates abundance covaried with that of heterotrophic bacteria. Heterotrophic nanoflagellates showed preference for larger bacteria from both the high and low nucleic acid content groups. Our results demonstrate that top-down control is fundamental in keeping heterotrophic bacterioplankton abundances low (< 5 × 10 5 cells mL−1) in Red Sea coastal waters.
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Affiliation(s)
- Eman I Sabbagh
- King Abdullah University of Science and Technology (KAUST), Red Sea Research Center, Biological and Environmental Sciences and Engineering Division, Thuwal, Kingdom of Saudi Arabia
| | - Tamara M Huete-Stauffer
- King Abdullah University of Science and Technology (KAUST), Red Sea Research Center, Biological and Environmental Sciences and Engineering Division, Thuwal, Kingdom of Saudi Arabia
| | - Maria L L Calleja
- King Abdullah University of Science and Technology (KAUST), Red Sea Research Center, Biological and Environmental Sciences and Engineering Division, Thuwal, Kingdom of Saudi Arabia.,Max Planck Institute for Chemistry, Hahn-Meitner Weg 1, 55128 Mainz, Germany
| | - Luis Silva
- King Abdullah University of Science and Technology (KAUST), Red Sea Research Center, Biological and Environmental Sciences and Engineering Division, Thuwal, Kingdom of Saudi Arabia
| | - Miguel Viegas
- King Abdullah University of Science and Technology (KAUST), Red Sea Research Center, Biological and Environmental Sciences and Engineering Division, Thuwal, Kingdom of Saudi Arabia
| | - Xosé Anxelu G Morán
- King Abdullah University of Science and Technology (KAUST), Red Sea Research Center, Biological and Environmental Sciences and Engineering Division, Thuwal, Kingdom of Saudi Arabia
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26
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Varela MM, Rodríguez-Ramos T, Guerrero-Feijóo E, Nieto-Cid M. Changes in Activity and Community Composition Shape Bacterial Responses to Size-Fractionated Marine DOM. Front Microbiol 2020; 11:586148. [PMID: 33329457 PMCID: PMC7714726 DOI: 10.3389/fmicb.2020.586148] [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] [Received: 07/22/2020] [Accepted: 09/30/2020] [Indexed: 12/21/2022] Open
Abstract
To study the response of bacteria to different size-fractions of naturally occurring dissolved organic matter (DOM), a natural prokaryotic community from North Atlantic mesopelagic waters (1000 m depth) was isolated and grown in (i) 0.1-μm filtered seawater (CONTROL), (ii) the low-molecular-weight (<1 kDa) DOM fraction (L-DOM), and (iii) the recombination of high- (>1 kDa) and low-molecular-weight DOM fractions (H + L-DOM), to test the potential effect of ultrafiltration on breaking the DOM size continuum. Prokaryotic abundance and leucine incorporation were consistently higher in the H + L-DOM niche than in the L-DOM and CONTROL treatments, suggesting a different interaction with each DOM fraction and the disruption of the structural DOM continuum by ultrafiltration, respectively. Rhodobacterales (Alphaproteobacteria) and Flavobacteriales (Bacteroidetes) were particularly enriched in L-DOM and closely related to the colored DOM (CDOM) fraction, indicating the tight link between these groups and changes in DOM aromaticity. Conversely, some other taxa that were rare or undetectable in the original bacterial community were enriched in the H + L-DOM treatment (e.g., Alteromonadales belonging to Gammaproteobacteria), highlighting the role of the rare biosphere as a seed bank of diversity against ecosystem disturbance. The relationship between the fluorescence of protein-like CDOM and community composition of populations in the H + L-DOM treatment suggested their preference for labile DOM. Conversely, the communities growing on the L-DOM niche were coupled to humic-like CDOM, which may indicate their ability to degrade more reworked DOM and/or the generation of refractory substrates (as by-products of the respiration processes). Most importantly, L- and/or H + L-DOM treatments stimulated the growth of unique bacterial amplicon sequence variants (ASVs), suggesting the potential of environmental selection (i.e., changes in DOM composition and availability), particularly in the light of climate change scenarios. Taken together, our results suggest that different size-fractions of DOM induced niche-specialization and differentiation of mesopelagic bacterial communities.
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Affiliation(s)
- Marta M. Varela
- Centro Oceanográfico de A Coruña, Instituto Español de Oceanografía (IEO), A Coruña, Spain
| | - Tamara Rodríguez-Ramos
- Centro Oceanográfico de A Coruña, Instituto Español de Oceanografía (IEO), A Coruña, Spain
| | - Elisa Guerrero-Feijóo
- Centro Oceanográfico de A Coruña, Instituto Español de Oceanografía (IEO), A Coruña, Spain
| | - Mar Nieto-Cid
- Centro Oceanográfico de A Coruña, Instituto Español de Oceanografía (IEO), A Coruña, Spain
- Laboratorio de Geoquímica Orgánica, Instituto de Investigaciones Marinas (CSIC), Vigo, Spain
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27
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Antibacterial Effects of Bicarbonate in Media Modified to Mimic Cystic Fibrosis Sputum. Int J Mol Sci 2020; 21:ijms21228614. [PMID: 33207565 PMCID: PMC7696793 DOI: 10.3390/ijms21228614] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/06/2020] [Accepted: 11/14/2020] [Indexed: 12/18/2022] Open
Abstract
Cystic fibrosis (CF) is a hereditary disease caused by mutations in the gene encoding an epithelial anion channel. In CF, Cl− and HCO3− hyposecretion, together with mucin hypersecretion, leads to airway dehydration and production of viscous mucus. This habitat is ideal for colonization by pathogenic bacteria. We have recently demonstrated that HCO3− inhibits the growth and biofilm formation of Pseudomonas aeruginosa and Staphylococcus aureus when tested in laboratory culture media. Using the same bacteria our aim was to investigate the effects of HCO3− in artificial sputum medium (ASM), whose composition resembles CF mucus. Control ASM containing no NaHCO3 was incubated in ambient air (pH 7.4 or 8.0). ASM containing NaHCO3 (25 and 100 mM) was incubated in 5% CO2 (pH 7.4 and 8.0, respectively). Viable P. aeruginosa and S. aureus cells were counted by colony-forming unit assay and flow cytometry after 6 h and 17 h of incubation. Biofilm formation was assessed after 48 h. The data show that HCO3− significantly decreased viable cell counts and biofilm formation in a concentration-dependent manner. These effects were due neither to extracellular alkalinization nor to altered osmolarity. These results show that HCO3− exerts direct antibacterial and antibiofilm effects on prevalent CF bacteria.
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28
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Song J, Klümper U, Riber L, Dechesne A, Smets BF, Sørensen SJ, Brandt KK. A converging subset of soil bacterial taxa is permissive to the IncP-1 plasmid pKJK5 across a range of soil copper contamination. FEMS Microbiol Ecol 2020; 96:5917080. [PMID: 33002118 DOI: 10.1093/femsec/fiaa200] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 09/28/2020] [Indexed: 12/29/2022] Open
Abstract
Stressors like metals or antibiotics can affect bacterial community permissiveness for plasmid uptake, but there is little knowledge about long-term effects of such stressors on the evolution of community permissiveness. We assessed the effect of more than 90 years of soil Cu contamination on bacterial community permissiveness (i.e. uptake ability) toward a gfp-tagged IncP-1 plasmid (pKJK5) introduced via an Escherichia coli donor. Plasmid transfer events from the donor to the recipient soil bacterial community were quantified and transconjugants were subsequently isolated by fluorescence activated cell sorting and identified by 16S rRNA gene amplicon sequencing. Transfer frequency of plasmid pKJK5 was reduced in bacterial communities extracted from highly Cu contaminated (4526 mg kg-1) soil compared to corresponding communities extracted from moderately (458 mg kg-1) Cu contaminated soil and a low Cu reference soil (15 mg kg-1). The taxonomic composition of the transconjugal pools showed remarkable similarities irrespective of the degree of soil Cu contamination and despite contrasting compositions of the extracted recipient communities and the original soil communities. Permissiveness assessed at the level of individual operational taxonomic units (OTUs; 16S rRNA gene 97% sequence similarity threshold) was only slightly affected by soil Cu level and high replicate variability of OTU-level permissiveness indicated a role of stochastic events in IncP-1 plasmid transfer or strain-to-strain permissiveness variability.
