Towards clinical application of non-invasive imaging to detect bacterial infections

Ohlsen, Knut; Hertlein, Tobias

doi:10.1080/21505594.2018.1425072

Cited by 12 publications

(16 citation statements)

References 17 publications

(19 reference statements)

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“…Such investigation of bacterial colonization in humans would benefit from methods for tracking bacteria using noninvasive imaging modalities. 5 Thus far, dedicated imaging of bacterial infections in preclinical studies mostly relies on optical imaging of genetically modified bioluminescent strains that express plasmid-integrated luciferase genes 6 or ultrasound imaging of strains that express acoustic reporter genes. 7 Although a useful preclinical tool, the use of genetically modified organisms (GMOs) purely for clinical-imaging purposes is not considered to be acceptable for safety reasons.…”

mentioning

confidence: 99%

Multimodal Tracking of Controlled Staphylococcus aureus Infections in Mice

et al. 2019

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There is a need to develop diagnostic and analytical tools that allow noninvasive monitoring of bacterial growth and dissemination in vivo. For such cell-tracking studies to hold translational value to controlled human infections, in which volunteers are experimentally colonized, they should not require genetic modification, and they should allow tracking over a number of replication cycles. To gauge if an antimicrobial peptide tracer, 99mTc-UBI29–41-Cy5, which contains both a fluorescent and a radioactive moiety, could be used for such in vivo bacterial tracking, we performed longitudinal imaging of a thigh-muscle infection with 99mTc-UBI29–41-Cy5-labeled Staphylococcus aureus. Mice were imaged using SPECT and fluorescence-imaging modalities at various intervals during a 28 h period. Biodistribution analyses were performed to quantitate radioactivity in the abscess and other tissues. SPECT and fluorescence imaging in mice showed clear retention of the 99mTc-UBI29–41-Cy5-labeled bacteria following inoculation in the thigh muscle. Despite bacterial replication, the signal intensity in the abscess only modestly decreased within a 28 h period: 52% of the total injected radioactivity per gram of tissue (%ID/g) at 4 h postinfection (pi) versus 44%ID/g at 28 h pi (15% decrease). After inoculation, a portion of the bacteria disseminated from the abscess, and S. aureus cultures were obtained from radioactive urine samples. Bacterial staining with 99mTc-UBI29–41-Cy5 allowed noninvasive bacterial-cell tracking during a 28 h period. Given the versatility of the presented bacterial-tracking method, we believe that this concept could pave the way for precise imaging capabilities during controlled-human-infection studies.

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confidence: 99%

Multimodal Tracking of Controlled Staphylococcus aureus Infections in Mice

et al. 2019

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“…According to previous studies, conventional imaging techniques have limitations in distinguishing bacterial infection from sterile inflammation. The ability to non- invasive identification of infection and more sensitively and specifically would aid in the diagnosis of infection[ 9 , 10 ]. Delayed diagnosis of odontogenic infections can allow their spread to neighboring head and neck regions.…”

Section: Discussionmentioning

confidence: 99%

Fascial space odontogenic infections: Ultrasonography as an alternative to magnetic resonance imaging

Ghali¹,

Katti²,

Shahbaz³

et al. 2021

WJCC

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BACKGROUND The introduction of modern diagnostic tools has transformed the field of maxillofacial radiology. Odontogenic infection and fascial space involvement have been evaluated with many diagnostic tools, including ultrasonography (USG) and magnetic resonance imaging (MRI). AIM To explore USG as an alternative model to MRI in the detection of fascial space spread of odontogenic infections. METHODS Among 20 patients, 50 fascial spaces were clinically diagnosed with odontogenic infection and included in this prospective study. Fascial space infection involvement was examined by USG and MRI. Results were compared for both and confirmed by microbiological testing. RESULTS Ultrasonography identified 42 (84%) of 50 involved fascial spaces. Whereas MRI identified all 50 (100%). USG could stage the infections from edematous change to cellulitis to complete abscess formation. CONCLUSION MRI was superior in recognizing deep fascial space infections compared to USG. However, USG is a significant addition and has a definite role in prognosticating the stage of infection and exact anatomic location in superficial space infections.

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“…While requiring fewer hosts to produce workable data, the requirement to minimize invasive observational effects can become a limitation [36]. One attractive route is to use fluorescent or luminescent pathogen strains, that can be imaged within a host non-invasively [37]. This path has been taken in diverse animal models, from mice [38] to nematodes [39], although calibration of infection burden is a concern – typically these reporter construct studies are more focused on location of infection [28,40] rather than estimating burden.…”

Section: Discussionmentioning

confidence: 99%

Mapping infectious disease mortality onto the within-host dynamics of pathogen growth

O'Sullivan

Waldetoft

Brown

2020

Preprint

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Infectious diseases remain a major cause of global mortality, yet basic questions concerning the relationship between within-host processes governing pathogen burden (pathogen replication, immune responses) and epidemiological patterns of mortality remain obscure. In standard epidemiological models of bacterial and viral infections ("compartmental models"), pathogen-induced mortality is described as a constant risk factor, unchanging with time since infection or the dynamics of the pathogen population inside the host. Here we review experimental data illustrating the failure of this assumption, with multiple infection models highlighting an accelerating risk of death with time since infection. Next, we show that the dynamics of infection-mediated death are phenomenologically similar to the dynamics of all-causes death, captured by an exponentially increasing instantaneous mortality or "hazard" (a Gompertz function). We then sketch a series of within-host pathogen models and highlight that multiple models are consistent with existing Gompertz-like infection mortality data, including: (1) exponential pathogen growth and a linear mapping between pathogen density and host hazard, and (2) linear pathogen growth and an exponential mapping between pathogen density and host hazard. We review critical experimental questions that our work highlights, requiring additional non-invasive data on pathogen burden throughout the course of infection, and end with a discussion on the unpicking of the mechanistic and dynamical basis of accelerating mortality risk during the course of human infections.

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Towards clinical application of non-invasive imaging to detect bacterial infections

Cited by 12 publications

References 17 publications

Multimodal Tracking of Controlled Staphylococcus aureus Infections in Mice

Multimodal Tracking of Controlled Staphylococcus aureus Infections in Mice

Fascial space odontogenic infections: Ultrasonography as an alternative to magnetic resonance imaging

Mapping infectious disease mortality onto the within-host dynamics of pathogen growth

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