Pre-processing tissue specimens with a tissue homogenizer: clinical and microbiological evaluation

Area of Science:

• Microbiology
• Diagnostic techniques
• Medical laboratory science

Background:

• Tissues are crucial specimens in diagnostic microbiology.
• Invasive methods for obtaining tissue samples necessitate maximizing microbiological yield.
• Evaluating novel pre-processing techniques is essential for improving diagnostic accuracy.

Purpose of the Study:

• To assess the added value of the gentleMACS Dissociator tissue homogenizer in detecting microorganisms from infected tissues.
• To compare the microbiological yield of homogenized tissue processing versus routine methods.
• To determine the efficacy of tissue pre-processing in enhancing the diagnosis of infections.

Main Methods:

• A comparative study involving 104 randomly collected tissue samples (41 bone, 63 soft tissue), including periprosthetic samples.
• Comparison of microbial detection between tissue homogenization using the gentleMACS Dissociator and standard microbiological procedures.
• Performance evaluation against clinical infection as the reference standard.

Main Results:

• No significant difference in microorganism detection between the two methods (McNemar test, p=0.3).
• High agreement in detected microorganisms (98.4%) between methods when cultures were positive.
• Sensitivity for detecting infected tissues was slightly lower with homogenization (83.6%) compared to routine processing (89.1%).

Conclusions:

• The gentleMACS Dissociator tissue homogenizer provides limited added value over routine tissue processing for microbiological analysis.
• Routine methods remain effective for microorganism detection in diverse tissue types, including bone and soft tissues.
• The study did not demonstrate a significant improvement in diagnostic yield using this specific tissue homogenization instrument.