1
|
Wang Q, Yang Q. Seizing the Hidden Assassin: Current Detection Strategies for Staphylococcus aureus and Methicillin-Resistant S. aureus. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024. [PMID: 39031091 DOI: 10.1021/acs.jafc.4c02421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/22/2024]
Abstract
Staphylococcus aureus (S. aureus) is a kind of pathogenic bacteria which can lead to food poisoning, hospital, and community infections. S. aureus and methicillin-resistant S. aureus (MRSA) have become headaches for public health worldwide. Therefore, strengthening the detection of S. aureus and MRSA is a critical step to prevent and control its spread and infection. This review summarized multiple detection methods (electrochemical, optical, and other biosensors) for sensitive and efficient detection of nonresistant and resistant S. aureus. First, we have introduced the principle and methods of detection platform for S. aureus and MRSA. We also contrasted various detection strategies. Finally, the current situation and prospect of S. aureus and MRSA detection in the future are explored in depth, and its development direction of detection methods is also predicted. In this review, we found that although biosensors have shown tremendous brilliance in the field of monitoring, they are currently in the experimental stage. It can be certain that we are very close to entering the commercialization stage. The point-of care testing available to nonprofessionals will become a new direction. We firmly believe that the monitoring system will be more perfect and stable and public life will be healthier and safer.
Collapse
Affiliation(s)
- Qi Wang
- College of Food Science and Engineering, Qingdao Agricultural University, no. 700 Changcheng Road, Qingdao 266109, China
| | - Qingli Yang
- College of Food Science and Engineering, Qingdao Agricultural University, no. 700 Changcheng Road, Qingdao 266109, China
| |
Collapse
|
2
|
Chialastri A, Hoffman H, Fink D, Dashnau JL. Clearance of residual genome editing components used for ex vivo genome-editing of allogeneic cell therapy products. Cytotherapy 2024:S1465-3249(24)00756-4. [PMID: 39023463 DOI: 10.1016/j.jcyt.2024.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2024] [Revised: 06/05/2024] [Accepted: 06/06/2024] [Indexed: 07/20/2024]
Abstract
BACKGROUND AIMS Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-associated genome editing (GE) components (e.g., nucleases, guide RNAs (gRNAs), and plasmids) are used to genetically modify cells during development of ex vivo genome-edited cell therapies. Prolonged presence of GE components may increase the risk of unintended genome modifications (e.g., off-target editing and chromosomal rearrangements). This risk is a function of the stability of the GE components, culture conditions (i.e., culture length, media changes, etc.), and the nature of the GE component (i.e., only plasmids can be integrated into a cell's genome). Testing for residual GE components on ex vivo genetically edited drug products is generally recommended in current regulatory guidance (CBER 2024). For allogenic cell therapies derived from induced pluripotent stem cells (iPSC), cells typically undergo clonal selection and extensive culturing following completion of genome editing. This post-engineering clonal selection substantially reduces the amount of residual GE components while the long-duration cell culture significantly reduces the presence of active residual GE components. Here we present a case in which the need for testing of the drug product for residual GE components has been eliminated. METHODS In silico modeling was used to estimate clearance mechanisms across a variety of relevant assumptions, including disposition of extracellular GE components via media changes and dilution of intracellular GE components via cell expansion. Determining the ability of each GE component-alone or in complex with other GE components-to modify genomic material was assessed by a series of both in vitro and ex vivo (i.e., engineering cells) studies. For the in vitro studies, a DNA cutting assay was developed to assess the ability of the component to cut a representative DNA strand. For the ex vivo modification of cells, an assessment of the knock-out of the relevant gene was completed by flow cytometry specifically assessing the presence or absence of protein expression on the modified cells. The persistence and stability of GE components were examined under cell-mimicking conditions and in ex vivo modified cells. The components were stressed under multiple conditions mimicking a range of culture conditions and tested in the aforementioned DNA cutting assay. The presence of residual gRNA was directly assessed in the ex vivo modified cells via a gRNA-specific digital droplet polymerase chain reaction (ddPCR) assay. RESULTS Simulations estimating genome editing residual clearance via dilution for extracellular residuals (via media changes) or intracellular residuals (via cell doubling) demonstrate clearance of measurable residuals within 28 days of cell culture. Studies simulating the stability of genome editing