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Li Y, Zhou Y, Du Y, Gao P, Yang L, Wang W. In vivo Labeling and Intravital Imaging of Bacterial Infection using a Near-infrared Fluorescent D-Amino Acid Probe. Chembiochem 2024; 25:e202400283. [PMID: 38715148 DOI: 10.1002/cbic.202400283] [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: 03/28/2024] [Revised: 04/28/2024] [Indexed: 06/27/2024]
Abstract
Bacterial infections still pose a severe threat to public health, necessitating novel tools for real-time analysis of microbial behaviors in living organisms. While genetically engineered strains with fluorescent or luminescent reporters are commonly used in tracking bacteria, their in vivo uses are often limited. Here, we report a near-infrared fluorescent D-amino acid (FDAA) probe, Cy7ADA, for in situ labeling and intravital imaging of bacterial infections in mice. Cy7ADA probe effectively labels various bacteria in vitro and pathogenic Staphylococcus aureus in mice after intraperitoneal injection. Because of Cy7's high tissue penetration and the quick excretion of free probes via urine, real-time visualization of the pathogens in a liver abscess model via intravital confocal microscopy is achieved. The biodistributions, including their intracellular localization within Kupffer cells, are revealed. Monitoring bacterial responses to antibiotics also demonstrates Cy7ADA's capability to reflect the bacterial load dynamics within the host. Furthermore, Cy7ADA facilitates three-dimensional pathogen imaging in tissue-cleared liver samples, showcasing its potential for studying the biogeography of microbes in different organs. Integrating near-infrared FDAA probes with intravital microscopy holds promise for wide applications in studying bacterial infections in vivo.
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Affiliation(s)
- Yixuan Li
- Department of Anesthesiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China, Key Laboratory of Anesthesiology (Shanghai Jiao Tong University), Ministry of Education, China
| | - Yingjun Zhou
- State Key Laboratory of Genetic Engineering, Department of Microbiology, Microbiome Center, School of Life Sciences, Fudan University, Shanghai, China
| | - Yahui Du
- Department of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
| | - Po Gao
- Department of Anesthesiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China, Key Laboratory of Anesthesiology (Shanghai Jiao Tong University), Ministry of Education, China
| | - Liqun Yang
- Department of Anesthesiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China, Key Laboratory of Anesthesiology (Shanghai Jiao Tong University), Ministry of Education, China
| | - Wei Wang
- State Key Laboratory of Genetic Engineering, Department of Microbiology, Microbiome Center, School of Life Sciences, Fudan University, Shanghai, China
- Beijing National Laboratory for Molecular Sciences, Beijing, China
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2
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Betts HM, Luckett JC, Hill PJ. Pilot Evaluation of S-(3-[ 18F]Fluoropropyl)-D-Homocysteine and O-(2-[ 18F]Fluoroethyl)-D-Tyrosine as Bacteria-Specific Radiotracers for PET Imaging of Infection. Mol Imaging Biol 2024:10.1007/s11307-024-01929-7. [PMID: 38942967 DOI: 10.1007/s11307-024-01929-7] [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: 02/05/2024] [Revised: 06/12/2024] [Accepted: 06/14/2024] [Indexed: 06/30/2024]
Abstract
PURPOSE There is currently no ideal radiotracer for imaging bacterial infections. Radiolabelled D-amino acids are promising candidates because they are actively incorporated into the peptidoglycan of the bacterial cell wall, a structural feature which is absent in human cells. This work describes fluorine-18 labelled analogues of D-tyrosine and D-methionine, O-(2-[18F]fluoroethyl)-D-tyrosine (D-[18F]FET) and S-(3-[18F]fluoropropyl)-D-homocysteine (D-[18F]FPHCys), and their pilot evaluation studies as potential radiotracers for imaging bacterial infection. PROCEDURES D-[18F]FET and D-[18F]FPHCys were prepared in classical fluorination-deprotection reactions, and their uptake in Staphylococcus aureus and Pseudomonas aeruginosa was evaluated over 2 h. Heat killed bacteria were used as controls. A clinically-relevant foreign body model of S. aureus infection was established in Balb/c mice, as well as a sterile foreign body to mimic inflammation. The ex vivo biodistribution of D-[18F]FPHCys in the infected and inflamed mice was evaluated after 1 h, by dissection and gamma counting. The uptake was compared to that of [18F]FDG. RESULTS In vitro uptake of both D-[18F]FET and D-[18F]FPHCys was specific to live bacteria. Uptake was higher in S. aureus than in P. aeruginosa for both radiotracers, and of the two, higher for D-[18F]FPHCys than D-[18F]FET. Blocking experiments with non-radioactive D-[19F]FPHCys confirmed specificity of uptake. In vivo, D-[18F]FPHCys had greater accumulation in S. aureus infection compared with sterile inflammation, which was statistically significant. As anticipated, [18F]FDG showed no significant difference in uptake between infection and inflammation. CONCLUSIONS D-[18F]FPHCys uptake was higher in infected tissues than inflammation, and represents a fluorine-18 labelled D-AA with potential to detect a S. aureus reference strain (Xen29) in vivo. Additional studies are needed to evaluate uptake of this radiotracer in clinical isolates.
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Affiliation(s)
- Helen M Betts
- Department of Nuclear Medicine, Nottingham University Hospitals NHS Trust, Queen's Medical Centre, Nottingham, NG7 2UH, UK.
- School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK.
| | - Jeni C Luckett
- School of Life Sciences, University of Nottingham, Biodiscovery Institute, University Park, Nottingham, NG7 2RD, UK
| | - Philip J Hill
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Sutton Bonington, LE17 5RD, UK
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3
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Pandey A, Chopra S, Cleary SJ, López-Álvarez M, Quimby FM, Alanizi AAA, Sakhamuri S, Zhang N, Looney MR, Craik CS, Wilson DM, Evans MJ. Imaging the Granzyme Mediated Host Immune Response to Viral and Bacterial Pathogens In Vivo Using Positron Emission Tomography. ACS Infect Dis 2024; 10:2108-2117. [PMID: 38819300 DOI: 10.1021/acsinfecdis.4c00114] [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: 06/01/2024]
Abstract
Understanding how the host immune system engages complex pathogens is essential to developing therapeutic strategies to overcome their virulence. While granzymes are well understood to trigger apoptosis in infected host cells or bacteria, less is known about how the immune system mobilizes individual granzyme species in vivo to combat diverse pathogens. Toward the goal of studying individual granzyme function directly in vivo, we previously developed a new class of radiopharmaceuticals termed "restricted interaction peptides (RIPs)" that detect biochemically active endoproteases using positron emission tomography (PET). In this study, we showed that secreted granzyme B proteolysis in response to diverse viral and bacterial pathogens could be imaged with [64Cu]Cu-GRIP B, a RIP that specifically targets granzyme B. Wild-type or germline granzyme B knockout mice were instilled intranasally with the A/PR/8/34 H1N1 influenza A strain to generate pneumonia, and granzyme B production within the lungs was measured using [64Cu]Cu-GRIP B PET/CT. Murine myositis models of acute bacterial (E. coli, P. aeruginosa, K. pneumoniae, and L. monocytogenes) infection were also developed and imaged using [64Cu]Cu-GRIP B. In all cases, the mice were studied in vivo using mPET/CT and ex vivo via tissue-harvesting, gamma counting, and immunohistochemistry. [64Cu]Cu-GRIP B uptake was significantly higher in the lungs of wild-type mice that received A/PR/8/34 H1N1 influenza A strain compared to mice that received sham or granzyme B knockout mice that received either treatment. In wild-type mice, [64Cu]Cu-GRIP B uptake was significantly higher in the infected triceps muscle versus normal muscle and the contralateral triceps inoculated with heat killed bacteria. In granzyme B knockout mice, [64Cu]Cu-GRIP B uptake above the background was not observed in the infected triceps muscle. Interestingly, live L. monocytogenes did not induce detectable granzyme B on PET, despite prior in vitro data, suggesting a role for granzyme B in suppressing their pathogenicity. In summary, these data show that the granzyme response elicited by diverse human pathogens can be imaged using PET. These results and data generated via additional RIPs specific for other granzyme proteases will allow for a deeper mechanistic study analysis of their complex in vivo biology.
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Affiliation(s)
- Apurva Pandey
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California 94158, United States
| | - Shalini Chopra
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California 94158, United States
| | - Simon J Cleary
- Department of Medicine, University of California, San Francisco, San Francisco, California 94158, United States
| | - Marina López-Álvarez
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California 94158, United States
| | - Fiona M Quimby
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California 94158, United States
| | - Aryn A A Alanizi
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California 94158, United States
| | - Sasank Sakhamuri
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California 94158, United States
| | - Ningjing Zhang
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California 94158, United States
| | - Mark R Looney
- Department of Medicine, University of California, San Francisco, San Francisco, California 94158, United States
| | - Charles S Craik
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California 94158, United States
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, California 94158, United States
| | - David M Wilson
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California 94158, United States
| | - Michael J Evans
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California 94158, United States
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California 94158, United States
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, California 94158, United States
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4
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Chu J, Yu X, Jiang G, Tao Y, Wu W, Han S. Bacterial imaging in tumour diagnosis. Microb Biotechnol 2024; 17:e14474. [PMID: 38808743 PMCID: PMC11135020 DOI: 10.1111/1751-7915.14474] [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: 01/16/2024] [Revised: 04/15/2024] [Accepted: 04/17/2024] [Indexed: 05/30/2024] Open
Abstract
Some bacteria, such as Escherichia coli (E. coli) and Salmonella typhimurium (S. typhimurium), have an inherent ability to locate solid tumours, making them a versatile platform that can be combined with other tools to improve the tumour diagnosis and treatment. In anti-cancer therapy, bacteria function by carrying drugs directly or expressing exogenous therapeutic genes. The application of bacterial imaging in tumour diagnosis, a novel and promising research area, can indeed provide dynamic and real-time monitoring in both pre-treatment assessment and post-treatment detection. Different imaging techniques, including optical technology, acoustic imaging, magnetic resonance imaging (MRI) and nuclear medicine imaging, allow us to observe and track tumour-associated bacteria. Optical imaging, including bioluminescence and fluorescence, provides high-sensitivity and high-resolution imaging. Acoustic imaging is a real-time and non-invasive imaging technique with good penetration depth and spatial resolution. MRI provides high spatial resolution and radiation-free imaging. Nuclear medicine imaging, including positron emission tomography (PET) and single photon emission computed tomography (SPECT) can provide information on the distribution and dynamics of bacterial population. Moreover, strategies of synthetic biology modification and nanomaterial engineering modification can improve the viability and localization ability of bacteria while maintaining their autonomy and vitality, thus aiding the visualization of gut bacteria. However, there are some challenges, such as the relatively low bacterial abundance and heterogeneously distribution within the tumour, the high dimensionality of spatial datasets and the limitations of imaging labeling tools. In summary, with the continuous development of imaging technology and nanotechnology, it is expected to further make in-depth study on tumour-associated bacteria and develop new bacterial imaging methods for tumour diagnosis.
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Affiliation(s)
- Jian Chu
- Huzhou Central HospitalAffiliated Central Hospital Huzhou UniversityHuzhouChina
- Key Laboratory of Multiomics Research and Clinical Transformation of Digestive CancerHuzhouChina
- Fifth School of Clinical Medicine of Zhejiang Chinese Medical University (Huzhou Central Hospital)HuzhouChina
| | - Xiang Yu
- Huzhou Central HospitalAffiliated Central Hospital Huzhou UniversityHuzhouChina
- Key Laboratory of Multiomics Research and Clinical Transformation of Digestive CancerHuzhouChina
- Fifth School of Clinical Medicine of Zhejiang Chinese Medical University (Huzhou Central Hospital)HuzhouChina
| | - Gaofei Jiang
- Key Lab of Organic‐Based Fertilizers of China, Jiangsu Provincial Key Lab for Solid Organic Waste UtilizationNanjing Agricultural UniversityNanjingChina
| | - Ye Tao
- Shanghai BIOZERON Biotechnology Co., Ltd.ShanghaiChina
| | - Wei Wu
- Huzhou Central HospitalAffiliated Central Hospital Huzhou UniversityHuzhouChina
- Key Laboratory of Multiomics Research and Clinical Transformation of Digestive CancerHuzhouChina
- Fifth School of Clinical Medicine of Zhejiang Chinese Medical University (Huzhou Central Hospital)HuzhouChina
| | - Shuwen Han
- Huzhou Central HospitalAffiliated Central Hospital Huzhou UniversityHuzhouChina
- Key Laboratory of Multiomics Research and Clinical Transformation of Digestive CancerHuzhouChina
- Fifth School of Clinical Medicine of Zhejiang Chinese Medical University (Huzhou Central Hospital)HuzhouChina
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5
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Calabria FF, Guadagnino G, Cimini A, Leporace M. PET/CT Imaging of Infectious Diseases: Overview of Novel Radiopharmaceuticals. Diagnostics (Basel) 2024; 14:1043. [PMID: 38786341 PMCID: PMC11120316 DOI: 10.3390/diagnostics14101043] [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: 04/06/2024] [Revised: 05/10/2024] [Accepted: 05/15/2024] [Indexed: 05/25/2024] Open
Abstract
Infectious diseases represent one of the most common causes of hospital admission worldwide. The diagnostic work-up requires a complex clinical approach, including laboratory data, CT and MRI, other imaging tools, and microbiologic cultures. PET/CT with 18F-FDG can support the clinical diagnosis, allowing visualization of increased glucose metabolism in activated macrophages and monocytes; this tracer presents limits in differentiating between aseptic inflammation and infection. Novel PET radiopharmaceuticals have been developed to overcome these limits; 11C/18F-labeled bacterial agents, several 68Ga-labeled molecules, and white blood cells labeled with 18F-FDG are emerging PET tracers under study, showing interesting preliminary results. The best choice among these tracers can be unclear. This overview aims to discuss the most common diagnostic applications of 18F-FDG PET/CT in infectious diseases and, as a counterpoint, to describe and debate the advantages and peculiarities of the latest PET radiopharmaceuticals in the field of infectious diseases, which will probably improve the diagnosis and prognostic stratification of patients with active infectious diseases.
