1
|
Dousa KM, Shin E, Kurz SG, Plummer M, Nantongo M, Bethel CR, Taracila MA, Nguyen DC, Kreiswith BN, Daley CL, Remy KE, Holland SM, Bonomo RA. Synergistic effects of sulopenem in combination with cefuroxime or durlobactam against Mycobacterium abscessus. mBio 2024; 15:e0060924. [PMID: 38742824 DOI: 10.1128/mbio.00609-24] [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: 02/28/2024] [Accepted: 03/11/2024] [Indexed: 05/16/2024] Open
Abstract
Mycobacterium abscessus (Mab) affects patients with immunosuppression or underlying structural lung diseases such as cystic fibrosis (CF). Additionally, Mab poses clinical challenges due to its resistance to multiple antibiotics. Herein, we investigated the synergistic effect of dual β-lactams [sulopenem and cefuroxime (CXM)] or the combination of sulopenem and CXM with β-lactamase inhibitors [BLIs-avibactam (AVI) or durlobactam (DUR)]. The sulopenem-CXM combination yielded low minimum inhibitory concentration (MIC) values for 54 clinical Mab isolates and ATCC19977 (MIC50 and MIC90 ≤0.25 µg/mL). Similar synergistic effects were observed in time-kill studies conducted at concentrations achievable in clinical settings. Sulopenem-CXM outperformed monotherapy, yielding ~1.5 Log10 CFU/mL reduction during 10 days. Addition of BLIs enhanced this antibacterial effect, resulting in an additional reduction of CFUs (~3 Log10 for sulopenem-CXM and AVI and ~4 Log10 for sulopenem-DUR). Exploration of the potential mechanisms of the synergy focused on their interactions with L,D-transpeptidases (Ldts; LdtMab1-LdtMab4), penicillin-binding-protein B (PBP B), and D,D-carboxypeptidase (DDC). Acyl complexes, identified via mass spectrometry analysis, demonstrated the binding of sulopenem with LdtMab2-LdtMab4, DDC, and PBP B and CXM with LdtMab2 and PBP B. Molecular docking and mass spectrometry data suggest the formation of a covalent adduct between sulopenem and LdtMab2 after the nucleophilic attack of the cysteine residue at the β-lactam carbonyl carbon, leading to the cleavage of the β-lactam ring and the establishment of a thioester bond linking the LdtMab2 with sulopenem. In conclusion, we demonstrated the biochemical basis of the synergy of sulopenem-CXM with or without BLIs. These findings potentially broaden the selection of oral therapeutic agents to combat Mab. IMPORTANCE Treating infections from Mycobacterium abscessus (Mab), particularly those resistant to common antibiotics like macrolides, is notoriously difficult, akin to a never-ending struggle for healthcare providers. The rate of treatment failure is even higher than that seen with multidrug-resistant tuberculosis. The role of combination β-lactams in inhibiting L,D-transpeptidation, the major peptidoglycan crosslink reaction in Mab, is an area of intense investigation, and clinicians have utilized this approach in the treatment of macrolide-resistant Mab, with reports showing clinical success. In our study, we found that cefuroxime and sulopenem, when used together, display a significant synergistic effect. If this promising result seen in lab settings, translates well into real-world clinical effectiveness, it could revolutionize current treatment methods. This combination could either replace the need for more complex intravenous medications or serve as a "step down" to an oral medication regimen. Such a shift would be much easier for patients to manage, enhancing their comfort and likelihood of sticking to the treatment plan, which could lead to better outcomes in tackling these tough infections. Our research delved into how these drugs inhibit cell wall synthesis, examined time-kill data and binding studies, and provided a scientific basis for the observed synergy in cell-based assays.