residuals estimate less than 7 days for the nuclease, gRNA and ribonucleoprotein (RNP) complex. gRNA was undetectable by 8 days post-engineering under actual engineering conditions. Additionally, without gRNA present, CRISPR Cas12a nucleases did not demonstrate evidence of cutting. In contrast, plasmid DNA can be randomly integrated into the genome and free plasmid is highly stable under cell culture-like conditions (50+ days). Additionally, plasmid DNA integrated in cells will propagate during mitosis, leading to the additional risk of expansion of an unintentional integration event. CONCLUSIONS Both the gRNA and nuclease in the RNP complex are required for DNA cutting. Neither individual component nor the complex are stable beyond 7 days in culture-mimicking conditions. These findings suggest that the risk of unplanned genomic modification resulting from residual gRNA or nuclease is minimal for processes in which extensive culture is performed after the completion of genome editing and clonal selection. However, the risk of residual plasmid DNA integration is significantly higher regardless of the manufacturing process. The residual plasmid itself is quite stable (at least 50 days) and the risk of random, off-target integration is present. By establishing the stability of these components, we have demonstrated that testing for residual gRNA or nuclease is not warranted for clonally derived allogeneic cell therapies.
Collapse
Affiliation(s)
- Alex Chialastri
- Century Therapeutics, Technical Development and Manufacturing
| | | | - Damien Fink
- Century Therapeutics, Technical Development and Manufacturing.
| | | |
Collapse
|
3
|
Hu M, Cheng X, Wu T. Modular CRISPR/Cas12a synergistic activation platform for detection and logic operations. Nucleic Acids Res 2024; 52:7384-7396. [PMID: 38828769 PMCID: PMC11229313 DOI: 10.1093/nar/gkae470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 05/14/2024] [Accepted: 05/30/2024] [Indexed: 06/05/2024] Open
Abstract
The revolutionary technology of CRISPR/Cas has reshaped the landscape of molecular biology and molecular engineering. This tool is of interest to researchers in multiple fields, including molecular diagnostics, molecular biochemistry circuits, and information storage. As CRISPR/Cas spreads to more niche areas, new application scenarios and requirements emerge. Developing programmability and compatibility of CRISPR/Cas becomes a critical issue in the new phase. Here, we report a redundancy-based modular CRISPR/Cas12a synergistic activation platform (MCSAP). The position, length, and concentration of the redundancy in the split DNA activators can finely regulate the activity of Cas12a. With the redundant structure as an interface, MCSAP serves as a modular plug-in to seamlessly integrate with the upstream molecular network. MCSAP successfully performs three different tasks: nucleic acid detection, enzyme detection, and logic operation. MCSAP can work as an effector for different molecular networks because of its compatibility and programmability. Our platform provides powerful yet easy-to-use tools and strategies for the fields of DNA nanotechnology, molecular engineering, and molecular biology.
Collapse
Affiliation(s)
- Minghao Hu
- School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
- Department of Oncology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Xianzhi Cheng
- School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Tongbo Wu
- School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| |
Collapse
|
4
|
Deng F, Li Y, Yang B, Sang R, Deng W, Kansara M, Lin F, Thavaneswaran S, Thomas DM, Goldys EM. Topological barrier to Cas12a activation by circular DNA nanostructures facilitates autocatalysis and transforms DNA/RNA sensing. Nat Commun 2024; 15:1818. [PMID: 38443394 PMCID: PMC10914725 DOI: 10.1038/s41467-024-46001-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 02/09/2024] [Indexed: 03/07/2024] Open
Abstract
Control of CRISPR/Cas12a trans-cleavage is crucial for biosensor development. Here, we show that small circular DNA nanostructures which partially match guide RNA sequences only minimally activate Cas12a ribonucleoproteins. However, linearizing these structures restores activation. Building on this finding, an Autocatalytic Cas12a Circular DNA Amplification Reaction (AutoCAR) system is established which allows a single nucleic acid target to activate multiple ribonucleoproteins, and greatly increases the achievable reporter cleavage rates per target. A rate-equation-based model explains the observed near-exponential rate trends. Autocatalysis is also sustained with DNA nanostructures modified with fluorophore-quencher pairs achieving 1 aM level (<1 copy/μL) DNA detection (106 times improvement), without additional amplification, within 15 min, at room temperature. The detection range is tuneable, spanning 3 to 11 orders of magnitude. We demonstrate 1 aM level detection of SNP mutations in circulating tumor DNA from blood plasma, genomic DNA (H. Pylori) and RNA (SARS-CoV-2) without reverse transcription as well as colorimetric lateral flow tests of cancer mutations with ~100 aM sensitivity.