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Affiliation(s)
- Ferdinando F. Calabria
- Department of Nuclear Medicine and Theragnostics, “Mariano Santo” Hospital, 87100 Cosenza, Italy;
| | - Giuliana Guadagnino
- Department of Infectious and Tropical Diseases, St. Annunziata Hospital, 87100 Cosenza, Italy
| | - Andrea Cimini
- Nuclear Medicine Unit, St Salvatore Hospital, 67100 L’Aquila, Italy;
| | - Mario Leporace
- Department of Nuclear Medicine and Theragnostics, “Mariano Santo” Hospital, 87100 Cosenza, Italy;
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6
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Alanizi AA, Sorlin AM, Parker MFL, López-Álvarez M, Qin H, Lee SH, Blecha J, Rosenberg OS, Engel J, Ohliger MA, Flavell RR, Wilson DM. Bioorthogonal Radiolabeling of Azide-Modified Bacteria Using [ 18F]FB-sulfo-DBCO. Bioconjug Chem 2024; 35:517-527. [PMID: 38482815 PMCID: PMC11036355 DOI: 10.1021/acs.bioconjchem.4c00024] [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: 01/22/2024] [Revised: 02/27/2024] [Accepted: 02/27/2024] [Indexed: 04/18/2024]
Abstract
Purpose: This study was motivated by the need for better positron emission tomography (PET)-compatible tools to image bacterial infection. Our previous efforts have targeted bacteria-specific metabolism via assimilation of carbon-11 labeled d-amino acids into the bacterial cell wall. Since the chemical determinants of this incorporation are not fully understood, we sought a high-throughput method to label d-amino acid derived structures with fluorine-18. Our strategy employed a chemical biology approach, whereby an azide (-N3) bearing d-amino acid is incorporated into peptidoglycan muropeptides, with subsequent "click" cycloaddition with an 18F-labeled strained cyclooctyne partner. Procedures: A water-soluble, 18F-labeled and dibenzocyclooctyne (DBCO)-derived radiotracer ([18F]FB-sulfo-DBCO) was synthesized. This tracer was incubated with pathogenic bacteria treated with azide-bearing d-amino acids, and incorporated 18F was determined via gamma counting. In vitro uptake in bacteria previously treated with azide-modified d-amino acids was compared to that in cultures treated with amino acid controls. The biodistribution of [18F]FB-sulfo-DBCO was studied in a cohort of healthy mice with implications for future in vivo imaging. Results: The new strain-promoted azide-alkyne cycloaddition (SPAAC) radiotracer [18F]FB-sulfo-DBCO was synthesized with high radiochemical yield and purity via N-succinimidyl 4-[18F]fluorobenzoate ([18F]SFB). Accumulation of [18F]FB-sulfo-DBCO was significantly higher in several bacteria treated with azide-modified d-amino acids than in controls; for example, we observed 7 times greater [18F]FB-sulfo-DBCO ligation in Staphylococcus aureus cultures incubated with 3-azido-d-alanine versus those incubated with d-alanine. Conclusions: The SPAAC radiotracer [18F]FB-sulfo-DBCO was validated in vitro via metabolic labeling of azide-bearing peptidoglycan muropeptides. d-Amino acid-derived PET radiotracers may be more efficiently screened via [18F]FB-sulfo-DBCO modification.
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Affiliation(s)
- Aryn A. Alanizi
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Alexandre M. Sorlin
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Matthew F. L. Parker
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
- Department
of Psychiatry, Renaissance School of Medicine
at Stony Brook University, Stony
Brook, New York 11794, United States
| | - Marina López-Álvarez
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Hecong Qin
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Sang Hee Lee
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Joseph Blecha
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Oren S. Rosenberg
- Department
of Medicine, University of California, San
Francisco, San Francisco, California 94158, United States
| | - Joanne Engel
- Department
of Medicine, University of California, San
Francisco, San Francisco, California 94158, United States
| | - Michael A. Ohliger
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
- Department
of Radiology, Zuckerberg San Francisco General
Hospital, San Francisco, California 94110, United States
| | - Robert R. Flavell
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - David M. Wilson
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
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7
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Sorlin A, López-Álvarez M, Biboy J, Gray J, Rabbitt SJ, Rahim JU, Lee SH, Bobba KN, Blecha J, Parker MF, Flavell RR, Engel J, Ohliger M, Vollmer W, Wilson DM. Peptidoglycan-Targeted [ 18F]3,3,3-Trifluoro-d-alanine Tracer for Imaging Bacterial Infection. JACS AU 2024; 4:1039-1047. [PMID: 38559735 PMCID: PMC10976610 DOI: 10.1021/jacsau.3c00776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 01/19/2024] [Accepted: 02/06/2024] [Indexed: 04/04/2024]
Abstract
Imaging is increasingly used to detect and monitor bacterial infection. Both anatomic (X-rays, computed tomography, ultrasound, and MRI) and nuclear medicine ([111In]-WBC SPECT, [18F]FDG PET) techniques are used in clinical practice but lack specificity for the causative microorganisms themselves. To meet this challenge, many groups have developed imaging methods that target pathogen-specific metabolism, including PET tracers integrated into the bacterial cell wall. We have previously reported the d-amino acid derived PET radiotracers d-methyl-[11C]-methionine, d-[3-11C]-alanine, and d-[3-11C]-alanine-d-alanine, which showed robust bacterial accumulation in vitro and in vivo. Given the clinical importance of radionuclide half-life, in the current study, we developed [18F]3,3,3-trifluoro-d-alanine (d-[18F]-CF3-ala), a fluorine-18 labeled tracer. We tested the hypothesis that d-[18F]-CF3-ala would be incorporated into bacterial peptidoglycan given its structural similarity to d-alanine itself. NMR analysis showed that the fluorine-19 parent amino acid d-[19F]-CF3-ala was stable in human and mouse serum. d-[19F]-CF3-ala was also a poor substrate for d-amino acid oxidase, the enzyme largely responsible for mammalian d-amino acid metabolism and a likely contributor to background signals using d-amino acid derived PET tracers. In addition, d-[19F]-CF3-ala showed robust incorporation into Escherichia coli peptidoglycan, as detected by HPLC/mass spectrometry. Based on these promising results, we developed a radiosynthesis of d-[18F]-CF3-ala via displacement of a bromo-precursor with [18F]fluoride followed by chiral stationary phase HPLC. Unexpectedly, the accumulation of d-[18F]-CF3-ala by bacteria in vitro was highest for Gram-negative pathogens in particular E. coli. In a murine model of acute bacterial infection, d-[18F]-CF3-ala could distinguish live from heat-killed E. coli, with low background signals. These results indicate the viability of [18F]-modified d-amino acids for infection imaging and indicate that improved specificity for bacterial metabolism can improve tracer performance.
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Affiliation(s)
- Alexandre
M. Sorlin
- Department
of Radiology, Biomedical Imaging University
of California, San Francisco, San Francisco, California 94158, United States
| | - Marina López-Álvarez
- Department
of Radiology, Biomedical Imaging University
of California, San Francisco, San Francisco, California 94158, United States
| | - Jacob Biboy
- The
Centre for Bacterial Cell Biology, Newcastle
University Newcastle, Newcastle
upon Tyne NE2 4AX, United Kingdom
| | - Joe Gray
- The
Centre for Bacterial Cell Biology, Newcastle
University Newcastle, Newcastle
upon Tyne NE2 4AX, United Kingdom
| | - Sarah J. Rabbitt
- Department
of Radiology, Biomedical Imaging University
of California, San Francisco, San Francisco, California 94158, United States
| | - Junaid Ur Rahim
- Department
of Radiology, Biomedical Imaging University
of California, San Francisco, San Francisco, California 94158, United States
| | - Sang Hee Lee
- Department
of Radiology, Biomedical Imaging University
of California, San Francisco, San Francisco, California 94158, United States
| | - Kondapa Naidu Bobba
- Department
of Radiology, Biomedical Imaging University
of California, San Francisco, San Francisco, California 94158, United States
| | - Joseph Blecha
- Department
of Radiology, Biomedical Imaging University
of California, San Francisco, San Francisco, California 94158, United States
| | - Mathew F.L. Parker
- Department
of Radiology, Biomedical Imaging University
of California, San Francisco, San Francisco, California 94158, United States
- Department
of Psychiatry, Renaissance School of Medicine
at Stony Brook University, Stony Brook, New York 11794, United States
| | - Robert R. Flavell
- Department
of Radiology, Biomedical Imaging University
of California, San Francisco, San Francisco, California 94158, United States
- UCSF
Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, California 94158, United States
- Department
of Pharmaceutical Chemistry, University
of California, San Francisco, San
Francisco, California 94158, United States
| | - Joanne Engel
- Department
of Medicine, University of California, San
Francisco, San Francisco, California 94158, United States
- Department
of Microbiology and Immunology, University
of California, San Francisco, San
Francisco, California 94158, United States
| | - Michael Ohliger
- Department
of Radiology, Biomedical Imaging University
of California, San Francisco, San Francisco, California 94158, United States
- Department
of Radiology, Zuckerberg San Francisco General
Hospital, San Francisco, California 94110, United States
| | - Waldemar Vollmer
- The
Centre for Bacterial Cell Biology, Newcastle
University Newcastle, Newcastle
upon Tyne NE2 4AX, United Kingdom
- Institute
for Molecular Bioscience, The University
of Queensland, Brisbane 4072, Australia
| | - David M. Wilson
- Department
of Radiology, Biomedical Imaging University
of California, San Francisco, San Francisco, California 94158, United States
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8
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Jiang H, Cao Z, Liu Y, Liu R, Zhou Y, Liu J. Bacteria-Based Living Probes: Preparation and the Applications in Bioimaging and Diagnosis. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2306480. [PMID: 38032119 PMCID: PMC10811517 DOI: 10.1002/advs.202306480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 11/06/2023] [Indexed: 12/01/2023]
Abstract
Bacteria can colonize a variety of in vivo biointerfaces, particularly the skin, nasal, and oral mucosa, the gastrointestinal tract, and the reproductive tract, but also target specific lesion sites, such as tumor and wound. By virtue of their prominent characteristics in motility, editability, and targeting ability, bacteria carrying imageable agents are widely developed as living probes for bioimaging and diagnosis of different diseases. This review first introduces the strategies used for preparing bacteria-based living probes, including biological engineering, chemical modification, intracellular loading, and optical manipulation. It then summarizes the recent progress of these living probes for fluorescence imaging, near-infrared imaging, ultrasonic imaging, photoacoustic imaging, magnetic resonance imaging, and positron emission tomography imaging. The biomedical applications of bacteria-based living probes are also reviewed particularly in the bioimaging and diagnosis of bacterial infections, cancers, and intestine-associated diseases. In addition, the advantages and challenges of bacteria-based living probes are discussed and future perspectives are also proposed. This review provides an updated overview of bacteria-based living probes, highlighting their great potential as a unique yet versatile platform for developing next-generation imageable agents for intelligent bioimaging, diagnosis, and even therapy.
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Affiliation(s)
- Hejin Jiang
- Shanghai Key Laboratory for Nucleic Acid Chemistry and NanomedicineInstitute of Molecular MedicineState Key Laboratory of Systems Medicine for CancerRenji HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai200127China
| | - Zhenping Cao
- Shanghai Key Laboratory for Nucleic Acid Chemistry and NanomedicineInstitute of Molecular MedicineState Key Laboratory of Systems Medicine for CancerRenji HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai200127China
| | - Ying Liu
- Shanghai Key Laboratory for Nucleic Acid Chemistry and NanomedicineInstitute of Molecular MedicineState Key Laboratory of Systems Medicine for CancerRenji HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai200127China
| | - Rui Liu
- Shanghai Key Laboratory for Nucleic Acid Chemistry and NanomedicineInstitute of Molecular MedicineState Key Laboratory of Systems Medicine for CancerRenji HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai200127China
| | - Yan Zhou
- Department of RadiologyRenji HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai200127China
| | - Jinyao Liu
- Shanghai Key Laboratory for Nucleic Acid Chemistry and NanomedicineInstitute of Molecular MedicineState Key Laboratory of Systems Medicine for CancerRenji HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai200127China
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9
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Babes EE, Bustea C, Ilias TI, Babes VV, Luca SA, Luca CT, Radu AF, Tarce AG, Bungau AF, Bustea C. Multimodality Imaging Diagnosis in Infective Endocarditis. Life (Basel) 2023; 14:54. [PMID: 38255669 PMCID: PMC10821102 DOI: 10.3390/life14010054] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 12/20/2023] [Accepted: 12/26/2023] [Indexed: 01/24/2024] Open
Abstract
Imaging is an important tool in the diagnosis and management of infective endocarditis (IE). Echocardiography is an essential examination, especially in native valve endocarditis (NVE), but its diagnostic accuracy is reduced in prosthetic valve endocarditis (PVE). The diagnostic ability is superior for transoesophageal echocardiography (TEE), but a negative test cannot exclude PVE. Both transthoracic echocardiography (TTE) and TEE can provide normal or inconclusive findings in up to 30% of cases, especially in patients with prosthetic devices. New advanced non-invasive imaging tests are increasingly used in the diagnosis of IE. Nuclear medicine imaging techniques have demonstrated their superiority over TEE for the diagnosis of PVE and cardiac implantable electronic device infective endocarditis (CIED-IE). Cardiac computed tomography angiography imaging is useful in PVE cases with inconclusive TTE and TEE investigations and for the evaluation of paravalvular complications. In the present review, imaging tools are described with their values and limitations for improving diagnosis in NVE, PVE and CIED-IE. Current knowledge about multimodality imaging approaches in IE and imaging methods to assess the local and distant complications of IE is also reviewed. Furthermore, a potential diagnostic work-up for different clinical scenarios is described. However, further studies are essential for refining diagnostic and management approaches in infective endocarditis, addressing limitations and optimizing advanced imaging techniques across different clinical scenarios.
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Affiliation(s)
- Elena Emilia Babes
- Doctoral School of Biomedical Sciences, University of Oradea, 410087 Oradea, Romania; (E.E.B.); (A.-F.R.); (A.F.B.)
- Department of Medical Disciplines, Faculty of Medicine and Pharmacy, University of Oradea, 410073 Oradea, Romania; (T.I.I.); (V.V.B.)
| | - Cristiana Bustea
- Department of Preclinical Disciplines, Faculty of Medicine and Pharmacy, University of Oradea, 410073 Oradea, Romania
| | - Tiberia Ioana Ilias
- Department of Medical Disciplines, Faculty of Medicine and Pharmacy, University of Oradea, 410073 Oradea, Romania; (T.I.I.); (V.V.B.)
| | - Victor Vlad Babes
- Department of Medical Disciplines, Faculty of Medicine and Pharmacy, University of Oradea, 410073 Oradea, Romania; (T.I.I.); (V.V.B.)
| | - Silvia-Ana Luca
- Department of Cardiology, “Victor Babes” University of Medicine and Pharmacy, 300041 Timisoara, Romania;
- Institute of Cardiovascular Diseases Timisoara, 300310 Timisoara, Romania
- Research Center of the Institute of Cardiovascular Diseases Timisoara, 300310 Timisoara, Romania
| | - Constantin Tudor Luca
- Department of Cardiology, “Victor Babes” University of Medicine and Pharmacy, 300041 Timisoara, Romania;
- Institute of Cardiovascular Diseases Timisoara, 300310 Timisoara, Romania
- Research Center of the Institute of Cardiovascular Diseases Timisoara, 300310 Timisoara, Romania
| | - Andrei-Flavius Radu
- Doctoral School of Biomedical Sciences, University of Oradea, 410087 Oradea, Romania; (E.E.B.); (A.-F.R.); (A.F.B.)
