Preclinical studies and prospective clinical applications for bacteria-targeted imaging: the future is bright

Abstract

Bacterial infections are a frequently occurring and major complication in human healthcare, in particular due to the rapid increase of antimicrobial resistance and the emergence of pan-drug-resistant microbes. Current anatomical and functional imaging modalities are insufficiently capable of distinguishing sites of bacterial infection from sterile inflammation. Therefore, definitive diagnosis of an infection can often only be obtained by tissue biopsy and subsequent culture and, occasionally, a definite diagnosis even appears to be impossible. To accurately diagnose bacterial infections early, novel imaging modalities are urgently needed. In this regard, bacteria-targeted imaging is an attractive option due to its specificity. Here, different bacteria-targeted imaging approaches are reviewed, and their promising future perspectives are discussed.

2018 international consensus meeting on musculoskeletal infection: Summary from the biofilm workgroup and consensus on biofilm related musculoskeletal infections

“…While advanced imaging has been used to spatially locate areas of active infection with good resolution, neither 99m Tc WBC SPECT‐CT with concordant 99m Tc sulphur colloid marrow map, nor PET‐CT, specifically identify biofilm. Targeted imaging methods which utilize binding of imaging agents to bacteria also do not distinguish between planktonic and sessile bacteria, and it is unknown if these techniques identify dormant cells such as persister cells . Optical imaging using fluorescence (fluorescein, indocyanine green, and IRDye‐800CW) has the potential for identifying microbes on or near a surface.…”

“…Optical imaging using fluorescence (fluorescein, indocyanine green, and IRDye‐800CW) has the potential for identifying microbes on or near a surface. While optical imaging techniques are possible in surgical wounds, none have emerged from the research setting for clinical use . Optical dyes (DMMB 1,9‐dimethyl methylene blue) can be used to stain the biofilm matrix, but this has yet to gain acceptance for clinical use.…”

Bacterial infection imaging with [ 18 F]fluoropropyl-trimethoprim

“…T he distinction between bacterial infection and other disease entities such as sterile inflammation and cancer can be challenging on the basis of symptoms and physical findings. In addition, it is accepted that there can be significant overlap between bacterial infection, inflammation, and cancer using both standard diagnostic imaging techniques [e.g., computed tomography, contrastenhanced magnetic resonance imaging, and positron emission tomography (PET)] and laboratory studies (e.g., white blood cell count, erythrocyte sedimentation rate) (1,2). This lack of diagnostic feature specificity is especially conspicuous when the pretest probability of the least likely etiology is higher due to individual variability such as genetic predisposition or known malignant disease and/or when perturbations such as prior surgery or radiotherapy alter the normal anatomy and provoke an inflammatory tissue reaction.…”

The efficacy of sarang semut extract (Myrmecodia pendens Merr & Perry) in inhibiting Porphyromonas gingivalis biofilm formation

“…Biofilm mass visualization was then performed by adding 10 μl of emersile oil (Thermo Fisher Scientific Inc, Oxoid, UK) to each cell well plate before observation was carried out under a light microscope (Olympus, Shinjuku, Tokyo, Japan) at a magnification of 400x. 16 results P. gingivalis has been ability a biofilm formation that is strongly in 9 hours and will be decreased in 6 hours ( Figure 1). While, the extract of sarang semut has the capability to inhibitory the biofilm formation of P. gingivalis in 9 hours compared 3 hours and 6 hours, specifically in concentration of 100%, 75%, and 50% (μg/ml), nonetheless the fosfomycin has been strongest biofilm inhibit of E-faecalis compared sarang semut extract (Figure 2).…”