Collapse
Affiliation(s)
- Fei Deng
- Graduate School of Biomedical Engineering, Faculty of Engineering, University of New South Wales, Sydney, NSW, 2052, Australia
- ARC Centre of Excellence for Nanoscale Biophotonics, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Yi Li
- Graduate School of Biomedical Engineering, Faculty of Engineering, University of New South Wales, Sydney, NSW, 2052, Australia.
- ARC Centre of Excellence for Nanoscale Biophotonics, University of New South Wales, Sydney, NSW, 2052, Australia.
| | - Biyao Yang
- Graduate School of Biomedical Engineering, Faculty of Engineering, University of New South Wales, Sydney, NSW, 2052, Australia
- ARC Centre of Excellence for Nanoscale Biophotonics, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Rui Sang
- Graduate School of Biomedical Engineering, Faculty of Engineering, University of New South Wales, Sydney, NSW, 2052, Australia
- ARC Centre of Excellence for Nanoscale Biophotonics, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Wei Deng
- School of Biomedical Engineering, University of Technology Sydney, Sydney, NSW, 2007, Australia
| | - Maya Kansara
- Garvan Institute of Medical Research, Darlinghurst, Sydney, NSW, 2011, Australia
- St Vincent's Clinical School, University of New South Wales, Sydney, NSW, 2011, Australia
- Omico, Australian Genomic Cancer Medicine Centre, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Frank Lin
- Garvan Institute of Medical Research, Darlinghurst, Sydney, NSW, 2011, Australia
- NHMRC Clinical Trials Centre, University of Sydney, Sydney, NSW, Australia
| | - Subotheni Thavaneswaran
- Garvan Institute of Medical Research, Darlinghurst, Sydney, NSW, 2011, Australia
- St Vincent's Clinical School, University of New South Wales, Sydney, NSW, 2011, Australia
- NHMRC Clinical Trials Centre, University of Sydney, Sydney, NSW, Australia
| | - David M Thomas
- Garvan Institute of Medical Research, Darlinghurst, Sydney, NSW, 2011, Australia
- St Vincent's Clinical School, University of New South Wales, Sydney, NSW, 2011, Australia
- Omico, Australian Genomic Cancer Medicine Centre, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Ewa M Goldys
- Graduate School of Biomedical Engineering, Faculty of Engineering, University of New South Wales, Sydney, NSW, 2052, Australia
- ARC Centre of Excellence for Nanoscale Biophotonics, University of New South Wales, Sydney, NSW, 2052, Australia
| |
Collapse
|
5
|
Fu X, Sun J, Yu B, Ye Y, Sheng L, Ji J, Zheng J, Fan M, Shao J, Sun X. Investigating enzyme kinetics and fluorescence sensing strategy of CRISPR/Cas12a for foodborne pathogenic bacteria. Anal Chim Acta 2024; 1290:342203. [PMID: 38246741 DOI: 10.1016/j.aca.2024.342203] [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: 10/29/2023] [Revised: 12/10/2023] [Accepted: 01/01/2024] [Indexed: 01/23/2024]
Abstract
Foodborne pathogenic bacteria are widespread in various foods, whose cross-contamination and re-contamination are critical influences on food safety. Rapid, accurate, and sensitive detection of foodborne pathogenic bacteria remains a topic of concern. CRISPR/Cas12a can recognize double-stranded DNA directly, showing great potential in nucleic acid detection. However, few studies have investigated the cleavage properties of CRISPR/Cas12a. In this study, the trans-cleavage properties of LbCas12a and AsCas12a were investigated to construct the detection methods for foodborne pathogenic bacteria. The highly sensitive fluorescent strategies for foodborne pathogens were constructed by analyzing the cleavage rates and properties of substrates at different substrate concentrations. Cas12a was activated in the presence of foodborne pathogenic target sequence was present, resulting in the cleavage of a single-stranded reporter ssDNA co-labelled by fluorescein quencher and fluorescein. The sensitivity and specificity of the Cas12a fluorescent strategy was investigated with Salmonella and Staphylococcus aureus as examples. The results showed that AsCas12a was slightly more capable of trans-cleavage than LbCas12a. The detection limits of AsCas12a for Salmonella and Staphylococcus aureus were 24.9 CFU mL-1 and 1.50 CFU mL-1, respectively. In all the seven bacteria, Staphylococcus aureus and Salmonella were accurately discriminated. The study provided a basis for constructing and improving the CRISPR/Cas12a fluorescence strategies. The AsCas12a-based detection strategy is expected to be a promising method for field detection.