- Department of Preclinical Disciplines, Faculty of Medicine and Pharmacy, University of Oradea, 410073 Oradea, Romania
| | - Alexandra Georgiana Tarce
- Medicine Program of Study, Faculty of Medicine and Pharmacy, University of Oradea, 410073 Oradea, Romania;
| | - Alexa Florina Bungau
- Doctoral School of Biomedical Sciences, University of Oradea, 410087 Oradea, Romania; (E.E.B.); (A.-F.R.); (A.F.B.)
- Department of Preclinical Disciplines, Faculty of Medicine and Pharmacy, University of Oradea, 410073 Oradea, Romania
| | - Cristian Bustea
- Department of Surgery, Oradea County Emergency Clinical Hospital, 410169 Oradea, Romania;
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10
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Lee SH, Kim JM, López-Álvarez M, Wang C, Sorlin AM, Bobba KN, Pichardo-González PA, Blecha J, Seo Y, Flavell RR, Engel J, Ohliger MA, Wilson DM. Imaging the Bacterial Cell Wall Using N-Acetyl Muramic Acid-Derived Positron Emission Tomography Radiotracers. ACS Sens 2023; 8:4554-4565. [PMID: 37992233 PMCID: PMC10749472 DOI: 10.1021/acssensors.3c01477] [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: 07/18/2023] [Revised: 10/10/2023] [Accepted: 11/07/2023] [Indexed: 11/24/2023]
Abstract
Imaging infections in patients is challenging using conventional methods, motivating the development of positron emission tomography (PET) radiotracers targeting bacteria-specific metabolic pathways. Numerous techniques have focused on the bacterial cell wall, although peptidoglycan-targeted PET tracers have been generally limited to the short-lived carbon-11 radioisotope (t1/2 = 20.4 min). In this article, we developed and tested new tools for infection imaging using an amino sugar component of peptidoglycan, namely, derivatives of N-acetyl muramic acid (NAM) labeled with the longer-lived fluorine-18 (t1/2 = 109.6 min) radioisotope. Muramic acid was reacted directly with 4-nitrophenyl 2-[18F]fluoropropionate ([18F]NFP) to afford the enantiomeric NAM derivatives (S)-[18F]FMA and (R)-[18F]FMA. Both diastereomers were easily isolated and showed robust accumulation by human pathogens in vitro and in vivo, including Staphylococcus aureus. These results form the basis for future clinical studies using fluorine-18-labeled NAM-derived PET radiotracers.
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Affiliation(s)
- Sang Hee Lee
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San
Francisco, California 94158, United States
| | - Jung Min Kim
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San
Francisco, California 94158, United States
| | - Marina López-Álvarez
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San
Francisco, California 94158, United States
| | - Chao Wang
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San
Francisco, California 94158, United States
| | - Alexandre M. Sorlin
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San
Francisco, California 94158, United States
| | - Kondapa Naidu Bobba
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San
Francisco, California 94158, United States
| | - Priamo A. Pichardo-González
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San
Francisco, California 94158, United States
| | - Joseph Blecha
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San
Francisco, California 94158, United States
| | - Youngho Seo
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San
Francisco, California 94158, United States
| | - Robert R. Flavell
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San
Francisco, California 94158, United States
- UCSF
Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, California 94158, United States
- Department
of Pharmaceutical Chemistry, University
of California, San Francisco, San
Francisco, California 94158, United States
| | - Joanne Engel
- Department
of Medicine, University of California, San
Francisco, San Francisco, California 94158, United States
- Department
of Microbiology and Immunology, University
of California, San Francisco, San
Francisco, California 94158, United States
| | - Michael A. Ohliger
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San
Francisco, California 94158, United States
- Department
of Radiology, Zuckerberg San Francisco General
Hospital, San Francisco, California 94110, United States
| | - David M. Wilson
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San
Francisco, California 94158, United States
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11
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Parker MFL, López-Álvarez M, Alanizi AA, Luu JM, Polvoy I, Sorlin AM, Qin H, Lee S, Rabbitt SJ, Pichardo-González PA, Ordonez AA, Blecha J, Rosenberg OS, Flavell RR, Engel J, Jain SK, Ohliger MA, Wilson DM. Evaluating the Performance of Pathogen-Targeted Positron Emission Tomography Radiotracers in a Rat Model of Vertebral Discitis-Osteomyelitis. J Infect Dis 2023; 228:S281-S290. [PMID: 37788505 PMCID: PMC11009497 DOI: 10.1093/infdis/jiad159] [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] [Indexed: 10/05/2023] Open
Abstract
BACKGROUND Vertebral discitis-osteomyelitis (VDO) is a devastating infection of the spine that is challenging to distinguish from noninfectious mimics using computed tomography and magnetic resonance imaging. We and others have developed novel metabolism-targeted positron emission tomography (PET) radiotracers for detecting living Staphylococcus aureus and other bacteria in vivo, but their head-to-head performance in a well-validated VDO animal model has not been reported. METHODS We compared the performance of several PET radiotracers in a rat model of VDO. [11C]PABA and [18F]FDS were assessed for their ability to distinguish S aureus, the most common non-tuberculous pathogen VDO, from Escherichia coli. RESULTS In the rat S aureus VDO model, [11C]PABA could detect as few as 103 bacteria and exhibited the highest signal-to-background ratio, with a 20-fold increased signal in VDO compared to uninfected tissues. In a proof-of-concept experiment, detection of bacterial infection and discrimination between S aureus and E coli was possible using a combination of [11C]PABA and [18F]FDS. CONCLUSIONS Our work reveals that several bacteria-targeted PET radiotracers had sufficient signal to background in a rat model of S aureus VDO to be potentially clinically useful. [11C]PABA was the most promising tracer investigated and warrants further investigation in human VDO.
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Affiliation(s)
- Matthew F L Parker
- Department of Radiology and Biomedical Imaging, University of California, San Francisco
- Department of Psychiatry, Renaissance School of Medicine at Stony Brook University, New York
| | - Marina López-Álvarez
- Department of Radiology and Biomedical Imaging, University of California, San Francisco
| | - Aryn A Alanizi
- Department of Radiology and Biomedical Imaging, University of California, San Francisco
| | - Justin M Luu
- Department of Radiology and Biomedical Imaging, University of California, San Francisco
| | - Ilona Polvoy
- Department of Radiology and Biomedical Imaging, University of California, San Francisco
| | - Alexandre M Sorlin
- Department of Radiology and Biomedical Imaging, University of California, San Francisco
| | - Hecong Qin
- Department of Radiology and Biomedical Imaging, University of California, San Francisco
| | - Sanghee Lee
- Department of Radiology and Biomedical Imaging, University of California, San Francisco
| | - Sarah J Rabbitt
- Department of Radiology and Biomedical Imaging, University of California, San Francisco
| | | | - Alvaro A Ordonez
- Center for Infection and Inflammation Imaging Research, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Joseph Blecha
- Department of Radiology and Biomedical Imaging, University of California, San Francisco
| | | | - Robert R Flavell
- Department of Radiology and Biomedical Imaging, University of California, San Francisco
| | - Joanne Engel
- Department of Medicine, University of California, San Francisco
- UCSF Department of Microbiology and Immunology, San Francisco, California
| | - Sanjay K Jain
- Center for Infection and Inflammation Imaging Research, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Michael A Ohliger
- Department of Radiology and Biomedical Imaging, University of California, San Francisco
- Department of Radiology, Zuckerberg San Francisco General Hospital, San Francisco, California
| | - David M Wilson
- Department of Radiology and Biomedical Imaging, University of California, San Francisco
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12
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Chen X, Gallagher F, Sellmyer MA, Ordonez AA, Kjaer A, Ohliger M, Wilson DM, Jain SK. Visualizing Bacterial Infections With Novel Targeted Molecular Imaging Approaches. J Infect Dis 2023; 228:S249-S258. [PMID: 37788506 PMCID: PMC10547462 DOI: 10.1093/infdis/jiad078] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023] Open
Abstract
Although nearly a century has elapsed since the discovery of penicillin, bacterial infections remain a major global threat. Global antibiotic use resulted in an astounding 42 billion doses of antibiotics administered in 2015 with 128 billion annual doses expected by 2030. This overuse of antibiotics has led to the selection of multidrug-resistant "super-bugs," resulting in increasing numbers of patients being susceptible to life-threatening infections with few available therapeutic options. New clinical tools are therefore urgently needed to identify bacterial infections and monitor response to antibiotics, thereby limiting overuse of antibiotics and improving overall health. Next-generation molecular imaging affords unique opportunities to target and identify bacterial infections, enabling spatial characterization as well as noninvasive, temporal monitoring of the natural course of the disease and response to therapy. These emerging noninvasive imaging approaches could overcome several limitations of current tools in infectious disease, such as the need for biological samples for testing with their associated sampling bias. Imaging of living bacteria can also reveal basic biological insights about their behavior in vivo.
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Affiliation(s)
- Xueyi Chen
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Ferdia Gallagher
- Department of Radiology, University of Cambridge, Cambridge, United Kingdom
| | - Mark A Sellmyer
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Alvaro A Ordonez
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Andreas Kjaer
- Department of Clinical Physiology and Nuclear Medicine and Cluster for Molecular Imaging, Copenhagen University Hospital-Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Michael Ohliger
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California, USA
| | - David M Wilson
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California, USA
| | - Sanjay K Jain
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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13
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Sorlin A, López-Álvarez M, Rabbitt SJ, Alanizi AA, Shuere R, Bobba KN, Blecha J, Sakhamuri S, Evans MJ, Bayles KW, Flavell RR, Rosenberg OS, Sriram R, Desmet T, Nidetzky B, Engel J, Ohliger MA, Fraser JS, Wilson DM. Chemoenzymatic Syntheses of Fluorine-18-Labeled Disaccharides from [ 18F] FDG Yield Potent Sensors of Living Bacteria In Vivo. J Am Chem Soc 2023; 145:17632-17642. [PMID: 37535945 PMCID: PMC10436271 DOI: 10.1021/jacs.3c03338] [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: 03/30/2023] [Indexed: 08/05/2023]
Abstract
Chemoenzymatic techniques have been applied extensively to pharmaceutical development, most effectively when routine synthetic methods fail. The regioselective and stereoselective construction of structurally complex glycans is an elegant application of this approach that is seldom applied to positron emission tomography (PET) tracers. We sought a method to dimerize 2-deoxy-[18F]-fluoro-d-glucose ([18F]FDG), the most common tracer used in clinical imaging, to form [18F]-labeled disaccharides for detecting microorganisms in vivo based on their bacteria-specific glycan incorporation. When [18F]FDG was reacted with β-d-glucose-1-phosphate in the presence of maltose phosphorylase, the α-1,4- and α-1,3-linked products 2-deoxy-[18F]-fluoro-maltose ([18F]FDM) and 2-deoxy-2-[18F]-fluoro-sakebiose ([18F]FSK) were obtained. This method was further extended with the use of trehalose (α,α-1,1), laminaribiose (β-1,3), and cellobiose (β-1,4) phosphorylases to synthesize 2-deoxy-2-[18F]fluoro-trehalose ([18F]FDT), 2-deoxy-2-[18F]fluoro-laminaribiose ([18F]FDL), and 2-deoxy-2-[18F]fluoro-cellobiose ([18F]FDC). We subsequently tested [18F]FDM and [18F]FSK in vitro, showing accumulation by several clinically relevant pathogens including Staphylococcus aureus and Acinetobacter baumannii, and demonstrated their specific uptake in vivo. Both [18F]FDM and [18F]FSK were stable in human serum with high accumulation in preclinical infection models. The synthetic ease and high sensitivity of [18F]FDM and [18F]FSK to S. aureus including methicillin-resistant (MRSA) strains strongly justify clinical translation of these tracers to infected patients. Furthermore, this work suggests that chemoenzymatic radiosyntheses of complex [18F]FDG-derived oligomers will afford a wide array of PET radiotracers for infectious and oncologic applications.
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Affiliation(s)
- Alexandre
M. Sorlin
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Marina López-Álvarez
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Sarah J. Rabbitt
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Aryn A. Alanizi
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Rebecca Shuere
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Kondapa Naidu Bobba
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Joseph Blecha
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Sasank Sakhamuri
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Michael J. Evans
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Kenneth W. Bayles
- Department
of Pathology and Microbiology, University
of Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Robert R. Flavell
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Oren S. Rosenberg
- Department
of Medicine University of California, San
Francisco, San Francisco, California 94158, United States
| | - Renuka Sriram
- Department
of Biotechnology, Ghent University, Gent B-9000, Belgium
| | - Tom Desmet
- Department
of Biotechnology, Ghent University, Gent B-9000, Belgium
| | - Bernd Nidetzky
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, Graz 8010, Austria
| | - Joanne Engel
- Department
of Biotechnology, Ghent University, Gent B-9000, Belgium
| | - Michael A. Ohliger
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
- Department
of Radiology Zuckerberg San Francisco General
Hospital, San Francisco, California 94110, United States
| | - James S. Fraser
- Department
of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, California 94158, United States
| | - David M. Wilson
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
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14
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Sorlin AM, López-Álvarez M, Rabbitt SJ, Alanizi AA, Shuere R, Bobba KN, Blecha J, Sakhamuri S, Evans MJ, Bayles KW, Flavell RR, Rosenberg OS, Sriram R, Desmet T, Nidetzky B, Engel J, Ohliger MA, Fraser JS, Wilson DM. Chemoenzymatic syntheses of fluorine-18-labeled disaccharides from [ 18 F]FDG yield potent sensors of living bacteria in vivo. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.20.541529. [PMID: 37293043 PMCID: PMC10245702 DOI: 10.1101/2023.05.20.541529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Chemoenzymatic techniques have been applied extensively to pharmaceutical development, most effectively when routine synthetic methods fail. The regioselective and stereoselective construction of structurally complex glycans is an elegant application of this approach, that is seldom applied to positron emission tomography (PET) tracers. We sought a method to dimerize 2-deoxy-[ 18 F]-fluoro-D-glucose ([ 18 F]FDG), the most common tracer used in clinical imaging, to form [ 18 F]-labeled disaccharides for detecting microorganisms in vivo based on their bacteria-specific glycan incorporation. When [ 18 F]FDG was reacted with β-D-glucose-1-phosphate in the presence of maltose phosphorylase, both the α-1,4 and α-1,3-linked products 2-deoxy-[ 18 F]-fluoro-maltose ([ 18 F]FDM) and 2-deoxy-2-[ 18 F]-fluoro-sakebiose ([ 18 F]FSK) were obtained. This method was further extended with the use of trehalose (α,α-1,1), laminaribiose (β-1,3), and cellobiose (β-1,4) phosphorylases to synthesize 2-deoxy-2-[ 18 F]fluoro-trehalose ([ 18 F]FDT), 2-deoxy-2-[ 18 F]fluoro-laminaribiose ([ 18 F]FDL), and 2-deoxy-2-[ 18 F]fluoro-cellobiose ([ 18 F]FDC). We subsequently tested [ 18 F]FDM and [ 18 F]FSK in vitro, showing accumulation by several clinically relevant pathogens including Staphylococcus aureus and Acinetobacter baumannii, and demonstrated their specific uptake in vivo. The lead sakebiose-derived tracer [ 18 F]FSK was stable in human serum and showed high uptake in preclinical models of myositis and vertebral discitis-osteomyelitis. Both the synthetic ease, and high sensitivity of [ 18 F]FSK to S. aureus including methicillin-resistant (MRSA) strains strongly justify clinical translation of this tracer to infected patients. Furthermore, this work suggests that chemoenzymatic radiosyntheses of complex [ 18 F]FDG-derived oligomers will afford a wide array of PET radiotracers for infectious and oncologic applications.
