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Nikanjam S, Yeganegi A, Alikhani MY, Farmany A, Ghiasian SA, Hasanzade R. Novel antimicrobial applications of copper oxide nanoparticles after combination with tissue conditioner used in complete prostheses. BMC Oral Health 2024; 24:752. [PMID: 38943115 PMCID: PMC11214236 DOI: 10.1186/s12903-024-04534-w] [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: 01/08/2024] [Accepted: 06/25/2024] [Indexed: 07/01/2024] Open
Abstract
BACKGROUND Tissue conditioners are used for treating and improving the tissues supporting complete dentures. On the other hand, recent advances in nanotechnology have revolutionized various fields of science, including dentistry. The present study aimed to investigate novel antimicrobial applications of copper oxide nanoparticle-based tissue conditioner used in complete prostheses. METHODS The present experimental study included 126 tissue conditioner samples with different concentrations of copper oxide nanoparticles (20%, 10%, 5%, 2.5%, 1.25%, 0.625%, and 0% w/w). The samples were incubated with Enterococcus faecalis, Pseudomonas aeruginosa, and Candida albicans in 24-well plates for 24 h. Then, samples from the wells were re-incubated for 24 h, and the microorganisms were counted. RESULTS The culture media containing E. faecalis and P. aeruginosa showed significantly different growth between different nanoparticle concentrations following 24 h (P < 0.001), showing a reduction in bacterial growth with increased nanoparticle concentration. Both bacteria did not show any growth at the 20% concentration. However, C. albicans showed significant differences in growth between different nanoparticle concentrations following 48 h (P < 0.001), showing a reduction in growth with increased nanoparticle concentration. Also, the least growth was observed at the 20% concentration. CONCLUSIONS In conclusion, the CuO nanoparticles were prepared using a green synthesis methon in the suitable sizes. Moreover, the tissue conditioners containing CuO nanoparticles showed acceptable antimicrobial properties against E. faecalis, P. aeruginosa, and C. albicans.
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Affiliation(s)
- Saeed Nikanjam
- Department of Prosthodontics, School of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran.
| | - Aria Yeganegi
- Department of Prosthodontics, School of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Mohammad-Yousef Alikhani
- Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Abbas Farmany
- Dental Implant Research Center, School of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Seyed Amir Ghiasian
- Department of Medical Parasitology and Mycology Department, School of Medicine, Hamadan University of Medical Sciences and Health Services, Hamadan, Iran
| | - Roghayeh Hasanzade
- Department of Biostatistics, School of Public Health and Research Center for Health Sciences, Hamadan University of Medical Sciences, Hamadan, Iran
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Antonov YA, Kulikov SN, Bezrodnykh EA, Zhuravleva IL, Berezin BB, Tikhonov VE. An insight into the effect of interaction with protein on antibacterial activity of chitosan derivatives. Int J Biol Macromol 2024; 259:129050. [PMID: 38158056 DOI: 10.1016/j.ijbiomac.2023.129050] [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: 09/20/2023] [Revised: 11/10/2023] [Accepted: 12/24/2023] [Indexed: 01/03/2024]
Abstract
Antimicrobial activity of chitosan in protein-rich media is of a particular interest for various protein-based drug delivery and other systems. For the first time, bacteriostatic activity of chitosan derivatives in the presence of caseinate sodium (CAS) was studied and discussed. Complexation of chitosan derivatives soluble in acidic (CH and RCH) or alkalescent (RCH) media with CAS was confirmed by fluorescent spectroscopy, turbodimetry, light scattering data and measurement of electrical potentials of CAS/chitosan derivative complexes. An addition of CH and RCH caused a static quenching of CAS. Binding constants Kb determined for CH/CAS and RCH/CAS complexes at pH 6.0 were equal to 29.8 × 106 M-1 and 8.9 × 106 M-1, respectively. Kb value of RCH/CAS complex at pH 7.4 was equal to 1.1 × 105'M-1. The poisoned food method was used for counting the number and the direct measurement of the size of bacterial colonies on the surfaces of turbid agar media containing CAS/chitosan derivative complexex. Complete suppression of E. coli cells growth and restriction of S. aureus cells growth were observed on the surface of acidic media. A high concentration of CAS reduced the activity. The activity of RCH in alkalescent media is low or absent. These results can be promising for preparation of microbiologically stable protein-based drug delivery systems.
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Affiliation(s)
- Yurij A Antonov
- N.M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, Russia
| | - Sergey N Kulikov
- Kazan Scientific Research Institute of Epidemiology and Microbiology, Kazan, Russia; Kazan Federal University, Kazan, Russia
| | - Evgeniya A Bezrodnykh
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow, Russia
| | - Irina L Zhuravleva
- N.M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, Russia
| | - Boris B Berezin
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow, Russia
| | - Vladimir E Tikhonov
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow, Russia.
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Chung E, Ren G, Johnston I, Matharu RK, Ciric L, Walecka A, Cheong YK. Applied Methods to Assess the Antimicrobial Activity of Metallic-Based Nanoparticles. Bioengineering (Basel) 2023; 10:1259. [PMID: 38002383 PMCID: PMC10669044 DOI: 10.3390/bioengineering10111259] [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: 10/12/2023] [Accepted: 10/24/2023] [Indexed: 11/26/2023] Open
Abstract
With the rise of antibiotic resistance, the drive to discover novel antimicrobial substances and standard testing methods with the aim of controlling transmissive diseases are substantially high. In healthcare sectors and industries, although methods for testing antibiotics and other aqueous-based reagents are well established, methods for testing nanomaterials, non-polar and other particle-based suspensions are still debatable. Hence, utilities of ISO standard validations of such substances have been recalled where corrective actions had to be taken. This paper reports a serial analysis obtained from testing the antimicrobial activities of 10 metallic-based nanomaterials against 10 different pathogens using five different in vitro assays, where the technique, limitation and robustness of each method were evaluated. To confirm antimicrobial activities of metallic-based nanomaterial suspensions, it was found that at least two methods must be used, one being the agar well diffusion method, which was found to be the most reliable method. The agar well diffusion method provided not only information on antimicrobial efficacy through the size of the inhibitory zones, but it also identified antimicrobial ions and synergistic effects released by the test materials. To ascertain the effective inhibitory concentration of nanoparticles, the resazurin broth dilution method is recommended, as MIC can be determined visually without utilising any equipment. This method also overcomes the limit of detection (LoD) and absorbance interference issues, which are often found in the overexpression of cell debris and nanoparticles or quantum dots with optical profiles. In this study, bimetallic AgCu was found to be the most effective antimicrobial nanoparticle tested against across the bacterial (MIC 7 µg/mL) and fungal (MIC 62.5 µg/mL) species.
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Affiliation(s)
- Etelka Chung
- Centre for Engineering Research, University of Hertfordshire, Hatfield AL10 9AB, UK; (E.C.); (I.J.)
| | - Guogang Ren
- Centre for Engineering Research, University of Hertfordshire, Hatfield AL10 9AB, UK; (E.C.); (I.J.)
| | - Ian Johnston
- Centre for Engineering Research, University of Hertfordshire, Hatfield AL10 9AB, UK; (E.C.); (I.J.)
| | - Rupy Kaur Matharu
- Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK;
- Department of Civil, Environmental and Geomatic Engineering, University College London, Gower Street, London WC1E 6BT, UK;
| | - Lena Ciric
- Department of Civil, Environmental and Geomatic Engineering, University College London, Gower Street, London WC1E 6BT, UK;
| | - Agnieszka Walecka
- Intensive Care Unit, Royal Free Hospital, Royal Free London NHS Foundation Trust, Pond Street, London NW3 2QG, UK;
| | - Yuen-Ki Cheong
- Centre for Engineering Research, University of Hertfordshire, Hatfield AL10 9AB, UK; (E.C.); (I.J.)
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Jumutc V, Suponenkovs A, Bondarenko A, Bļizņuks D, Lihachev A. Hybrid Approach to Colony-Forming Unit Counting Problem Using Multi-Loss U-Net Reformulation. SENSORS (BASEL, SWITZERLAND) 2023; 23:8337. [PMID: 37837169 PMCID: PMC10575106 DOI: 10.3390/s23198337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/03/2023] [Accepted: 10/07/2023] [Indexed: 10/15/2023]
Abstract
Colony-Forming Unit (CFU) counting is a complex problem without a universal solution in biomedical and food safety domains. A multitude of sophisticated heuristics and segmentation-driven approaches have been proposed by researchers. However, U-Net remains the most frequently cited and used deep learning method in these domains. The latter approach provides a segmentation output map and requires an additional counting procedure to calculate unique segmented regions and detect microbial colonies. However, due to pixel-based targets, it tends to generate irrelevant artifacts or errant pixels, leading to inaccurate and mixed post-processing results. In response to these challenges, this paper proposes a novel hybrid counting approach, incorporating a multi-loss U-Net reformulation and a post-processing Petri dish localization algorithm. Firstly, a unique innovation lies in the multi-loss U-Net reformulation. An additional loss term is introduced in the bottleneck U-Net layer, focusing on the delivery of an auxiliary signal that indicates where to look for distinct CFUs. Secondly, the novel localization algorithm automatically incorporates an agar plate and its bezel into the CFU counting techniques. Finally, the proposition is further enhanced by the integration of a fully automated solution, which comprises a specially designed uniform Petri dish illumination system and a counting web application. The latter application directly receives images from the camera, processes them, and sends the segmentation results to the user. This feature provides an opportunity to correct the CFU counts, offering a feedback loop that contributes to the continued development of the deep learning model. Through extensive experimentation, the authors of this paper have found that all probed multi-loss U-Net architectures incorporated into the proposed hybrid approach consistently outperformed their single-loss counterparts, as well as other comparable models such as self-normalized density maps and YOLOv6, by at least 1% to 3% in mean absolute and symmetric mean absolute percentage errors. Further significant improvements were also reported through the means of the novel localization algorithm. This reaffirms the effectiveness of the proposed hybrid solution in addressing contemporary challenges of precise in vitro CFU counting.
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Affiliation(s)
- Vilen Jumutc
- Institute of Smart Computer Technologies, Riga Technical University, LV-1048 Riga, Latvia; (V.J.); (A.S.); (A.B.)
| | - Artjoms Suponenkovs
- Institute of Smart Computer Technologies, Riga Technical University, LV-1048 Riga, Latvia; (V.J.); (A.S.); (A.B.)
| | - Andrey Bondarenko
- Institute of Smart Computer Technologies, Riga Technical University, LV-1048 Riga, Latvia; (V.J.); (A.S.); (A.B.)
| | - Dmitrijs Bļizņuks
- Institute of Smart Computer Technologies, Riga Technical University, LV-1048 Riga, Latvia; (V.J.); (A.S.); (A.B.)
| | - Alexey Lihachev
- Institute of Atomic Physics and Spectroscopy, University of Latvia, LV-1586 Riga, Latvia;
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Zhang X, Hou X, Ma L, Shi Y, Zhang D, Qu K. Analytical methods for assessing antimicrobial activity of nanomaterials in complex media: advances, challenges, and perspectives. J Nanobiotechnology 2023; 21:97. [PMID: 36941596 PMCID: PMC10026445 DOI: 10.1186/s12951-023-01851-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 03/07/2023] [Indexed: 03/23/2023] Open
Abstract
Assessing the antimicrobial activity of engineered nanomaterials (ENMs), especially in realistic scenarios, is of great significance for both basic research and applications. Multiple analytical methods are available for analysis via off-line or on-line measurements. Real-world samples are often complex with inorganic and organic components, which complicates the measurements of microbial viability and/or metabolic activity. This article highlights the recent advances achieved in analytical methods including typical applications and specifics regarding their accuracy, cost, efficiency, and user-friendliness. Methodological drawbacks, technique gaps, and future perspectives are also discussed. This review aims to help researchers select suitable methods for gaining insight into antimicrobial activities of targeted ENMs in artificial and natural complex matrices.