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Affiliation(s)
- Jianxiao Song
- School of Ecology and Environment, Northwestern Polytechnical University, 1 Dongxiang Road, Chang'an District, Xi'an Shaanxi,710129, P.R. China.,Section for Microbial Ecology and Biotechnology, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark.,Section of Microbiology, Department of Biology, University of Copenhagen, Universitetsparken 15, Building 1, 2100 Copenhagen, Denmark
| | - Uli Klümper
- Institute for Hydrobiology, Technische Universität Dresden, Dresden 01217, Germany.,Environment and Sustainability Institute, Medical School, University of Exeter, Penryn Campus, Cornwall, TR10 9FE, UK
| | - Leise Riber
- Section for Microbial Ecology and Biotechnology, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark.,Section of Microbiology, Department of Biology, University of Copenhagen, Universitetsparken 15, Building 1, 2100 Copenhagen, Denmark
| | - Arnaud Dechesne
- Department of Environmental Engineering, Technical University of Denmark, Miljøvej Building 115, 2800 Kgs. Lyngby, Denmark
| | - Barth F Smets
- Department of Environmental Engineering, Technical University of Denmark, Miljøvej Building 115, 2800 Kgs. Lyngby, Denmark
| | - Søren J Sørensen
- Section of Microbiology, Department of Biology, University of Copenhagen, Universitetsparken 15, Building 1, 2100 Copenhagen, Denmark
| | - Kristian K Brandt
- Section for Microbial Ecology and Biotechnology, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
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29
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Arandia-Gorostidi N, González JM, Huete-Stauffer TM, Ansari MI, Morán XAG, Alonso-Sáez L. Light supports cell-integrity and growth rates of taxonomically diverse coastal photoheterotrophs. Environ Microbiol 2020; 22:3823-3837. [PMID: 32643243 DOI: 10.1111/1462-2920.15158] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 06/29/2020] [Accepted: 07/06/2020] [Indexed: 11/28/2022]
Abstract
Despite the widespread distribution of proteorhodopsin (PR)-containing bacteria in the oceans, the use of light-derived energy to promote bacterial growth has only been shown in a few bacterial isolates, and there is a paucity of data describing the metabolic effects of light on environmental photoheterotrophic taxa. Here, we assessed the effects of light on the taxonomic composition, cell integrity and growth responses of microbial communities in monthly incubations between spring and autumn under different environmental conditions. The photoheterotrophs expressing PR in situ were dominated by Pelagibacterales and SAR116 in July and November, while members of Euryarchaeota, Gammaproteobacteria and Bacteroidetes dominated the PR expression in spring. Cell-membrane integrity decreased under dark conditions throughout most of the assessment, with maximal effects in summer, under low-nutrient conditions. A positive effect of light on growth was observed in one incubation (out of nine), coinciding with a declining phytoplankton bloom. Light-enhanced growth was found in Gammaproteobacteria (Alteromonadales) and Bacteroidetes (Polaribacter and Tenacibaculum). Unexpectedly, some Pelagibacterales also exhibited higher growth rates under light conditions. We propose that the energy harvested by PRs helps to maintain cell viability in dominant coastal photoheterotrophic oligotrophs while promoting the growth of some widespread taxa benefiting from the decline of phytoplankton blooms.
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Affiliation(s)
- Nestor Arandia-Gorostidi
- Instituto Español de Oceanografía, Centro Oceanográfico de Gijón/Xixón, Gijón/Xixón, Asturias, Spain.,Department of Earth System Science, Stanford University, Stanford, CA, USA
| | - José M González
- Department of Microbiology, University of La Laguna, La Laguna, Spain
| | - Tamara M Huete-Stauffer
- Instituto Español de Oceanografía, Centro Oceanográfico de Gijón/Xixón, Gijón/Xixón, Asturias, Spain.,Red Sea Research Center, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Mohd I Ansari
- Red Sea Research Center, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Xosé Anxelu G Morán
- Red Sea Research Center, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Laura Alonso-Sáez
- Instituto Español de Oceanografía, Centro Oceanográfico de Gijón/Xixón, Gijón/Xixón, Asturias, Spain.,AZTI, Marine Research, Basque Research and Technology Alliance (BRTA), Txatxarramendi ugartea z/g, Sukarrieta, Bizkaia, 48395, Spain
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30
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Hussain MW, Bhardwaj V, Giri A, Chande A, Patra A. Multifunctional ionic porous frameworks for CO 2 conversion and combating microbes. Chem Sci 2020; 11:7910-7920. [PMID: 34123075 PMCID: PMC8163429 DOI: 10.1039/d0sc01658f] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 07/01/2020] [Indexed: 01/14/2023] Open
Abstract
Porous organic frameworks (POFs) with a heteroatom rich ionic backbone have emerged as advanced materials for catalysis, molecular separation, and antimicrobial applications. The loading of metal ions further enhances Lewis acidity, augmenting the activity associated with such frameworks. Metal-loaded ionic POFs, however, often suffer from physicochemical instability, thereby limiting their scope for diverse applications. Herein, we report the fabrication of triaminoguanidinium-based ionic POFs through Schiff base condensation in a cost-effective and scalable manner. The resultant N-rich ionic frameworks facilitate selective CO2 uptake and afford high metal (Zn(ii): 47.2%) loading capacity. Owing to the ionic guanidinium core and ZnO infused mesoporous frameworks, Zn/POFs showed pronounced catalytic activity in the cycloaddition of CO2 and epoxides into cyclic organic carbonates under solvent-free conditions with high catalyst recyclability. The synergistic effect of infused ZnO and cationic triaminoguanidinium frameworks in Zn/POFs led to robust antibacterial (Gram-positive, Staphylococcus aureus and Gram-negative, Escherichia coli) and antiviral activity targeting HIV-1 and VSV-G enveloped lentiviral particles. We thus present triaminoguanidinium-based POFs and Zn/POFs as a new class of multifunctional materials for environmental remediation and biomedical applications.
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Affiliation(s)
- Md Waseem Hussain
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal Bhopal Bypass Road, Bhauri Bhopal 462066 Madhya Pradesh India
| | - Vipin Bhardwaj
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal Bhopal Bypass Road, Bhauri Bhopal 462066 Madhya Pradesh India
| | - Arkaprabha Giri
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal Bhopal Bypass Road, Bhauri Bhopal 462066 Madhya Pradesh India
| | - Ajit Chande
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal Bhopal Bypass Road, Bhauri Bhopal 462066 Madhya Pradesh India
| | - Abhijit Patra
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal Bhopal Bypass Road, Bhauri Bhopal 462066 Madhya Pradesh India
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31
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Baños I, Montero MF, Benavides M, Arístegui J. INT Toxicity over Natural Bacterial Assemblages from Surface Oligotrophic Waters: Implications for the Assessment of Respiratory Activity. MICROBIAL ECOLOGY 2020; 80:237-242. [PMID: 31915852 DOI: 10.1007/s00248-019-01479-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 12/22/2019] [Indexed: 06/10/2023]
Abstract
Plankton community respiration (R) is a major component of the carbon flux in aquatic ecosystems. However, current methods to measure actual respiration from oxygen consumption at relevant spatial scales are not sensitive enough in oligotrophic environments where respiration rates are very low. To overcome this drawback, more sensitive indirect enzymatic approaches are commonly used as R proxies. The in vivo electron transport system (ETSvivo) assay, which measures the reduction of (2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyl tetrazolium chloride salt, INT) to INT-formazan in the presence of natural substrate levels, was recently proposed as an indirect reliable estimation of R for natural plankton communities. However, under in vivo conditions, formazan salts could be toxic to the cells. Here, we test the toxicity of 0.2 mM of final INT concentration, widely used for ETSvivo assays, on natural bacterial assemblages collected in coastal and oceanic waters off Gran Canaria (Canary Islands, subtropical North Atlantic), in eight independent experiments. After 0.5 h of incubation, a significant but variable decline in cell viability (14-49%) was observed in all samples inoculated with INT. Moreover, INT also inhibited leucine uptake in less than 90 min of incubation. In the light of these results, we argue that enzymatic respiratory rates obtained with the ETSvivo method need to be interpreted with caution to derive R in oceanic regions where bacteria largely contribute to community respiration. Moreover, the variable toxicity on bacterial assemblages observed in our experiments questions the use of a single R/ETSvivo relationship as a universal proxy for regional studies.