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15
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Abstract
Bacterial infections are a major threat to human health. Rapid and accurate diagnosis of bacterial infections is essential for early interventions and rational use of antibiotic treatments. However, antibiotics are often initiated empirically while diagnostic tests are being performed. Moreover, traditional diagnostic tools, namely microscopy, microbiology and molecular techniques, are dependent upon sampling suspected sites of infection, and then performing tests. This approach is often invasive, labor intensive, time consuming, and subject to the uncertainties of incorrect sampling and contamination. There are currently no imaging approaches for the specific detection of bacterial infections. Therefore, there is a need for new noninvasive approaches to detect, localize and monitor bacterial infections with high sensitivity and specificity.
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Affiliation(s)
- Sanjay K Jain
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, MD; Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, MD; Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD.
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16
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Maeda Y, Murakami T. Diagnosis by Microbial Culture, Breath Tests and Urinary Excretion Tests, and Treatments of Small Intestinal Bacterial Overgrowth. Antibiotics (Basel) 2023; 12:antibiotics12020263. [PMID: 36830173 PMCID: PMC9952535 DOI: 10.3390/antibiotics12020263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/19/2023] [Accepted: 01/19/2023] [Indexed: 01/31/2023] Open
Abstract
Small intestinal bacterial overgrowth (SIBO) is characterized as the increase in the number and/or alteration in the type of bacteria in the upper gastrointestinal tract and accompanies various bowel symptoms such as abdominal pain, bloating, gases, diarrhea, and so on. Clinically, SIBO is diagnosed by microbial culture in duodenum/jejunum fluid aspirates and/or the breath tests (BT) of hydrogen/methane gases after ingestion of carbohydrates such as glucose. The cultural analysis of aspirates is regarded as the golden standard for the diagnosis of SIBO; however, this is invasive and is not without risk to the patients. BT is an inexpensive and safe diagnostic test but lacks diagnostic sensitivity and specificity depending on the disease states of patients. Additionally, the urinary excretion tests are used for the SIBO diagnosis using chemically synthesized bile acid conjugates such as cholic acid (CA) conjugated with para-aminobenzoic acid (PABA-CA), ursodeoxycholic acid (UDCA) conjugated with PABA (PABA-UDCA) or conjugated with 5-aminosalicylic acid (5-ASA-UDCA). These conjugates are split by bacterial bile acid (cholylglycine) hydrolase. In the tests, the time courses of the urinary excretion rates of PABA or 5-ASA, including their metabolites, are determined as the measure of hydrolytic activity of intestinal bacteria. Although the number of clinical trials with this urinary excretion tests is small, results demonstrated the usefulness of bile acid conjugates as SIBO diagnostic substrates. PABA-UDCA disulfate, a single-pass type unabsorbable compound without the hydrolysis of conjugates, was likely to offer a simple and rapid method for the evaluation of SIBO without the use of radioisotopes or expensive special apparatus. Treatments of SIBO with antibiotics, probiotics, therapeutic diets, herbal medicines, and/or fecal microbiota transplantation are also reviewed.
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Affiliation(s)
- Yorinobu Maeda
- Laboratory of Drug Information Analytics, Faculty of Pharmacy & Pharmaceutical Sciences, Fukuyama University, Sanzou, Gakuen-cho, Fukuyama 729-0292, Hiroshima, Japan
| | - Teruo Murakami
- Faculty of Pharmaceutical Sciences, Hiroshima International University, 5-1-1 Hiro-koshingai, Kure 737-0112, Hiroshima, Japan
- Correspondence: ; Tel.: +81-82-872-4310
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17
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Chen D, Guo J, Li A, Sun C, Lin H, Lin H, Yang C, Wang W, Gao J. Metabolic fluorine labeling and hotspot imaging of dynamic gut microbiota in mice. SCIENCE ADVANCES 2023; 9:eabg6808. [PMID: 36706178 PMCID: PMC9882976 DOI: 10.1126/sciadv.abg6808] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 12/23/2022] [Indexed: 06/18/2023]
Abstract
Real-time localization and microbial activity information of indigenous gut microbiota over an extended period of time remains a challenge with existing visualizing methods. Here, we report a metabolic fluorine labeling (MEFLA)-based strategy for monitoring the dynamic gut microbiota via 19F magnetic resonance imaging (19F MRI). In situ labeling of different microbiota subgroups is achieved by using a panel of peptidoglycan-targeting MEFLA probes containing 19F atoms of different chemical shifts, and subsequent real-time in vivo imaging is accomplished by multiplexed hotspot 19F MRI with high sensitivity and unlimited penetration. Using this method, we realize extended visualization (>24 hours) of native gut microbes located at different intestinal sections and semiquantitative analysis of their metabolic dynamics modulated by various conditions, such as the host death and different β-lactam antibiotics. Our strategy holds great potential for noninvasive and real-time assessing of the metabolic activities and locations of the highly dynamic gut microbiota.
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Affiliation(s)
- Dongxia Chen
- Department of Chemical Biology, The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, Fujian Provincial Key Laboratory of Chemical Biology, and State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Junnan Guo
- Department of Chemical Biology, The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, Fujian Provincial Key Laboratory of Chemical Biology, and State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Ao Li
- Department of Chemical Biology, The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, Fujian Provincial Key Laboratory of Chemical Biology, and State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Chengjie Sun
- Department of Chemical Biology, The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, Fujian Provincial Key Laboratory of Chemical Biology, and State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Huibin Lin
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acid Chemistry and Nanomedicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Hongyu Lin
- Department of Chemical Biology, The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, Fujian Provincial Key Laboratory of Chemical Biology, and State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Chaoyong Yang
- Department of Chemical Biology, The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, Fujian Provincial Key Laboratory of Chemical Biology, and State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acid Chemistry and Nanomedicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Wei Wang
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acid Chemistry and Nanomedicine, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China
| | - Jinhao Gao
- Department of Chemical Biology, The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, Fujian Provincial Key Laboratory of Chemical Biology, and State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
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18
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Microbiota in vivo imaging approaches to study host-microbe interactions in preclinical and clinical setting. Heliyon 2022; 8:e12511. [PMID: 36593827 PMCID: PMC9803719 DOI: 10.1016/j.heliyon.2022.e12511] [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: 05/25/2022] [Revised: 10/14/2022] [Accepted: 12/13/2022] [Indexed: 12/24/2022] Open
Abstract
In vivo imaging in preclinical and clinical settings can enhance knowledge of the host-microbiome interactions. Imaging techniques are a crucial node between findings at the molecular level and clinical implementation in diagnostics and therapeutics. The purpose of this study was to review existing knowledge on the microbiota in the field of in vivo imaging and provide guidance for future research, emphasizing the critical role that molecular imaging plays in increasing understanding of the host-microbe interaction. Preclinical microbiota animal models lay the foundation for the clinical translatability of novel microbiota-based therapeutics. Adopting animal models in which factors such as host genetic landscape, microbiota profile, and diet can be controlled enables investigating how the microbiota contributes to immunological dysregulation and inflammatory disorders. Current preclinical imaging of gut microbiota relies on models where the bacteria can be isolated, labelled, and re-administered. In vivo, optical imaging, ultrasound and magnetic resonance imaging define the bacteria's biodistribution in preclinical models, whereas nuclear imaging investigates bacterial metabolic activity. For the clinical investigation of microbe-host interactions, molecular nuclear imaging is increasingly becoming a promising approach. Future microbiota research should develop selective imaging probes to investigate in vivo microbiota profiles and individual strains of specific microbes. Preclinical knowledge can be translated into the molecular imaging field with great opportunities for studying the microbiome.
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19
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Shegani A, Kealey S, Luzi F, Basagni F, Machado JDM, Ekici SD, Ferocino A, Gee AD, Bongarzone S. Radiosynthesis, Preclinical, and Clinical Positron Emission Tomography Studies of Carbon-11 Labeled Endogenous and Natural Exogenous Compounds. Chem Rev 2022; 123:105-229. [PMID: 36399832 PMCID: PMC9837829 DOI: 10.1021/acs.chemrev.2c00398] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The presence of positron emission tomography (PET) centers at most major hospitals worldwide, along with the improvement of PET scanner sensitivity and the introduction of total body PET systems, has increased the interest in the PET tracer development using the short-lived radionuclides carbon-11. In the last few decades, methodological improvements and fully automated modules have allowed the development of carbon-11 tracers for clinical use. Radiolabeling natural compounds with carbon-11 by substituting one of the backbone carbons with the radionuclide has provided important information on the biochemistry of the authentic compounds and increased the understanding of their in vivo behavior in healthy and diseased states. The number of endogenous and natural compounds essential for human life is staggering, ranging from simple alcohols to vitamins and peptides. This review collates all the carbon-11 radiolabeled endogenous and natural exogenous compounds synthesised to date, including essential information on their radiochemistry methodologies and preclinical and clinical studies in healthy subjects.
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Affiliation(s)
- Antonio Shegani
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Steven Kealey
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Federico Luzi
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Filippo Basagni
- Department
of Pharmacy and Biotechnology, Alma Mater
Studiorum−University of Bologna, via Belmeloro 6, 40126 Bologna, Italy
| | - Joana do Mar Machado
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Sevban Doğan Ekici
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom
| | - Alessandra Ferocino
- Institute
of Organic Synthesis and Photoreactivity, Italian National Research Council, via Piero Gobetti 101, 40129 Bologna, Italy
| | - Antony D. Gee
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom,A.G.: email,
| | - Salvatore Bongarzone
- School
of Biomedical Engineering & Imaging Sciences, King’s College London, King’s Health Partners, St Thomas’ Hospital, London SE1 7EH, United Kingdom,S.B.:
email,
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20
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Lee IK, Jacome DA, Cho JK, Tu V, Young AJ, Dominguez T, Northrup JD, Etersque JM, Lee HS, Ruff A, Aklilu O, Bittinger K, Glaser LJ, Dorgan D, Hadjiliadis D, Kohli RM, Mach RH, Mankoff DA, Doot RK, Sellmyer MA. Imaging sensitive and drug-resistant bacterial infection with [11C]-trimethoprim. J Clin Invest 2022; 132:156679. [PMID: 36106638 PMCID: PMC9479701 DOI: 10.1172/jci156679] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 07/19/2022] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Several molecular imaging strategies can identify bacterial infections in humans. PET affords the potential for sensitive infection detection deep within the body. Among PET-based approaches, antibiotic-based radiotracers, which often target key bacterial-specific enzymes, have considerable promise. One question for antibiotic radiotracers is whether antimicrobial resistance (AMR) reduces specific accumulation within bacteria, diminishing the predictive value of the diagnostic test. METHODS Using a PET radiotracer based on the antibiotic trimethoprim (TMP), [11C]-TMP, we performed in vitro uptake studies in susceptible and drug-resistant bacterial strains and whole-genome sequencing (WGS) in selected strains to identify TMP resistance mechanisms. Next, we queried the NCBI database of annotated bacterial genomes for WT and resistant dihydrofolate reductase (DHFR) genes. Finally, we initiated a first-in-human protocol of [11C]-TMP in patients infected with both TMP-sensitive and TMP-resistant organisms to demonstrate the clinical feasibility of the tool. RESULTS We observed robust [11C]-TMP uptake in our panel of TMP-sensitive and -resistant bacteria, noting relatively variable and decreased uptake in a few strains of P. aeruginosa and E. coli. WGS showed that the vast majority of clinically relevant bacteria harbor a WT copy of DHFR, targetable by [11C]-TMP, and that despite the AMR, these strains should be “imageable.” Clinical imaging of patients with [11C]-TMP demonstrated focal radiotracer uptake in areas of infectious lesions. CONCLUSION This work highlights an approach to imaging bacterial infection in patients, which could affect our understanding of bacterial pathogenesis as well as our ability to better diagnose infections and monitor response to therapy. TRIAL REGISTRATION ClinicalTrials.gov NCT03424525. FUNDING Institute for Translational Medicine and Therapeutics, Burroughs Wellcome Fund, NIH Office of the Director Early Independence Award (DP5-OD26386), and University of Pennsylvania NIH T32 Radiology Research Training Grant (5T32EB004311-12).
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Affiliation(s)
- Iris K. Lee
- Department of Radiology and
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | | | - Vincent Tu
- Department of Gastroenterology, Hepatology and Nutrition, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | | | | | | | - Jean M. Etersque
- Department of Radiology and
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | | | | | - Kyle Bittinger
- Department of Gastroenterology, Hepatology and Nutrition, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Laurel J. Glaser
- Department of Pathology and Laboratory Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Daniel Dorgan
- Department of Medicine, Division of Allergy, Pulmonary, and Critical Care Medicine, and
| | - Denis Hadjiliadis
- Department of Medicine, Division of Allergy, Pulmonary, and Critical Care Medicine, and
| | - Rahul M. Kohli
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Medicine, Division of Infectious Disease, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | | | | | - Mark A. Sellmyer
- Department of Radiology and
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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21
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Abstract
The authors define molecular imaging, according to the Society of Nuclear Medicine and Molecular Imaging, as the visualization, characterization, and measurement of biological processes at the molecular and cellular levels in humans and other living systems. Although practiced for many years clinically in nuclear medicine, expansion to other imaging modalities began roughly 25 years ago and has accelerated since. That acceleration derives from the continual appearance of new and highly relevant animal models of human disease, increasingly sensitive imaging devices, high-throughput methods to discover and optimize affinity agents to key cellular targets, new ways to manipulate genetic material, and expanded use of cloud computing. Greater interest by scientists in allied fields, such as chemistry, biomedical engineering, and immunology, as well as increased attention by the pharmaceutical industry, have likewise contributed to the boom in activity in recent years. Whereas researchers and clinicians have applied molecular imaging to a variety of physiologic processes and disease states, here, the authors focus on oncology, arguably where it has made its greatest impact. The main purpose of imaging in oncology is early detection to enable interception if not prevention of full-blown disease, such as the appearance of metastases. Because biochemical changes occur before changes in anatomy, molecular imaging-particularly when combined with liquid biopsy for screening purposes-promises especially early localization of disease for optimum management. Here, the authors introduce the ways and indications in which molecular imaging can be undertaken, the tools used and under development, and near-term challenges and opportunities in oncology.