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Affiliation(s)
- Xuzhi Zhang
- Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China
| | - Xiangyi Hou
- School of Marine Ecology and Environment, Shanghai Ocean University, Shanghai, 201306, China
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China
| | - Liangyu Ma
- Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China
| | - Yaqi Shi
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China
| | - Dahai Zhang
- Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China.
| | - Keming Qu
- Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China.
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Bhuyan S, Yadav M, Giri SJ, Begum S, Das S, Phukan A, Priyadarshani P, Sarkar S, Jayswal A, Kabyashree K, Kumar A, Mandal M, Ray SK. Microliter spotting and micro-colony observation: A rapid and simple approach for counting bacterial colony forming units. J Microbiol Methods 2023; 207:106707. [PMID: 36931327 DOI: 10.1016/j.mimet.2023.106707] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 03/13/2023] [Accepted: 03/13/2023] [Indexed: 03/17/2023]
Abstract
For enumerating viable bacteria, traditional dilution plating to count colony forming units (CFUs) has always been the preferred method in microbiology owing to its simplicity, albeit being laborious and time-consuming. Similar CFU counts can be obtained by quantifying growing micro-colonies in conjunction with the benefits of a microscope. Here, we employed a simple method of five to ten microliter spotting of a diluted bacterial culture multiple times on a single Petri dish followed by determining CFU by counting micro-colonies using a phase-contrast microscope. In this method, the CFU of an Escherichia coli culture can be estimated within a four-hour period after spotting. Further, within a ten-hour period after spotting, CFU in a culture of Ralstonia solanacearum, a bacterium with a generation time of around 2 h, can be estimated. The CFU number determined by micro-colonies observed for 106-fold dilutions or lower is similar to that obtained by the dilution plating method for 107-fold dilutions or lower. Micro-colony numbers observed in the early hours of growth (2 h in case of E. coli and 8 h in case of R. solanacearum) were found to remain consistent at later hours (4 h in case of E. coli and 10 h in case of R. solanacearum), where the visibility of the colonies was better due to a noticeable increase in the size of the colonies. This suggested that micro-colonies observed in the early hours indeed represent the bacterial number in the culture. Practical applications to this counting method were employed in studying the rifampicin-resistant mutation rate as well as performing a fluctuation test in E. coli. The spotting method described here to enumerate bacterial CFU results in reduction of labour, time and resources.
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Affiliation(s)
- Shuvam Bhuyan
- Department of Molecular Biology & Biotechnology, Tezpur University, Tezpur 784028, Assam, India
| | - Mohit Yadav
- Department of Molecular Biology & Biotechnology, Tezpur University, Tezpur 784028, Assam, India
| | - Shubhra Jyoti Giri
- Department of Molecular Biology & Biotechnology, Tezpur University, Tezpur 784028, Assam, India
| | - Shuhada Begum
- Department of Molecular Biology & Biotechnology, Tezpur University, Tezpur 784028, Assam, India
| | - Saurav Das
- Department of Molecular Biology & Biotechnology, Tezpur University, Tezpur 784028, Assam, India
| | - Akash Phukan
- Department of Molecular Biology & Biotechnology, Tezpur University, Tezpur 784028, Assam, India
| | - Pratiksha Priyadarshani
- Department of Molecular Biology & Biotechnology, Tezpur University, Tezpur 784028, Assam, India
| | - Sharmilee Sarkar
- Department of Molecular Biology & Biotechnology, Tezpur University, Tezpur 784028, Assam, India
| | - Anurag Jayswal
- Department of Molecular Biology & Biotechnology, Tezpur University, Tezpur 784028, Assam, India
| | - Kristi Kabyashree
- Department of Molecular Biology & Biotechnology, Tezpur University, Tezpur 784028, Assam, India; National Institute of Plant Genome Research, Aruna Asaf Ali Marg, 110067, Delhi, India
| | - Aditya Kumar
- Department of Molecular Biology & Biotechnology, Tezpur University, Tezpur 784028, Assam, India.
| | - Manabendra Mandal
- Department of Molecular Biology & Biotechnology, Tezpur University, Tezpur 784028, Assam, India.
| | - Suvendra Kumar Ray
- Department of Molecular Biology & Biotechnology, Tezpur University, Tezpur 784028, Assam, India.
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Establishing the lower bacterial concentration threshold for different optical counting techniques. J Microbiol Methods 2022; 203:106620. [PMID: 36372252 DOI: 10.1016/j.mimet.2022.106620] [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: 08/31/2022] [Revised: 11/07/2022] [Accepted: 11/07/2022] [Indexed: 11/13/2022]
Abstract
This work compares several physical and optical techniques used in fundamental research and industrial applications to detect bacteria in water. Optical techniques such as, UV-absorbance spectroscopy, laser particle counting, turbidimetry and Z-Sizer light scattering, and a direct observational physical technique, the plate count method, were compared when measuring the concentration of E.coli in tenfold dilution from a stock solution. Estimates of the detection threshold limit of E.coli for the different optical counting techniques and the relationship between colony-forming units (CFU) and tenfold dilutions was established. Optical methods have generated interest due to the rapid response of just minutes, non-destructive approach and minimal sample preparation but their use is still limited to concentrations of up to 4 Log E.coli/mL. In contrast, the plate count method is still a reliable technique for water quality analysis despite its long response time of 24 h.
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Masri A, Brown DM, Smith DGE, Stone V, Johnston HJ. Comparison of In Vitro Approaches to Assess the Antibacterial Effects of Nanomaterials. J Funct Biomater 2022; 13:255. [PMID: 36412895 PMCID: PMC9703965 DOI: 10.3390/jfb13040255] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/04/2022] [Accepted: 11/17/2022] [Indexed: 07/24/2023] Open
Abstract
The antibacterial properties of nanomaterials (NMs) can be exploited in a range of consumer products (e.g., wound dressings, food packaging, textiles, medicines). There is also interest in the exploitation of NMs as treatments for infectious diseases to help combat antibiotic resistance. Whilst the antibacterial activity of NMs has been assessed in vitro and in vivo in numerous studies, the methodology used is very varied. Indeed, while numerous approaches are available to assess the antibacterial effect of NMs in vitro, they have not yet been systematically assessed for their suitability and sensitivity for testing NMs. It is therefore timely to consider what assays should be prioritised to screen the antibacterial properties of NMs. The majority of existing in vitro studies have focused on investigating the antibacterial effects exhibited by silver (Ag) NMs and have employed a limited range of assays. We therefore compared the antibacterial effects of copper oxide (CuO) NMs to Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus subtilis at various concentrations (12.5-200 µg/mL) using a battery of tests (well and disc diffusion, plate counts-time-kill method, optical density measurement-OD, Alamar Blue and live/dead viability assays, and quantitative polymerase chain reaction). CuO NMs were most toxic to B. subtilis and E. coli, while P. aeruginosa was the least sensitive strain. All assays employed detected the antibacterial activity of CuO NMs; however, they varied in their sensitivity, time, cost, technical difficulty and requirement for specialized equipment. In the future, we suggest that a combination of approaches is used to provide a robust assessment of the antibacterial activity of NMs. In particular, we recommend that the time-kill and OD assays are prioritised due to their greater sensitivity. We also suggest that standard operating protocols are developed so that the antibacterial activity of NMs can be assessed using a harmonised approach.
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de Castro RJA, Rêgo MTAM, Brandão FS, Pérez ALA, De Marco JL, Poças-Fonseca MJ, Nichols C, Alspaugh JA, Felipe MSS, Alanio A, Bocca AL, Fernandes L. Engineered Fluorescent Strains of Cryptococcus neoformans: a Versatile Toolbox for Studies of Host-Pathogen Interactions and Fungal Biology, Including the Viable but Nonculturable State. Microbiol Spectr 2022; 10:e0150422. [PMID: 36005449 PMCID: PMC9603711 DOI: 10.1128/spectrum.01504-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 08/05/2022] [Indexed: 12/31/2022] Open
Abstract
Cryptococcus neoformans is an opportunistic fungal pathogen known for its remarkable ability to infect and subvert phagocytes. This ability provides survival and persistence within the host and relies on phenotypic plasticity. The viable but nonculturable (VBNC) phenotype was recently described in C. neoformans, whose study is promising in understanding the pathophysiology of cryptococcosis. The use of fluorescent strains is improving host interaction research, but it is still underexploited. Here, we fused histone H3 or the poly(A) binding protein (Pab) to enhanced green fluorescent protein (eGFP) or mCherry, obtaining a set of C. neoformans transformants with different colors, patterns of fluorescence, and selective markers (hygromycin B resistance [Hygr] or neomycin resistance [Neor]). We validated their similarity to the parental strain in the stress response, the expression of virulence-related phenotypes, mating, virulence in Galleria mellonella, and survival within murine macrophages. PAB-GFP, the brightest transformant, was successfully applied for the analysis of phagocytosis by flow cytometry and fluorescence microscopy. Moreover, we demonstrated that an engineered fluorescent strain of C. neoformans was able to generate VBNC cells. GFP-tagged Pab1, a key regulator of the stress response, evidenced nuclear retention of Pab1 and the assembly of cytoplasmic stress granules, unveiling posttranscriptional mechanisms associated with dormant C. neoformans cells. Our results support that the PAB-GFP strain is a useful tool for research on C. neoformans. IMPORTANCE Cryptococcus neoformans is a human-pathogenic yeast that can undergo a dormant state and is responsible for over 180,000 deaths annually worldwide. We engineered a set of fluorescent transformants to aid in research on C. neoformans. A mutant with GFP-tagged Pab1 improved fluorescence-based techniques used in host interaction studies. Moreover, this mutant induced a viable but nonculturable phenotype and uncovered posttranscriptional mechanisms associated with dormant C. neoformans. The experimental use of fluorescent mutants may shed light on C. neoformans-host interactions and fungal biology, including dormant phenotypes.
