Transportation protocols for accurate assessment of microbial burden classification using molecular methods

Area of Science:

• Microbiology
• Clinical Diagnostics
• Biotechnology

Background:

• Point-of-care testing (POCT) offers cost-effective and rapid diagnostics, crucial for pandemic preparedness and reducing hospital visits.
• Current POCT faces limitations like skin flora contamination and insufficient specimen volume, hindering reliable microbiological testing outside clinical settings.
• Accurate bacterial infection identification and antimicrobial susceptibility profiling are vital for effective patient management.

Purpose of the Study:

• To develop and validate a hybrid testing procedure for patient-side specimen collection and transportation.
• To enable molecular microbial classification and early identification of susceptibility profiles directly from whole blood or urine.
• To optimize transportation conditions for direct-from-specimen viable pathogen detection, differentiating contaminants from true pathogens.

Main Methods:

• Feasibility study involving testing of various transportation conditions (tubes, temperature, duration) for direct-from-specimen viable pathogen detection.
• Evaluation of molecular assays for differentiating between contaminant and causative bacteria in urine specimens.
• Assessment of optimal growth conditions for low-concentration blood specimens post-transportation.

Main Results:

• Direct-from-urine assays successfully detected viable pathogens (≥10^5 CFU/mL) after transportation, while contaminants (≤10^4 CFU/mL) were not detected.
• Direct-from-blood assays identified contrived blood samples with pathogen concentrations as low as 0.8 CFU/mL as positive after transportation.
• The developed method demonstrated the potential to bypass traditional blood culture for early pathogen detection.

Conclusions:

• The hybrid testing procedure shows feasibility for reliable patient-side microbiological specimen collection and transportation.
• Optimized conditions enable accurate differentiation of pathogens from contaminants in urine and sensitive detection in blood.
• This approach holds promise for improving early bacterial infection diagnosis and antimicrobial susceptibility testing in decentralized healthcare settings.