Collapse
Affiliation(s)
- XuRan Fu
- School of Food Science and Technology, International Joint Laboratory on Food Safety, Synergetic Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu, 214122, PR China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing, 214200, PR China
| | - JiaDi Sun
- School of Food Science and Technology, International Joint Laboratory on Food Safety, Synergetic Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu, 214122, PR China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing, 214200, PR China.
| | - Bingqian Yu
- School of Food Science and Technology, International Joint Laboratory on Food Safety, Synergetic Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu, 214122, PR China
| | - Yongli Ye
- School of Food Science and Technology, International Joint Laboratory on Food Safety, Synergetic Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu, 214122, PR China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing, 214200, PR China
| | - Lina Sheng
- School of Food Science and Technology, International Joint Laboratory on Food Safety, Synergetic Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu, 214122, PR China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing, 214200, PR China
| | - Jian Ji
- School of Food Science and Technology, International Joint Laboratory on Food Safety, Synergetic Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu, 214122, PR China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing, 214200, PR China
| | - Jiayu Zheng
- Product Quality Comprehensive Inspection and Testing Center, Baoying, Jiangsu, 225800, PR China
| | - Minghong Fan
- Product Quality Comprehensive Inspection and Testing Center, Baoying, Jiangsu, 225800, PR China
| | - Jingdong Shao
- Comprehensive Technology Center of Zhangjiagang Customs, Zhangjiagang, Jiangsu, 215600, PR China
| | - XiuLan Sun
- School of Food Science and Technology, International Joint Laboratory on Food Safety, Synergetic Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu, 214122, PR China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing, 214200, PR China.
| |
Collapse
|
6
|
Luo Y, Chen Y, Xie H, Zhu W, Zhang G. Interpretable CRISPR/Cas9 off-target activities with mismatches and indels prediction using BERT. Comput Biol Med 2024; 169:107932. [PMID: 38199209 DOI: 10.1016/j.compbiomed.2024.107932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 12/25/2023] [Accepted: 01/01/2024] [Indexed: 01/12/2024]
Abstract
Off-target effects of CRISPR/Cas9 can lead to suboptimal genome editing outcomes. Numerous deep learning-based approaches have achieved excellent performance for off-target prediction; however, few can predict the off-target activities with both mismatches and indels between single guide RNA (sgRNA) and target DNA sequence pair. In addition, data imbalance is a common pitfall for off-target prediction. Moreover, due to the complexity of genomic contexts, generating an interpretable model also remains challenged. To address these issues, firstly we developed a BERT-based model called CRISPR-BERT for enhancing the prediction of off-target activities with both mismatches and indels. Secondly, we proposed an adaptive batch-wise class balancing strategy to combat the noise exists in imbalanced off-target data. Finally, we applied a visualization approach for investigating the generalizable nucleotide position-dependent patterns of sgRNA-DNA pair for off-target activity. In our comprehensive comparison to existing methods on five mismatches-only datasets and two mismatches-and-indels datasets, CRISPR-BERT achieved the best performance in terms of AUROC and PRAUC. Besides, the visualization analysis demonstrated how implicit knowledge learned by CRISPR-BERT facilitates off-target prediction, which shows potential in model interpretability. Collectively, CRISPR-BERT provides an accurate and interpretable framework for off-target prediction, further contributes to sgRNA optimization in practical use for improved target specificity in CRISPR/Cas9 genome editing. The source code is available at https://github.com/BrokenStringx/CRISPR-BERT.