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Affiliation(s)
- Isabel Baños
- Instituto de Oceanografía y Cambio Global, IOCAG, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - María F Montero
- Instituto de Oceanografía y Cambio Global, IOCAG, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Mar Benavides
- Aix-Marseille Université, Université de Toulon, CNRS, IRD, Mediterranean Institute of Oceanography (MIO), UM 110, 13288, Marseille, France
| | - Javier Arístegui
- Instituto de Oceanografía y Cambio Global, IOCAG, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain.
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32
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Bai L, Deng Y, Li J, Ji M, Ruan W. Role of the proportion of cattle manure and biogas residue on the degradation of lignocellulose and humification during composting. BIORESOURCE TECHNOLOGY 2020; 307:122941. [PMID: 32272325 DOI: 10.1016/j.biortech.2020.122941] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 01/28/2020] [Accepted: 01/29/2020] [Indexed: 06/11/2023]
Abstract
The effects of different proportions of cattle manure (CM) and biogas residue (BR) on the degradation of lignocellulose and humification during composting were investigated. The results showed that increasing the CM content prolonged the thermophilic period duration, thus promoting organic matter degradation and enhancing the humification degree during composting. Compared with the initial compost, the cellulose content decreased 3.90%-22.81%. The addition of CM increased humic acid content by 17.21%-26.02% compared with the control. The excitation-emission matrix (EEM) fluorescence spectroscopy analysis indicated that a higher CM content was conducive to the formation of protein-like substances, but a disadvantage for humic substances. The cell viability decreased as CM content increased. The redundancy analysis (RDA) demonstrated that proportions of CM and BR were positively correlated with cellulose content and negatively correlated with cell viability and the content of lignin. The results suggest that adding 6.7% CM was optimal for BR composting.
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Affiliation(s)
- Ling Bai
- School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China; Jiangsu Key Laboratory of Anaerobic Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Yun Deng
- School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China; Jiangsu Key Laboratory of Anaerobic Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Jing Li
- School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China; Jiangsu Key Laboratory of Anaerobic Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Mengmeng Ji
- School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China; Jiangsu Key Laboratory of Anaerobic Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Wenquan Ruan
- School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China; Jiangsu Key Laboratory of Anaerobic Biotechnology, Jiangnan University, Wuxi 214122, China.
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Layglon N, Misson B, Durieu G, Coclet C, D'Onofrio S, Dang DH, François D, Mullot JU, Mounier S, Lenoble V, Omanović D, Garnier C. Long-term monitoring emphasizes impacts of the dredging on dissolved Cu and Pb contamination along with ultraplankton distribution and structure in Toulon Bay (NW Mediterranean Sea, France). MARINE POLLUTION BULLETIN 2020; 156:111196. [PMID: 32510358 DOI: 10.1016/j.marpolbul.2020.111196] [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: 07/26/2019] [Revised: 04/16/2020] [Accepted: 04/16/2020] [Indexed: 06/11/2023]
Abstract
A long-term monitoring during dredging and non-dredging periods was performed. Total and dissolved Cu and Pb concentrations, DGT-labile Pb, ultraphytoplankton abundance and structure were monitored at four sites: dredging site, dumping site (inside/outside of a geotextile bag) and reference site. During the reference period (non-dredging), an increasing contamination in Pb, Cu and a progressive shift from Synechococcus to photosynthetic picoeukaryotes dominance was observed from reference to dumping site. Pb concentrations were significantly higher during dredging period, pointing out sediment resuspension as Pb major source of contamination. Unlike Pb, Cu concentrations were not statistically different during the two periods. Dredging period did not impact on ultraphytoplankton abundance and structure but influence heterotrophic prokaryotes abundance. Sediment resuspension is therefore a major driver of chemical and biological qualities in Toulon Bay. Furthermore, although the geotextile bag reduces particulate transport of the dredged sediment, the transport in the dissolved phase remains a major problem.
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Affiliation(s)
- Nicolas Layglon
- Université de Toulon, Aix Marseille Université, CNRS, IRD, Mediterranean Institute of Oceanography (MIO), UM110, France.
| | - Benjamin Misson
- Université de Toulon, Aix Marseille Université, CNRS, IRD, Mediterranean Institute of Oceanography (MIO), UM110, France
| | - Gaël Durieu
- Université de Toulon, Aix Marseille Université, CNRS, IRD, Mediterranean Institute of Oceanography (MIO), UM110, France
| | - Clément Coclet
- Université de Toulon, Aix Marseille Université, CNRS, IRD, Mediterranean Institute of Oceanography (MIO), UM110, France; MAPIEM, EA4323, Université de Toulon, Toulon, France
| | - Sébastien D'Onofrio
- Université de Toulon, Aix Marseille Université, CNRS, IRD, Mediterranean Institute of Oceanography (MIO), UM110, France
| | - Duc Huy Dang
- School of the Environment, Chemistry Department, Trent University, Peterborough, ON, Canada
| | - David François
- LASEM-Toulon, Base Navale De Toulon, BP 61, 83800 Toulon, France
| | | | - Stéphane Mounier
- Université de Toulon, Aix Marseille Université, CNRS, IRD, Mediterranean Institute of Oceanography (MIO), UM110, France
| | - Véronique Lenoble
- Université de Toulon, Aix Marseille Université, CNRS, IRD, Mediterranean Institute of Oceanography (MIO), UM110, France
| | - Dario Omanović
- Center for Marine and Environmental Research, Ruđer Bošković Institute, P.O. Box 180, 10002 Zagreb, Croatia
| | - Cédric Garnier
- Université de Toulon, Aix Marseille Université, CNRS, IRD, Mediterranean Institute of Oceanography (MIO), UM110, France
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Morán XAG, Baltar F, Carreira C, Lønborg C. Responses of physiological groups of tropical heterotrophic bacteria to temperature and dissolved organic matter additions: food matters more than warming. Environ Microbiol 2020; 22:1930-1943. [PMID: 32249543 PMCID: PMC7384166 DOI: 10.1111/1462-2920.15007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/09/2020] [Accepted: 03/07/2020] [Indexed: 12/18/2022]
Abstract
Compared to higher latitudes, tropical heterotrophic bacteria may be less responsive to warming because of strong bottom‐up control. In order to separate both drivers, we determined the growth responses of bacterial physiological groups to temperature after adding dissolved organic matter (DOM) from mangroves, seagrasses and glucose to natural seawater from the Great Barrier Reef. Low (LNA) and high (HNA) nucleic acid content, membrane‐intact (Live) and membrane‐damaged (Dead) plus actively respiring (CTC+) cells were monitored for 4 days. Specific growth rates of the whole community were significantly higher (1.9 day‐1) in the mangrove treatment relative to the rest (0.2–0.4 day‐1) at in situ temperature and their temperature dependence, estimated as activation energy, was also consistently higher. Strong bottom‐up control was suggested in the other treatments. Cell size depended more on DOM than temperature. Mangrove DOM resulted in significantly higher contributions of Live, HNA and CTC+ cells to total abundance, while the seagrass leachate reduced Live cells below 50%. Warming significantly decreased Live and CTC+ cells contributions in most treatments. Our results suggest that only in the presence of highly labile compounds, such as mangroves DOM, can we anticipate increases in heterotrophic bacteria biomass in response to warming in tropical regions.