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Affiliation(s)
- Raffael Júnio Araújo de Castro
- Laboratory of Applied Immunology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
- CNRS, Unité de Mycologie Moléculaire, Centre National de Référence Mycoses et Antifongiques, Institut Pasteur, Paris, France
| | - Marco Túlio Aidar Mariano Rêgo
- Laboratory of Applied Immunology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
| | - Fabiana S. Brandão
- Faculty of Health Science, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
| | - Ana Laura Alfonso Pérez
- Department of Cell Biology, Institute of Biological Sciences, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasilia, Federal District, Brazil
| | - Janice Lisboa De Marco
- Department of Cell Biology, Institute of Biological Sciences, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasilia, Federal District, Brazil
| | - Marcio José Poças-Fonseca
- Department of Genetics and Morphology, Institute of Biological Sciences, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
| | - Connie Nichols
- Duke University School of Medicine, Department of Medicine, Durham, North Carolina, USA
| | - J. Andrew Alspaugh
- Duke University School of Medicine, Department of Medicine, Durham, North Carolina, USA
| | - Maria Sueli S. Felipe
- Catholic University of Brasilia, Campus Asa Norte, Asa Norte, Brasília, Federal District, Brazil
| | - Alexandre Alanio
- CNRS, Unité de Mycologie Moléculaire, Centre National de Référence Mycoses et Antifongiques, Institut Pasteur, Paris, France
- Laboratoire de Mycologie et Parasitologie, AP-HP, Hôpital Saint Louis, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Anamélia Lorenzetti Bocca
- Laboratory of Applied Immunology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
| | - Larissa Fernandes
- Laboratory of Applied Immunology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Brasília, Federal District, Brazil
- Faculty of Ceilândia, Campus UnB Ceilândia, University of Brasília, Ceilândia Sul, Brasília, Federal District, Brazil
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Large TP, Mack S, Villiers E, Oliver J. In vitro susceptibility of canine corneal bacterial pathogens to three cross-linking protocols. Vet Ophthalmol 2022; 26 Suppl 1:134-142. [PMID: 35713165 DOI: 10.1111/vop.13006] [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: 11/16/2021] [Revised: 06/07/2022] [Accepted: 06/08/2022] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To assess in vitro antibacterial efficacy of three cross-linking (XL) protocols on bacteria associated with canine ulcerative keratitis. METHODS Three XL protocols: UVA 3 mW/cm2 for 60 min, UVA 3 mW/cm2 for 30 min, and UVA 30 mW/cm2 for 3 min with and without application of riboflavin and a riboflavin-only protocol were performed in vitro on the four most common bacterial genera isolated from cases of canine ulcerative keratitis treated at Dick White Referrals, UK. Zones of bacterial growth inhibition (GIZ) associated with treatment were measured and compared. RESULTS The four most common isolates were Pseudomonas aeruginosa (PA) (48/140, 34.3%), Streptococcus spp. (32/140, 22.9%), Staphylococcus spp. (24/140, 17.1%) and Escherichia coli (EC) (11/140, 7.9%). PA, EC, Streptococcus canis (SC), and Staphylococcus pseudintermedius (SP), isolated from canine corneas, were selected for testing. EC and SC demonstrated growth inhibition following all UVA/riboflavin protocols. PA and SP only displayed growth inhibition following the 60 min UVA/riboflavin protocol. GIZ areas for 60 min UVA/riboflavin protocols were significantly greater than 30 and 3 min UVA/riboflavin protocols (p < .01) and there was no significant difference between 30 and 3 min UVA/riboflavin protocols. In respect to GIZ areas, EC was significantly more susceptible to XL than SP (p = <.01). CONCLUSIONS All UVA/riboflavin XL protocols caused growth inhibition of EC and SC in vitro. PA and SP did not show clear growth inhibition in vitro following exposure to XL protocol settings of UVA 3 mW/cm2 for 30 min and UVA 30 mW/cm2 for 3 min.
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Affiliation(s)
- Thomas P Large
- Dick White Referrals, Six Mile Bottom, Cambridgeshire, UK
| | - Sarah Mack
- Dick White Referrals, Six Mile Bottom, Cambridgeshire, UK
| | | | - James Oliver
- Dick White Referrals, Six Mile Bottom, Cambridgeshire, UK
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Curcumin and Silver Doping Enhance the Spinnability and Antibacterial Activity of Melt-Electrospun Polybutylene Succinate Fibers. NANOMATERIALS 2022; 12:nano12020283. [PMID: 35055300 PMCID: PMC8781972 DOI: 10.3390/nano12020283] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 01/12/2022] [Accepted: 01/14/2022] [Indexed: 02/04/2023]
Abstract
Melt electrospinning is a polymer processing technology for the manufacture of microfibers and nanofibers. Additives are required to reduce the melt viscosity and increase its conductivity in order to minimize the fiber diameter, and can also impart additional beneficial properties. We investigated the preparation of polybutylene succinate (PBS) microfibers incorporating different weight percentages of two multifunctional additives (the organic dye curcumin and inorganic silver nanoparticles) using a single-nozzle laboratory-scale device. We determined the influence of these additives on the polymer melt viscosity, electrical conductivity, degradation profile, thermal behavior, fiber diameter, and antibacterial activity. The formation of a Taylor cone followed by continuous fiber deposition was observed for compounds containing up to 3% (w/w) silver nanoparticles and up to 10% (w/w) curcumin, the latter achieving the minimum average fiber diameter of 12.57 µm. Both additives reduced the viscosity and increased the electrical conductivity of the PBS melt, and also retained their specific antibacterial properties when compounded and spun into fibers. This is the first report describing the effect of curcumin and silver nanoparticles on the properties of PBS fibers manufactured using a single-nozzle melt-electrospinning device. Our results provide the basis to develop environmentally benign antibacterial melt-electrospun PBS fibers for biomedical applications.
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12
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Muhsin SA, Al-Amidie M, Shen Z, Mlaji Z, Liu J, Abdullah A, El-Dweik M, Zhang S, Almasri M. A microfluidic biosensor for rapid simultaneous detection of waterborne pathogens. Biosens Bioelectron 2022; 203:113993. [PMID: 35114471 DOI: 10.1016/j.bios.2022.113993] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 01/07/2022] [Accepted: 01/08/2022] [Indexed: 01/05/2023]
Abstract
A microfluidic based biosensor was investigated for rapid and simultaneous detection of Salmonella, Legionella, and Escherichia coli O157:H7 in tap water and wastewater. The biosensor consisted of two sets of focusing electrodes connected in parallel and three sets of interdigitated electrodes (IDE) arrays. The electrodes enabled the biosensor to concentrate and detect bacteria at both low and high concentrations. The focusing region was designed with vertical metal sidewall pairs and multiple tilted thin-film finger pairs to generate positive dielectrophoresis (p-DEP) to force the bacteria moving toward the microchannel centerline. As a result, the bacterial pathogens were highly concentrated when they reached the detection electrode arrays. The detection IDE arrays were coated with three different antibodies against the target bacterial pathogens and a cross-linker to enhance the binding of antibodies to the detection electrode. As the binding of bacterial pathogen to its specific antibodies took place, the impedance value changed. The results demonstrated that the biosensors were capable of detecting Salmonella, Legionella, and E. coli 0157:H7 simultaneously with a detection limit of 3 bacterial cells/ml in 30 - 40 min.
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Affiliation(s)
- Sura A Muhsin
- Department of Electrical and Computer Engineering, University of Missouri, 411 S. 6th St., room 201, Columbia, MO, 65211, USA
| | - Muthana Al-Amidie
- Department of Electrical and Computer Engineering, University of Missouri, 411 S. 6th St., room 201, Columbia, MO, 65211, USA; Department of Electrical Engineering, University of Babylon, Babil, 51001, Iraq
| | - Zhenyu Shen
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO, 65211, USA
| | - Zahar Mlaji
- Department of Electrical and Computer Engineering, University of Missouri, 411 S. 6th St., room 201, Columbia, MO, 65211, USA
| | - Jiayu Liu
- Department of Electrical and Computer Engineering, University of Missouri, 411 S. 6th St., room 201, Columbia, MO, 65211, USA
| | - Amjed Abdullah
- Department of Electrical and Computer Engineering, University of Missouri, 411 S. 6th St., room 201, Columbia, MO, 65211, USA
| | - Majed El-Dweik
- Co-operative Research and Life Physical Sciences, Lincoln University, Jefferson City, MO, 65101, USA
| | - Shuping Zhang
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO, 65211, USA
| | - Mahmoud Almasri
- Department of Electrical and Computer Engineering, University of Missouri, 411 S. 6th St., room 201, Columbia, MO, 65211, USA.
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13
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Jiang S, Wang F, Cao X, Slater B, Wang R, Sun H, Wang H, Shen X, Yao Z. Novel application of ion exchange membranes for preparing effective silver and copper based antibacterial membranes. CHEMOSPHERE 2022; 287:132131. [PMID: 34492413 DOI: 10.1016/j.chemosphere.2021.132131] [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: 07/27/2021] [Revised: 08/30/2021] [Accepted: 08/31/2021] [Indexed: 06/13/2023]
Abstract
Ion exchange membranes (IEMs) are widely used in water treatment applications such as electrodialysis. However, the exploration of IEMs as effective antibacterial food contact materials (e.g., food packaging membranes) against pathogenic bacteria to ensure food safety has not been reported. Here, we report a simple but effective method to prepare high performance antibacterial membranes via ion exchange coupled with in-situ reduction. The general membrane properties are characterized using SEM, EDS, FTIR, XPS, XRD, DSC, TGA, water uptake, etc. The distribution of silver and copper in the membranes are generally in line with the distribution of sulfur, indicating that the antibacterial ions are introduced into the membranes via ion exchange and are bonded with the sulfonate groups in the membranes. The antibacterial performance is investigated using zone of inhibition tests and continuous bacteria growth inhibition tests. All of the prepared membranes show obvious antibacterial activities compared to the bare cation exchange membranes. The diameters of inhibition zone against Staphylococcus aureus (S. aureus) are all larger than those of Escherichia coli (E. coli), indicating that the prepared membranes are more efficient in inhibiting S. aureus compared to E. coli. Furthermore, the silver-based membrane shows more sustainable antibacterial activities compared to the copper-based membrane. Especially, the results clearly reveal that the silver-based membrane is capable of killing bacteria instead of just inhibiting the growth of bacteria. We have shown for the first time that membranes derived from IEMs have the potential as food contact materials to inhibit the growth of pathogenic bacteria so as to eliminate the risk of bacterial infections and meanwhile delay food spoilage due to bacteria growth.
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Affiliation(s)
- Shanxue Jiang
- School of Ecology and Environment, Beijing Technology and Business University, Beijing, 100048, China; State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing, 100048, China
| | - Fang Wang
- School of Ecology and Environment, Beijing Technology and Business University, Beijing, 100048, China; State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing, 100048, China
| | - Xinyue Cao
- School of Ecology and Environment, Beijing Technology and Business University, Beijing, 100048, China; State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing, 100048, China
| | - Ben Slater
- Institute of Porous Materials, Ecole Normale Supérieure, 24 Rue Lhomond, 75005, Paris, France
| | - Rongrong Wang
- School of Ecology and Environment, Beijing Technology and Business University, Beijing, 100048, China
| | - Haishu Sun
- Department of Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Huijiao Wang
- School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing, 100083, China
| | - Xianbao Shen
- School of Ecology and Environment, Beijing Technology and Business University, Beijing, 100048, China; State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing, 100048, China
| | - Zhiliang Yao
- School of Ecology and Environment, Beijing Technology and Business University, Beijing, 100048, China; State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing, 100048, China.
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14
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Bezrodnykh EA, Antonov YA, Berezin BB, Kulikov SN, Tikhonov VE. Molecular features of the interaction and antimicrobial activity of chitosan in a solution containing sodium dodecyl sulfate. Carbohydr Polym 2021; 270:118352. [PMID: 34364599 DOI: 10.1016/j.carbpol.2021.118352] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 04/21/2021] [Accepted: 06/13/2021] [Indexed: 10/21/2022]
Abstract
Molecular interaction of chitosan with sodium dodecyl sulfate (SDS) is a more complicated process than it has been imagined so far. For the first time it has been shown that the shorter chitosan chains are, the more preferably they interact with the SDS and the larger-in-size microparticles they form. The influence of ionic strength, urea and temperature on microparticles formation allows interpreting the mechanism of microparticles formation as a cooperative electrostatic interaction between SDS and chitosan with simultaneous decrease in the surface charge of the complexes initiating the aggregation of microparticles. It is shown that hydrogen bonding is mainly responsible for the aggregation while hydrophobic interaction has a lesser effect. Chitosan demonstrates a high bacteriostatic activity in the presence of SDS in solution and can be promising for preparation of microbiologically stable pharmaceutical hydrocolloids, cosmetic products and chitosan-based Pickering emulsions containing strong anionic surfactants.