Collapse
Affiliation(s)
- Khalid M Dousa
- Louis Stokes Cleveland VA Medical Center, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Eunjeong Shin
- Louis Stokes Cleveland VA Medical Center, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Sebastian G Kurz
- Department of Medicine, University of Tübingen, Tübingen, Germany
| | - Mark Plummer
- Yale Center for Molecular Discovery, Yale University, New Haven, Connecticut, USA
| | - Mary Nantongo
- Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- Louis Stokes Cleveland VA Medical Center, Cleveland, Ohio, USA
| | - Christopher R Bethel
- Louis Stokes Cleveland VA Medical Center, Case Western Reserve University, Cleveland, Ohio, USA
| | - Magdalena A Taracila
- Louis Stokes Cleveland VA Medical Center, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - David C Nguyen
- Department of Pediatrics, Division of Pediatric Infectious Diseases and Department of Internal Medicine, Division of Infectious Diseases, Rush Medical College, Chicago, Illinois, USA
| | - Barry N Kreiswith
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA
| | - Charles L Daley
- Division of Mycobacterial and Respiratory Infections, National Jewish Health, Denver, Colorado, USA
| | - Kenneth E Remy
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Steven M Holland
- Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Robert A Bonomo
- Louis Stokes Cleveland VA Medical Center, Case Western Reserve University, Cleveland, Ohio, USA
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- CWRU-Cleveland VAMC Center for Antimicrobial Resistance and Epidemiology (Case VA CARES), Cleveland, Ohio, USA
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- Department of Proteomics and Bioinformatics, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
- GRECC, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio, USA
| |
Collapse
|
2
|
Pozuelo Torres M, van Ingen J. Dual β-lactam therapy to improve treatment outcome in Mycobacterium abscessus disease. Clin Microbiol Infect 2024; 30:738-742. [PMID: 38527611 DOI: 10.1016/j.cmi.2024.03.019] [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: 01/10/2024] [Revised: 03/06/2024] [Accepted: 03/10/2024] [Indexed: 03/27/2024]
Abstract
BACKGROUND Antibiotic treatment of Mycobacterium abscessus disease is toxic and poorly effective and lacks a firm evidence base. Dual β-lactam and β-lactam/β-lactamase inhibitor combinations may be interesting leads to improve treatment outcomes. OBJECTIVES To summarize the current preclinical studies on dual β-lactam and β-lactam/β-lactamase inhibitor combinations against M. abscessus. SOURCES We performed a literature search using the National Center for Biotechnology Information's PubMed interface with additional snowball sampling. CONTENT Select combinations of β-lactam antibiotics, as well as β-lactam/β-lactamase inhibitor combinations show promising in vitro activity and synergy against M. abscessus. β-Lactam antibiotics differ in their ability to reach and interfere with their targets and their resistance to the M. abscessus β-lactamase. The synergy is typically observed for combinations of β-lactam antibiotics or a β-lactam antibiotic with a β-lactamase inhibitor. No additional killing capacity was demonstrated in three-drug combinations of synergistic β-lactam antibiotics and a β-lactamase inhibitor. The efficacy of select dual β-lactam antibiotics and β-lactam/β-lactamase inhibitor combinations is retained in intracellular infection assays and mouse models, but no combination has a complete preclinical portfolio. IMPLICATIONS Future clinical strategies should entail either dual β-lactam or β-lactam/β-lactamase inhibitor combinations. Imipenem-ceftaroline and an all-oral tebipenem-avibactam combination are promising leads but still require a complete preclinical portfolio, target product profiles as well as clinical trial confirmation.
Collapse
Affiliation(s)
- Marta Pozuelo Torres
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Jakko van Ingen
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands.
| |
Collapse
|
3
|
Yuliani Y, Ilmi AFN, Petsong S, Sawatpanich A, Chirakul S, Chatsuwan T, Palaga T, Rotcheewaphan S. CRISPR Interference-Mediated Silencing of the mmpL3 Gene in Mycobacterium smegmatis and Its Impact on Antimicrobial Susceptibility. Antibiotics (Basel) 2024; 13:483. [PMID: 38927150 PMCID: PMC11200583 DOI: 10.3390/antibiotics13060483] [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: 04/28/2024] [Revised: 05/17/2024] [Accepted: 05/22/2024] [Indexed: 06/28/2024] Open
Abstract
BACKGROUND The discovery of novel therapeutic agents, especially those targeting mycobacterial membrane protein large 3 (mmpL3), has shown promise. In this study, the CRISPR interference-Streptococcus thermophilus nuclease-deactivated Cas9 (CRISPRi-dCas9Sth1) system was utilized to suppress mmpL3 expression in Mycobacterium smegmatis, and its impacts on susceptibility to antimicrobial agents were evaluated. METHODS The repression of the mmpL3 gene was confirmed by RT-qPCR. The essentiality, growth curve, viability, and antimicrobial susceptibility of the mmpL3 knockdown strain were investigated. RESULTS mmpL3 silencing was achieved by utilizing 0.5 and 1 ng/mL anhydrotetracycline (ATc), resulting in reductions in the expression of 60.4% and 74.4%, respectively. mmpL3 silencing led to a significant decrease in bacterial viability when combined with one-half of the minimal inhibitory concentrations (MICs) of rifampicin, rifabutin, ceftriaxone, or isoniazid, along with 0.1 or 0.5 ng/mL ATc (p < 0.05). However, no significant difference was observed for clarithromycin or amikacin. CONCLUSIONS The downregulation of the mmpL3 gene in mycobacteria was achieved through the use of CRISPRi-dCas9Sth1, resulting in growth deficiencies and resensitization to certain antimicrobial agents. The impact was dependent upon the level of gene expression.