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Affiliation(s)
- Xosé Anxelu G Morán
- King Abdullah University of Science and Technology (KAUST), Red Sea Research Center (RSRC), Thuwal, 23955-6900, Saudi Arabia
| | - Federico Baltar
- Department of Functional and Evolutionary Ecology, University of Vienna, 1090, Althanstraße 14, Vienna, Austria.,Department of Marine Science, University of Otago, Dunedin, 9054, New Zealand.,NIWA/University of Otago Research Centre for Oceanography, Dunedin, 9054, New Zealand
| | - Cátia Carreira
- Departamento de Biologia and CESAM, Universidade de Aveiro, Campus Universitário de Santiago, Aveiro, 3810-193, Portugal
| | - Christian Lønborg
- Australian Institute of Marine Science, Townsville, Queensland, 4810, Australia
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Benito V, Etxebarria J, Goñi-de-Cerio F, Gonzalez I, Brettes P, Urkiaga A. Better understanding of the activated sludge process combining fluorescence-based methods and flow cytometry: A case study. J Environ Sci (China) 2020; 90:51-58. [PMID: 32081340 DOI: 10.1016/j.jes.2019.11.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 11/12/2019] [Accepted: 11/13/2019] [Indexed: 06/10/2023]
Abstract
This study aims to demonstrate the validity of fluorescence-based methods, together with flow cytometry, as a complementary tool to conventional physicochemical analyses carried out in wastewater treatment plants (WWTPs), for the control of the currently largely unknown activated sludge process. Staining with SYTO 9, propidium iodide and 5-(and 6)-carboxy-2',7'-difluorodihydrofluorescein diacetate (carboxy-H2DFFDA) was used for cell viability and oxidative stress monitoring of the bacterial population forming the activated sludge of a WWTP. Throughout the period of research, several unstable periods were detected, where the non-viable bacteria exceeded the 75% of the total bacterial population in the activated sludge, but only in one case the cells with oxidative stress grew to 9%, exceeding the typical values of 2%-5% of this plant. These periods coincided in two cases with high values of total suspended solids (SST) and chemical oxygen demand (COD) in the effluent, and with an excess of ammonia in other case. A correlation between flow cytometric and physicochemical data was found, which enabled to clarify the possible origin of each case of instability in the biological system. This experience supports the application of bacterial fluorescence staining, together with flow cytometric analysis, as a simple, rapid and reliable tool for the control and better understanding of the bacteria dynamics in a biological wastewater treatment process.
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Affiliation(s)
- Vanesa Benito
- GAIKER, Parque Tecnológico, Ed. 202, 48170, Zamudio, Bizkaia, Spain.
| | | | | | - Iñigo Gonzalez
- EDAR Galindo, Bilbao Bizkaia Water Consortium, Sestao 48910, Bizkaia, Spain
| | - Pilar Brettes
- GAIKER, Parque Tecnológico, Ed. 202, 48170, Zamudio, Bizkaia, Spain
| | - Ana Urkiaga
- GAIKER, Parque Tecnológico, Ed. 202, 48170, Zamudio, Bizkaia, Spain
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36
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Pandur Ž, Dogsa I, Dular M, Stopar D. Liposome destruction by hydrodynamic cavitation in comparison to chemical, physical and mechanical treatments. ULTRASONICS SONOCHEMISTRY 2020; 61:104826. [PMID: 31670247 DOI: 10.1016/j.ultsonch.2019.104826] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 08/09/2019] [Accepted: 10/08/2019] [Indexed: 05/08/2023]
Abstract
Liposomes are widely applied in research, diagnostics, medicine and in industry. In this study we show for the first time the effect of hydrodynamic cavitation on liposome stability and compare it to the effect of well described chemical, physical and mechanical treatments. Fluorescein loaded giant 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) lipid vesicles were treated with hydrodynamic cavitation as promising method in inactivation of biological samples. Hydrodynamic treatment was compared to various chemical, physical and mechanical stressors such as ionic strength and osmolarity agents (glucose, Na+, Ca2+, and Fe3+), free radicals, shear stresses (pipetting, vortex mixing, rotational shear stress), high pressure, electroporation, centrifugation, surface active agents (Triton X-100, ethanol), microwave irradiation, heating, freezing-thawing, ultrasound (ultrasonic bath, sonotrode). The fluorescence intensity of individual fluorescein loaded lipid vesicles was measured with confocal laser microscopy. The distribution of lipid vesicle size, vesicle fluorescence intensity, and the number of fluorescein loaded vesicles was determined before and after treatment with different stressors. The different environmental stressors were ranked in order of their relative effect on liposome fluorescein release. Of all tested chemical, physical and mechanical treatments for stability of lipid vesicles, the most detrimental effect on vesicles stability had hydrodynamic cavitation, vortex mixing with glass beads and ultrasound. Here we showed, for the first time that hydrodynamic cavitation was among the most effective physico-chemical treatments in destroying lipid vesicles. This work provides a benchmark for lipid vesicle robustness to a variety of different physico-chemical and mechanical parameters important in lipid vesicle preparation and application.
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Affiliation(s)
- Žiga Pandur
- University of Ljubljana, Biotechnical Faculty, Večna pot 111, Ljubljana 1000, Slovenia; University of Ljubljana, Faculty of Mechanical Engineering, Aškerčeva 6, Ljubljana 1000, Slovenia
| | - Iztok Dogsa
- University of Ljubljana, Biotechnical Faculty, Večna pot 111, Ljubljana 1000, Slovenia
| | - Matevž Dular
- University of Ljubljana, Faculty of Mechanical Engineering, Aškerčeva 6, Ljubljana 1000, Slovenia
| | - David Stopar
- University of Ljubljana, Biotechnical Faculty, Večna pot 111, Ljubljana 1000, Slovenia.
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Yamaguchi N, Fujii Y. Rapid On-Site Monitoring of Bacteria in Freshwater Environments Using a Portable Microfluidic Counting System. Biol Pharm Bull 2020; 43:87-92. [DOI: 10.1248/bpb.b19-00549] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Nobuyasu Yamaguchi
- Osaka Institute of Public Health
- Graduate School of Pharmaceutical Sciences, Osaka University
| | - Yudai Fujii
- Graduate School of Pharmaceutical Sciences, Osaka University
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38
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Cal-Sabater P, Caro I, Castro MJ, Cao MJ, Mateo J, Quinto EJ. Flow Cytometry to Assess the Counts and Physiological State of Cronobacter sakazakii Cells after Heat Exposure. Foods 2019; 8:foods8120688. [PMID: 31888256 PMCID: PMC6963341 DOI: 10.3390/foods8120688] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/06/2019] [Accepted: 12/11/2019] [Indexed: 11/26/2022] Open
Abstract
Cronobacter sakazakii is an opportunistic pathogen that is associated with outbreaks of neonatal necrotizing enterocolitis, septicaemia, and meningitis. Reconstituted powdered infant formulae is the most common vehicle of infection. The aim of the present study is to gain insight into the physiological states of C. sakazakii cells using flow cytometry to detect the compromised cells, which are viable but non-culturable using plate-based methods, and to evaluate the impact of milk heat treatments on those populations. Dead-cell suspensions as well as heat-treated and non-heat-treated cell suspensions were used. After 60 or 65 °C treatments, the number of compromised cells increased as a result of cells with compromised membranes shifting from the heat-treated suspension. These temperatures were not effective at killing all bacteria but were effective at compromising their membranes. Thus, mild heat treatments are not enough to guarantee the safety of powered infant formulae. Flow cytometry was capable of detecting C. sakazakii’s compromised cells that cannot be detected with classical plate count methods; thus, it could be used as a screening test to decrease the risk derived from the presence of pathogenic viable but non-culturable cells in this food that is intended for newborns’ nutrition.