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Affiliation(s)
- Evgeniya A Bezrodnykh
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow, Russia
| | - Yury A Antonov
- N.M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Kosygin Str. 4, 119334 Moscow, Russia
| | - Boris B Berezin
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow, Russia
| | - Sergey N Kulikov
- Kazan Scientific Research Institute of Epidemiology and Microbiology, Kazan, Russia; Kazan Federal University, Kazan, Russia
| | - Vladimir E Tikhonov
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow, Russia.
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15
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Sukumaran L, Radhakrishnan M. Effect of frozen storage on the inhibition of microbial population, chemical and sensory characteristics of coconut neera. J Appl Microbiol 2021; 131:1830-1839. [PMID: 33721389 DOI: 10.1111/jam.15068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 01/07/2021] [Accepted: 03/09/2021] [Indexed: 11/27/2022]
Abstract
AIM In this study, the effect of frozen storage on the inhibition of microbial population in coconut neera for shelf life extension was analysed. METHODS AND RESULTS The aliquots of fresh neera were frozen at -6 and -20°C. The microbial reduction and chemical qualities were analysed during storage days, and were compared with the control. The highest reduction in microbes was obtained at -20°C for lactic acid bacteria, yeast and total viable count. Moreover, the fluorescence cell staining and cell density analysis exhibited a decline at -20°C, however it showed higher at -6°C. At the end of 28 days, neera exhibited a pH of 5·37, total soluble solid of 14·0 °Brix and total acidity of 0·82 mg l-1 at -20°C. Besides, color, viscosity, total protein and ethanol showed a less difference with control and better sensory attribute up to 21 days at -20°C. CONCLUSIONS Frozen storage at -20°C resulted in a better inhibition of lactic acid bacteria, which preserves neera from the metabolic conversion. The physicochemical qualities of neera were preserved for a longer period when stored at -20°C than at atmospheric storage. SIGNIFICANCE AND IMPACT OF THE STUDY Frozen storage reduced microbial population and preserves the chemical properties with acceptable sensory attributes and increases the shelf life of coconut neera, making it fit for consumption.
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Affiliation(s)
- L Sukumaran
- Centre of Excellence in Nonthermal Processing, Indian Institute of Food Processing Technology, Ministry of Food Processing Industries, Government of India, Thanjavur, Tamil Nadu, India.,Affiliated to Bharathidasan University, Palkalaiperur, Tiruchirappalli, Tamil Nadu, India
| | - M Radhakrishnan
- Centre of Excellence in Nonthermal Processing, Indian Institute of Food Processing Technology, Ministry of Food Processing Industries, Government of India, Thanjavur, Tamil Nadu, India
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16
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Thanaphongdecha P, Karinshak SE, Ittiprasert W, Mann VH, Chamgramol Y, Pairojkul C, Fox JG, Suttiprapa S, Sripa B, Brindley PJ. Infection with Helicobacter pylori Induces Epithelial to Mesenchymal Transition in Human Cholangiocytes. Pathogens 2020; 9:E971. [PMID: 33233485 PMCID: PMC7700263 DOI: 10.3390/pathogens9110971] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 11/14/2020] [Accepted: 11/18/2020] [Indexed: 02/08/2023] Open
Abstract
Recent reports suggest that the East Asian liver fluke infection, caused by Opisthorchis viverrini, which is implicated in opisthorchiasis-associated cholangiocarcinoma, serves as a reservoir of Helicobacter pylori. The opisthorchiasis-affected cholangiocytes that line the intrahepatic biliary tract are considered to be the cell of origin of this malignancy. Here, we investigated interactions in vitro among human cholangiocytes, Helicobacter pylori strain NCTC 11637, and the congeneric bacillus, Helicobacter bilis. Exposure to increasing numbers of H. pylori at 0, 1, 10, 100 bacilli per cholangiocyte of the H69 cell line induced phenotypic changes including the profusion of thread-like filopodia and a loss of cell-cell contact, in a dose-dependent fashion. In parallel, following exposure to H. pylori, changes were evident in levels of mRNA expression of epithelial to mesenchymal transition (EMT)-encoding factors including snail, slug, vimentin, matrix metalloprotease, zinc finger E-box-binding homeobox, and the cancer stem cell marker CD44. Analysis to quantify cellular proliferation, migration, and invasion in real-time by both H69 cholangiocytes and CC-LP-1 line of cholangiocarcinoma cells using the xCELLigence approach and Matrigel matrix revealed that exposure to 10 H. pylori bacilli per cell stimulated migration and invasion by the cholangiocytes. In addition, 10 bacilli of H. pylori stimulated contact-independent colony establishment in soft agar. These findings support the hypothesis that infection by H. pylori contributes to the malignant transformation of the biliary epithelium.
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Affiliation(s)
- Prissadee Thanaphongdecha
- Research Center for Neglected Tropical Diseases of Poverty, Department of Microbiology, Immunology and Tropical Medicine, School of Medicine & Health Sciences, The George Washington University, Washington, DC 20037, USA; (P.T.); (S.E.K.); (W.I.); (V.H.M.)
- Tropical Disease Research Laboratory, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand;
| | - Shannon E. Karinshak
- Research Center for Neglected Tropical Diseases of Poverty, Department of Microbiology, Immunology and Tropical Medicine, School of Medicine & Health Sciences, The George Washington University, Washington, DC 20037, USA; (P.T.); (S.E.K.); (W.I.); (V.H.M.)
| | - Wannaporn Ittiprasert
- Research Center for Neglected Tropical Diseases of Poverty, Department of Microbiology, Immunology and Tropical Medicine, School of Medicine & Health Sciences, The George Washington University, Washington, DC 20037, USA; (P.T.); (S.E.K.); (W.I.); (V.H.M.)
| | - Victoria H. Mann
- Research Center for Neglected Tropical Diseases of Poverty, Department of Microbiology, Immunology and Tropical Medicine, School of Medicine & Health Sciences, The George Washington University, Washington, DC 20037, USA; (P.T.); (S.E.K.); (W.I.); (V.H.M.)
| | - Yaovalux Chamgramol
- Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; (Y.C.); (C.P.)
| | - Chawalit Pairojkul
- Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; (Y.C.); (C.P.)
| | - James G. Fox
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA 02139, USA;
| | - Sutas Suttiprapa
- Tropical Disease Research Laboratory, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand;
| | - Banchob Sripa
- Tropical Disease Research Laboratory, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand;
- Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand; (Y.C.); (C.P.)
| | - Paul J. Brindley
- Research Center for Neglected Tropical Diseases of Poverty, Department of Microbiology, Immunology and Tropical Medicine, School of Medicine & Health Sciences, The George Washington University, Washington, DC 20037, USA; (P.T.); (S.E.K.); (W.I.); (V.H.M.)
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17
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Abbott IJ, Roberts JA, Meletiadis J, Peleg AY. Antimicrobial pharmacokinetics and preclinical in vitro models to support optimized treatment approaches for uncomplicated lower urinary tract infections. Expert Rev Anti Infect Ther 2020; 19:271-295. [PMID: 32820686 DOI: 10.1080/14787210.2020.1813567] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
INTRODUCTION Urinary tract infections (UTIs) are extremely common. Millions of people, particularly healthy women, are affected worldwide every year. One-in-two women will have a recurrence within 12-months of an initial UTI. Inadequate treatment risks worsening infection leading to acute pyelonephritis, bacteremia and sepsis. In an era of increasing antimicrobial resistance, it is critical to provide optimized antimicrobial treatment. AREAS COVERED Literature was searched using PubMed and Google Scholar (up to 06/2020), examining the etiology, diagnosis and oral antimicrobial therapy for uncomplicated UTIs, with emphasis on urinary antimicrobial pharmacokinetics (PK) and the application of dynamic in vitro models for the pharmacodynamic (PD) profiling of pathogen response. EXPERT OPINION The majority of antimicrobial agents included in international guidelines were developed decades ago without well-described dose-response relationships. Microbiology laboratories still apply standard diagnostic methodology that has essentially remained unchanged for decades. Furthermore, it is uncertain how relevant standard in vitro susceptibility is for predicting antimicrobial efficacy in urine. In order to optimize UTI treatments, clinicians must exploit the urine-specific PK of antimicrobial agents. Dynamic in vitro models are valuable tools to examine the PK/PD and urodynamic variables associated with UTIs, while informing uropathogen susceptibility reporting, optimized dosing schedules, clinical trials and treatment guidelines.
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Affiliation(s)
- Iain J Abbott
- Department of Infectious Diseases, the Alfred Hospital and Central Clinical School, Monash University, Melbourne, Australia
| | - Jason A Roberts
- University of Queensland Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Brisbane, Australia.,School of Pharmacy, Centre for Translational Anti-infective Pharmacodynamics, The University of Queensland, Brisbane, Australia.,Department of Intensive Care Medicine, Royal Brisbane and Women's Hospital, Brisbane, Australia.,Division of Anaesthesiology Critical Care Emergency and Pain Medicine, Nîmes University Hospital, University of Montpellier, Nîmes, France
| | - Joseph Meletiadis
- Clinical Microbiology Laboratory, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Haidari, Greece
| | - Anton Y Peleg
- Department of Infectious Diseases, the Alfred Hospital and Central Clinical School, Monash University, Melbourne, Australia.,Infection and Immunity Program, Monash Biomedicine Discovery Institute, Department of Microbiology, Monash University, Clayton, Australia
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18
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Elsherbiny DA, Abdelgawad AM, El-Naggar ME, El-Sherbiny RA, El-Rafie MH, El-Sayed IET. Synthesis, antimicrobial activity, and sustainable release of novel α-aminophosphonate derivatives loaded carrageenan cryogel. Int J Biol Macromol 2020; 163:96-107. [DOI: 10.1016/j.ijbiomac.2020.06.251] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/06/2020] [Accepted: 06/25/2020] [Indexed: 01/06/2023]
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19
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Grainha T, Magalhães AP, Melo LDR, Pereira MO. Pitfalls Associated with Discriminating Mixed-Species Biofilms by Flow Cytometry. Antibiotics (Basel) 2020; 9:antibiotics9110741. [PMID: 33121057 PMCID: PMC7694060 DOI: 10.3390/antibiotics9110741] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/19/2020] [Accepted: 10/21/2020] [Indexed: 11/21/2022] Open
Abstract
Since biofilms are ubiquitous in different settings and act as sources of disease for humans, reliable methods to characterize and quantify these microbial communities are required. Numerous techniques have been employed, but most of them are unidirectional, labor intensive and time consuming. Although flow cytometry (FCM) can be a reliable choice to quickly provide a multiparametric analysis, there are still few applications on biofilms, and even less on the study of inter-kingdom communities. This work aimed to give insights into the application of FCM in order to more comprehensively analyze mixed-species biofilms, formed by different Pseudomonas aeruginosa and Candida albicans strains, before and after exposure to antimicrobials. For comparison purposes, biofilm culturability was also assessed determining colony-forming units. The results showed that some aspects, namely the microbial strain used, the morphological state of the cells and the biofilm matrix, make the accurate analysis of FCM data difficult. These aspects were even more challenging when double-species biofilms were being inspected, as they could engender data misinterpretations. The outcomes draw our attention towards the need to always take into consideration the characteristics of the biofilm samples to be analyzed through FCM, and undoubtedly link to the need for optimization of the processes tailored for each particular case study.
