Membrane filter contact technique for bacteriological sampling of moist surfaces

Area of Science:

• Microbiology
• Surface Science
• Food Safety

Background:

• Accurate bacterial recovery from surfaces is crucial for infection control and food safety.
• Traditional sampling methods like Rodac plates have limitations in efficiency and consistency.

Purpose of the Study:

• To evaluate the efficiency of the membrane filter contact technique for recovering Staphylococcus aureus from artificially contaminated surfaces.
• To compare the performance of 3- and 5-micron membrane filters with other conventional sampling methods.

Main Methods:

• Utilized a membrane filter contact technique with 3- and 5-micron filters for bacterial recovery.
• Compared results with Rodac plates, velvet pads, velveteen pads, and smaller-pore membrane filters.
• Validated the technique on artificially contaminated bovine muscle surfaces.

Main Results:

• 3- and 5-micron membrane filters demonstrated significantly higher Staphylococcus aureus recovery rates (0.96-0.99) compared to Rodac plates (0.49) and other methods.
• On bovine muscle, 5-micron filters recovered 52 CFU/cm², comparable to biopsy dilutions (69 CFU/cm²) and superior to Rodac plates (5 CFU/cm²).

Conclusions:

• The membrane filter contact technique is a highly efficient and easy-to-perform method for sampling moist surfaces.
• This technique shows promise for culturing clinical surfaces such as surgical wounds and burns.