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Affiliation(s)
- Paloma Cal-Sabater
- Department of Nutrition and Food Science, Faculty of Medicine, University of Valladolid, 47005 Valladolid, Spain; (P.C.-S.); (I.C.)
- Department of Nursery, Faculty of Nursery, University of Valladolid, 47005 Valladolid, Spain; (M.J.C.); (M.J.C.)
| | - Irma Caro
- Department of Nutrition and Food Science, Faculty of Medicine, University of Valladolid, 47005 Valladolid, Spain; (P.C.-S.); (I.C.)
| | - María J. Castro
- Department of Nursery, Faculty of Nursery, University of Valladolid, 47005 Valladolid, Spain; (M.J.C.); (M.J.C.)
| | - María J. Cao
- Department of Nursery, Faculty of Nursery, University of Valladolid, 47005 Valladolid, Spain; (M.J.C.); (M.J.C.)
| | - Javier Mateo
- Department of Hygiene and Food Technology, Faculty of Veterinary Medicine, University of León, 24071 León, Spain;
| | - Emiliano J. Quinto
- Department of Nutrition and Food Science, Faculty of Medicine, University of Valladolid, 47005 Valladolid, Spain; (P.C.-S.); (I.C.)
- Correspondence:
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39
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Zou X, Zhang S, Chen L, Hu J, Hong FF. Determination of live and dead Komagataeibacter xylinus cells and first attempt at precise control of inoculation in nanocellulose production. Microb Biotechnol 2019; 13:458-469. [PMID: 31651088 PMCID: PMC7017834 DOI: 10.1111/1751-7915.13494] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 09/24/2019] [Accepted: 09/27/2019] [Indexed: 12/27/2022] Open
Abstract
The timely enumeration of cells of nanocellulose-producing bacteria is challenging due to their unique growth properties. To better understand the metabolism of the bacteria and better control the concentration of living cells during cultivation, a prompt cell counting technology is crucial and urgently required. In this work, two fluorescent dyes, the asymmetrical anthocyanidin dye SYBR Green I (SG) and propidium iodide (PI), were first combined for Komagataeibacter xylinus species to determine live/dead bacterial cells quantitatively and promptly. The number of live and dead K. xylinus cells determined using an epifluorescence microscope corresponded well to the results obtained using a fluorescence microplate reader. The R2 values were 0.9986 and 0.9920, respectively, and were similar to those obtained with the LIVE/DEAD® BacLightTM commercial kit. SG/PI double-staining showed proper efficiency in distinguishing live/dead cells for the K. xylinus strain (R2 = 0.9898). The technology was applied to standardize four different K. xylinus strains, and the initial cell concentration of the strains was precisely controlled (no significant difference among the strains, P> 0.05). The cellulose yield per live cell was calculated, and significant differences (P < 0.05) were found among the four strains in the following order: DHU-ATCC-1> DHU-ZCY-1> DHU-ZGD-1> ATCC 23770. The study shows (i) the application of the SG/PI staining to standardizing inocula for bacterial cellulose production so that a more accurate comparison can be made between different strains, and (ii) the lower cost of using SG rather than the SYTO 9 of the commercially available LIVE/DEAD® BacLightTM kit.
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Affiliation(s)
- Xiaozhou Zou
- Key Lab of Science and Technology of Eco-textile, Ministry of Education, Donghua University, Shanghai, China.,College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, North Renmin Road 2999, Shanghai, 201620, China
| | - Shuo Zhang
- College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, North Renmin Road 2999, Shanghai, 201620, China
| | - Lin Chen
- College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, North Renmin Road 2999, Shanghai, 201620, China
| | - Junqing Hu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, China
| | - Feng F Hong
- Key Lab of Science and Technology of Eco-textile, Ministry of Education, Donghua University, Shanghai, China.,College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, North Renmin Road 2999, Shanghai, 201620, China.,State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai, China.,Scientific Research Base of Bacterial Nanofiber Manufacturing and Composite Technology, China Textile Engineering Society, Shanghai, 201620, China
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40
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Côté H, Pichette A, Simard F, Ouellette ME, Ripoll L, Mihoub M, Grimard D, Legault J. Balsacone C, a New Antibiotic Targeting Bacterial Cell Membranes, Inhibits Clinical Isolates of Methicillin-Resistant Staphylococcus aureus (MRSA) Without Inducing Resistance. Front Microbiol 2019; 10:2341. [PMID: 31681206 PMCID: PMC6804428 DOI: 10.3389/fmicb.2019.02341] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 09/25/2019] [Indexed: 12/20/2022] Open
Abstract
New options are urgently needed for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections. Balsacone C is a new dihydrochalcone extracted from Populus balsamifera that has been reported previously as being active against Staphylococcus aureus. Here, we evaluate the antibacterial activity of balsacone C against MRSA. Thirty-four (34) MRSA isolates were obtained from hospitalized patients; these isolates were then characterized for their resistance. Most of these MRSA (>85%) were resistant to penicillin, amoxicillin/clavulanic acid, ciprofloxacin, moxifloxacin, levofloxacin, clindamycin, erythromycin, and cefoxitin as well as being sensitive to linezolid, trimethoprim/sulfamethoxazole, rifampicin, and gentamicin. When tested against all MRSA isolates and various gram-positive bacteria, the antibacterial activity of balsacone C produced a MIC of 3-11.6 mg/mL. We observed no resistant isolates of MRSA (against balsacone C) even after 30 passages. Microscopy fluorescence showed that bacteria cell membrane integrity was compromised by low concentrations of balsacone C. Scanning electron microscope (SEM) confirmed balsacone C-provoked changes in the bacterial cell membrane and we find a dose-dependent release of DNA and proteins. This loss of cellular integrity leads to cell death and suggests a low potential for the development of spontaneous resistance.
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Affiliation(s)
- Héloïse Côté
- Laboratoire d’Analyse et de Séparation des Essences Végétales, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
| | - André Pichette
- Laboratoire d’Analyse et de Séparation des Essences Végétales, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
- Centre de Recherche sur la Boréalie, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
| | - François Simard
- Laboratoire d’Analyse et de Séparation des Essences Végétales, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
| | - Marie-Eve Ouellette
- Laboratoire d’Analyse et de Séparation des Essences Végétales, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
| | - Lionel Ripoll
- Laboratoire d’Analyse et de Séparation des Essences Végétales, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
- Centre de Recherche sur la Boréalie, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
| | - Mouadh Mihoub
- Laboratoire d’Analyse et de Séparation des Essences Végétales, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
| | - Doria Grimard
- Laboratoire de Microbiologie, Complexe Hospitalier de la Sagamie, Chicoutimi, QC, Canada
| | - Jean Legault
- Laboratoire d’Analyse et de Séparation des Essences Végétales, Département des Sciences Fondamentales, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
- Centre de Recherche sur la Boréalie, Université du Québec à Chicoutimi, Chicoutimi, QC, Canada
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41
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Cavalaro RI, Cruz RGD, Dupont S, de Moura Bell JMLN, Vieira TMFDS. In vitro and in vivo antioxidant properties of bioactive compounds from green propolis obtained by ultrasound-assisted extraction. FOOD CHEMISTRY-X 2019; 4:100054. [PMID: 31650128 PMCID: PMC6804792 DOI: 10.1016/j.fochx.2019.100054] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 09/12/2019] [Accepted: 09/16/2019] [Indexed: 01/20/2023]
Abstract
Ultrasound improves the bioactives content from green propolis in a lower time. Optimization allowed good extraction of artepillin C and p-coumaric acid. Green propolis had similar effects to synthetic antioxidant in emulsion systems. Green propolis did not change the S. cerevisiae membrane.