Collapse
Affiliation(s)
- Yonita Yuliani
- Medical Sciences, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand; (Y.Y.); (A.F.N.I.)
| | - Azizah Fitriana Nurul Ilmi
- Medical Sciences, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand; (Y.Y.); (A.F.N.I.)
| | - Suthidee Petsong
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand; (S.P.); (A.S.); (S.C.); (T.C.)
| | - Ajcharaporn Sawatpanich
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand; (S.P.); (A.S.); (S.C.); (T.C.)
| | - Sunisa Chirakul
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand; (S.P.); (A.S.); (S.C.); (T.C.)
- Center of Excellence in Antimicrobial Stewardship, Chulalongkorn University, Bangkok 10330, Thailand
| | - Tanittha Chatsuwan
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand; (S.P.); (A.S.); (S.C.); (T.C.)
- Center of Excellence in Antimicrobial Stewardship, Chulalongkorn University, Bangkok 10330, Thailand
| | - Tanapat Palaga
- Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand;
| | - Suwatchareeporn Rotcheewaphan
- Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok 10330, Thailand; (S.P.); (A.S.); (S.C.); (T.C.)
- Center of Excellence in Antimicrobial Stewardship, Chulalongkorn University, Bangkok 10330, Thailand
| |
Collapse
|
4
|
Chen L, Shashkina E, Kurepina N, Calado Nogueira de Moura V, Daley CL, Kreiswirth BN. In vitro activity of cefoxitin, imipenem, meropenem, and ceftaroline in combination with vaborbactam against Mycobacterium abscessus. Antimicrob Agents Chemother 2024; 68:e0017424. [PMID: 38557171 PMCID: PMC11064484 DOI: 10.1128/aac.00174-24] [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: 01/31/2024] [Accepted: 02/28/2024] [Indexed: 04/04/2024] Open
Abstract
Mycobacterium abscessus (MAB) infections pose a growing public health threat. Here, we assessed the in vitro activity of the boronic acid-based β-lactamase inhibitor, vaborbactam, with different β-lactams against 100 clinical MAB isolates. Enhanced activity was observed with meropenem and ceftaroline with vaborbactam (1- and >4-fold MIC50/90 reduction). CRISPRi-mediated blaMAB gene knockdown showed a fourfold MIC reduction to ceftaroline but not the other β-lactams. Our findings demonstrate vaborbactam's potential in combination therapy against MAB infections.