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Affiliation(s)
- Steven P. Rowe
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Martin G. Pomper
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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22
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Erba PA, Bartoli F, Sollini M, Raffaella B, Zanca R, Enrica E, Lazzeri E. Alternative Nuclear Imaging Tools for Infection Imaging. Curr Cardiol Rep 2022; 24:879-891. [PMID: 35696046 PMCID: PMC9288362 DOI: 10.1007/s11886-022-01708-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/21/2022] [Indexed: 11/30/2022]
Abstract
Purpose of Review Cardiovascular infections are serious disease associated with high morbidity and mortality. Their diagnosis is challenging, requiring a proper management for a prompt recognition of the clinical manifestations, and a multidisciplinary approach involving cardiologists, cardiothoracic surgeons, infectious diseases specialist, imagers, and microbiologists. Imaging plays a central role in the diagnostic workout, including molecular imaging techniques. In this setting, two different strategies might be used to image infections: the first is based on the use of agents targeting the microorganism responsible for the infection. Alternatively, we can target the components of the pathophysiological changes of the inflammatory process and/or the host response to the infectious pathogen can be considered. Understanding the strength and limitations of each strategy is crucial to select the most appropriate imaging tool. Recent Findings Currently, multislice computed tomography (MSCT) and nuclear imaging (18F-fluorodeoxyglucose positron emission tomography/computed tomography, and leucocyte scintigraphy) are part of the diagnostic strategies. The main role of nuclear medicine imaging (PET/CT and SPECT/CT) is the confirmation of valve/CIED involvement and/or associated perivalvular infection and the detection of distant septic embolism. Proper patients’ preparation, imaging acquisition, and reconstruction as well as imaging reading are crucial to maximize the diagnostic information. Summary In this manuscript, we described the use of molecular imaging techniques, in particular WBC imaging, in patients with infective endocarditis, cardiovascular implantable electronic device infections, and infections of composite aortic graft, underlying the strength and limitations of such approached as compared to the other imaging modalities.
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Affiliation(s)
- Paola Anna Erba
- Regional Center of Nuclear Medicine, Department of Translational Research and Advanced Technologies in Medicine and Surgery, University of Pisa, Via Roma 57, 56126, Pisa, Italy.
- Medical Imaging Center, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
| | - Francesco Bartoli
- Regional Center of Nuclear Medicine, Department of Translational Research and Advanced Technologies in Medicine and Surgery, University of Pisa, Via Roma 57, 56126, Pisa, Italy
| | - Martina Sollini
- Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Italy
- IRCCS Humanitas Research Hospital, Rozzano, Italy
| | - Berchiolli Raffaella
- Vascular Surgery Unit, Department of Translational Research and Advanced Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Roberta Zanca
- Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Italy
- IRCCS Humanitas Research Hospital, Rozzano, Italy
| | - Esposito Enrica
- Regional Center of Nuclear Medicine, Department of Translational Research and Advanced Technologies in Medicine and Surgery, University of Pisa, Via Roma 57, 56126, Pisa, Italy
| | - Elena Lazzeri
- Regional Center of Nuclear Medicine, Department of Translational Research and Advanced Technologies in Medicine and Surgery, University of Pisa, Via Roma 57, 56126, Pisa, Italy
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23
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Woong Yoo S, Young Kwon S, Kang SR, Min JJ. Molecular imaging approaches to facilitate bacteria-mediated cancer therapy. Adv Drug Deliv Rev 2022; 187:114366. [PMID: 35654213 DOI: 10.1016/j.addr.2022.114366] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 05/06/2022] [Accepted: 05/25/2022] [Indexed: 12/14/2022]
Abstract
Bacteria-mediated cancer therapy is a potential therapeutic strategy for cancer that has unique properties, including broad tumor-targeting ability, various administration routes, the flexibility of delivery, and facilitating the host's immune responses. The molecular imaging of bacteria-mediated cancer therapy allows the therapeutically injected bacteria to be visualized and confirms the accurate delivery of the therapeutic bacteria to the target lesion. Several hurdles make bacteria-specific imaging challenging, including the need to discriminate therapeutic bacterial infection from inflammation or other pathologic lesions. To realize the full potential of bacteria-specific imaging, it is necessary to develop bacteria-specific targets that can be associated with an imaging assay. This review describes the current status of bacterial imaging techniques together with the advantages and disadvantages of several imaging modalities. Also, we describe potential targets for bacterial-specific imaging and related applications.
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Affiliation(s)
- Su Woong Yoo
- Department of Nuclear Medicine, Chonnam National University Hwasun Hospital, Hwasun, Jeonnam, Korea
| | - Seong Young Kwon
- Department of Nuclear Medicine, Chonnam National University Hwasun Hospital, Hwasun, Jeonnam, Korea; Department of Nuclear Medicine, Chonnam National University Medical School, Hwasun, Jeonnam, Korea
| | - Sae-Ryung Kang
- Department of Nuclear Medicine, Chonnam National University Hwasun Hospital, Hwasun, Jeonnam, Korea
| | - Jung-Joon Min
- Department of Nuclear Medicine, Chonnam National University Hwasun Hospital, Hwasun, Jeonnam, Korea; Department of Nuclear Medicine, Chonnam National University Medical School, Hwasun, Jeonnam, Korea.
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24
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MicroPET imaging of bacterial infection with nitroreductase-specific responsive 18F-labelled nitrogen mustard analogues. Eur J Nucl Med Mol Imaging 2022; 49:2645-2654. [PMID: 35122512 DOI: 10.1007/s00259-022-05710-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 01/26/2022] [Indexed: 11/04/2022]
Abstract
PURPOSE Bacterial infection and antibiotic resistance are serious threats to human health. This study aimed to develop two novel radiotracers, 18F-NTRP and 18F-NCRP, that possess a specific nitroreductase (NTR) response to image deep-seated bacterial infections using positron emission tomography (PET). This method can distinguish infection from sterile inflammation. METHODS 18F-NTRP and 18F-NCRP were synthesized via a one-step method; all the steps usually involved in tracer radiosynthesis were successfully adapted in the All-In-One automated module. After the physiochemical properties of 18F-NTRP and 18F-NCRP were characterized, their specificity and selectivity for NTR were verified in E. coli and S. aureus. The ex vivo biodistribution of the tracers was evaluated in normal mice. MicroPET-CT imaging was performed in mouse models of bacterial infection and inflammation after the administration of 18F-NTRP or 18F-NCRP. RESULTS Fully automated radiosynthesis of 18F-NTRP and 18F-NCRP was achieved within 90-110 min with overall decay-uncorrected, isolated radiochemical yields of 21.24 ± 4.25% and 11.3 ± 3.78%, respectively. The molar activities of 18F-NTRP and 18F-NCRP were 320 ± 40 GBq/μmol and 275 ± 33 GBq/µmol, respectively. In addition, 18F-NTRP and 18F-NCRP exhibited high selectivity and specificity for NTR response. PET-CT imaging in bacteria-infected mouse models with 18F-NTRP or 18F-NCRP showed significant radioactivity uptake in either E. coli- or S. aureus-infected muscles. The uptake for E. coli-infected muscles, 2.4 ± 0.2%ID/g with 18F-NTRP and 4.05 ± 0.49%ID/g with 18F-NCRP, was up to three times greater than that for uninfected control muscles. Furthermore, for both 18F-NTRP and 18F-NCRP, the uptake in bacterial infection was 2.6 times higher than that in sterile inflammation, allowing an effective distinction of infection from inflammation. CONCLUSION 18F-NTRP and 18F-NCRP are worth further investigation to verify their potential clinical application for distinguishing bacterial infection from sterile inflammation via their specific NTR responsiveness.
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25
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Ordonez AA, Parker MF, Miller RJ, Plyku D, Ruiz-Bedoya CA, Tucker EW, Luu JM, Dikeman DA, Lesniak WG, Holt DP, Dannals RF, Miller LS, Rowe SP, Wilson DM, Jain SK. 11C-Para-aminobenzoic acid PET imaging of S. aureus and MRSA infection in preclinical models and humans. JCI Insight 2022; 7:154117. [PMID: 35014627 PMCID: PMC8765043 DOI: 10.1172/jci.insight.154117] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Tools for noninvasive detection of bacterial pathogens are needed but are not currently available for clinical use. We have previously shown that para-aminobenzoic acid (PABA) rapidly accumulates in a wide range of pathogenic bacteria, motivating the development of related PET radiotracers. In this study, 11C-PABA PET imaging was used to accurately detect and monitor infections due to pyogenic bacteria in multiple clinically relevant animal models. 11C-PABA PET imaging selectively detected infections in muscle, intervertebral discs, and methicillin-resistant Staphylococcus aureus–infected orthopedic implants. In what we believe to be first-in-human studies in healthy participants, 11C-PABA was safe, well-tolerated, and had a favorable biodistribution, with low background activity in the lungs, muscles, and brain. 11C-PABA has the potential for clinical translation to detect and localize a broad range of bacteria.
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Affiliation(s)
- Alvaro A Ordonez
- Center for Infection and Inflammation Imaging Research and.,Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Matthew Fl Parker
- Department of Radiology and Biomedical Imaging, UCSF, San Francisco, California, USA
| | | | - Donika Plyku
- Russell H. Morgan Department of Radiology and Radiological Sciences, and
| | - Camilo A Ruiz-Bedoya
- Center for Infection and Inflammation Imaging Research and.,Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Elizabeth W Tucker
- Center for Infection and Inflammation Imaging Research and.,Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Justin M Luu
- Department of Radiology and Biomedical Imaging, UCSF, San Francisco, California, USA
| | | | - Wojciech G Lesniak
- Russell H. Morgan Department of Radiology and Radiological Sciences, and
| | - Daniel P Holt
- Russell H. Morgan Department of Radiology and Radiological Sciences, and
| | - Robert F Dannals
- Russell H. Morgan Department of Radiology and Radiological Sciences, and
| | | | - Steven P Rowe
- Russell H. Morgan Department of Radiology and Radiological Sciences, and
| | - David M Wilson
- Department of Radiology and Biomedical Imaging, UCSF, San Francisco, California, USA
| | - Sanjay K Jain
- Center for Infection and Inflammation Imaging Research and.,Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Russell H. Morgan Department of Radiology and Radiological Sciences, and
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26
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Signore A, Conserva M, Varani M, Galli F, Lauri C, Velikyan I, Roivainen A. PET imaging of bacteria. Nucl Med Mol Imaging 2022. [DOI: 10.1016/b978-0-12-822960-6.00077-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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27
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Mota F, De Jesus P, Jain SK. Kit-based synthesis of 2-deoxy-2-[ 18F]-fluoro-D-sorbitol for bacterial imaging. Nat Protoc 2021; 16:5274-5286. [PMID: 34686858 PMCID: PMC8611807 DOI: 10.1038/s41596-021-00613-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 08/09/2021] [Indexed: 02/08/2023]
Abstract
Clinically available imaging tools for diagnosing infections rely on structural changes in the affected tissues. They therefore lack specificity and cannot differentiate between oncologic, inflammatory and infectious processes. We have developed 2-deoxy-2-[18F]fluoro-D-sorbitol (18F-FDS) as an imaging agent to visualize infections caused by Enterobacterales, which represent the largest group of bacterial pathogens in humans and are responsible for severe infections, often resulting in sepsis or death. A clinical study in 26 prospectively enrolled patients demonstrated that 18F-FDS positron emission tomography (PET) was safe, and could detect and localize infections due to drug-susceptible or multi-drug-resistant Enterobacterales strains as well as differentiate them from other pathologies (sterile inflammation or cancer). 18F-FDS is cleared almost exclusively through renal filtration and has also shown potential as a PET agent for functional renal imaging. Since most PET radionuclides have a short half-life, maximal clinical impact will require fast, on-demand synthesis with limited infrastructure and personnel. To meet this demand, we developed a kit-based solid phase method that uses commercially and widely available 2-deoxy-2-[18F]fluoro-D-glucose as the precursor and allows 18F-FDS to be produced and purified in one step at room temperature. The 18F-FDS kit consists of a solid-phase extraction cartridge packed with solid supported borohydride (MP-borohydride), which can be attached to a second cartridge to reduce pH. We evaluated the effects of different solid supported borohydride reagents, cartridge size, starting radioactivity, volumes and flow rates in the radiochemical yield and purity. The optimized protocol can be completed in <30 min and allows the synthesis of 18F-FDS in >70% radiochemical yield and >90% radiochemical purity.
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Affiliation(s)
- Filipa Mota
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA,Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Patricia De Jesus
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA,Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Sanjay K. Jain
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, MD, USA,Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD, USA,Correspondence and requests for materials should be addressed to Sanjay K. Jain.
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28
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Abstract
Most studies of gut microbiota have focused on relationships between a specific disease and the presence/abundance of one or a few bacterial species/genera. Whether the spatial and temporal distribution of gut microbiota, as a whole, affects or correlates with health is unknown, largely due to the absence of tools for dynamically monitoring the overall gut microbiota landscape inside living subjects. Here, we describe a novel, noninvasive, live imaging method for gut microbiota using 2-deoxy-2-[18F]fluoro-d-sorbitol (18F-FDS), a compound that specifically labeled gut bacteria in mice and hamsters following oral administration. Positron emission tomography-computed tomography (PET-CT) scanning showed that the radiolabel signal was concentrated in the gut (especially the large intestine), was absent when mice gut microbiota was depleted by antibiotic treatment, and was restored after transplanting antibiotic-treated mice with a fecal or probiotic bacterial mixture. Thus, 18F-FDS images microbiota, not gut tissue. The tissue distribution of 18F-FDS was the highest in the gut (∼3-fold higher than average), in contrast to 2-deoxy-2-[18F]fluoro-d-glucose, which concentrated in brain and many other organs. 2-[18F]fluoro-aminobenzoic acid, another bacterium-specific radioactive tracer, was unsuited for gut microbiota imaging due to unexpected stomach retention following oral administration. When similar gut microbiota imaging was done with hamsters, the spatial resolution increased significantly over that with mice, suggesting that even higher spatial resolution can be achieved with humans or large animals. Thus, our work establishes a new tool for noninvasive, live imaging of gut microbiota; the new tool may enable exploration of relationships between gut microbiota landscape and diseases in clinical settings. IMPORTANCE Gut microbiota dysbiosis correlates with many diseases, but such correlations derive mostly from relationships between one or a few bacteria and a particular disease. Since microbiota resemble complex forest ecosystems more closely than individual patches of trees, the overall landscape (spatial and temporal distribution) of gut bacteria may also affect/reflect disease development. Such a possibility has not been explored due to a lack of tools for directly visualizing natural landscape patterns of gut microbiota. The present work identified 2-deoxy-2-[18F]fluoro-d-sorbitol as a gut microbiota-specific radioactive tracer and developed a novel PET-CT scan-based imaging method that enables noninvasive, real-time imaging of the overall gut bacterial landscape. The method showed increased spatial resolution when hamsters replaced mice, suggesting that even higher spatial resolution could be achieved with larger animals such as humans. This novel technology establishes the feasibility of investigating spatial-temporal distribution dynamics of gut microbiota with many human diseases.