Green propolis presents a potential source of bioactive compounds, responsible for its antioxidant capacity. The effects of ethanol concentration, solid-solvent ratio, and extraction time were evaluated in regard to the total phenolic content (TPC) and antioxidant capacity of the extracts by the use of central composite rotatable designs. Optimum extraction conditions lead to significant reduction of extraction time compared to conventional extraction methods. Under optimum conditions, extracts were composed of 1614.80 mg GAE. g−1 and 807 mg artepillin C. g−1. Extracts were effective in retarding the oxidation in oil-in-water emulsions subjected to accelerated tests. Green propolis extracts (up to 200 mg.kg−1) did not increase Saccharomyces cerevisiae cell damage after 4 h of exposure, indicating its antioxidant effect and potential innocuity. Results demonstrated the antioxidant properties of the propolis extract was similar or better than the ones from synthetic antioxidants and warrant further investigation to determine its potential industrial application.
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Affiliation(s)
- Renata Iara Cavalaro
- Department of Agri-Food Industry, Food & Nutrition, "Luiz de Queiroz" College of Agriculture, University of Sao Paulo, 13418-900 Piracicaba, São Paulo, Brazil
| | - Richtier Gonçalves da Cruz
- Department of Agri-Food Industry, Food & Nutrition, "Luiz de Queiroz" College of Agriculture, University of Sao Paulo, 13418-900 Piracicaba, São Paulo, Brazil.,Univ. Bourgogne Franche-Comté, AgroSup Dijon, PAM UMR A 02.102, F-21000 Dijon, France
| | - Sebastien Dupont
- Univ. Bourgogne Franche-Comté, AgroSup Dijon, PAM UMR A 02.102, F-21000 Dijon, France
| | | | - Thais Maria Ferreira de Souza Vieira
- Department of Agri-Food Industry, Food & Nutrition, "Luiz de Queiroz" College of Agriculture, University of Sao Paulo, 13418-900 Piracicaba, São Paulo, Brazil.,Department of Food Science and Technology, University of California Davis, One Shields Avenue, Davis, CA 95616, USA
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42
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Kong Y, Peng Y, Zhang Z, Zhang M, Zhou Y, Duan Z. Removal of Microcystis aeruginosa by ultrasound: Inactivation mechanism and release of algal organic matter. ULTRASONICS SONOCHEMISTRY 2019; 56:447-457. [PMID: 31101283 DOI: 10.1016/j.ultsonch.2019.04.017] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 04/03/2019] [Accepted: 04/08/2019] [Indexed: 06/09/2023]
Abstract
The efficacy of ultrasonic irradiation for removal of Microcystis aeruginosa and release of algal organic matter (AOM) was investigated under different ultrasound conditions, including ultrasonic frequency, power density, and time. Laboratory results suggested that the ultrasonic efficiency and the release of AOM were influenced by frequency, power density, and time. The mechanism of AOM algae removal by ultrasound was systematically explored. The inactivation of algae resulted from mechanical and chemical effects caused by ultrasound. Mechanical destruction and free-radical oxidation considerably affected the structure and physiological function of algal cells. The SEM and TEM images indicated that ultrasound could damage the cell membrane, wall, and organelle. Flow cell cytometry results showed decreases in the size, internal granularity, integrity, and activity of algal cells, revealing that ultrasound exerted severe damage to the structure and function of algal cells. The activity of the antioxidant system of algal cells was then studied by investigating changes in MDA, SOD, and CAT concentration after ultrasound to confirm the inactivation of the cells. The release of AOM was explored by determining changes in water quality indices (UV254, DOC, and SUVA) at 10 min and 48 h after ultrasound. This study provides information about the safety of ultrasound usage on algae removal and references for ultrasonic parameters to be selected to ensure effective and safe algae removal.
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Affiliation(s)
- Yuan Kong
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
| | - Yazhou Peng
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
| | - Zhi Zhang
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China.
| | - Meng Zhang
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
| | - Yuanhang Zhou
- Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China
| | - Zhuang Duan
- Zhuhai Planning and Design Institute, Zhuhai, Guangdong 519000, China
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Jindal S, Yang L, Day PJ, Kell DB. Involvement of multiple influx and efflux transporters in the accumulation of cationic fluorescent dyes by Escherichia coli. BMC Microbiol 2019; 19:195. [PMID: 31438868 PMCID: PMC6704527 DOI: 10.1186/s12866-019-1561-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 07/31/2019] [Indexed: 12/11/2022] Open
Abstract
Background It is widely believed that most xenobiotics cross biomembranes by diffusing through the phospholipid bilayer, and that the use of protein transporters is an occasional adjunct. According to an alternative view, phospholipid bilayer transport is negligible, and several different transporters may be involved in the uptake of an individual molecular type. We recognise here that the availability of gene knockout collections allows one to assess the contributions of all potential transporters, and flow cytometry based on fluorescence provides a convenient high-throughput assay for xenobiotic uptake in individual cells. Results We used high-throughput flow cytometry to assess the ability of individual gene knockout strains of E coli to take up two membrane-permeable, cationic fluorescent dyes, namely the carbocyanine diS-C3(5) and the DNA dye SYBR Green. Individual strains showed a large range of distributions of uptake. The range of modal steady-state uptakes for the carbocyanine between the different strains was 36-fold. Knockouts of the ATP synthase α- and β-subunits greatly inhibited uptake, implying that most uptake was ATP-driven rather than being driven by a membrane potential. Dozens of transporters changed the steady-state uptake of the dye by more than 50% with respect to that of the wild type, in either direction (increased or decreased); knockouts of known influx and efflux transporters behaved as expected, giving credence to the general strategy. Many of the knockouts with the most reduced uptake were transporter genes of unknown function (‘y-genes’). Similarly, several overexpression variants in the ‘ASKA’ collection had the anticipated, opposite effects. Similar results were obtained with SYBR Green (the range being approximately 69-fold). Although it too contains a benzothiazole motif there was negligible correlation between its uptake and that of the carbocyanine when compared across the various strains (although the membrane potential is presumably the same in each case). Conclusions Overall, we conclude that the uptake of these dyes may be catalysed by a great many transporters of putatively broad and presently unknown specificity, and that the very large range between the ‘lowest’ and the ‘highest’ levels of uptake, even in knockouts of just single genes, implies strongly that phospholipid bilayer transport is indeed negligible. This work also casts serious doubt upon the use of such dyes as quantitative stains for representing either bioenergetic parameters or the amount of cellular DNA in unfixed cells (in vivo). By contrast, it opens up their potential use as transporter assay substrates in high-throughput screening. Electronic supplementary material The online version of this article (10.1186/s12866-019-1561-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Srijan Jindal
- Department of Chemistry, The University of Manchester, 131 Princess St, Manchester, M1 7DN, UK.,Manchester Institute of Biotechnology, The University of Manchester, 131 Princess St, Manchester, M1 7DN, UK.,Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK
| | - Lei Yang
- Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Building 220, Kemitorvet, 2800 Kgs, Lyngby, Denmark
| | - Philip J Day
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess St, Manchester, M1 7DN, UK.,Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK
| | - Douglas B Kell
- Department of Chemistry, The University of Manchester, 131 Princess St, Manchester, M1 7DN, UK. .,Manchester Institute of Biotechnology, The University of Manchester, 131 Princess St, Manchester, M1 7DN, UK. .,Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Building 220, Kemitorvet, 2800 Kgs, Lyngby, Denmark. .,Department of Biochemistry, Institute of Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown St, Liverpool, L69 7ZB, UK.