Collapse
Affiliation(s)
- Liang Chen
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA
- Department of Medical Sciences, Hackensack Meridian School of Medicine, Nutley, New Jersey, USA
| | - Elena Shashkina
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA
| | - Natalia Kurepina
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA
| | | | - Charles L. Daley
- Department of Medicine, National Jewish Health, Denver, Colorado, USA
- The University of Colorado, Aurora, Colorado, USA
| | - Barry N. Kreiswirth
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey, USA
- Department of Medical Sciences, Hackensack Meridian School of Medicine, Nutley, New Jersey, USA
| |
Collapse
|
5
|
Daniel C, Willcocks S, Bhakta S. Rapid Gene Silencing Followed by Antimicrobial Susceptibility Testing for Target Validation in Antibiotic Discovery. Methods Mol Biol 2024; 2833:23-33. [PMID: 38949697 DOI: 10.1007/978-1-0716-3981-8_3] [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: 07/02/2024]
Abstract
Mycobacterium tuberculosis is the main causative agent of tuberculosis (TB)-an ancient yet widespread global infectious disease to which 1.6 million people lost their lives in 2021. Antimicrobial resistance (AMR) has been an ongoing crisis for decades; 4.95 million deaths were associated with antibiotic resistance in 2019. While AMR is a multi-faceted problem, drug discovery is an urgent part of the solution and is at the forefront of modern research.The landscape of drug discovery for TB has undoubtedly been transformed by the development of high-throughput gene-silencing techniques that enable interrogation of every gene in the genome, and their relative contribution to fitness, virulence, and AMR. A recent advance in this area is CRISPR interference (CRISPRi). The application of this technique to antimicrobial susceptibility testing (AST) is the subject of ongoing research in basic science.CRISPRi technology can be used in conjunction with the high-throughput SPOT-culture growth inhibition assay (HT-SPOTi) to rapidly evaluate and assess gene essentiality including non-essential, conditionally essential (by using appropriate culture conditions), and essential genes. In addition, the HT-SPOTi method can develop drug susceptibility and drug resistance profiles.This technology is further useful for drug discovery groups who have designed target-based inhibitors rationally and wish to validate the primary mechanisms of their novel compounds' antibiotic action against the proposed target.
Collapse
Affiliation(s)
- Chris Daniel
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, School of Natural Sciences, Birkbeck, University of London, London, UK
| | - Sam Willcocks
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, School of Natural Sciences, Birkbeck, University of London, London, UK
- Division of Biosciences, College of Health, Medicine and Life Sciences, Brunel University London, Uxbridge, UK
| | - Sanjib Bhakta
- Mycobacteria Research Laboratory, Institute of Structural and Molecular Biology, School of Natural Sciences, Birkbeck, University of London, London, UK.
| |
Collapse
|
6
|
Mayorga-Ramos A, Zúñiga-Miranda J, Carrera-Pacheco SE, Barba-Ostria C, Guamán LP. CRISPR-Cas-Based Antimicrobials: Design, Challenges, and Bacterial Mechanisms of Resistance. ACS Infect Dis 2023; 9:1283-1302. [PMID: 37347230 PMCID: PMC10353011 DOI: 10.1021/acsinfecdis.2c00649] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Indexed: 06/23/2023]
Abstract
The emergence of antibiotic-resistant bacterial strains is a source of public health concern across the globe. As the discovery of new conventional antibiotics has stalled significantly over the past decade, there is an urgency to develop novel approaches to address drug resistance in infectious diseases. The use of a CRISPR-Cas-based system for the precise elimination of targeted bacterial populations holds promise as an innovative approach for new antimicrobial agent design. The CRISPR-Cas targeting system is celebrated for its high versatility and specificity, offering an excellent opportunity to fight antibiotic resistance in pathogens by selectively inactivating genes involved in antibiotic resistance, biofilm formation, pathogenicity, virulence, or bacterial viability. The CRISPR-Cas strategy can enact antimicrobial effects by two approaches: inactivation of chromosomal genes or curing of plasmids encoding antibiotic resistance. In this Review, we provide an overview of the main CRISPR-Cas systems utilized for the creation of these antimicrobials, as well as highlighting promising studies in the field. We also offer a detailed discussion about the most commonly used mechanisms for CRISPR-Cas delivery: bacteriophages, nanoparticles, and conjugative plasmids. Lastly, we address possible mechanisms of interference that should be considered during the intelligent design of these novel approaches.
