Lumen claims of the STERRAD 100NX sterilizer: testing performance limits when processing equipment containing long, narrow lumens.

BACKGROUND: According to manufacturers information, the STERRAD 100NX sterilizer-a low temperature H(2)O(2) gas plasma sterilizer-can adequately process single channel stainless steel lumens with an inside diameter of 0.7 mm or larger and a maximum length of 500 mm using standard cycle sterilizing conditions. The aim of this study was to qualify the performance of this H(2)O(2) gas plasma sterilizer under different experimental settings representing worst case conditions. METHODS: Inoculated carriers were placed at the midpoint position of specified lumens and then submitted to flex scope sterilizing conditions. To simulate insufficient cleaning or crystalline residues, we added organic and inorganic challenges to our inoculated carriers. RESULTS: For experiments done with unchallenged carriers, quantitative analysis reached a log(10) reduction rate of ≥5.71, whereas qualitative results showed no growth in 24 out of 30 biologic indicators tested using flex scope half cycle conditions. Any additional kind of challenge significantly impaired the sterilization outcome. CONCLUSION: The findings of our current study emphasize the importance of a thorough validated cleaning of medical devices as well as timing for cleaning and decontamination before being exposed to the H(2)O(2) sterilization process and, furthermore, the need for strict adherence to manufacturer's recommendations.

Challenging the Sterrad 100NX sterilizer with different carrier materials and wrappings under experimental "clean" and "dirty" conditions.

BACKGROUND: Sterrad sterilizers have been developed for the sterilization of thermolabile materials. The aim of the present study was to challenge the efficacy of this low-temperature hydrogen peroxide-based sterilization system with different carrier materials and wrappings under experimental "clean" and "dirty" conditions. METHODS: We tested the sporocidal effect of the Sterrad 100NX sterilizer (Advanced Sterilization Products, Irvine, CA) on the carrier materials titanium, polyethylene, and polyurethane with single versus 3 wrappings of inoculated carriers. To simulate insufficient cleaning or crystalline residues, carriers were charged with spore inocula containing organic and inorganic burdens. RESULTS: Our qualitative results show that irrespective of the number of wrappings in the "clean" condition, sterilization by the Sterrad 100NX was equally effective on all 3 carrier materials, reaching a log-10 reduction rate of ≥ 6 under standard half-cycle conditions. Any additional organic or inorganic challenge significantly impaired the sterilization outcome. CONCLUSION: Results of our current study emphasize the utmost importance of thorough and reliable cleaning of medical devices before being exposed to a subsequent hydrogen peroxide sterilization process. Any institution using this sterilization technology should have a well-established and validated cleaning process and enforce a rigorous quality assurance program for all steps of the presterilization processing of medical devices.

Glycyrrhizin inhibits influenza A virus uptake into the cell.

We investigated the mechanism by which glycyrrhizin (GL), the main active component of licorice roots, protects cells from infection with influenza A virus (IAV). We found that GL treatment leads to a clear reduction in the number of IAV-infected human lung cells as well as a reduction in the CCID50 titer by 90%. The antiviral effect, however, was limited to one or two virus replication cycles. Analysis of different GL treatment protocols suggested that the antiviral effect of GL was limited to an early step in the virus replication cycle. A direct inhibitory action of GL on IAV particles could be excluded and GL did not interact with virus receptor binding either. The antiviral effect of GL was abolished by treatment 1h after virus infection, whereas pre-treatment and treatment during and after virus adsorption led to a reduction in the cytopathic effect, reduced viral RNA within the cells and in the cell supernatants, and reduced viral hemagglutination titers. Detailed virus uptake analyses unambiguously demonstrated reduced virus uptake in various GL-treated cells. These observations lead to the conclusion, that the antiviral activity of GL is mediated by an interaction with the cell membrane which most likely results in reduced endocytotic activity and hence reduced virus uptake. These insights might help in the design of structurally related compounds leading to potent anti-influenza therapeutics.