Evaluation of the Stability of Endoscope Samples.

BACKGROUND

Endoscope-related infections remain a concern despite improved reprocessing protocols. Transport conditions between sampling and analysis may significantly affect sample reliability, yet current guidelines remain imprecise.

AIM: To evaluate the stability of endoscope samples collected using a pharmacopoeia diluent neutralizer with sodium thiosulfate (PND + thio) stored at 5 °C ± 3 °C, and to determine the maximum acceptable time before microbiological analysis.

METHODS

Artificially contaminated endoscope samples were prepared using four indicator microorganisms (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans). Samples were stored at 5 °C ± 3 °C and analysed at predefined time points up to 72 hours. Microbial counts were compared to initial values using statistical analysis and ISO 11133 acceptance criteria.

FINDINGS: Microbial concentrations remained stable or within acceptable variation ranges up to 48 hours for all tested microorganisms. The presence of neutralizing and surfactant agents appeared to preserve microbial viability and counteract disinfectant residues.

CONCLUSION

Endoscope samples collected with PND + thio can be stored up to 48 hours at 5 °C ± 3 °C without compromising microbiological analysis, supporting more flexible and sustainable transport conditions.