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Zarmehrkhorshid R, Shafiei R, Delvigne F. Modified semi-continuous fermentation for resuscitating nongrowing cells during high-temperature gluconic acid production by Acetobacter senegalensis. J Appl Microbiol 2019; 127:1101-1112. [PMID: 31283860 DOI: 10.1111/jam.14371] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 06/26/2019] [Accepted: 07/02/2019] [Indexed: 11/28/2022]
Abstract
AIMS The formation of metabolically inactive and nongrowing cells is an inevitable by-product of intensive fermentation. This study investigated whether co-feeding can be used to resuscitate nongrowing Acetobacter senegalensis cells to enable them to produce gluconic acid in successive fermentation runs at 38°C. METHODS AND RESULTS In the first fermentation cycle, 75 g l-1 of glucose were converted to gluconic acid. Subsequently, however, stationary-phase cells were unable to initiate a new fermentation cycle. The majority of stationary-phase cells (97%) were nonculturable on glucose at 38°C. In addition, 54 and 41% of cells contained non-active cellular dehydrogenases and a compromised cell envelope respectively. Co-feeding stationary-phase cells with a mixture of ethanol, glucose and acetic acid for 7 h enabled these cells to grow on 75 g l-1 of glucose and produce gluconic acid. Additionally, 74% of cells contained active forms of cellular dehydrogenases after 7 h of co-feeding. However, co-feeding did not improve cell envelope integrity. Quantification of cellular NAD content showed that stationary-phase cells contained moderately reduced levels of total NAD (NADt) as compared with exponential-phase cells. Interestingly, the analysis of stationary-phase cells showed that co-feeding resulted in higher levels of NADt and NADH, suggesting that the regeneration of NADH is one of the limiting factors of glucose consumption. Expression of catalase and superoxide dismutase was increased in stationary-phase cells, but analysis of protein carbonylation and lipid peroxidation did not confirm an extensive oxidative stress. CONCLUSIONS Co-feeding with favourable nutrients may enable resuscitation of cells and utilization of less-favourable carbon sources in successive cycles. SIGNIFICANCE AND IMPACT OF THE STUDY This study proposed a unique method for resuscitation of nongrowing cells during high-temperature fermentation. By applying this method, cells can be used for consecutive fermentation cycles.
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Affiliation(s)
- R Zarmehrkhorshid
- Microbial Processes and Interactions (MiPI), Gembloux Agro-Bio Tech, TERRA Research and Teaching Centre, University of Liège, Gembloux, Belgium
| | - R Shafiei
- Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran
| | - F Delvigne
- Microbial Processes and Interactions (MiPI), Gembloux Agro-Bio Tech, TERRA Research and Teaching Centre, University of Liège, Gembloux, Belgium
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45
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Jacquemin C, Bertrand C, Franquet E, Mounier S, Misson B, Oursel B, Cavalli L. Effects of catchment area and nutrient deposition regime on phytoplankton functionality in alpine lakes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 674:114-127. [PMID: 31004889 DOI: 10.1016/j.scitotenv.2019.04.117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 03/11/2019] [Accepted: 04/09/2019] [Indexed: 06/09/2023]
Abstract
High mountain lakes are a network of sentinels, sensitive to any events occurring within their waterbodies, their surrounding catchment and their airshed. In this paper, we investigate how catchments impact the taxonomic and functional composition of phytoplankton communities in high mountain lakes, and how this impact varies according to the atmospheric nutrient deposition regime. For two years, we sampled the post snow-melt and the late summer phytoplankton, with a set of biotic and abiotic parameters, in six French alpine lakes with differing catchments (size and vegetation cover) and contrasting nitrogen (N) and phosphorus (P) deposition regimes. Whatever the nutrient deposition regime, we found that the lakes with the smallest rocky catchments showed the lowest functional richness of phytoplankton communities. The lakes with larger vegetated catchments were characterized by the coexistence of phytoplankton taxa with more diverse strategies in the acquisition and utilization of nutrient resources. The nutrient deposition regime appeared to interact with catchment characteristics in determining which functional groups ultimately developed in lakes. Photoautotroph taxa dominated the phytoplankton assemblages under high NP deposition regime while mixotroph taxa were even more favored in lakes with large vegetated catchments under low NP deposition regime. Phytoplankton functional changes were likely related to the leaching of terrestrial organic matter from catchments evidenced by analyses of carbon (δ13C) and nitrogen (δ15N) stable isotope ratios in seston and zooplankton. Plankton δ15N values indicated greater water-soil interaction in lakes with larger vegetated catchments, while δ13C values indicated the effective mineralization of the organic matter in lakes. The role played by catchments should be considered when seeking to determine the vulnerability of high altitude lakes to future changes, as catchments' own properties will vary under changes related to climate and airborne contaminants.
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Affiliation(s)
- Coralie Jacquemin
- Aix Marseille Univ, Univ Avignon, CNRS, IRD, IMBE, Marseille, France.
| | - Céline Bertrand
- Aix Marseille Univ, Univ Avignon, CNRS, IRD, IMBE, Marseille, France.
| | - Evelyne Franquet
- Aix Marseille Univ, Univ Avignon, CNRS, IRD, IMBE, Marseille, France.
| | - Stéphane Mounier
- Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France.
| | - Benjamin Misson
- Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France.
| | - Benjamin Oursel
- Aix Marseille Univ, Univ Avignon, CNRS, IRD, IMBE, Marseille, France.
| | - Laurent Cavalli
- Aix Marseille Univ, Univ Avignon, CNRS, IRD, IMBE, Marseille, France.
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46
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Corno G, Yang Y, Eckert EM, Fontaneto D, Fiorentino A, Galafassi S, Zhang T, Di Cesare A. Effluents of wastewater treatment plants promote the rapid stabilization of the antibiotic resistome in receiving freshwater bodies. WATER RESEARCH 2019; 158:72-81. [PMID: 31015144 DOI: 10.1016/j.watres.2019.04.031] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 04/12/2019] [Accepted: 04/13/2019] [Indexed: 06/09/2023]
Abstract
Treated wastewater discharged into the environment acts as a disturbance of the natural microbial communities in terms of taxonomic composition and of functional gene pool, including antibiotic resistance genes. We tested whether stochastic and heterogeneous site-specific trajectories or generalities, potentially driven by deterministic processes, control the fate of allochthonous bacteria from anthropogenic sources and the persistence of their functional traits in freshwater. Finding generalities would allow the identification of wastewater treatments that could be effective in abating determinants of antibiotic resistance. We analysed the short-term response of native bacterial communities in waters exposed to the disturbance of wastewater at different dilutions, using a metagenomic approach that revealed both microbial community composition and the scope and abundance of the resistome that can pose indirect risks to human health. We found that the taxonomic composition of the communities after the disturbance was driven by case-specific stochastic processes, whereas the resistome had a deterministic trajectory, rapidly stabilising its functional traits with higher proportions of wastewater effluents, regardless of differences in taxonomic composition, richness of antibiotic resistance genes and of bacterial taxa, phenotypic features of the bacterial communities, and type of wastewater treatment. The observed deterministic proliferation of resistomes in freshwater bodies receiving wastewater effluents, suggests that this process may contribute to the global propagation of antibiotic resistance, and thus calls for new legislations promoting alternative tertiary treatments for the wastewater reuse, and targeting bacterial functional traits and not only bacterial abundances.
