Extended sterilizations cycles are becoming more and more common as manufacturers are incorporating complex materials and designs into medical devices. It can be very difficult for the sterilant to penetrate a narrow path or throughout a very dense or heavy load with traditional sterilization cycle times so increased sterilization cycles are something manufacturers are dictating more and more. Certainly longer cycles are intended to allow for fewer positive biological indicators, but are all biological indicators designed to provide accurate results in extended cycles?
For self-contained biological indicators, as the spores are exposed to an extended insult, the recovery/growth media is exposed as well. In many instances, this added exposure will start to caramelize pH indicator color within the growth media and the media itself will appear altered post-sterilization. A logical question to ask is “Can this media still sustain growth for a low number of injured spores?”
Mesa has performed a study on its ProSpore Ampoule self-contained biological indicator to address this topic specifically by exposing ampoules to a typical 20 minute cycle in addition to an extended 120 minute cycle, looking at the color change of the media post-sterilization in addition to the media’s effectiveness throughout the incubation process. The results of this study can be seen here.
In the world of Biological Indicators (BIs), many technical terms are used to describe the attributes of a specific production lots of indicators. Many of these terms are attributes included on the Certificate of Analysis for an individual BI product detailing the subtle differences that cause any specific lot to perform or behave as it does.
In the latest edition of Spore News, Garrett Krushefski explains some common terms related to biological indicators including D-value, Z-value, Fbio and more. Driven by customer feedback, this issue gives an in-depth look at several industry terms and the impact each one has on BI performance and how this information can be used to evaluate the specific characteristics of a particular BI lot.
Click here (http://us1.campaign-archive1.com/?u=dbc324d0e9836c1d17ab7d4aa&id=be503f03da&e=4b1215ae34) to read the complete Spore News article and don’t forget to sign up to receive Spore News in your Inbox!
For more information on biological indicators click here! http://www.mesalabs.com/biological-indicators/
In the Resistance Performance Tests section of USP 31, it states to culture biological indicators (BI) ‘within a noted time, not more than four hours’ after the sterilization process. In reality however, this is not always possible due to several different situations. For instance, many ethylene oxide cycles can take several hours to aerate post-sterilization preventing access to the load and the BIs contained within. Clinical monitoring services will also have difficulty meeting this 4-hour window due to the fact that these services are mailed exposed indicators from a clinical setting for culturing and the BI may be in transit for a number of days before they are able to be transferred into culture media and incubated.
Biological Indicators have proven themselves to be extremely valuable tools for verifying sterilization conditions within sterilization cycles over the several decades in which they have been utilized. As many would say, “The bugs don’t lie”. And, what better way to test for the destruction of microorganisms that to test the cycle with highly resistant biological indicator containing a quantified amount of bacterial spores?
Biological Indicators will continue to be the gold standard for sterilization verification, but there are more tools available to provide additional information about cycle parameters and specifics. Used in conjunction with biological indicators, chemical indicators provide an inexpensive supplemental benefit of being able to monitor many more locations within the cycle than may be possible with biological indicators alone.
Chemical Indicators come in a variety of options and all are designed to target the specific information that is sought after. From the Bowie-Dick test, (which tests a sterilizer’s ability to remove all of the air from the chamber) to Class 4, 5 and 6 Integrators and Emulators, chemical indicators can provide valuable information to the user and about the items being sterilized.
To learn more about Mesa’s Chemical Indicator offerings, please see our CI page here or contact us for samples and pricing.
A customer recently contacted us detailing how positive biological indicators (BIs) were popping up in their Vapor Hydrogen Peroxide (VHP) process. The customer explained that they had no trouble with a square shaped room but when the configuration of the room changed (to an L-shaped room for example), they would experience unexpected positives. The positive BIs always seemed to occur in the same general area.
So what is wrong with the BIs?
Since the positive discs are showing up in the same general area of the room, it is most likely that the user may have a problem with the delivery of the lethal gas to some areas of the room. In this instance, the BI is doing exactly what it was designed to do, identifying the area of the chamber/room that is not receiving an appropriate dose of sterilant.
Mesa’s Technical Support team explained that the BIs are indicating that the circulation is not sufficient in this area in order to achieve the sterilization levels that the user is trying to accomplish. As is often the case for VHP sterilization, fans are needed in order to help the sterilant circulate throughout the more difficult areas to reach.
The BI Support team also pointed to the following documents from Mesa that have helped this user in redefining their procedures:
addresses Parameters Effecting Vapor Hydrogen Peroxide BI Performance
addresses Proper BI Placement During VHP BI Performance, and
addresses Using Replicate BI’s
For more information on VHP sterilization and BIs, please send any inquiries to email@example.com.
Mesa is preparing to exhibit at the Interphex expo, a top pharmaceutical and biopharmaceutical trade show held each year. Many key people in this industry attend to see new products, meet new customers, and to network with fellow community members. There are over 1000 product lines that represent every product category at the show and 650+ supplies that come to feature their latest innovations.
This year it will be held again at the Javits Center in New York, New York. The show exhibits will be open Tuesday April 23, 2013 through Thursday April 25, 2013. There are also 52 conference sessions that can be attended in 3 days.
While there, Mesa will be highlighting 2 new products: Intenna and Thermowell. DataTrace® InTenna is attached to the vessel by using a standard clamp fitting and sealed inside the vessel through any common service outlet. This enhanced capability means that retort cook cycles will always be able to hit their mark using the real-time feedback of the wireless data. DataTrace® Thermowell Data Logger allows for the addition/removal of the logger without breaking the seal! This logger is ideal for monitoring temperatures in a sealed container such as a can or bottle or for an SIP or CIP system at the typical monitor points where the Thermowell can be welded directly into piping allowing the logger to be easily removed and replaced when desired without shutting down the process. (more…)
Last week, we announced the launch of our new Smart-Well® 1710 incubator as part of our Smart-Read EZTest® Biological Monitoring System. In this video, we show you how to configure and use the new Smart-Well Incubator using the easy-to-use touch screen interface. (more…)
When selecting a biological indicator (BI), there are a lot of things to consider, but the three most important considerations are below:
1. What Type of Sterilization Is It?
Sterilization processes vary from chemicals to extreme temperatures to plasma infused chambers. These processes are all detrimental to the survival of biological materials but the selection of what particular biological indicator to use for each individual process is of extreme importance.
Biological indicators are made up of bacterial spores presented on or within some form of carrier which can vary depending on the specific application. The spores themselves have been selected for a particular process due to their inherent resistance. Geobacillus stearothermophilus is the ideal species to select for Steam and H202, Bacillus atrophaeus is appropriate for monitoring Ethylene Oxide and Dry Heat sterilization and Bacillus pumilus spores have shown specific resistance to gamma irradiation sterilization processes.
2. What Product Is Being Sterilized?
A cold, 2 Liter flask of water would take much longer to reach sterilization temperatures than a 100 ml flask of water in a steam sterilizer. Similarly, the products that are introduced to the sterilization cycle can have a dramatic effect on the sterilizer’s ability to effectively deliver lethal insult. Is the product a solid or a liquid? If solid, it is porous? What is the position within the pack/product that will be the most difficult spot to achieve sterilization conditions? All of this information is useful when discussing proper BI placement and selection. (more…)
In this video, we show you how to position a biological indicator in the center of a length of tubing for the most accurate validation of a sterilization process. This is done by using our ProLine PCD biological indicator.
In this video, we discuss why DriAmp Biological Indicators are a better choice than paper strip style indicators for dry heat sterilization processes.