Collapse
Affiliation(s)
- Arianna Mayorga-Ramos
- Centro
de Investigación Biomédica (CENBIO), Facultad de Ciencias
de la Salud Eugenio Espejo, Universidad
UTE, Quito 170527, Ecuador
| | - Johana Zúñiga-Miranda
- Centro
de Investigación Biomédica (CENBIO), Facultad de Ciencias
de la Salud Eugenio Espejo, Universidad
UTE, Quito 170527, Ecuador
| | - Saskya E. Carrera-Pacheco
- Centro
de Investigación Biomédica (CENBIO), Facultad de Ciencias
de la Salud Eugenio Espejo, Universidad
UTE, Quito 170527, Ecuador
| | - Carlos Barba-Ostria
- Escuela
de Medicina, Colegio de Ciencias de la Salud Quito, Universidad San Francisco de Quito USFQ, Quito 170902, Ecuador
| | - Linda P. Guamán
- Centro
de Investigación Biomédica (CENBIO), Facultad de Ciencias
de la Salud Eugenio Espejo, Universidad
UTE, Quito 170527, Ecuador
| |
Collapse
|
7
|
Nguyen TQ, Heo BE, Park Y, Jeon S, Choudhary A, Moon C, Jang J. CRISPR Interference-Based Inhibition of MAB_0055c Expression Alters Drug Sensitivity in Mycobacterium abscessus. Microbiol Spectr 2023; 11:e0063123. [PMID: 37158736 PMCID: PMC10269454 DOI: 10.1128/spectrum.00631-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 04/21/2023] [Indexed: 05/10/2023] Open
Abstract
There is an unmet medical need for effective treatments against Mycobacterium abscessus infections. Although advanced molecular genetic tools to validate drug targets and resistance of M. abscessus exist, the practical design and construction of plasmids are relatively laborious and time-consuming. Thus, for this purpose, we used CRISPR interference (CRISPRi) combined with catalytically deactivated Cas9 to inhibit the gene expression of a predicted LysR-type transcriptional regulator gene, MAB_0055c, in M. abscessus and evaluated its contribution to the development of drug resistance. Our results showed that silencing the MAB_0055c gene lead to increased rifamycin susceptibility depending on the hydroquinone moiety. These results demonstrate that CRISPRi is an excellent approach for studying drug resistance in M. abscessus. IMPORTANCE In this study, we utilized CRISPR interference (CRISPRi) to specifically target the MAB_0055c gene in M. abscessus, a bacterium that causes difficult-to-treat infections. The study found that silencing the gene lead to increased rifabutin and rifalazil susceptibility. This study is the first to establish a link between the predicted LysR-type transcriptional regulator gene and antibiotic resistance in mycobacteria. These findings underscore the potential of using CRISPRi as a tool for elucidating resistance mechanisms, essential drug targets, and drug mechanisms of action, which could pave the way for more effective treatments for M. abscessus infections. The results of this study could have important implications for the development of new therapeutic options for this challenging-to-treat bacterial infection.
Collapse
Affiliation(s)
- Thanh Quang Nguyen
- Division of Life Science, Department of Bio & Medical Big Data (BK21 Four Program), Research Institute of Life Science, Gyeongsang National University, Jinju, Republic of Korea
| | - Bo Eun Heo
- Division of Life Science, Department of Bio & Medical Big Data (BK21 Four Program), Research Institute of Life Science, Gyeongsang National University, Jinju, Republic of Korea
| | - Yujin Park
- Division of Life Science, Department of Bio & Medical Big Data (BK21 Four Program), Research Institute of Life Science, Gyeongsang National University, Jinju, Republic of Korea
| | - Seunghyeon Jeon
- Division of Life Science, Department of Bio & Medical Big Data (BK21 Four Program), Research Institute of Life Science, Gyeongsang National University, Jinju, Republic of Korea
| | - Arunima Choudhary
- Division of Life Science, Department of Bio & Medical Big Data (BK21 Four Program), Research Institute of Life Science, Gyeongsang National University, Jinju, Republic of Korea
| | - Cheol Moon
- Department of Clinical Laboratory Science, Semyung University, Jecheon, Republic of Korea
| | - Jichan Jang
- Division of Life Science, Department of Bio & Medical Big Data (BK21 Four Program), Research Institute of Life Science, Gyeongsang National University, Jinju, Republic of Korea
| |
Collapse
|
8
|
Finin P, Khan RMN, Oh S, Boshoff HIM, Barry CE. Chemical approaches to unraveling the biology of mycobacteria. Cell Chem Biol 2023; 30:420-435. [PMID: 37207631 PMCID: PMC10201459 DOI: 10.1016/j.chembiol.2023.04.014] [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: 02/06/2023] [Revised: 04/07/2023] [Accepted: 04/27/2023] [Indexed: 05/21/2023]
Abstract
Mycobacterium tuberculosis (Mtb), perhaps more than any other organism, is intrinsically appealing to chemical biologists. Not only does the cell envelope feature one of the most complex heteropolymers found in nature1 but many of the interactions between Mtb and its primary host (we humans) rely on lipid and not protein mediators.2,3 Many of the complex lipids, glycolipids, and carbohydrates biosynthesized by the bacterium still have unknown functions, and the complexity of the pathological processes by which tuberculosis (TB) disease progress offers many opportunities for these molecules to influence the human response. Because of the importance of TB in global public health, chemical biologists have applied a wide-ranging array of techniques to better understand the disease and improve interventions.