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Affiliation(s)
- Gianluca Corno
- Microbial Ecology Group, Water Research Institute - National Research Council (CNR-IRSA), Largo Tonolli 50, 28922, Verbania, Italy.
| | - Ying Yang
- School of Marine Sciences, Sun Yat-Sen University, Xingang Xi Road 135, 510275, Guangzhou, China
| | - Ester M Eckert
- Microbial Ecology Group, Water Research Institute - National Research Council (CNR-IRSA), Largo Tonolli 50, 28922, Verbania, Italy
| | - Diego Fontaneto
- Microbial Ecology Group, Water Research Institute - National Research Council (CNR-IRSA), Largo Tonolli 50, 28922, Verbania, Italy
| | - Antonino Fiorentino
- Microbial Ecology Group, Water Research Institute - National Research Council (CNR-IRSA), Largo Tonolli 50, 28922, Verbania, Italy
| | - Silvia Galafassi
- Microbial Ecology Group, Water Research Institute - National Research Council (CNR-IRSA), Largo Tonolli 50, 28922, Verbania, Italy
| | - Tong Zhang
- Environmental Biotechnology Laboratory, The University of Hong Kong, Hong Kong, China
| | - Andrea Di Cesare
- Microbial Ecology Group, Water Research Institute - National Research Council (CNR-IRSA), Largo Tonolli 50, 28922, Verbania, Italy
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Oehler C, Janett F, Schmitt S, Malama E, Bollwein H. Development of a flow cytometric assay to assess the bacterial count in boar semen. Theriogenology 2019; 133:125-134. [PMID: 31091483 DOI: 10.1016/j.theriogenology.2019.04.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 04/25/2019] [Accepted: 04/30/2019] [Indexed: 01/26/2023]
Abstract
The aim of the study was to develop a new flow cytometric assay for the determination of the bacterial count in commercially processed boar semen. In total 224 fresh boar semen samples collected at an AI-station were analyzed. The number of total viable counts (TVC) was determined by using flow cytometry after staining with SYBR Green I and Propidium Iodide (PI). In the first part of the study 111 fresh boar semen samples were spiked with pure cultures of defined numbers of bacteria commonly detected in boar ejaculates and analyzed by flow cytometry. In the second part, 113 fresh semen samples were assessed on the day of collection through flow cytometry and the Most Probable Number (MPN) method, as the standard bacteriological method. The first part of the study showed a strong correlation between the detected and expected numbers (r = 0.96; P < 0.001), while in the second part of the study the TVC determined by flow cytometry and by the MPN method correlated only moderately (r = 0.28; P < 0.01; median MPN: 24,000 ± MAD 21,600 bacteria/mL; median flow cytometry: 24,426 ± MAD 15,610 bacteria/mL). In summary flow cytometry is a fast alternative to the classical culture technique to determine highly contaminated boar ejaculates. The developed flow cytometric protocol enables one to enumerate the viable bacteria within fresh boar ejaculates without requiring numerous treatment steps, and thus offering the possibility of an on-line use in AI-centers.
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Affiliation(s)
- Christin Oehler
- Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
| | - Fredi Janett
- Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Sarah Schmitt
- Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Eleni Malama
- Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Heinrich Bollwein
- Clinic of Reproductive Medicine, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
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Chifflet S, Quéméneur M, Barani A, Angeletti B, Didry M, Grégori G, Pradel N. Impact of sterilization methods on dissolved trace metals concentrations in complex natural samples: Optimization of UV irradiation. MethodsX 2019; 6:1133-1146. [PMID: 31193445 PMCID: PMC6529719 DOI: 10.1016/j.mex.2019.04.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 04/18/2019] [Indexed: 11/27/2022] Open
Abstract
Sterilization is essential for discriminating biotic responses from abiotic reactions in laboratory experiments investigating biogeochemical processes of complex natural samples. However, the conventional methods used to effectively sterilize materials or culture media do not allow sterilizing complex natural samples while maintaining biogeochemical balances. The aim of this study was to develop a low-cost and easy-to-use method to obtain geochemically unmodified and sterilized samples from complex lacustrine or coastal marine ecosystems. In preliminary assays, the impact of several sterilization methods (autoclaving, chemical poisoning, microwave, UV irradiation) on the trace metals balances was studied using borosilicate glass (BG), fluorinated ethylene-propylene (FEP) or polyethylene terephthalate (PET) bottles. Unlike other methods, UV sterilization had minor effects on the distribution of dissolved trace metals. Additional tests using complex lacustrine and coastal marine samples under 10 g/L sediments were performed using a homemade UV sterilization chamber designed to simultaneously irradiate a large number samples. Results showed: •very reproducible UV tests in BG and FEP bottles•faster sterilization using FEP bottles than using BG bottles•low variations of dissolved trace metals concentrations, except for Al, Cu, Fe and Zn.
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Affiliation(s)
- Sandrine Chifflet
- Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
| | - Marianne Quéméneur
- Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
| | - Aude Barani
- Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
| | - Bernard Angeletti
- Aix Marseille Univ., CNRS-IRD-Collège de France, CEREGE UM34, 13545, Aix en Provence, France
| | - Morgane Didry
- Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
| | - Gérald Grégori
- Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
| | - Nathalie Pradel
- Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO UM 110, 13288, Marseille, France
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Aiyer KS, Rai R, Vijayakumar BS. Assessing Activity of Antimicrobial Agents and Screening Antibiotic-Resistant Bacteria Through DREAM Assay. Appl Biochem Biotechnol 2019; 188:1158-1167. [DOI: 10.1007/s12010-019-02981-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 02/20/2019] [Indexed: 11/25/2022]
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50
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Wang Z, Wang C, You Y, Xu W, Lv Z, Liu Z, Chen W, Shi Y, Wang J. Response of Pseudomonas fluorescens to dimethyl phthalate. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 167:36-43. [PMID: 30292974 DOI: 10.1016/j.ecoenv.2018.09.078] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 09/14/2018] [Accepted: 09/18/2018] [Indexed: 06/08/2023]
Abstract
Dimethyl phthalate (DMP) is a ubiquitous pollutant that is very harmful to organisms due to its mutagenicity, teratogenicity and carcinogenicity. Pseudomonas fluorescens (P. fluorescens) is one of the most important bacteria in the environment. In this study, the response of P. fluorescens to DMP was investigated. It was found that DMP greatly inhibited the growth and glucose utilization of P. fluorescens when the concentration of DMP was ranged from 20 to 40 mg/l. The surface hydrophobicity and membrane permeability of P. fluorescens were also increased by DMP. DMP could lead to the deformations of cell membrane and the mis-opening of membrane channels. RNA-Seq and RT-qPCR results showed that the expression of some genes in P. fluorescens were altered, including the genes involved in energy metabolism, ATP-binding cassette (ABC) transporting and two-component systems. Additionally, the productions of lactic acid and pyruvic acid were reduced and the activity of hexokinase was inhibited in P. fluorescens by DMP. Clearly, the results suggested that DMP contamination could alter the biological function of P. fluorescens in the environment.
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Affiliation(s)
- Zhigang Wang
- School of Life Science and Agriculture and Forestry, Qiqihar University, Qiqihar, Heilongjiang, 161006, China.
| | - Chunlong Wang
- School of Life Science and Agriculture and Forestry, Qiqihar University, Qiqihar, Heilongjiang, 161006, China.
| | - Yimin You
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
| | - Weihui Xu
- School of Life Science and Agriculture and Forestry, Qiqihar University, Qiqihar, Heilongjiang, 161006, China.
| | - Zhihang Lv
- School of Life Science and Agriculture and Forestry, Qiqihar University, Qiqihar, Heilongjiang, 161006, China.
| | - Zeping Liu
- School of Life Science and Agriculture and Forestry, Qiqihar University, Qiqihar, Heilongjiang, 161006, China.
| | - Wenjing Chen
- School of Life Science and Agriculture and Forestry, Qiqihar University, Qiqihar, Heilongjiang, 161006, China.
| | - Yiran Shi
- School of Life Science and Agriculture and Forestry, Qiqihar University, Qiqihar, Heilongjiang, 161006, China.
| | - Junhe Wang
- Qiqihar Branch of Heilongjiang Academy of Agricultural Sciences, Qiqihar, Heilongjiang, 161006, China.
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