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Affiliation(s)
| | | | - Luís D. R. Melo
- Correspondence: (L.D.R.M.); (M.O.P.); Tel.: +351-253-601-989 (L.D.R.M.); +351-253-604-402 (M.O.P.)
| | - Maria O. Pereira
- Correspondence: (L.D.R.M.); (M.O.P.); Tel.: +351-253-601-989 (L.D.R.M.); +351-253-604-402 (M.O.P.)
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20
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Hui Chong LS, Zhang J, Bhat KS, Yong D, Song J. Bioinspired cell-in-shell systems in biomedical engineering and beyond: Comparative overview and prospects. Biomaterials 2020; 266:120473. [PMID: 33120202 DOI: 10.1016/j.biomaterials.2020.120473] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 10/07/2020] [Accepted: 10/18/2020] [Indexed: 12/28/2022]
Abstract
With the development in tissue engineering, cell transplantation, and genetic technologies, living cells have become an important therapeutic tool in clinical medical care. For various cell-based technologies including cell therapy and cell-based sensors in addition to fundamental studies on single-cell biology, the cytoprotection of individual living cells is a prerequisite to extend cell storage life or deliver cells from one place to another, resisting various external stresses. Nature has evolved a biological defense mechanism to preserve their species under unfavorable conditions by forming a hard and protective armor. Particularly, plant seeds covered with seed coat turn into a dormant state against stressful environments, due to mechanical and water/gas constraints imposed by hard seed coat. However, when the environmental conditions become hospitable to seeds, seed coat is ruptured, initiating seed germination. This seed dormancy and germination mechanism has inspired various approaches that artificially induce cell sporulation via chemically encapsulating individual living cells within a thin but tough shell forming a 3D "cell-in-shell" structure. Herein, the recent advance of cell encapsulation strategies along with the potential advantages of the 3D "cell-in-shell" system is reviewed. Diverse coating materials including polymeric shells and hybrid shells on different types of cells ranging from microbes to mammalian cells will be discussed in terms of enhanced cytoprotective ability, control of division, chemical functionalization, and on-demand shell degradation. Finally, current and potential applications of "cell-in-shell" systems for cell-based technologies with remaining challenges will be explored.
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Affiliation(s)
- Lydia Shi Hui Chong
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, 637457, Singapore; Singapore Institute of Manufacturing Technology, Agency for Science, Technology and Research, 2 Fusionopolis Way, 168384, Singapore
| | - Jingyi Zhang
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, 637457, Singapore; Singapore Institute of Manufacturing Technology, Agency for Science, Technology and Research, 2 Fusionopolis Way, 168384, Singapore
| | - Kiesar Sideeq Bhat
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, 637457, Singapore
| | - Derrick Yong
- Singapore Institute of Manufacturing Technology, Agency for Science, Technology and Research, 2 Fusionopolis Way, 168384, Singapore
| | - Juha Song
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, 637457, Singapore.
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21
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Yang Q, Keerthisinghe TP, Tan TRJ, Cao X, Setyawati MI, DeLoid G, Ng KW, Loo SCJ, Demokritou P, Fang M. A high-throughput method to characterize the gut bacteria growth upon engineered nanomaterial treatment. ENVIRONMENTAL SCIENCE. NANO 2020; 7:3155-3166. [PMID: 33101690 PMCID: PMC7577393 DOI: 10.1039/d0en00568a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Human are increasingly exposed to various types of engineered nanomaterials (ENMs) via dietary ingestion of nano-enabled food products, but these ENMs' impact on the gut bacteria health is still poorly understood. Current efforts in understanding the impact of these ENMs are hampered by their optical interferences in conventional quantification and viability assays, such as optical density and whole cell fluorescence staining assays. Therefore, there is a need to develop a more reliable bacteria quantification method in the presence of ENMs to effectively screen the potential adverse effects arising from the exposure of increasing ENMs on human gut microbiome. In this study, we developed a DNA-based quantification (DBQ) method in a 96-well plate format. Post-spiking method was used to correct the interference from ENMs on the reading. We showed the applicability of this method for several types of ENMs, i.e., cellulose nanofiber (CNF), graphene oxide (GO), silicon dioxide (SiO2), and chitosan, both in pure bacterial culture and in vitro human gut microbiome community. The detection limit for the highest dosing of CNF, GO, SiO2, and chitosan ENMs was approximately 0.18, 0.19, 0.05, and 0.24 as OD600, respectively. The method was also validated by a dose response experiment of E. coli with chitosan in the course of 8 hr. We believe that this method has great potential to be used in screening the effect of ENMs on the growth of gut bacteria or any other in vitro models and normalization for metabolites or proteins analysis.
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Affiliation(s)
- Qin Yang
- School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
- Nanyang Environment and Water Research Institute, Nanyang Technological University, 637141, Singapore
| | - Tharushi Prabha Keerthisinghe
- School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
- Nanyang Environment and Water Research Institute, Nanyang Technological University, 637141, Singapore
| | - Tiffany Rou Jie Tan
- School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
- Nanyang Environment and Water Research Institute, Nanyang Technological University, 637141, Singapore
| | - Xiaoqiong Cao
- Center for Nanotechnology and Nanotoxicology, Department of Environmental Health, T.H. Chan School of Public Health, Harvard University, 655 Huntington Ave, Boston, MA, 02115 USA
| | - Magdiel Inggrid Setyawati
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Glen DeLoid
- Center for Nanotechnology and Nanotoxicology, Department of Environmental Health, T.H. Chan School of Public Health, Harvard University, 655 Huntington Ave, Boston, MA, 02115 USA
| | - Kee Woei Ng
- Nanyang Environment and Water Research Institute, Nanyang Technological University, 637141, Singapore
- Center for Nanotechnology and Nanotoxicology, Department of Environmental Health, T.H. Chan School of Public Health, Harvard University, 655 Huntington Ave, Boston, MA, 02115 USA
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Say Chye Joachim Loo
- Center for Nanotechnology and Nanotoxicology, Department of Environmental Health, T.H. Chan School of Public Health, Harvard University, 655 Huntington Ave, Boston, MA, 02115 USA
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551
| | - Philip Demokritou
- Center for Nanotechnology and Nanotoxicology, Department of Environmental Health, T.H. Chan School of Public Health, Harvard University, 655 Huntington Ave, Boston, MA, 02115 USA
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Mingliang Fang
- School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
- Nanyang Environment and Water Research Institute, Nanyang Technological University, 637141, Singapore
- Singapore Phenome Center, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 636921, Singapore
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Pascoe J, Hendon-Dunn CL, Birch CP, Williams GA, Chambers MA, Bacon J. Optimisation of Mycobacterium bovis BCG Fermentation and Storage Survival. Pharmaceutics 2020; 12:pharmaceutics12090900. [PMID: 32971826 PMCID: PMC7558299 DOI: 10.3390/pharmaceutics12090900] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 09/02/2020] [Accepted: 09/10/2020] [Indexed: 11/16/2022] Open
Abstract
Mycobacterium bovis Bacillus Calmette–Guérin (M. bovis BCG) was generated over a century ago for protection against Mycobacterium tuberculosis (Mtb) and is one the oldest vaccines still in use. The BCG vaccine is currently produced using a pellicle growth method, which is a complex and lengthy process that has been challenging to standardise. Fermentation for BCG vaccine production would reduce the complexity associated with pellicle growth and increase batch to batch reproducibility. This more standardised growth lends itself to quantification of the total number of bacilli in the BCG vaccine by alternative approaches, such as flow cytometry, which can also provide information about the metabolic status of the bacterial population. The aim of the work reported here was to determine which batch fermentation conditions and storage conditions give the most favourable outcomes in terms of the yield and stability of live M. bovis BCG Danish bacilli. We compared different media and assessed growth over time in culture, using total viable counts, total bacterial counts, and turbidity throughout culture. We applied fluorescent viability dyes and flow cytometry to measure real-time within-culture viability. Culture samples were stored in different cryoprotectants at different temperatures to assess the effect of these combined conditions on bacterial titres. Roisin’s minimal medium and Middlebrook 7H9 medium gave comparable, high titres in fermenters. Flow cytometry proved to be a useful tool for enumeration of total bacterial counts and in the assessment of within-culture cell viability and cell death. Of the cryoprotectants evaluated, 5% (v/v) DMSO showed the most significant positive effect on survival and reduced the negative effects of low temperature storage on M. bovis BCG Danish viability. In conclusion, we have shown a reproducible, more standardised approach for the production, evaluation, and storage of high titre, viable, BCG vaccine.
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Affiliation(s)
- Jordan Pascoe
- TB Research Group, Public Health England, National Infection Service, Porton Down, Salisbury, Wiltshire SP4 0JG, UK; (J.P.); (C.L.H.-D.)
| | - Charlotte L. Hendon-Dunn
- TB Research Group, Public Health England, National Infection Service, Porton Down, Salisbury, Wiltshire SP4 0JG, UK; (J.P.); (C.L.H.-D.)
| | - Colin P.D. Birch
- Department of Epidemiological Sciences, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK;
| | - Gareth A. Williams
- Department of Bacteriology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK; (G.A.W.); (M.A.C.)
| | - Mark A. Chambers
- Department of Bacteriology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK; (G.A.W.); (M.A.C.)
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK
| | - Joanna Bacon
- TB Research Group, Public Health England, National Infection Service, Porton Down, Salisbury, Wiltshire SP4 0JG, UK; (J.P.); (C.L.H.-D.)
- Correspondence:
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Alamri A, Salloot Z, Alshaia A, Ibrahim MS. The Effect of Bioactive Glass-Enhanced Orthodontic Bonding Resins on Prevention of Demineralization: A Systematic Review. Molecules 2020; 25:E2495. [PMID: 32471284 PMCID: PMC7321359 DOI: 10.3390/molecules25112495] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 05/22/2020] [Accepted: 05/26/2020] [Indexed: 12/12/2022] Open
Abstract
At present, bioactive glasses (BAGs) are demonstrating promising results in the remineralization of hard tissues. Their bioactive properties can potentially overcome the demineralization effect accompanying orthodontic treatment. This review aimed to evaluate the effectiveness of bioactive glass enhanced orthodontic bonding resins on enamel remineralization, in addition to their antibacterial, ion release and acid neutralization effect. Four databases (PubMed, MEDLINE, Web of Science and Scopus) were searched. Two hundred and fifty-one full-text articles were screened independently, out of which seven studies satisfied the inclusion criteria. Quality appraisal was performed by two independent reviewers. Methodologies used to assess the anti-demineralization effect included Micro-Computed Tomography, Polarized Light Microscopy and Hardness Testing (Knoop and Berkovich). All seven articles confirmed the superior remineralization effect of BAG orthodontic bonding resins compared to their non-BAG counterparts. A proportional relationship was proved between BAG concentrations and increased anti-demineralization effect. The addition of antibacterial agents to BAG does not necessarily improve its anti-demineralization effect. Although studies have confirmed the effectiveness of BAG orthodontic bonding resins on enamel remineralization, there was a degree of heterogeneity across studies due to the lack of an in vitro studies standardized protocol.
