Comparison of the Biological Activity of High-
Level Disinfection and Sterilization in Medical
Devices and Biomedical Equipment

Adiela María Cortés Cortés; Jhon Henry Galvis García

Abstract

Comparison of the Biological Activity of High- Level Disinfection and Sterilization in Medical Devices and Biomedical Equipment

The need to select suitable disinfectants for disinfection processes in biomedical equipment and in hospital environment has been highlighted for several decades in multiple scientific articles. Dozens of notes documenting infections in patients have also been published after inadequate disinfection procedures which have been applied to the elements used for their care and treatment. Hence, the aim of the investigation was to compare the biological activity of high-level disinfection and sterilization in medical devices and biomedical equipment with different biochemical and molecular analytical techniques (spectrophotometry, in-house PCR, luminometry, etc.). The swabs were taken from medical devices and biomedical equipment treated by High-Level Disinfection (Glutaraldehyde 0.17%, pH=6, without activator) and different methods of sterilization (Steam, Ethylene Oxide, Plasma, Hydrogen Peroxide, etc.) in different institutions of reference in Colombia. Samples were seeded in culture media specific for the growth of microorganisms of the species Bacillus subtilis, Clostridium difficile and Mycobacterium tuberculosis. The genetic identity of the microorganisms was determined, reporting 7 polymorphic variants of Mycobacterium tuberculosis, in addition, bioburden was evidenced in biomedical devices and equipment that were previously submitted to sterilization processes. Samples taken from devices and equipment treated with Glutaraldehyde 0.17% (pH=6, without activator) did not report growth of the microorganisms of interest. Comparisons between sterilization methods (Ethylene Oxide, Formaldehyde, Vapor, etc.), evidences failures in the elimination of both reproductive and vegetative forms of microorganisms of pathological interest, specifically Acinetobacter baumannii, Staphylococcus warneri, Staphylococcus epidermidis, Brevibacterium spp., Pseudomona luteola and Sphingomonas paucimobilis.