The overall goal of these experiments is to convert chemical energy from unique effector driven oxidation reduction reactions into a practical source for safely and controllably, generating the well-known disinfectant chlorine dioxide without the use of electricity equipment or acids for a variety of cross-cutting military applications. This is achieved by adding a novel chemical effector to the chloride sulfite redox reaction at certain sub sto geometric ratios to generate chlorine dioxide. The portable chemical sterilizer.
A modern field autoclave was invented by embellishing a rigid plastic suitcase with valves and inlet valve connected to a circulating tube, a reactor vessel and scrubbers to remove chemicals and protect users and the environment by modifying the STO geometric ratios of the reagents. A unique two-step mixing process called kinetics control was developed to produce aqueous chlorine dioxide inside a collapsible spray bottle called defends. A new mixed chemical technology called Defend all based on an alternative chemical system without the use of acids or an effector rapidly.
And Controllably generates dilute solutions of chlorine dioxide with one step mixing for even broader all purpose applications. Validation studies demonstrated that the PCS sterilizes bacterial spores and inactivates pathogens on fresh produce, spraying and wiping with defends inactivates pathogens on porous or hard surfaces, and defend all decontaminates bacterial spores inoculated on textiles. We've done a lot of interest in reaction chemistry for the production of chlorine dioxide, and while we use a number of different chemical systems, it's the same chlorine dioxides that's produced.
It's a well-known disinfectant and decontaminating agent can be used for a variety of materials, surfaces, and applications. But we've really focused on the basic method of improving ways to produce the chlorine dioxide, the faster, cheaper, safer than other available methods. The visual demonstration of these methods is critical in conveying their simplicity while also highlighting their differences and their versatility.
The chemical techniques sound difficult probably because they're done at the laboratory level. Anyone familiar with handling laboratory chemicals, as Dr.Duna mentioned, could readily learn these techniques, but for a microbiologist like me, they sound scary. On the other hand, the microbiology techniques involved are standard procedures.
It's just a matter of developing the right validation approach as we have done. The PCS is a medical sterilization device that is portable energy independent and has potential to become a disruptive technology as a modern field autoclave for forward medical units. A commercial pelican rigid plastic suitcase was embellished with a number of special design features to accommodate a novel set of simple chemical reagents that react and produce chlorine dioxide to effectuate sterilization.
The PCS is set up with a wide mouthed reaction vessel that serves as a receptacle to receive and mix dry chemicals with water to generate sterin four stilts attached to the base except trays of surgical instruments or other microbiologically contaminated objects. And two check valves installed in the suitcase wall relieve potential pressure generated by the chemical reaction during the sterilization cycle. A filtered inlet valve is installed in the front of the suitcase to allow an inflow of air by pumping, particularly for flushing.
The PCS chamber. After a chemical sterilization cycle is complete, a circulating tube is connected to the inlet valve and helps distribute incoming air uniformly throughout the chamber. Homemade disposable scrubbers, engrafted over the outlet valves, filter and remove sterile and other hazards, and thereby ensure the health and safety of users and protect the environment to operate a sterilization cycle, place the PCS on a level surface place a surgical tray of clean, non-sterile surgical instruments or fresh cut produce in autoclave paper on the stilts.
Mix the dry chemicals and water in the wide mouthed reaction vessel, then close and lock the PCS. The reaction proceeds and controllably produces chlorine dioxide, heat and humidity inside the suitcase. At 25 minutes, connect a battery operated air pump or hand pump to the filtered inlet valve to pump air through the chamber.
After five minutes, stop the air flushing, open the case and remove treated items. The reaction vessel contains benign chemical salts in water that are easily disposed of. The PCS is now available for immediate reuse with another tray of contaminated instruments and a fresh packet of dry chemicals and water.
To validate the sterilization cycle, use commercially available BT shore biological indicators containing spores of b stero thermophilus, or of B atrophy spores. Place the indicators inside the case for exposure to chlorine dioxide. After completion of the cycle, remove and activate the indicators.
Then incubate for 24 to 48 hours to validate sterility. To validate the PCS cycle against live cultures, place aqueous suspensions of B steroid thermophilus inside the PCS and expose to a chemical sterilization cycle. Recover treated b steroid thermophilus spores on antibiotic assay medium with 1%soluble starch.
Note that no recovery confirms sterility examine treated spores with phase contrast. Microscopy spores are metabolically dormant organisms that have extreme resistance to lethal agents. Spores structure is very different from that of growing cells, and the diagram shown indicates the layers present in a spore.