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Affiliation(s)
- Abdulaziz Alamri
- Preventive Dental Sciences Department, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia; (A.A.); (Z.S.)
| | - Zainah Salloot
- Preventive Dental Sciences Department, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia; (A.A.); (Z.S.)
| | - Alaa Alshaia
- College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia;
| | - Maria Salem Ibrahim
- Preventive Dental Sciences Department, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia; (A.A.); (Z.S.)
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Georgiou PC, Mouton JW, Pournaras S, Meletiadis J. Bacterial quantification in tissue homogenates from in vivo pharmacodynamic studies using growth curves. J Med Microbiol 2020; 69:676-684. [PMID: 32228800 DOI: 10.1099/jmm.0.001183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Introduction. Quantification of bacterial load in tissue homogenates in in vivo pharmacodynamic studies is cumbersome and time-consuming.Aim. We therefore developed a new method for quantifying bacterial load in tissue homogenates of animals treated with a β-lactam and β-lactamase inhibitor using growth curves.Methods. The log10 colony-forming units (c.f.u.) ml-1 of 184 thigh and lung homogenates from female CD-1 mice infected intranasally and intramuscularly with 4 Pseudomonas aeruginosa, 4 Klebsiella pneumoniae, 3 Enterobacter cloacae and 2 Escherichia coli strains treated with a β-lactam drug and tazobactam were calculated using the standard approach of serial quantitative cultures and analysis of growth curves. Growth curves were obtained with continuous (every 10 min) monitoring of optical density at 630 nm (OD630) after 20 µl tissue homogenates were inoculated in total volume of 200 µl Mueller-Hinton broth in 96-well microtitration plates and incubated at 37 °C for 18 h.Results. The best correlation between log10 c.f.u. ml-1 determined with the serial quantitative cultures and growth curves was found at the time point corresponding to an OD630 of 0.25 increase above the baseline OD (average of first five timepoints) (R 2=0.918-0.999). The median (range) differences between the two methods was -0.19 (-1.79-1.69) with 86-97 % of all isolates and species being within 1 log10 c.f.u. ml-1 with 1 h hands-on-time and <13 h of incubation for 96 samples. Pharmacodynamic analysis showed similar dose-response relationships and 1 log kill dose estimations (paired t-test, P=0.112).Conclusion. The new technique resulted in comparable c.f.u. counts to those for the standard serial dilution/culture technique with minimal hands-on and turnaround times.
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Affiliation(s)
- Panagiota-Christina Georgiou
- Clinical Microbiology Laboratory, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Johan W Mouton
- Department of Medical Microbiology and Infectious Diseases, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Spyros Pournaras
- Clinical Microbiology Laboratory, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Joseph Meletiadis
- Clinical Microbiology Laboratory, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece.,Department of Medical Microbiology and Infectious Diseases, Erasmus Medical Center, Rotterdam, The Netherlands
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Alt G, Mägi M, Lodjak J, Mänd R. Experimental study of the effect of preen oil against feather bacteria in passerine birds. Oecologia 2020; 192:723-733. [DOI: 10.1007/s00442-020-04599-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 01/10/2020] [Indexed: 02/02/2023]
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Lee S, Thio SK, Park SY, Bae S. An automated 3D-printed smartphone platform integrated with optoelectrowetting (OEW) microfluidic chip for on-site monitoring of viable algae in water. HARMFUL ALGAE 2019; 88:101638. [PMID: 31582154 DOI: 10.1016/j.hal.2019.101638] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 06/20/2019] [Accepted: 06/26/2019] [Indexed: 06/10/2023]
Abstract
A sudden increase of algae and their associated toxins in aquatic ecosystems can detrimentally affect the quality of the water, causing serious socio-economic and public health problems. To prevent the spread of harmful algae in aquatic ecosystems, it is essential to track the water's quality through rapid and in-situ monitoring systems. Conventional methods of algae quantification such as microscopy, hemocytometry, and UV-vis spectroscopy, however, are often unsuitable or inconvenient for in-situ assessment as they require skilled labor and expensive equipment. In this study, we developed a three-dimensional (3D)-printed smartphone platform integrated with a light-driven microfluidic chip operated by optoelectrowetting (OEW). This OEW-driven microfluidic chip not only allows multiplexed drop-wise functions such as droplet transportation, merging, mixing, immobilization on a detection zone, for on-chip water sample preparation but also fluorescent detection and counting of target algae cells using a commercially-available smartphone. Two freshwater algae (C. reinhardtii and M. aeruginosa) and two marine water algae (Amphiprora sp and C. closterium) were employed to validate the 3D-printed smartphone platform in this study. The fluorescence images of viable algae and the cell counting from the microfluidic chip were comparable to the results from a hemocytometer (P > 0.05). We have further conducted tests with spiked samples using freshwater and marine water that were directly collected from environmental samples, showing the same order of magnitude of cell numbers in the spiked and control cultures of algae cells (106 cell/mL, P > 0.05). Unlike traditional quantification methods, the 3D-printed smartphone platform integrated with the OEW offers a highly portable, user-friendly, low-cost tool that enables simple on-chip sample preparation and detection of viable algae. Thus, this stand-alone technology has the potential for rapid and in-situ monitoring of water quality, while using the smartphone's wireless communication capabilities to report the quality of the water in real-time.
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Affiliation(s)
- Seunguk Lee
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore
| | - Si Kuan Thio
- Department of Mechanical Engineering, National University of Singapore, Singapore
| | - Sung-Yong Park
- Department of Mechanical Engineering, National University of Singapore, Singapore
| | - Sungwoo Bae
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore.
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27
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Jiang X, Yucel Falco C, Dalby KN, Siegumfeldt H, Arneborg N, Risbo J. Surface engineered bacteria as Pickering stabilizers for foams and emulsions. Food Hydrocoll 2019. [DOI: 10.1016/j.foodhyd.2018.10.044] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Singh A, Yelverton CJ, Barnard TG. Rapid Quantification of the Total Viable Bacterial Population on Human Hands Using Flow Cytometry with SYBR® Green I. CYTOMETRY PART B-CLINICAL CYTOMETRY 2019; 96:397-403. [PMID: 30851153 DOI: 10.1002/cyto.b.21776] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 02/06/2019] [Indexed: 02/03/2023]
Abstract
BACKGROUND Monitoring the efficiency of hand washing typically relies on determining the presence or absence of targeted organisms on the hands, not necessarily determining if the method is working. The results focus on the organism studied and do not give a true reflection of the efficiency of the hygiene intervention. To obtain a better picture, this study tested flow cytometry with SYBR® Green I to quantify bacterial populations on the hands of participants in a healthcare training clinic at a University in South Africa. METHODS Participants "washed" both hands in a buffer solution in a sterile bag, and the total and viable bacterial populations numbers were determined using flow cytometry and compared with standard culture-based methods, testing for total coliforms, E. coli and heterotrophic organisms (IDEXX Colilert®-18 Quanti-Trays™ and SimPlates®) and fastidious organisms with hemolytic activity (Blood Agar). RESULTS Compared to the culture-based method, flow cytometry rapidly distinguished total, viable, and dead bacterial populations in all samples. As expected, the culture-based methods gave lower bacterial counts and were limited by the detection limit of each test, requiring further testing with additional costs. Although the exact bacterial species in the population could not be identified with flow cytometry, viable counts from flow cytometric analysis were two times more precise than the data obtained with any of the culture-based methods tested. CONCLUSIONS Flow cytometry was found to be suitable for immediate, accurate, and automatic detection of bacteria, and because it describes the viable bacterial population, it is ideal to monitor hand hygiene interventions. © 2019 International Clinical Cytometry Society.
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Affiliation(s)
- Atheesha Singh
- Water and Health Research Centre, University of Johannesburg, Doornfontein, South Africa
| | | | - Tobias G Barnard
- Water and Health Research Centre, University of Johannesburg, Doornfontein, South Africa
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Vukomanovic M, Torrents E. High time resolution and high signal-to-noise monitoring of the bacterial growth kinetics in the presence of plasmonic nanoparticles. J Nanobiotechnology 2019; 17:21. [PMID: 30709404 PMCID: PMC6357367 DOI: 10.1186/s12951-019-0459-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 01/21/2019] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Emerging concepts for designing innovative drugs (i.e., novel generations of antimicrobials) frequently include nanostructures, new materials, and nanoparticles (NPs). Along with numerous advantages, NPs bring limitations, partly because they can limit the analytical techniques used for their biological and in vivo validation. From that standpoint, designing innovative drug delivery systems requires advancements in the methods used for their testing and investigations. Considering the well-known ability of resazurin-based methods for rapid detection of bacterial metabolisms with very high sensitivity, in this work we report a novel optimization for tracking bacterial growth kinetics in the presence of NPs with specific characteristics, such as specific optical properties. RESULTS Arginine-functionalized gold composite (HAp/Au/arginine) NPs, used as the NP model for validation of the method, possess plasmonic properties and are characterized by intensive absorption in the UV/vis region with a surface plasmon resonance maximum at 540 nm. Due to the specific optical properties, the NP absorption intensively interferes with the light absorption measured during the evaluation of bacterial growth (optical density; OD600). The results confirm substantial nonspecific interference by NPs in the signal detected during a regular turbidity study used for tracking bacterial growth. Instead, during application of a resazurin-based method (Presto Blue), when a combination of absorption and fluorescence detection is applied, a substantial increase in the signal-to-noise ratio is obtained that leads to the improvement of the accuracy of the measurements as verified in three bacterial strains tested with different growth rates (E. coli, P. aeruginosa, and S. aureus). CONCLUSIONS Here, we described a novel procedure that enables the kinetics of bacterial growth in the presence of NPs to be followed with high time resolution, high sensitivity, and without sampling during the kinetic study. We showed the applicability of the Presto Blue method for the case of HAp/Au/arginine NPs, which can be extended to various types of metallic NPs with similar characteristics. The method is a very easy, economical, and reliable option for testing NPs designed as novel antimicrobials.
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Affiliation(s)
- Marija Vukomanovic
- Bacterial Infections: Antimicrobial Therapies, Institute for Bioengineering of Catalonia (IBEC), The Institute of Science and Technology, Baldiri Reixac 15-21, 08028, Barcelona, Spain.
- Advanced Materials Department, Institute Jozef Stefan, Jamova 39, Ljubljana, Slovenia.
| | - Eduard Torrents
- Bacterial Infections: Antimicrobial Therapies, Institute for Bioengineering of Catalonia (IBEC), The Institute of Science and Technology, Baldiri Reixac 15-21, 08028, Barcelona, Spain.