Collapse
Affiliation(s)
- Ye Luo
- College of Engineering, Shantou University, Shantou, 515063, China
| | - Yaowen Chen
- College of Engineering, Shantou University, Shantou, 515063, China
| | - HuanZeng Xie
- College of Engineering, Shantou University, Shantou, 515063, China
| | - Wentao Zhu
- College of Engineering, Shantou University, Shantou, 515063, China
| | - Guishan Zhang
- College of Engineering, Shantou University, Shantou, 515063, China.
| |
Collapse
|
7
|
Li T, Cheng N. Sensitive and Portable Signal Readout Strategies Boost Point-of-Care CRISPR/Cas12a Biosensors. ACS Sens 2023; 8:3988-4007. [PMID: 37870387 DOI: 10.1021/acssensors.3c01338] [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] [Indexed: 10/24/2023]
Abstract
Point-of-care (POC) detection is getting more and more attention in many fields due to its accuracy and on-site test property. The CRISPR/Cas12a system is endowed with excellent sensitivity, target identification specificity, and signal amplification ability in biosensing because of its unique trans-cleavage ability. As a result, a lot of research has been made to develop CRISPR/Cas12a-based biosensors. In this review, we focused on signal readout strategies and summarized recent sensitivity-improving strategies in fluorescence, colorimetric, and electrochemical signaling. Then we introduced novel portability-improving strategies based on lateral flow assays (LFAs), microfluidic chips, simplified instruments, and one-pot design. In the end, we also provide our outlook for the future development of CRISPR/Cas12a biosensors.
Collapse
Affiliation(s)
- Tong Li
- Beijing Laboratory for Food Quality and Safety, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Nan Cheng
- Beijing Laboratory for Food Quality and Safety, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| |
Collapse
|
8
|
Tian T, Zhou X. CRISPR-Based Biosensing Strategies: Technical Development and Application Prospects. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2023; 16:311-332. [PMID: 37018798 DOI: 10.1146/annurev-anchem-090822-014725] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Biosensing based on CRISPR-Cas systems is a young but rapidly evolving technology. The unprecedented properties of the CRISPR-Cas system provide an innovative tool for developing new-generation biosensing strategies. To date, a series of nucleic acid and non-nucleic acid detection methods have been developed based on the CRISPR platform. In this review, we first introduce the core biochemical properties underpinning the development of CRISPR bioassays, such as diverse reaction temperatures, programmability in design, high reaction efficiency, and recognition specificity, and highlight recent efforts to improve these parameters. We then introduce the technical developments, including how to improve sensitivity and quantification capabilities, develop multiplex assays, achieve convenient one-pot assays, create advanced sensors, and extend the applications of detection. Finally, we analyze obstacles to the commercial application of CRISPR detection technology and explore development opportunities and directions.