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29
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Ten Hove D, Slart RHJA, Sinha B, Glaudemans AWJM, Budde RPJ. 18F-FDG PET/CT in Infective Endocarditis: Indications and Approaches for Standardization. Curr Cardiol Rep 2021; 23:130. [PMID: 34363148 PMCID: PMC8346431 DOI: 10.1007/s11886-021-01542-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/18/2021] [Indexed: 12/13/2022]
Abstract
Purpose of Review Additional imaging modalities, such as FDG-PET/CT, have been included into the workup for patients with suspected infective endocarditis, according to major international guidelines published in 2015. The purpose of this review is to give an overview of FDG-PET/CT indications and standardized approaches in the setting of suspected infective endocarditis. Recent Findings There are two main indications for performing FDG-PET/CT in patients with suspected infective endocarditis: (i) detecting intracardiac infections and (ii) detection of (clinically silent) disseminated infectious disease. The diagnostic performance of FDG-PET/CT for intracardiac lesions depends on the presence of native valves, prosthetic valves, or implanted cardiac devices, with a sensitivity that is poor for native valve endocarditis and cardiac device-related lead infections, but much better for prosthetic valve endocarditis and cardiac device-related pocket infections. Specificity is high for all these indications. The detection of disseminated disease may also help establish the diagnosis and/or impact patient management. Summary Based on current evidence, FDG-PET/CT should be considered for detection of disseminated disease in suspected endocarditis. Absence of intracardiac lesions on FDG-PET/CT cannot rule out native valve endocarditis, but positive findings strongly support the diagnosis. For prosthetic valve endocarditis, standard use of FDG-PET/CT is recommended because of its high sensitivity and specificity. For implanted cardiac devices, FDG-PET/CT is also recommended, but should be evaluated with careful attention to clinical context, because its sensitivity is high for pocket infections, but low for lead infections. In patients with prosthetic valves with or without additional aortic prosthesis, combination with CTA should be considered. Optimal timing of FDG-PET/CT is important, both during clinical workup and technically (i.e., post tracer injection). In addition, procedural standardization is key and encompasses patient preparation, scan acquisition, reconstruction, subsequent analysis, and clinical interpretation. The recommendations discussed here will hopefully contribute to improved standardization and enhanced performance of FDG-PET/CT in the clinical management of patients with suspected infective endocarditis.
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Affiliation(s)
- D Ten Hove
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713GZ, Groningen, The Netherlands. .,Department of Microbiology and Infection Prevention, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
| | - R H J A Slart
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713GZ, Groningen, The Netherlands.,Department of Biomedical Photonic Imaging, Faculty of Science and Technology, University of Twente, Enschede, the Netherlands
| | - B Sinha
- Department of Microbiology and Infection Prevention, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - A W J M Glaudemans
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713GZ, Groningen, The Netherlands
| | - R P J Budde
- Department of Radiology and Nuclear Medicine, Erasmus University Medical Center, Rotterdam, the Netherlands
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30
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Siddiqui NA, Houson HA, Kamble NS, Blanco JR, O'Donnell RE, Hassett DJ, Lapi SE, Kotagiri N. Leveraging copper import by yersiniabactin siderophore system for targeted PET imaging of bacteria. JCI Insight 2021; 6:144880. [PMID: 34027898 PMCID: PMC8262292 DOI: 10.1172/jci.insight.144880] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 04/21/2021] [Indexed: 12/27/2022] Open
Abstract
There is an emerging need for accurate and rapid identification of bacteria in the human body to achieve diverse biomedical objectives. Copper homeostasis is vital for the survival of bacterial species owing to the roles of the metal as a nutrient, respiratory enzyme cofactor, and a toxin. Here, we report the development of a copper-64–labeled bacterial metal chelator, yersiniabactin, to exploit a highly conserved metal acquisition pathway for noninvasive and selective imaging of bacteria. Compared with traditional techniques used to manufacture probes, our strategy simplifies the process considerably by combining the function of metal attachment and cell recognition to the same molecule. We demonstrate, for the first time to our knowledge, how a copper-64 PET probe can be used to identify specific bacterial populations, monitor antibiotic treatment outcomes, and track bacteria in diverse niches in vivo.
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Affiliation(s)
- Nabil A Siddiqui
- Division of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati, Cincinnati, Ohio, USA
| | - Hailey A Houson
- Division of Advanced Medical Imaging Research, Department of Radiology and Chemistry, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Nitin S Kamble
- Division of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati, Cincinnati, Ohio, USA
| | - Jose R Blanco
- Division of Advanced Medical Imaging Research, Department of Radiology and Chemistry, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Robert E O'Donnell
- Department of Internal Medicine, Heart, Lung and Vascular Institute, and
| | - Daniel J Hassett
- Department of Molecular Genetics, Biochemistry and Microbiology, College of Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Suzanne E Lapi
- Division of Advanced Medical Imaging Research, Department of Radiology and Chemistry, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Nalinikanth Kotagiri
- Division of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati, Cincinnati, Ohio, USA
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31
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Recent Progress in the Molecular Imaging of Tumor-Treating Bacteria. Nucl Med Mol Imaging 2021; 55:7-14. [PMID: 33643484 DOI: 10.1007/s13139-021-00689-4] [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: 01/09/2021] [Revised: 01/13/2021] [Accepted: 01/20/2021] [Indexed: 12/20/2022] Open
Abstract
Bacterial cancer therapy (BCT) approaches have been extensively investigated because bacteria can show unique features of strong tropism for cancer, proliferation inside tumors, and antitumor immunity, while bacteria are also possible agents for drug delivery. Despite the rapidly increasing number of preclinical studies using BCT to overcome the limitations of conventional cancer treatments, very few BCT studies have advanced to clinical trials. In patients undergoing BCT, the precise localization and quantification of bacterial density in different body locations is important; however, most clinical trials have used subjective clinical signs and invasive sampling to confirm bacterial colonization. There is therefore a need to improve the visualization of bacterial densities using noninvasive and repetitive in vivo imaging techniques that can facilitate the clinical translation of BCT. In vivo optical imaging techniques using bioluminescence and fluorescence, which are extensively employed to image the therapeutic process of BCT in small animal research, are hard to apply to the human body because of their low penetrative power. Thus, new imaging techniques need to be developed for clinical trials. In this review, we provide an overview of the various in vivo bacteria-specific imaging techniques available for visualizing tumor-treating bacteria in BCT studies.
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32
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Ordonez AA, Tucker EW, Anderson CJ, Carter CL, Ganatra S, Kaushal D, Kramnik I, Lin PL, Madigan CA, Mendez S, Rao J, Savic RM, Tobin DM, Walzl G, Wilkinson RJ, Lacourciere KA, Via LE, Jain SK. Visualizing the dynamics of tuberculosis pathology using molecular imaging. J Clin Invest 2021; 131:145107. [PMID: 33645551 PMCID: PMC7919721 DOI: 10.1172/jci145107] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Nearly 140 years after Robert Koch discovered Mycobacterium tuberculosis, tuberculosis (TB) remains a global threat and a deadly human pathogen. M. tuberculosis is notable for complex host-pathogen interactions that lead to poorly understood disease states ranging from latent infection to active disease. Additionally, multiple pathologies with a distinct local milieu (bacterial burden, antibiotic exposure, and host response) can coexist simultaneously within the same subject and change independently over time. Current tools cannot optimally measure these distinct pathologies or the spatiotemporal changes. Next-generation molecular imaging affords unparalleled opportunities to visualize infection by providing holistic, 3D spatial characterization and noninvasive, temporal monitoring within the same subject. This rapidly evolving technology could powerfully augment TB research by advancing fundamental knowledge and accelerating the development of novel diagnostics, biomarkers, and therapeutics.
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Affiliation(s)
- Alvaro A. Ordonez
- Center for Infection and Inflammation Imaging Research
- Center for Tuberculosis Research
- Department of Pediatrics, and
| | - Elizabeth W. Tucker
- Center for Infection and Inflammation Imaging Research
- Center for Tuberculosis Research
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | | | - Claire L. Carter
- Hackensack Meridian Health Center for Discovery and Innovation, Nutley, New Jersey, USA
| | - Shashank Ganatra
- Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, Texas, USA
| | - Deepak Kaushal
- Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, Texas, USA
| | - Igor Kramnik
- Pulmonary Center, Department of Medicine, Boston University School of Medicine, Boston, Massachusets, USA
- National Emerging Infectious Diseases Laboratories, Boston University, Boston, Massachusetts, USA
| | - Philana L. Lin
- Children’s Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Cressida A. Madigan
- Department of Biological Sciences, UCSD, San Diego, La Jolla, California, USA
| | - Susana Mendez
- National Institute of Allergy and Infectious Diseases (NIAID), NIH, Rockville, Maryland, USA
| | - Jianghong Rao
- Molecular Imaging Program at Stanford, Department of Radiology and Chemistry, Stanford University, Stanford, California, USA
| | - Rada M. Savic
- Department of Bioengineering and Therapeutic Sciences, School of Pharmacy and Medicine, UCSF, San Francisco, California, USA
| | - David M. Tobin
- Department of Molecular Genetics and Microbiology, Duke University, Durham, North Carolina, USA
| | - Gerhard Walzl
- SAMRC Centre for Tuberculosis Research, DST/NRF Centre of Excellence for Biomedical Tuberculosis Research, Division of Molecular Biology and Human Genetics, Faculty of Medicine and Health Sciences, Department of Biomedical Sciences, Stellenbosch University, Cape Town, South Africa
| | - Robert J. Wilkinson
- Department of Infectious Diseases, Imperial College London, London, United Kingdom
- Wellcome Centre for Infectious Diseases Research in Africa and Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- The Francis Crick Institute, London, United Kingdom
| | - Karen A. Lacourciere
- National Institute of Allergy and Infectious Diseases (NIAID), NIH, Rockville, Maryland, USA
| | - Laura E. Via
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, and Tuberculosis Imaging Program, Division of Intramural Research, NIAID, NIH, Bethesda, Maryland, USA
| | - Sanjay K. Jain
- Center for Infection and Inflammation Imaging Research
- Center for Tuberculosis Research
- Department of Pediatrics, and
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Renick PJ, Mulgaonkar A, Co CM, Wu CY, Zhou N, Velazquez A, Pennington J, Sherwood A, Dong H, Castellino L, Öz OK, Tang L, Sun X. Imaging of Actively Proliferating Bacterial Infections by Targeting the Bacterial Metabolic Footprint with d-[5- 11C]-Glutamine. ACS Infect Dis 2021; 7:347-361. [PMID: 33476123 DOI: 10.1021/acsinfecdis.0c00617] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Since most d-amino acids (DAAs) are utilized by bacterial cells but not by mammalian eukaryotic hosts, recently DAA-based molecular imaging strategies have been extensively explored for noninvasively differentiating bacterial infections from the host's inflammatory responses. Given glutamine's pivotal role in bacterial survival, cell growth, biofilm formation, and even virulence, here we report a new positron emission tomography (PET) imaging approach using d-5-[11C]glutamine (d-[5-11C]-Gln) for potential clinical assessment of bacterial infection through a comparative study with its l-isomer counterpart, l-[5-11C]-Gln. In both control and infected mice, l-[5-11C]-Gln had substantially higher uptake levels than d-[5-11C]-Gln in most organs except the kidneys, showing the expected higher use of l-[5-11C]-Gln by mammalian tissues and more efficient renal excretion of d-[5-11C]-Gln. Importantly, our work demonstrates that PET imaging with d-[5-11C]-Gln is capable of detecting infections induced by both Escherichia coli (E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) in a dual-infection murine myositis model with significantly higher infection-to-background contrast than with l-[5-11C]-Gln (in E. coli, 1.64; in MRSA, 2.62, p = 0.0004). This can be attributed to the fact that d-[5-11C]-Gln is utilized by bacteria while being more efficiently cleared from the host tissues. We confirmed the bacterial infection imaging specificity of d-[5-11C]-Gln by comparing its uptake in active bacterial infections versus sterile inflammation and with 2-deoxy-2-[18F]fluoroglucose ([18F]FDG). These results together demonstrate the translational potential of PET imaging with d-[5-11C]-Gln for the noninvasive detection of bacterial infectious diseases in humans.
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34
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Ordoñez AA, Jain SK. Imaging of Bacterial Infections. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00089-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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35
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Giron MC, Mazzi U. Molecular imaging of microbiota-gut-brain axis: searching for the right targeted probe for the right target and disease. Nucl Med Biol 2020; 92:72-77. [PMID: 33262001 DOI: 10.1016/j.nucmedbio.2020.11.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 11/05/2020] [Accepted: 11/11/2020] [Indexed: 12/16/2022]
Abstract
The highly bidirectional dialogue between the gut and the brain is markedly stimulated and influenced by the microbiome through integrated neuroendocrine, neurological and immunological processes. Gut microbiota itself communicate with the host producing hormonal intermediates, metabolites, proteins, and toxins responsible for a variety of biochemical and functional inputs, thereby shaping host homeostasis. Indeed, a dysregulated microbiota-gut-brain axis might be the origin of many neuroimmune-mediated disorders, e.g. autism, multiple sclerosis, depression, Alzheimer's and Parkinson's disease, which appear months or even years prior to a diagnosis, corroborating the theory that the pathological process is spread from the gut to the brain. A much deeper comprehension of how commensal microbe can be manipulated to interfere with disease progression is crucial for developing new strategies to diagnose and treat diseases. In recent years, the potential of positron-emission-tomography (PET) in the field of bacteria detection has gained attention. The uptake of several PET tracers has been evaluated to investigate infection pathophysiology, e.g. sterile or pathogen-mediated infection, monitoring of progression, or as a surrogate endpoint in clinical trials. In this minireview, we briefly describe the role of microbiome-gut-brain axis in health and disease and we discuss the imaging modalities and agents that could be applied to study the dynamic interactions between microbiome, gut and brain. These are key aspects in understanding the biochemical lexicon underpinning the microbiome-host crosstalk that would enable the development of diagnostics and therapeutics by targeting the human microbiota.
