Fiber optic microendoscopy for preclinical study of bacterial infection dynamics

Area of Science:

• Medical imaging
• Microscopy
• Infectious disease research

Background:

• Bacterial infections in skin and lungs pose significant health challenges.
• Accurate and early detection of bacterial load is crucial for effective treatment.
• Current diagnostic methods may have limitations in sensitivity or in situ visualization.

Purpose of the Study:

• To evaluate the utility of fiber optic microendoscopy for imaging and quantifying bacterial infections.
• To assess the detection limits of this technology for Mycobacterium bovis Bacillus Calmette-Guérin (BCG) in different tissues.
• To demonstrate the in situ visualization capabilities of the microendoscope in an animal model.

Main Methods:

• Development and application of a contact probe fiber bundle fluorescence microendoscope.
• Characterization of the microendoscope's resolution (4 µm), field of view (750 µm), and outer diameter (1 mm).
• Induction of subcutaneous and intra-tracheal infections with fluorescent Mycobacterium bovis BCG in an animal model.

Main Results:

• Successful in situ detection of fluorescent Mycobacterium bovis BCG in both skin and lung tissues.
• Detection of bacterial infections from inocula as low as 10(4) colony forming units (CFUs) in skin.
• Detection of bacterial infections from inocula as low as 10(7) CFUs in the trachea.

Conclusions:

• Fiber optic microendoscopy is a viable tool for imaging and quantifying bacterial infections in deep tissues.
• The technology demonstrates high sensitivity for detecting Mycobacterium bovis BCG in vivo.
• This approach offers potential for improved diagnostics and monitoring of bacterial infections.