Collapse
Affiliation(s)
- Tian Tian
- School of Life Sciences, South China Normal University, Guangzhou, China;
| | - Xiaoming Zhou
- School of Life Sciences, South China Normal University, Guangzhou, China;
| |
Collapse
|
9
|
Joseph RC, Sandoval NR. Single and multiplexed gene repression in solventogenic Clostridium via Cas12a-based CRISPR interference. Synth Syst Biotechnol 2022; 8:148-156. [PMID: 36687471 PMCID: PMC9842803 DOI: 10.1016/j.synbio.2022.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 11/28/2022] [Accepted: 12/20/2022] [Indexed: 12/25/2022] Open
Abstract
The Gram-positive, spore-forming, obligate anaerobic firmicute species that make up the Clostridium genus have broad feedstock consumption capabilities and produce value-added metabolic products, but genetic manipulation is difficult, limiting their broad appeal. CRISPR-Cas systems have recently been applied to Clostridium species, primarily using Cas9 as a counterselection marker in conjunction with plasmid-based homologous recombination. CRISPR interference is a method that reduces gene expression of specific genes via precision targeting of a nuclease deficient Cas effector protein. Here, we develop a dCas12a-based CRISPR interference system for transcriptional gene repression in multiple mesophilic Clostridium species. We show the Francisella novicida Cas12a-based system has a broader applicability due to the low GC content in Clostridium species compared to CRISPR Cas systems derived from other bacteria. We demonstrate >99% reduction in transcript levels of targeted genes in Clostridium acetobutylicum and >75% reduction in Clostridium pasteurianum. We also demonstrate multiplexed repression via use of a single synthetic CRISPR array, achieving 99% reduction in targeted gene expression and elucidating a unique metabolic profile for their reduced expression. Overall, this work builds a foundation for high throughput genetic screens without genetic editing, a key limitation in current screening methods used in the Clostridium community.
Collapse
Affiliation(s)
| | - Nicholas R. Sandoval
- Corresponding author. Department of Chemical and Biomolecular Engineering, Tulane University, St. Charles Ave, New Orleans, LA, 70118, United States.
| |
Collapse
|
10
|
Sheng A, Yang J, Tang L, Niu L, Cheng L, Zeng Y, Chen X, Zhang J, Li G. Hydrazone chemistry-mediated CRISPR/Cas12a system for bacterial analysis. Nucleic Acids Res 2022; 50:10562-10570. [PMID: 36156138 PMCID: PMC9561268 DOI: 10.1093/nar/gkac809] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 08/21/2022] [Accepted: 09/09/2022] [Indexed: 11/29/2022] Open
Abstract
In this study, a hydrazone chemistry-mediated clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR-associated protein 12a (Cas12a) system has been proposed for the fist time and constructed. In our system, hydrazone chemistry is designed and employed to accelerate the formation of a whole activation strand by taking advantage of the proximity effect induced by complementary base pairing, thus activating the CRISPR/Cas12a system quickly and efficiently. Moreover, the introduction of hydrazone chemistry can improve the specificity of the CRISPR/Cas12a system, allowing it to effectively distinguish single-base mismatches. The established system has been further applied to analyze Pseudomonas aeruginosa by specific recognition of the probe strand with a characteristic fragment in 16S rDNA to release the hydrazine group-modified activation strand. The method shows a wide linear range from 3.8 × 102 colony-forming units (CFU)/ml to 3.8 × 106 CFU/ml, with the lowest detection limit of 24 CFU/ml. Therefore, the introduction of hydrazone chemistry may also broaden the application of the CRISPR/Cas12a system.
Collapse
Affiliation(s)
- Anzhi Sheng
- Center for Molecular Recognition and Biosensing, School of Life Sciences, Shanghai University, Shanghai 200444, PR China.,Department of Central Laboratory, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, PR China
| | - Jingyi Yang
- Center for Molecular Recognition and Biosensing, School of Life Sciences, Shanghai University, Shanghai 200444, PR China
| | - Longfei Tang
- Center for Molecular Recognition and Biosensing, School of Life Sciences, Shanghai University, Shanghai 200444, PR China
| | - Lili Niu
- Center for Molecular Recognition and Biosensing, School of Life Sciences, Shanghai University, Shanghai 200444, PR China
| | - Liangfen Cheng
- Center for Molecular Recognition and Biosensing, School of Life Sciences, Shanghai University, Shanghai 200444, PR China
| | - Yujing Zeng
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, PR China
| | - Xu Chen
- Center for Molecular Recognition and Biosensing, School of Life Sciences, Shanghai University, Shanghai 200444, PR China
| | - Juan Zhang
- Center for Molecular Recognition and Biosensing, School of Life Sciences, Shanghai University, Shanghai 200444, PR China
| | - Genxi Li
- Center for Molecular Recognition and Biosensing, School of Life Sciences, Shanghai University, Shanghai 200444, PR China.,State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, PR China
| |
Collapse
|