Lack of sporicidal activity in diallyl-disulphide-oxide and a nanotechnology-product for sterilizing medical and dental instruments

César I. Velázquez-Ramírez, Rogelio J. Scougall-Vilchis, Leonor Sánchez-Pérez, A Enrique Acosta-Gio


Objective: To evaluate sporicidal activity in products commercially available for sterilization of medical and dental instruments. Method: In simulated use and under worst-case scenario conditions, Bacillus atrophaeus spores were suspended in diallyl disulphide oxide (DDO), a nanotechnology product (NANO) or three SOW solutions. After 6 hour exposure, the spore suspensions were filtered, washed and incubated. Results: The DDO and NANO formulations evaluated lack sporicidal activity and are inadequate to sterilize instruments. The three SOW solutions evaluated are sporicidal but their activities are inhibited by protein. Their respective sterilization contact times remain to be determined. Conclusions: The results identify formulations that pose a risk to patients, and unveil failures in the regulatory evaluation of products. The absence of science-based regulatory standards results in the commercialization of unsafe products without the required sporicidal activity. To strengthen national and local health systems, the international infection prevention community must critically review the regulatory expectations for sporicidal products and disseminate information on the basics of antimicrobial effectiveness testing.

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