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Almeida ETDC, de Souza GT, de Sousa Guedes JP, Barbosa IM, de Sousa CP, Castellano LRC, Magnani M, de Souza EL. Mentha piperita L. essential oil inactivates spoilage yeasts in fruit juices through the perturbation of different physiological functions in yeast cells. Food Microbiol 2019; 82:20-29. [PMID: 31027774 DOI: 10.1016/j.fm.2019.01.023] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 01/29/2019] [Accepted: 01/31/2019] [Indexed: 10/27/2022]
Abstract
This study evaluated the efficacy of the essential oil from Mentha piperita L. (MPEO) to inactivate cells of the potentially spoilage yeasts Candida albicans, Candida tropicalis, Pichia anomala and Saccharomyces cerevisiae in cashew, guava, mango and pineapple juices during 72 h of refrigerated storage. Damage in different physiological functions caused by MPEO in S. cerevisiae in cashew and guava juices were investigated using flow cytometry (FC). The effects of the incorporation of an effective anti-yeast MPEO dose on sensory characteristics of juices were also evaluated. MPEO displayed minimum inhibitory concentration of 1.875 μL/mL against all tested yeasts. A >5 log reduction in counts of C. albicans, P. anomala and S. cerevisiae was observed in cashew and guava juices with 7.5 and 3.75 μL/mL MPEO. Tested MPEO concentrations (1.875, 3.75 and 7.5 μL/mL) were not effective to cause >5 log reduction in counts of target yeasts in mango and pineapple juices during 72 h of exposure. Incorporation of 1.875 μL/mL MPEO in cashew and guava juices strongly compromised membrane permeability, membrane potential, enzymatic activity and efflux pump activity in S. cerevisiae cells. This same MPEO concentration did not affect appearance, odor and viscosity in fruit juices, but negatively affected their taste and aftertaste. These results show the efficacy of MPEO to inactivate potentially spoilage yeasts in fruit juices through disturbance of different physiological functions in yeast cells. However, the combined use of MPEO with other technologies should be necessary to decrease its effective anti-yeast dose in fruit juices and, consequently, the possible negative impacts on specific sensory properties of these products.
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Affiliation(s)
- Erika Tayse da Cruz Almeida
- Laboratory of Food Microbiology, Department of Nutrition, Health Sciences Center, Federal University of Paraíba, João Pessoa, Brazil
| | - Geany Targino de Souza
- Laboratory of Microbial Processes in Foods, Department of Food Engineering, Center of Technology, Federal University of Paraíba, João Pessoa, Brazil
| | - Jossana Pereira de Sousa Guedes
- Laboratory of Food Microbiology, Department of Nutrition, Health Sciences Center, Federal University of Paraíba, João Pessoa, Brazil
| | - Isabella Medeiros Barbosa
- Laboratory of Food Microbiology, Department of Nutrition, Health Sciences Center, Federal University of Paraíba, João Pessoa, Brazil
| | - Cristina Paiva de Sousa
- Laboratory of Microbiology and Biomolecules, Department of Morphology and Pathology, Center for Biological and Health Sciences, Federal University of São Carlos, São Carlos, Brazil
| | - Lúcio Roberto Cançado Castellano
- Laboratory of Culture and Cell Analysis, Technical School of Health, Health Sciences Center, Federal University of Paraíba, João Pessoa, Brazil
| | - Marciane Magnani
- Laboratory of Microbial Processes in Foods, Department of Food Engineering, Center of Technology, Federal University of Paraíba, João Pessoa, Brazil
| | - Evandro Leite de Souza
- Laboratory of Food Microbiology, Department of Nutrition, Health Sciences Center, Federal University of Paraíba, João Pessoa, Brazil.
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Yang K, Zhu Y, Qi Y, Zhang T, Liu M, Zhang J, Wei X, Fan M, Zhang G. Analysis of proteomic responses of freeze-dried Oenococcus oeni to access the molecular mechanism of acid acclimation on cell freeze-drying resistance. Food Chem 2019; 285:441-449. [PMID: 30797368 DOI: 10.1016/j.foodchem.2019.01.120] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 12/24/2018] [Accepted: 01/17/2019] [Indexed: 10/27/2022]
Abstract
Malolactic fermentation (MLF), usually induced by Oenococcus oeni (O. oeni), is an important process to improve wine quality. Acid acclimation has been proven to be useful for enhancing the viability of lyophilized O. oeni. To explain the involved mechanisms, cell integrity, morphology and protein patterns of lyophilized O. oeni SD-2a were investigated with acid acclimation. After lyophilization, improvement of cell integrity and more extracellular polymeric substances (EPS) were observed in acid acclimated cells. Combined with GO and KEGG analysis, different abundant proteins were noticeably enriched in the carbohydrate metabolism process, especially amino sugar and nucleotide sugar metabolism. The most significant result was the over-expression of proteins participating in cell wall biosynthesis, EPS production, ATP binding and the bacterial secretion system. This result indicated the important role of acid acclimation on cell envelope properties. In addition, protein response to stress and arginine deiminase pathway were also proven to be over-expressed.
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Affiliation(s)
- Kun Yang
- College of Biological and Chemical Engineering, Anhui Polytechnic University, Wuhu 241000, China; College of Food Science and Engineering, Northwest A & F University, Yangling 712100, China
| | - Yang Zhu
- School of Agriculture and Food Sciences, University of Queensland, QLD 4046, Australia
| | - Yiman Qi
- College of Food Science and Engineering, Northwest A & F University, Yangling 712100, China
| | - Tingjing Zhang
- College of Food Science and Technology, Henan University of Technology, Zhenzhou 450001, China
| | - Miaomiao Liu
- College of Food Science and Engineering, Northwest A & F University, Yangling 712100, China
| | - Jie Zhang
- College of Food Science and Engineering, Northwest A & F University, Yangling 712100, China
| | - Xinyuan Wei
- College of Food Science and Engineering, Northwest A & F University, Yangling 712100, China
| | - Mingtao Fan
- College of Food Science and Engineering, Northwest A & F University, Yangling 712100, China.
| | - Guoqiang Zhang
- College of Biological and Chemical Engineering, Anhui Polytechnic University, Wuhu 241000, China.
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Sai-Anand G, Sivanesan A, Benzigar MR, Singh G, Gopalan AI, Baskar AV, Ilbeygi H, Ramadass K, Kambala V, Vinu A. Recent Progress on the Sensing of Pathogenic Bacteria Using Advanced Nanostructures. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2019. [DOI: 10.1246/bcsj.20180280] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Gopalan Sai-Anand
- Global Innovative Center for Advanced Nanomaterials, Faculty of Built Environment and Engineering, The University of Newcastle, Callaghan 2308, New South Wales, Australia
- Future Industries Institute, Division of Information Technology, Engineering and Environment, University of South Australia, Mawson Lakes, South Australia 5095, Australia
| | - Arumugam Sivanesan
- Future Industries Institute, Division of Information Technology, Engineering and Environment, University of South Australia, Mawson Lakes, South Australia 5095, Australia
- Metrohm Australia, 56 Buffalo Road, Gladesville, NSW 2111, Australia
| | - Mercy R Benzigar
- Future Industries Institute, Division of Information Technology, Engineering and Environment, University of South Australia, Mawson Lakes, South Australia 5095, Australia
| | - Gurwinder Singh
- Global Innovative Center for Advanced Nanomaterials, Faculty of Built Environment and Engineering, The University of Newcastle, Callaghan 2308, New South Wales, Australia
- Future Industries Institute, Division of Information Technology, Engineering and Environment, University of South Australia, Mawson Lakes, South Australia 5095, Australia
| | - Anantha-Iyengar Gopalan
- Research Institute of Advanced Energy Technology, Kyungpook National University, Daegu 41566, Korea
| | - Arun Vijay Baskar
- Global Innovative Center for Advanced Nanomaterials, Faculty of Built Environment and Engineering, The University of Newcastle, Callaghan 2308, New South Wales, Australia
- Future Industries Institute, Division of Information Technology, Engineering and Environment, University of South Australia, Mawson Lakes, South Australia 5095, Australia
| | - Hamid Ilbeygi
- Future Industries Institute, Division of Information Technology, Engineering and Environment, University of South Australia, Mawson Lakes, South Australia 5095, Australia
| | - Kavitha Ramadass
- Global Innovative Center for Advanced Nanomaterials, Faculty of Built Environment and Engineering, The University of Newcastle, Callaghan 2308, New South Wales, Australia
- Future Industries Institute, Division of Information Technology, Engineering and Environment, University of South Australia, Mawson Lakes, South Australia 5095, Australia
| | - Venkata Kambala
- Hudson Marketing Pty Ltd, Level 2/131 Macquarie St, Sydney NSW 2000, Australia
| | - Ajayan Vinu
- Global Innovative Center for Advanced Nanomaterials, Faculty of Built Environment and Engineering, The University of Newcastle, Callaghan 2308, New South Wales, Australia
- Future Industries Institute, Division of Information Technology, Engineering and Environment, University of South Australia, Mawson Lakes, South Australia 5095, Australia
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Target-induced aptamer displacement on gold nanoparticles and rolling circle amplification for ultrasensitive live Salmonella typhimurium electrochemical biosensing. J Electroanal Chem (Lausanne) 2018. [DOI: 10.1016/j.jelechem.2018.07.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Gao H, Zhang X, Chen C, Li K, Ding D. Unity Makes Strength: How Aggregation-Induced Emission Luminogens Advance the Biomedical Field. ACTA ACUST UNITED AC 2018. [DOI: 10.1002/adbi.201800074] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Heqi Gao
- State Key Laboratory of Medicinal Chemical Biology; Key Laboratory of Bioactive Materials; Ministry of Education; College of Life Sciences; Nankai University; Tianjin 300071 China
| | - Xiaoyan Zhang
- State Key Laboratory of Medicinal Chemical Biology; Key Laboratory of Bioactive Materials; Ministry of Education; College of Life Sciences; Nankai University; Tianjin 300071 China
| | - Chao Chen
- State Key Laboratory of Medicinal Chemical Biology; Key Laboratory of Bioactive Materials; Ministry of Education; College of Life Sciences; Nankai University; Tianjin 300071 China
| | - Kai Li
- Institute of Materials Research & Engineering; A*STAR; Singapore 138634 Singapore
- Department of Biomedical Engineering; Southern University of Science and Technology; Shenzhen Guangdong 510855 China
| | - Dan Ding
- State Key Laboratory of Medicinal Chemical Biology; Key Laboratory of Bioactive Materials; Ministry of Education; College of Life Sciences; Nankai University; Tianjin 300071 China
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Schumacher A, Vranken T, Malhotra A, Arts JJC, Habibovic P. In vitro antimicrobial susceptibility testing methods: agar dilution to 3D tissue-engineered models. Eur J Clin Microbiol Infect Dis 2018; 37:187-208. [PMID: 28871407 PMCID: PMC5780537 DOI: 10.1007/s10096-017-3089-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 07/20/2017] [Indexed: 12/22/2022]
Abstract
In the field of orthopaedic surgery, bacterial invasion of implants and the resulting periprosthetic infections are a common and unresolved problem. Antimicrobial susceptibility testing methods help to define the optimal treatment and identify antimicrobial resistance. This review discusses proven gold-standard techniques and recently developed models for antimicrobial susceptibility testing, while also providing a future outlook. Conventional, gold-standard methods, such as broth microdilution, are still widely applied in clinical settings. Although recently developed methods based on microfluidics and microdroplets have shown advantages over conventional methods in terms of testing speed, safety and the potential to provide a deeper insight into resistance mechanisms, extensive validation is required to translate this research to clinical practice. Recent optical and mechanical methods are complex and expensive and, therefore, not immediately clinically applicable. Novel osteoblast infection and tissue models best resemble infections in vivo. However, the integration of biomaterials into these models remains challenging and they require a long tissue culture, making their rapid clinical implementation unlikely. A method applicable for both clinical and research environments is difficult to realise. With a continuous increase in antimicrobial resistance, there is an urgent need for methods that analyse recurrent infections to identify the optimal treatment approaches. Graphical abstract Timeline of published and partly applied antimicrobial susceptibility testing methods, listed according to their underlying mechanism, complexity and application in research or clinics.