Collapse
Affiliation(s)
- Peter Finin
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, NIAID, NIH, Bethesda, MD, USA
| | - R M Naseer Khan
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, NIAID, NIH, Bethesda, MD, USA
| | - Sangmi Oh
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, NIAID, NIH, Bethesda, MD, USA
| | - Helena I M Boshoff
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, NIAID, NIH, Bethesda, MD, USA
| | - Clifton E Barry
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, NIAID, NIH, Bethesda, MD, USA.
| |
Collapse
|
9
|
Gupta R, Rohde KH. Implementation of a mycobacterial CRISPRi platform in Mycobacterium abscessus and demonstration of the essentiality of ftsZ Mab. Tuberculosis (Edinb) 2023; 138:102292. [PMID: 36495774 DOI: 10.1016/j.tube.2022.102292] [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: 08/13/2022] [Revised: 11/22/2022] [Accepted: 11/27/2022] [Indexed: 12/04/2022]
Abstract
Mycobacterium abscessus (Mab) is a highly drug-resistant non-tuberculous mycobacterial species that causes debilitating TB-like pulmonary infections. The lack of genetic tools has hampered characterization of its extensive repertoire of virulence factors, antimicrobial resistance mechanisms, and drug targets. In this study, we evaluated the performance of a mycobacterial single plasmid CRISPRi-dCas9 system optimized for M. tuberculosis and M. smegmatis for inducible gene silencing in Mab. The efficacy of CRISPRi-mediated repression of two antibiotic resistance genes (blaMab, whiB7Mab) and two putative essential genes (ftsZMab,topAMab) was determined by measuring mRNA transcript levels and phenotypic outcomes. While our results support the utility of this mycobacterial CRISPRi dCas9Sth1 single-plasmid platform for inducible silencing of specific target genes in Mab, they also highlighted several caveats and nuances that may warrant species-specific optimization for Mab. We observed overall lower levels of gene repression in Mab including variable silencing of different target genes despite use of PAMs of similar predicted strength. In addition, leaky gene repression in the absence of inducer was noted for some genes but not others. Nonetheless, using CRISPRi we demonstrated the silencing of multiple target genes and validated ftsZMab as an essential gene and promising drug target for the first time.
Collapse
Affiliation(s)
- Rashmi Gupta
- Division of Immunity and Pathogenesis, College of Medicine, Burnett School of Biomedical Sciences, University of Central Florida, 6900 Lake Nona Blvd, FL, 32827, USA.
| | - Kyle H Rohde
- Division of Immunity and Pathogenesis, College of Medicine, Burnett School of Biomedical Sciences, University of Central Florida, 6900 Lake Nona Blvd, FL, 32827, USA.
| |
Collapse
|
10
|
Strongly Bactericidal All-Oral β-Lactam Combinations for the Treatment of Mycobacterium abscessus Lung Disease. Antimicrob Agents Chemother 2022; 66:e0079022. [PMID: 36047786 PMCID: PMC9487536 DOI: 10.1128/aac.00790-22] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Bioactive forms of oral β-lactams were screened in vitro against Mycobacterium abscessus with and without the bioactive form of the oral β-lactamase inhibitor avibactam ARX1796. Sulopenem was equally active without avibactam, while tebipenem, cefuroxime, and amoxicillin required avibactam for optimal activity. Systematic pairwise combination of the four β-lactams revealed strong bactericidal synergy for each of sulopenem, tebipenem, and cefuroxime combined with amoxicillin in the presence of avibactam. These all-oral β-lactam combinations warrant clinical evaluation.
Collapse
|