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Affiliation(s)
- Maria Cecilia Giron
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Italy.
| | - Ulderico Mazzi
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Italy
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36
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Li Y, Daryaee F, Yoon GE, Noh D, Smith-Jones PM, Si Y, Walker SG, Turkman N, Meimetis L, Tonge PJ. Positron Emission Tomography Imaging of Staphylococcus aureus Infection Using a Nitro-Prodrug Analogue of 2-[ 18F]F- p-Aminobenzoic Acid. ACS Infect Dis 2020; 6:2249-2259. [PMID: 32672928 DOI: 10.1021/acsinfecdis.0c00374] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Deep-seated bacterial infections caused by pathogens such as Staphylococcus aureus are difficult to diagnose and treat and are thus a major threat to human health. In previous work we demonstrated that positron emission tomography (PET) imaging with 2-[18F]F-p-aminobenzoic acid (2-[18F]F-PABA) could noninvasively identify, localize, and monitor S. aureus infection with excellent sensitivity and specificity in a rodent soft tissue infection model. However, 2-[18F]F-PABA is rapidly N-acetylated and eliminated, and in an attempt to improve radiotracer accumulation in bacteria we adopted a prodrug strategy in which the acid was protected by an ester and the amine was replaced with a nitro group. Metabolite analysis indicated that the nitro group of ethyl 2-[18F]fluoro-4-nitrobenzoate (2-[18F]F-ENB) is converted to the corresponding amine by bacteria-specific nitroreductases while the ester is hydrolyzed in vivo into the acid. PET/CT imaging of 2-[18F]F-ENB and the corresponding acid 2-[18F]F-NB in a rat soft tissue infection model demonstrated colocalization of the radiotracer with the bioluminescent signal arising from S. aureus Xen29, and demonstrated that the tracer could differentiate S. aureus infection from sterile inflammation. Significantly, the accumulation of both 2-[18F]F-ENB and 2-[18F]F-NB at the site of infection was 17-fold higher than at the site of sterile inflammation compared to 8-fold difference observed for 2-[18F]F-PABA, supporting the proposal that the active radiotracer in vivo is 2-[18F]F-NB. Collectively, these data suggest that 2-[18F]F-ENB and 2-[18F]F-NB have the potential for translation to humans as a rapid, noninvasive diagnostic tool to identify and localize S. aureus infections.
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Affiliation(s)
- Yong Li
- Chronus Pharmaceuticals, 25 Health Sciences Drive, Stony Brook, New York 11790, United States
| | - Fereidoon Daryaee
- Chronus Pharmaceuticals, 25 Health Sciences Drive, Stony Brook, New York 11790, United States
| | - Grace E. Yoon
- The Facility for Experimental Radiopharmaceutical Manufacturing, Department of Psychiatry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Doyoung Noh
- The Facility for Experimental Radiopharmaceutical Manufacturing, Department of Psychiatry, Stony Brook University, Stony Brook, New York 11794, United States
| | - Peter M. Smith-Jones
- The Facility for Experimental Radiopharmaceutical Manufacturing, Department of Psychiatry, Stony Brook University, Stony Brook, New York 11794, United States
| | | | - Stephen G. Walker
- Department of Oral Biology and Pathology, Stony Brook University, Stony Brook, New York 11794, United States
| | | | - Labros Meimetis
- Chronus Pharmaceuticals, 25 Health Sciences Drive, Stony Brook, New York 11790, United States
| | - Peter J. Tonge
- Chronus Pharmaceuticals, 25 Health Sciences Drive, Stony Brook, New York 11790, United States
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37
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Locke LW, Shankaran K, Gong L, Stoodley P, Vozar SL, Cole SL, Tweedle MF, Wozniak DJ. Evaluation of Peptide-Based Probes toward In Vivo Diagnostic Imaging of Bacterial Biofilm-Associated Infections. ACS Infect Dis 2020; 6:2086-2098. [PMID: 32603591 PMCID: PMC7429274 DOI: 10.1021/acsinfecdis.0c00125] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The clinical management of bacterial biofilm infections represents an enormous challenge in today's healthcare setting. The NIH estimates that 65% of bacterial infections are biofilm-related, and therapeutic outcomes are positively correlated with early intervention. Currently, there is no reliable imaging technique to detect biofilm infections in vivo, and current clinical protocols for accurate and direct biofilm identification are nonexistent. In orthopedic implant-associated biofilm infections, for example, current detection methods are based on nonspecific X-ray or radiolabeled white blood cell imaging, coupled with peri-prosthetic tissue or fluid samples taken invasively, and must be cultured. This approach is time-consuming and often fails to detect biofilm bacteria due to sampling errors and a lack of sensitivity. The ability to quantify bacterial biofilms by real-time noninvasive imaging is an urgent unmet clinical need that would revolutionize the management and treatment of these devastating types of infections. In the present study, we assembled a collection of fluorescently labeled peptide candidates to specifically explore their biofilm targeting properties. We evaluated these fluorescently labeled peptides using various in vitro assays for their ability to specifically and nondestructively target biofilms produced by model bacterial pathogen Pseudomonas aeruginosa. The lead candidate that emerged, 4Iphf-HN17, demonstrated rapid biofilm labeling kinetics, a lack of bactericidal activity, and biofilm targeting specificity in human cell infection models. In vivo fluorescently labeled 4Iphf-HN17 showed enhanced accumulation in biofilm-infected wounds, thus warranting further study.
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Affiliation(s)
- Landon W. Locke
- Dept. of Microbial Infection and Immunity, The Ohio State University
| | - Kothandaraman Shankaran
- Dept. of Radiology, The Wright Center for Innovation in Biomedical Eng, The Ohio State University
| | - Li Gong
- Dept. of Radiology, The Wright Center for Innovation in Biomedical Eng, The Ohio State University
| | - Paul Stoodley
- Dept. of Microbial Infection and Immunity, The Ohio State University
| | | | - Sara L. Cole
- Campus Microscopy and Imaging Facility, The Ohio State University
| | - Michael F. Tweedle
- Dept. of Radiology, The Wright Center for Innovation in Biomedical Eng, The Ohio State University
| | - Daniel J. Wozniak
- Dept. of Microbial Infection and Immunity, The Ohio State University,Dept. of Microbiology, The Ohio State University
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Polvoy I, Flavell RR, Rosenberg OS, Ohliger MA, Wilson DM. Nuclear Imaging of Bacterial Infection: The State of the Art and Future Directions. J Nucl Med 2020; 61:1708-1716. [PMID: 32764120 DOI: 10.2967/jnumed.120.244939] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 06/23/2020] [Indexed: 12/11/2022] Open
Abstract
Increased mortality rates from infectious diseases is a growing public health concern. Successful management of acute bacterial infections requires early diagnosis and treatment, which are not always easy to achieve. Structural imaging techniques such as CT and MRI are often applied to this problem. However, these methods generally rely on secondary inflammatory changes and are frequently not specific to infection. The use of nuclear medicine techniques can add crucial complementary information, allowing visualization of infectious pathophysiology beyond morphologic imaging. This review will discuss the current structural and functional imaging techniques used for the diagnosis of bacterial infection and their roles in different clinical scenarios. We will also present several new radiotracers in development, with an emphasis on probes targeting bacteria-specific metabolism. As highlighted by the current coronavirus disease 2019 epidemic, caused by the novel severe acute respiratory syndrome coronavirus 2, similar thinking may apply in imaging viral pathogens; for this case, prominent effects on host proteins, most notably angiotensin-converting enzyme 2, might also provide worthwhile imaging targets.
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Affiliation(s)
- Ilona Polvoy
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California
| | - Robert R Flavell
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California
| | - Oren S Rosenberg
- Department of Medicine, University of California, San Francisco, San Francisco, California; and
| | - Michael A Ohliger
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California.,Department of Radiology, Zuckerberg San Francisco General Hospital, San Francisco, California
| | - David M Wilson
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California
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Signore A, Artiko V, Conserva M, Ferro-Flores G, Welling MM, Jain SK, Hess S, Sathekge M. Imaging Bacteria with Radiolabelled Probes: Is It Feasible? J Clin Med 2020; 9:jcm9082372. [PMID: 32722355 PMCID: PMC7464306 DOI: 10.3390/jcm9082372] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 07/13/2020] [Accepted: 07/23/2020] [Indexed: 12/17/2022] Open
Abstract
Bacterial infections are the main cause of patient morbidity and mortality worldwide. Diagnosis can be difficult and delayed as well as the identification of the etiological pathogen, necessary for a tailored antibiotic therapy. Several non-invasive diagnostic procedures are available, all with pros and cons. Molecular nuclear medicine has highly contributed in this field by proposing several different radiopharmaceuticals (antimicrobial peptides, leukocytes, cytokines, antibiotics, sugars, etc.) but none proved to be highly specific for bacteria, although many agents in development look promising. Indeed, factors including the number and strain of bacteria, the infection site, and the host condition, may affect the specificity of the tested radiopharmaceuticals. At the Third European Congress on Infection/Inflammation Imaging, a round table discussion was dedicated to debate the pros and cons of different radiopharmaceuticals for imaging bacteria with the final goal to find a consensus on the most relevant research steps that should be fulfilled when testing a new probe, based on experience and cumulative published evidence.
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Affiliation(s)
- Alberto Signore
- Nuclear Medicine Unit, Department of Medical-Surgical Sciences and of Translational Medicine, Faculty of Medicine and Psychology, Sapienza University of Rome, 00189 Rome, Italy;
- Correspondence: ; Tel.: +39-06-33775471; Fax: +39-06-33776614
| | - Vera Artiko
- Center for Nuclear Medicine, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, 101801 Beograd, Serbia;
| | - Martina Conserva
- Nuclear Medicine Unit, Department of Medical-Surgical Sciences and of Translational Medicine, Faculty of Medicine and Psychology, Sapienza University of Rome, 00189 Rome, Italy;
| | - Guillermina Ferro-Flores
- Department of Radioactive Materials, Instituto Nacional de Investigaciones Nucleares, Carretera Mexico-Toluca S/N, La Marquesa, Ocoyoacac 52750, Estado de Mexico, Mexico;
| | - Mick M. Welling
- Interventional Molecular Imaging Laboratory, Department of Radiology, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands;
| | - Sanjay K. Jain
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA;
| | - Søren Hess
- Department of Radiology and Nuclear Medicine, Hospital South West Jutland, University Hospital of Southern Denmark, 6700 Esbjerg, Denmark;
| | - Mike Sathekge
- Nuclear Medicine Department, University of Pretoria, Pretoria 0001, South Africa;
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40
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Horgan SJ, Mediratta A, Gillam LD. Cardiovascular Imaging in Infective Endocarditis: A Multimodality Approach. Circ Cardiovasc Imaging 2020; 13:e008956. [PMID: 32683888 DOI: 10.1161/circimaging.120.008956] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Multimodality imaging plays a pivotal role in the evaluation and management of infective endocarditis (IE)-a condition with high morbidity and mortality. The diagnosis of IE is primarily based on the modified Duke criteria with echocardiography as the first-line imaging modality. Both transthoracic and transesophageal echocardiography delineate vegetation location and size, assess for paravalvular extension of infection, and have the added advantage of defining the hemodynamic effects of valvular or device infection. Native and prosthetic valve IE, infections relating to cardiac implantable electronic devices, and indwelling catheters are effectively evaluated with echocardiography. However, complementary imaging is occasionally required when there remains diagnostic uncertainty following transesophageal echocardiography. Multidetector computed tomography and nuclear imaging techniques such as positron emission tomography and white blood cell scintigraphy have been shown to reduce the rate of misdiagnosed IE particularly in the setting of prosthetic valve endocarditis, paravalvular extension of infection, and cardiac implantable electronic devices. In this review, we describe a modern approach to cardiac imaging in native and prosthetic valve endocarditis, as well as cardiac implantable electronic devices including pacing devices and left ventricular assist devices. Current guidelines addressing the role of multimodality imaging in IE are discussed. The utility of imaging in the assessment of local and distant endocarditis complications such as pericardial sequelae, myocarditis, and embolic events is also addressed.
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Affiliation(s)
- Stephen J Horgan
- Gagnon Cardiovascular Institute, Morristown Medical Center/Atlantic Health System, NJ
| | - Anuj Mediratta
- Gagnon Cardiovascular Institute, Morristown Medical Center/Atlantic Health System, NJ
| | - Linda D Gillam
- Gagnon Cardiovascular Institute, Morristown Medical Center/Atlantic Health System, NJ
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41
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Parker MFL, Flavell RR, Luu JM, Rosenberg OS, Ohliger MA, Wilson DM. Small Molecule Sensors Targeting the Bacterial Cell Wall. ACS Infect Dis 2020; 6:1587-1598. [PMID: 32433879 DOI: 10.1021/acsinfecdis.9b00515] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
This review highlights recent efforts to detect bacteria using engineered small molecules that are processed and incorporated similarly to their natural counterparts. There are both scientific and clinical justifications for these endeavors. The use of detectable, cell-wall targeted chemical probes has elucidated microbial behavior, with several fluorescent labeling methods in widespread laboratory use. Furthermore, many existing efforts including ours, focus on developing new imaging tools to study infection in clinical practice. The bacterial cell wall, a remarkably rich and complex structure, is an outstanding target for bacteria-specific detection. Several cell wall components are found in bacteria but not mammals, especially peptidoglycan, lipopolysaccharide, and teichoic acids. As this review highlights, the development of laboratory tools for fluorescence microscopy has vastly outstripped related positron emission tomography (PET) or single photon emission computed tomography (SPECT) radiotracer development. However, there is great synergy between these chemical strategies, which both employ mimicry of endogenous substrates to incorporate detectable structures. As the field of bacteria-specific imaging grows, it will be important to understand the mechanisms involved in microbial incorporation of radionuclides. Additionally, we will highlight the clinical challenges motivating this imaging effort.
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Affiliation(s)
- Matthew F. L. Parker
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California 94158, United States
| | - Robert R. Flavell
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California 94158, United States
| | - Justin M. Luu
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California 94158, United States
| | - Oren S. Rosenberg
- Department of Medicine, University of California, San Francisco, San Francisco, California 94158, United States
| | - Michael A. Ohliger
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California 94158, United States
- Department of Radiology, Zuckerberg San Francisco General Hospital, San Francisco, California 94110, United States
| | - David M. Wilson
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, California 94158, United States
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Qiao Y, Hayashi H, Chong Teo S. Chemical Toolbox to Decode the Microbiota Lexicon. Chem Asian J 2020; 15:2117-2128. [PMID: 32558250 DOI: 10.1002/asia.202000541] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 06/14/2020] [Indexed: 12/15/2022]
Abstract
The human microbiota deploys a diverse range of molecules and metabolites to engage in chemical communications with the host, mediating fundamental aspects of host health. Studies of the structures and activities of bioactive molecules produced by the microbiota are imperative to address their implications in microbiota associated diseases in human. By drawing experiences from different research fields, chemists and chemical biologists, who are experts in dealing with chemical molecules, are uniquely positioned to contribute to the emerging knowledge of human microbiota. In this minireview, we discuss the current chemical tools and methods that are pertinent to the discovery of microbiota molecules and metabolites, characterizations of their protein targets, as well as evaluations of their biodistributions in hosts. These are key aspects in understanding the chemical underpinnings of the microbiota-host interactions that would enable future development of diagnostics and therapeutics targeting the human microbiota.