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Affiliation(s)
- A Schumacher
- Department of Instructive Biomaterials Engineering, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Universiteitssingel 40, Room C3.577, 6229 ER, Maastricht, Netherlands.
- Science and Technology Faculty, University of Twente, Drienerlolaan 5, 7522 NB, Enschede, The Netherlands.
| | - T Vranken
- Department of Orthopaedic Surgery, CAPHRI Care and Public Health Research Institute, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - A Malhotra
- Department of Instructive Biomaterials Engineering, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Universiteitssingel 40, Room C3.577, 6229 ER, Maastricht, Netherlands
| | - J J C Arts
- Department of Orthopaedic Surgery, CAPHRI Care and Public Health Research Institute, Maastricht University Medical Centre, Maastricht, The Netherlands
- Orthopaedic Biomechanics Group, Department of Biomedical Engineering, Eindhoven University of Technology (TU/e), Eindhoven, The Netherlands
| | - P Habibovic
- Department of Instructive Biomaterials Engineering, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Universiteitssingel 40, Room C3.577, 6229 ER, Maastricht, Netherlands
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Bankier C, Cheong Y, Mahalingam S, Edirisinghe M, Ren G, Cloutman-Green E, Ciric L. A comparison of methods to assess the antimicrobial activity of nanoparticle combinations on bacterial cells. PLoS One 2018; 13:e0192093. [PMID: 29390022 PMCID: PMC5794139 DOI: 10.1371/journal.pone.0192093] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 01/16/2018] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Bacterial cell quantification after exposure to antimicrobial compounds varies widely throughout industry and healthcare. Numerous methods are employed to quantify these antimicrobial effects. With increasing demand for new preventative methods for disease control, we aimed to compare and assess common analytical methods used to determine antimicrobial effects of novel nanoparticle combinations on two different pathogens. METHODS Plate counts of total viable cells, flow cytometry (LIVE/DEAD BacLight viability assay) and qPCR (viability qPCR) were used to assess the antimicrobial activity of engineered nanoparticle combinations (NPCs) on Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa) bacteria at different concentrations (0.05, 0.10 and 0.25 w/v%). Results were analysed using linear models to assess the effectiveness of different treatments. RESULTS Strong antimicrobial effects of the three NPCs (AMNP0-2) on both pathogens could be quantified using the plate count method and flow cytometry. The plate count method showed a high log reduction (>8-log) for bacteria exposed to high NPC concentrations. We found similar antimicrobial results using the flow cytometry live/dead assay. Viability qPCR analysis of antimicrobial activity could not be quantified due to interference of NPCs with qPCR amplification. CONCLUSION Flow cytometry was determined to be the best method to measure antimicrobial activity of the novel NPCs due to high-throughput, rapid and quantifiable results.
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Affiliation(s)
- Claire Bankier
- Department of Civil, Environmental and Geomatic Engineering, University College London, London, United Kingdom
| | - Yuen Cheong
- School of Engineering and Technology, University of Hertfordshire, Hatfield, United Kingdom
| | | | - Mohan Edirisinghe
- Department of Mechanical Engineering, University College London, London, United Kingdom
| | - Guogang Ren
- School of Engineering and Technology, University of Hertfordshire, Hatfield, United Kingdom
| | - Elaine Cloutman-Green
- Department of Civil, Environmental and Geomatic Engineering, University College London, London, United Kingdom
- Department of Microbiology, Virology, and Infection Prevention Control, Great Ormond Street Hospital NHS Foundation Trust, London, United Kingdom
| | - Lena Ciric
- Department of Civil, Environmental and Geomatic Engineering, University College London, London, United Kingdom
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Jung IY, Kim JS, Choi BR, Lee K, Lee H. Hydrogel Based Biosensors for In Vitro Diagnostics of Biochemicals, Proteins, and Genes. Adv Healthc Mater 2017; 6. [PMID: 28371450 DOI: 10.1002/adhm.201601475] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 02/16/2017] [Indexed: 12/22/2022]
Abstract
Hydrogel-based biosensors have drawn considerable attention due to their various advantages over conventional detection systems. Recent studies have shown that hydrogel biosensors can be excellent alternative systems to detect a wide range of biomolecules, including small biochemicals, pathogenic proteins, and disease specific genes. Due to the excellent physical properties of hydrogels such as the high water content and stimuli-responsive behavior of cross-linked network structures, this system can offer substantial improvement for the design of novel detection systems for various diagnostic applications. The other main advantage of hydrogels is the role of biomimetic three-dimensional (3D) matrix immobilizing enzymes and aptamers within the detection systems, which enhances their stability. This provides ideal reaction conditions for enzymes and aptamers to interact with substrates within the aqueous environment of the hydrogel. In this review, we have highlighted various novel detection approaches utilizing the outstanding properties of the hydrogel. This review summarizes the recent progress of hydrogel-based biosensors and discusses their future perspectives and clinical limitations to overcome.
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Affiliation(s)
- Il Young Jung
- College of PharmacyGraduate School of Pharmaceutical SciencesEwha Womans University Seoul 03760 Republic of Korea
| | - Ji Su Kim
- College of PharmacyGraduate School of Pharmaceutical SciencesEwha Womans University Seoul 03760 Republic of Korea
| | - Bo Ram Choi
- College of PharmacyGraduate School of Pharmaceutical SciencesEwha Womans University Seoul 03760 Republic of Korea
| | - Kyuri Lee
- College of PharmacyGraduate School of Pharmaceutical SciencesEwha Womans University Seoul 03760 Republic of Korea
| | - Hyukjin Lee
- College of PharmacyGraduate School of Pharmaceutical SciencesEwha Womans University Seoul 03760 Republic of Korea
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Janko C, Pöttler M, Matuszak J, Unterweger H, Hornung A, Friedrich RP, Alexiou C. Innovative toxikologische Untersuchungsmethoden für Eisenoxidnanopartikel in der Nanomedizin. CHEM-ING-TECH 2017. [DOI: 10.1002/cite.201600077] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Juzwa W, Duber A, Myszka K, Białas W, Czaczyk K. Identification of microbes from the surfaces of food-processing lines based on the flow cytometric evaluation of cellular metabolic activity combined with cell sorting. BIOFOULING 2016; 32:841-851. [PMID: 27406324 DOI: 10.1080/08927014.2016.1201657] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 06/09/2016] [Indexed: 06/06/2023]
Abstract
In this study the design of a flow cytometry-based procedure to facilitate the detection of adherent bacteria from food-processing surfaces was evaluated. The measurement of the cellular redox potential (CRP) of microbial cells was combined with cell sorting for the identification of microorganisms. The procedure enhanced live/dead cell discrimination owing to the measurement of the cell physiology. The microbial contamination of the surface of a stainless steel conveyor used to process button mushrooms was evaluated in three independent experiments. The flow cytometry procedure provided a step towards monitoring of contamination and enabled the assessment of microbial food safety hazards by the discrimination of active, mid-active and non-active bacterial sub-populations based on determination of their cellular vitality and subsequently single cell sorting to isolate microbial strains from discriminated sub-populations. There was a significant correlation (r = 0.97; p < 0.05) between the bacterial cell count estimated by the pour plate method and flow cytometry, despite there being differences in the absolute number of cells detected. The combined approach of flow cytometric CRP measurement and cell sorting allowed an in situ analysis of microbial cell vitality and the identification of species from defined sub-populations, although the identified microbes were limited to culturable cells.
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Affiliation(s)
- W Juzwa
- a Department of Biotechnology and Food Microbiology , Poznan University of Life Sciences , Poznań , Poland
| | - A Duber
- b Institute of Environmental Engineering, Poznan University of Technology , Poznań , Poland
| | - K Myszka
- a Department of Biotechnology and Food Microbiology , Poznan University of Life Sciences , Poznań , Poland
| | - W Białas
- a Department of Biotechnology and Food Microbiology , Poznan University of Life Sciences , Poznań , Poland
| | - K Czaczyk
- a Department of Biotechnology and Food Microbiology , Poznan University of Life Sciences , Poznań , Poland
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Agnihothram SS, Vermudez SA, Mullis L, Townsend TA, Manjanatha MG, Azevedo MP. Silicon Dioxide Impedes Antiviral Response and Causes Genotoxic Insult During Calicivirus Replication. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2016; 16:7720-7730. [PMID: 27547159 PMCID: PMC4986603 DOI: 10.1166/jnn.2016.12828] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Noroviruses (NoV) are the leading cause of nonbacterial gastroenteritis in humans, and replicate extensively in the human gastrointestinal (GI) tract. Silica (also known as silicon dioxide, SiO2) nanoparticles (NPs) used in processed foods, dairy products, and beverages also accumulate in the GI tract. We investigated the effect of silica NPs on NoV replication and host cell response during virus infection, using murine norovirus (MNV-1) infection of RAW 264.7 murine macrophages. Pretreatment with 10 μg/ml silica significantly reduced the viability of macrophages, but no cumulative effects on viability of macrophages were observed with MNV-1 infection. No difference was observed between exposure to control or silica NPs on either the quantity of viral genome copies or the production of infectious virus in macrophages infected with MNV-1. Silica NPs reduced the ability of macrophages to upregulate genes encoding bone morphogenic proteins (BMPs), chemokine ligands and cytokines for which expression levels were otherwise found to be upregulated in response to MNV-1 infection. Furthermore, silica NPs reduced the levels of proinflammatory cytokines secreted by macrophages in response to MNV infection. Finally, silica NPs with MNV-1 infection produced a genotoxic insult to macrophages. Strikingly, this genotoxic insult was also found to occur as a synergistic effect of silica NPs and feline calicivirus infection in feline kidney epithelial cells. Taken together, our study suggests important safety considerations related to reducing exposure to silica NPs affecting the GI tract in individuals infected with NoVs and possibly other foodborne viruses.
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Affiliation(s)
- Sudhakar S Agnihothram
- United States Food and Drug Administration, National Center for Toxicological Research (NCTR), Division of Microbiology, Honolulu, Hawaii, 96816, USA
| | - Sheryl Anne Vermudez
- United States Food and Drug Administration, National Center for Toxicological Research (NCTR), Division of Microbiology, Honolulu, Hawaii, 96816, USA; Chaminade University of Honolulu, Honolulu, Hawaii, 96816, USA
| | - Lisa Mullis
- United States Food and Drug Administration, National Center for Toxicological Research (NCTR), Division of Microbiology, Honolulu, Hawaii, 96816, USA
| | - Todd A Townsend
- United States Food and Drug Administration, National Center for Toxicological Research (NCTR), Division of Genetic and Molecular Toxicology, Honolulu, Hawaii, 96816, USA
| | - Mugimane G Manjanatha
- United States Food and Drug Administration, National Center for Toxicological Research (NCTR), Division of Genetic and Molecular Toxicology, Honolulu, Hawaii, 96816, USA
| | - Marli P Azevedo
- United States Food and Drug Administration, National Center for Toxicological Research (NCTR), Division of Microbiology, Honolulu, Hawaii, 96816, USA
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