This electron micrograph of a dormant bacillus serious spore shows most of the spore layers. Although the outer membrane and inner membrane cannot be seen, the exo spor is readily seen for be serious. Although not all spore species have this layer, high resolution atomic force microscopy images show chlorine dioxide treated bacillus subtles spores remain intact without collapsing during air drying and that the spore coat architecture and topology are unal altered by chlorine dioxide.
Treatment for hard non-porous surface sterilization, inoculate glass, or metal surfaces with aqueous suspensions of B steroid, thermophilus spores and air dry. Then place the inoculated hard surfaces inside the PCS and expose to a sterilization cycle. Use commercially available high check swab tests to recover spores from the surface.
Obtaining no growth on the high check swabs confirms sterility of the treated surfaces. Defense is a collapsible handheld bottle fitted with a hand operated spray trigger device containing a chemical sanitizing solution. The flexible plastic bottle has a gusted bottom to stand up when full of disinfectant solution and packs tightly when empty.
The chemically resistant plastic affords multiple reuses per sprayer to generate chemical sanitizing solution Inside the defense system, use one to 10 grams total quantity of simple dry chemical reagents to generate up to 800 milliliters of 50 to 500 parts per million chlorine dioxide solution. To use the novel two step mixing process to generate aqueous chlorine dioxide solutions in the defense spray bottle within two to nine minutes. First, dissolve all reagents in the small volume of water, then dilute solution to its final working volume.
Dispense the disinfectant solution by spraying as a fine mist or aerosol and sanitizing the contaminated target surfaces. The chlorine dioxide solution of defends remains stable for an eight hour shift. For validation of defends on porous surfaces, prepare Petri dishes of Baird Parker agar containing egg yolk.
Telluride and yeast extract inoculate the agar surface to tend to the fifth with a three strain cocktail of staphylococcus aureus and spread the inoculum uniformly over the agar surface using a glass hockey stick. As aureus growth on this medium is observable as distinctive black colonies that don't show up when cells are killed. Spray defense's disinfectant solution onto the agar surface using consistent study force to dispense approximately equal volumes of solution per spray, trigger a pulse and rotate plates 90 degrees between successive pulses to uniformly cover the agar surface.
Also use a glass hockey stick, applying light pressure to spread solution over the agar surface equivalent to mechanical abrasion from wiping or scrubbing for microbiological validation on hard surfaces. Inoculate type 304 sterilized custom stainless steel coupons with 0.2 milliliters, volume of staph aureus, ashia coli or listeria monocytogenes. Spread the inocular uniformly across the coupon surface, then allow to air dry for 30 minutes at room temperature in a laminar flow hood, immerse inoculated coupons into solution for contact times of 5 2, 1 and 0.5 minutes.
Then quench with sodium sulfite solution prior to enumerating survivors to generate, defend all chlorine dioxide solution, a more dilute solution of chlorine dioxide that can be used on textiles. Add water and dry reagents to a large beaker. The appearance of chlorine dioxide is visually obvious as a pale yellow color.
Use a chlorine dioxide dipstick test to confirm the concentration is one to 500 parts per million to validate, defend all inoculate sterile strips of textile materials with B and RACs stern allow to let air dry in a laminar flow hood once dry. Use forceps to pick up the strips and place into a 100 milliliter stomach or bag. Add the textile samples to a stomach or bag containing 20 milliliters of chlorine dioxide solution.
After 10 minutes, quench the process with a small amount of sodium sulfate. Next, mix the textile strip and solution for two minutes in the stomach or bag. Then remove and serially dilute into pre-made agar plates, then incubate for 24 hours and finally enumerate to validate sterility validation.
Studies demonstrated that the PCS sterilizes bacterial spores and inactivates pathogens on fresh produce, spraying and wiping with defends inactivates pathogens on porous or hard surfaces, and defend all decontaminates bacterial spores, inoculated on textiles at less stringent chlorine dioxide conditions. The PCS inactivated al monocytogenes and e coli spot inoculated on the exterior of tomatoes validation experiments with the defense sprayer system showed that chlorine dioxide solution inactivates the foodborne pathogenic bacteria as aureus as evidenced by no growth of black colonies on BPA specifically, 100 PP m solutions of chlorine dioxide effectuated a greater than seven log reduction of a three strain cocktail of s aureus, inoculated under stainless steel surfaces in contact times of one, three and five minutes. The series of chemical systems and inventions that we've just shown all focus on the disinfectant activity of chlorine dioxide.
Each one of them can be used for applications such as textile decontamination, cleaning, hot surfaces, fresh produce, or surgical instrument sterilization, and the microbiological validation procedures. We've also shown show just how effective this chemical agent is and of course, with all chemicals reagents, remember to handle them safely and appropriately in all laboratory environments at all times.
