Radiochemical Approaches to Imaging Bacterial Infections: Intracellular versus Extracellular Targets

• Published in: International journal of molecular sciences 2019-11, Vol.20 (22), p.5808
• Main Authors: Northrup, Justin D, Mach, Robert H, Sellmyer, Mark A
• Format: Article
• Language: English
• Subjects: Animals; Anti-Bacterial Agents - therapeutic use; Antibiotics; Antimicrobial agents; Bacteria; Bacteria - drug effects; Bacterial infections; Bacterial Infections - diagnosis; Bacterial Infections - drug therapy; Bacterial Infections - microbiology; Binding sites; Biopsy; Breast; Cancer therapies; chemistry; Computed tomography; Culture techniques; Diagnostic Imaging - methods; Drug Discovery - methods; Humans; infection imaging; Iodine; Ligands; Magnetic resonance imaging; Mass spectrometry; Mass spectroscopy; Medical imaging; Membrane proteins; molecular imaging; Molybdenum; Neuroendocrine tumors; NMR; Nosocomial infections; Nuclear magnetic resonance; Patients; Penicillins - therapeutic use; Photon emission; Positron emission; Positron emission tomography; Radioactive tracers; Radiochemistry; Radioisotopes; Review; Single photon emission computed tomography; Somatostatin; Somatostatin receptors; Tomography; Ultrasound
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms20225808

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.