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Affiliation(s)
- Yuan Qiao
- School of Physical and Mathematical Sciences (SPMS), Nanyang Technological University (NTU), 21 Nanyang Link, CBC 04-22, Singapore, 637371, Singapore
| | - Hirohito Hayashi
- School of Physical and Mathematical Sciences (SPMS), Nanyang Technological University (NTU), 21 Nanyang Link, CBC 04-22, Singapore, 637371, Singapore
| | - Seng Chong Teo
- School of Physical and Mathematical Sciences (SPMS), Nanyang Technological University (NTU), 21 Nanyang Link, CBC 04-22, Singapore, 637371, Singapore
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43
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Kalita M, Parker MFL, Luu JM, Stewart MN, Blecha JE, VanBrocklin HF, Evans MJ, Flavell RR, Rosenberg OS, Ohliger MA, Wilson DM. Arabinofuranose-derived positron-emission tomography radiotracers for detection of pathogenic microorganisms. J Labelled Comp Radiopharm 2020; 63:231-239. [PMID: 32222086 DOI: 10.1002/jlcr.3835] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/06/2020] [Accepted: 02/26/2020] [Indexed: 12/16/2022]
Abstract
PURPOSE Detection of bacteria-specific metabolism via positron emission tomography (PET) is an emerging strategy to image human pathogens, with dramatic implications for clinical practice. In silico and in vitro screening tools have recently been applied to this problem, with several monosaccharides including l-arabinose showing rapid accumulation in Escherichia coli and other organisms. Our goal for this study was to evaluate several synthetically viable arabinofuranose-derived 18 F analogs for their incorporation into pathogenic bacteria. PROCEDURES We synthesized four radiolabeled arabinofuranose-derived sugars: 2-deoxy-2-[18 F]fluoro-arabinofuranoses (d-2-18 F-AF and l-2-18 F-AF) and 5-deoxy-5-[18 F]fluoro-arabinofuranoses (d-5-18 F-AF and l-5-18 F-AF). The arabinofuranoses were synthesized from 18 F- via triflated, peracetylated precursors analogous to the most common radiosynthesis of 2-deoxy-2-[18 F]fluoro-d-glucose ([18 F]FDG). These radiotracers were screened for their uptake into E. coli and Staphylococcus aureus. Subsequently, the sensitivity of d-2-18 F-AF and l-2-18 F-AF to key human pathogens was investigated in vitro. RESULTS All 18 F radiotracer targets were synthesized in high radiochemical purity. In the screening study, d-2-18 F-AF and l-2-18 F-AF showed greater accumulation in E. coli than in S. aureus. When evaluated in a panel of pathologic microorganisms, both d-2-18 F-AF and l-2-18 F-AF demonstrated sensitivity to most gram-positive and gram-negative bacteria. CONCLUSIONS Arabinofuranose-derived 18 F PET radiotracers can be synthesized with high radiochemical purity. Our study showed absence of bacterial accumulation for 5-substitued analogs, a finding that may have mechanistic implications for related tracers. Both d-2-18 F-AF and l-2-18 F-AF showed sensitivity to most gram-negative and gram-positive organisms. Future in vivo studies will evaluate the diagnostic accuracy of these radiotracers in animal models of infection.
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Affiliation(s)
- Mausam Kalita
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California
| | - Matthew F L Parker
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California
| | - Justin M Luu
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California
| | - Megan N Stewart
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California
| | - Joseph E Blecha
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California
| | - Henry F VanBrocklin
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California
| | - Michael J Evans
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California
| | - Robert R Flavell
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California
| | - Oren S Rosenberg
- Department of Medicine, University of California San Francisco, San Francisco, California
| | - Michael A Ohliger
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California.,Department of Radiology, Zuckerberg San Francisco General Hospital, San Francisco, California
| | - David M Wilson
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California
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44
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Khalilinia E, Ebrahimi A. π-Stacking effects on acid capacity of p-aminobenzoic acid. Struct Chem 2020. [DOI: 10.1007/s11224-020-01530-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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45
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Ruiz-Bedoya CA, Ordonez AA, Werner RA, Plyku D, Klunk MH, Leal J, Lesniak WG, Holt DP, Dannals RF, Higuchi T, Rowe SP, Jain SK. 11C-PABA as a PET Radiotracer for Functional Renal Imaging: Preclinical and First-in-Human Study. J Nucl Med 2020; 61:1665-1671. [PMID: 32198314 DOI: 10.2967/jnumed.119.239806] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 03/09/2020] [Indexed: 12/22/2022] Open
Abstract
para-Aminobenzoic acid (PABA) has been previously used as an exogenous marker to verify completion of 24-h urine sampling. Therefore, we hypothesized that PABA radiolabeled with 11C might allow high-quality dynamic PET of the kidneys with less radiation exposure than other agents because of its shorter biologic and physical half-life. We evaluated if 11C-PABA can visualize renal anatomy and quantify function in healthy rats and rabbits and in a first-in-humans study on healthy volunteers. Methods: Healthy rats and rabbits were injected with 11C-PABA intravenously. Subsequently, dynamic PET was performed, followed by postmortem tissue-biodistribution studies. 11C-PABA PET was directly compared with the current standard, 99mTc-mercaptoacetyltriglycin, in rats. Three healthy human subjects also underwent dynamic PET after intravenous injection of 11C-PABA. Results: In healthy rats and rabbits, dynamic PET demonstrated a rapid accumulation of 11C-PABA in the renal cortex, followed by rapid excretion through the pelvicalyceal system. In humans, 11C-PABA PET was safe and well tolerated. There were no adverse or clinically detectable pharmacologic effects in any subject. The cortex was delineated on PET, and the activity gradually transited to the medulla and then pelvis with high spatiotemporal resolution. Conclusion: 11C-PABA demonstrated fast renal excretion with a very low background signal in animals and humans. These results suggest that 11C-PABA might be used as a novel radiotracer for functional renal imaging, providing high-quality spatiotemporal images with low radiation exposure.
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Affiliation(s)
- Camilo A Ruiz-Bedoya
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, Maryland.,Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Alvaro A Ordonez
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, Maryland.,Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Rudolf A Werner
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - Donika Plyku
- Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Mariah H Klunk
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, Maryland.,Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Jeff Leal
- Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Wojciech G Lesniak
- Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Daniel P Holt
- Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Robert F Dannals
- Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Takahiro Higuchi
- Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan; and.,Department of Nuclear Medicine, University Hospital, University of Würzburg, Würzburg, Germany
| | - Steven P Rowe
- Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Sanjay K Jain
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, Maryland .,Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland.,Russell H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
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46
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Parker ML, Luu JM, Schulte B, Huynh TL, Stewart MN, Sriram R, Yu MA, Jivan S, Turnbaugh PJ, Flavell RR, Rosenberg OS, Ohliger MA, Wilson DM. Sensing Living Bacteria in Vivo Using d-Alanine-Derived 11C Radiotracers. ACS CENTRAL SCIENCE 2020; 6:155-165. [PMID: 32123733 PMCID: PMC7047270 DOI: 10.1021/acscentsci.9b00743] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Indexed: 06/05/2023]
Abstract
Incorporation of d-amino acids into peptidoglycan is a unique metabolic feature of bacteria. Since d-amino acids are not metabolic substrates in most mammalian tissues, this difference can be exploited to detect living bacteria in vivo. Given the prevalence of d-alanine in peptidoglycan muropeptides, as well as its role in several antibiotic mechanisms, we targeted this amino acid for positron emission tomography (PET) radiotracer development. d-[3-11C]Alanine and the dipeptide d-[3-11C]alanyl-d-alanine were synthesized via asymmetric alkylation of glycine-derived Schiff-base precursors with [11C]methyl iodide in the presence of a cinchonidinium phase-transfer catalyst. In cell experiments, both tracers showed accumulation by a wide variety of both Gram-positive and Gram-negative pathogens including Staphylococcus aureus and Pseudomonas aeruginosa. In a mouse model of acute bacterial myositis, d-[3-11C]alanine was accumulated by living microorganisms but was not taken up in areas of sterile inflammation. When compared to existing clinical nuclear imaging tools, specifically 2-deoxy-2-[18F]fluoro-d-glucose and a gallium citrate radiotracer, d-alanine showed more bacteria-specific uptake. Decreased d-[3-11C]alanine uptake was also observed in antibiotic-sensitive microbes after antimicrobial therapy, when compared to that in resistant organisms. Finally, prominent uptake of d-[3-11C]alanine uptake was seen in rodent models of discitis-osteomyelitis and P. aeruginosa pneumonia. These data provide strong justification for clinical translation of d-[3-11C]alanine to address a number of important human infections.
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Affiliation(s)
- Matthew
F. L. Parker
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Justin M. Luu
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Brailee Schulte
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Tony L. Huynh
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Megan N. Stewart
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Renuka Sriram
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Michelle A. Yu
- Department
of Medicine, University of California, San
Francisco, San Francisco, California 94158, United States
| | - Salma Jivan
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Peter J. Turnbaugh
- Department
of Microbiology and Immunology, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Robert R. Flavell
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Oren S. Rosenberg
- Department
of Medicine, University of California, San
Francisco, San Francisco, California 94158, United States
| | - Michael A. Ohliger
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
- Department
of Radiology, Zuckerberg San Francisco General
Hospital, San Francisco, California 94110, United States
| | - David M. Wilson
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
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Mota F, Ordonez AA, Firth G, Ruiz-Bedoya CA, Ma MT, Jain SK. Radiotracer Development for Bacterial Imaging. J Med Chem 2020; 63:1964-1977. [PMID: 32048838 DOI: 10.1021/acs.jmedchem.9b01623] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Bacterial infections remain a major threat to humanity and are a leading cause of death and disability. Antimicrobial resistance has been declared as one of the top ten threats to human health by the World Health Organization, and new technologies are urgently needed for the early diagnosis and monitoring of deep-seated and complicated infections in hospitalized patients. This review summarizes the radiotracers as applied to imaging of bacterial infections. We summarize the recent progress in the development of pathogen-specific imaging and the application of radiotracers in understanding drug pharmacokinetics as well as the local biology at the infection sites. We also highlight the opportunities for medicinal chemists in radiotracer development for bacterial infections, with an emphasis on target selection and radiosynthetic approaches. Imaging of infections is an emerging field. Beyond clinical applications, these technologies could provide unique insights into disease pathogenesis and expedite bench-to-bedside translation of new therapeutics.
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Affiliation(s)
- Filipa Mota
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States.,Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States.,Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States
| | - Alvaro A Ordonez
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States.,Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States.,Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States
| | - George Firth
- School of Biomedical Engineering and Imaging Sciences, St. Thomas' Hospital, King's College London, London SE1 7EH, United Kingdom
| | - Camilo A Ruiz-Bedoya
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States.,Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States.,Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States
| | - Michelle T Ma
- School of Biomedical Engineering and Imaging Sciences, St. Thomas' Hospital, King's College London, London SE1 7EH, United Kingdom
| | - Sanjay K Jain
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States.,Center for Tuberculosis Research, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States.,Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States
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Molecular Imaging of Diabetic Foot Infections: New Tools for Old Questions. Int J Mol Sci 2019; 20:ijms20235984. [PMID: 31795077 PMCID: PMC6928969 DOI: 10.3390/ijms20235984] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 11/20/2019] [Accepted: 11/26/2019] [Indexed: 02/07/2023] Open
Abstract
Diabetic foot infections (DFIs) are a common, complex, and costly medical problem with increasing prevalence. Diagnosing DFIs is a clinical challenge due to the poor specificity of the available methods to accurately determine the presence of infection in these patients. However, failure to perform an opportune diagnosis and provide optimal antibiotic therapy can lead to higher morbidity for the patient, unnecessary amputations, and increased healthcare costs. Novel developments in bacteria-specific molecular imaging can provide a non-invasive assessment of the infection site to support diagnosis, determine the extension and location of the infection, guide the selection of antibiotics, and monitor the response to treatment. This is a review of recent research in molecular imaging of infections in the context of DFI. We summarize different clinical and preclinical methods and the translational implications aimed to improve the care of patients with DFI.
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49
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Northrup JD, Mach RH, Sellmyer MA. Radiochemical Approaches to Imaging Bacterial Infections: Intracellular versus Extracellular Targets. Int J Mol Sci 2019; 20:E5808. [PMID: 31752318 PMCID: PMC6888724 DOI: 10.3390/ijms20225808] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 11/04/2019] [Accepted: 11/12/2019] [Indexed: 02/03/2023] Open
Abstract
The discovery of penicillin began the age of antibiotics, which was a turning point in human healthcare. However, to this day, microbial infections are still a concern throughout the world, and the rise of multidrug-resistant organisms is an increasing challenge. To combat this threat, diagnostic imaging tools could be used to verify the causative organism and curb inappropriate use of antimicrobial drugs. Nuclear imaging offers the sensitivity needed to detect small numbers of bacteria in situ. Among nuclear imaging tools, radiolabeled antibiotics traditionally have lacked the sensitivity or specificity necessary to diagnose bacterial infections accurately. One reason for the lack of success is that the antibiotics were often chelated to a radiometal. This was done without addressing the ramifications of how the radiolabeling would impact probe entry to the bacterial cell, or the mechanism of binding to an intracellular target. In this review, we approach bacterial infection imaging through the lens of bacterial specific molecular targets, their intracellular or extracellular location, and discuss radiochemistry strategies to guide future probe development.
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Affiliation(s)
- Justin D. Northrup
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA; (J.D.N.); (R.H.M.)
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA
- Institute for Translational Medicine and Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Robert H. Mach
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA; (J.D.N.); (R.H.M.)
| | - Mark A. Sellmyer
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA; (J.D.N.); (R.H.M.)
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA
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50
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Abstract
Molecular imaging is an emerging technology that enables the noninvasive visualization, characterization, and quantification of molecular events within living subjects. Positron emission tomography (PET) is a clinically available molecular imaging tool with significant potential to study pathogenesis of infections in humans. Molecular imaging is an emerging technology that enables the noninvasive visualization, characterization, and quantification of molecular events within living subjects. Positron emission tomography (PET) is a clinically available molecular imaging tool with significant potential to study pathogenesis of infections in humans. PET enables dynamic assessment of infectious processes within the same subject with high temporal and spatial resolution and obviates the need for invasive tissue sampling, which is difficult in patients and generally limited to a single time point, even in animal models. This review presents current state-of-the-art concepts on the application of molecular imaging for infectious diseases and details how PET imaging can facilitate novel insights into infectious processes, ongoing development of pathogen-specific imaging, and simultaneous in situ measurements of intralesional antimicrobial pharmacokinetics in multiple compartments, including privileged sites. Finally, the potential clinical applications of this promising technology are also discussed.
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