BactiBarrier Testing and Analysis

Transcription

1 BactiBarrier Testing and Analysis ÆGIS Microbe Shield Program: A History of Confidence 1 Commercialization and Real World Experience... American Hospital Supply Corporation (now part of Baxter International) was reviewing the use of antimicrobials on surgical drapes and other medical non-woven products. The stringent rules governing the use of any particulates or chemicals that could enter the body via a wound, etc. made this review protocol very severe. Every available antimicrobial, medical and industrial, was screened for basic toxicity, effectiveness against the types of microorganisms encountered in surgery and compatibility with the variety of physical, chemical, and biological contaminants found on fabrics and in wounds, but most importantly, the agents durability to leaching. The consequences of contamination into a wound area are profound; formation of granules, granulosis, fibrin clots, and coagulation, into blood stream can cause clogging of critical blood vessels resulting in death. This work eliminated all other antimicrobials except what is known today as the ÆGIS Antimicrobial. American Hospital Supply Corporation, outside university laboratories, private laboratories and Dow Corning contributed over thirty (30) studies verifying the safety and performance of this technology in medical use. FDA listings were obtained and ISO-BAC Medical Nonwovens were introduced to the market in 1979 and are still being manufactured today. A publication on this work is available. A New, Durable Antimicrobial Finish for Textiles 2 I. In Vitro Microbiological Studies Once the odor-causing bacteria were isolated, it was necessary to determine if treatment with AEM 5700 Antimicrobial would inhibit the growth of these microorganisms on the socks. ORLON/nylon socks treated with AEM 5700 were supplied by Burlington Socks/Adler*. The socks were tested against each of the bacterial isolates from the foot according to AATCC Test Method modified to include 0.1 percent triton X-100 in a saline inoculum. The results of this testing are in Table II. The socks treated with AEM 5700 were effective in inhibiting the growth of the odor- causing bacteria on the sock. A biostatic finish on a textile such as a sock must be durable to repeated home laundering if the benefit of the treatment is to be realized for the life of the article. Table III shows the antimicrobial activity of BIOGUARD socks following repeated laundering. The antimicrobial applied to the socks was durable for 10 laundering cycles in the detergents tested. The in vitro tests indicated that the socks treated with AEM 5700 Antimicrobial do have a durable antimicrobial finish. To study the practicality of inhibiting the growth of odor- causing bacteria on socks under actual use conditions, an in vivo organoleptic test was completed.

2 BactiBarrier Testing and Analysis - 2 Table I: Bacteria Isolated From Worn Untreated Socks Lab Identification Number Gram Stain Identification I Positive Micrococcus sp. II Positive Staph epidermidis III Negative Enterobacter aglormerans IV Negative Acinetobacter calcoaceticus V Negative Enterobacter aglomerans VI Positive Micrococcus sp. VII Positive Microccus sp. VIII Positive Staph aureus (pigmented) XI Positive Staph aureus (nonpigmented) Table II: Antimicrobial Testing of Bioguard Socks Against Bacteria Isolated From Socks Organism % Bacterial Reduction* I Micrococcus sp. 99 II Staph epidermidis 96 III Enterobacter aglormerans 90 IV Acinetobacter calcoaceticus 99 V Enterobacter aglomerans 69 VI Micrococcus sp. 100 VII Microccus sp. 99 VIII Staph aureus (pigmented) 99 XI Staph aureus (nonpigmented) 99 *Percent bacterial reduction as measured against an untreated control sock. Table III: Durability of Laundered Bioguard Socks Number of Wash Cycles % Bacterial Reduction

3 BactiBarrier Testing and Analysis - 3 Table IV: Antimicrobial Activity of Laundered Bioguard Socks Using Various Detergents Detergent % Bacterial Reduction* Water Only 99.6 Tide 99.2 Arm and Hammer 98.9 Dynamo 98.6 Cheer 99.2 *Percent bacterial reduction as measured against an untreated control sock. II. In Vivo Organoleptic Evaluation Burlington Socks/Adler supplied untreated ORLON/nylon control socks and socks treated with AEM 5700 Antimicrobial to an independent test laboratory* to compare the odors of socks following normal wear by male panelists. The socks included unwashed and washed (ten laundry cycles) control and treated socks. The male panelists were each given a control and treated sock daily during the test period. Each sock was to be worn on a specific foot. At the end of a workday, panelists reported to the lab to remove the socks, seal them in plastic bags, and receive socks for the next day. Odor evaluations were made by four odor judges 14 hours after removal of the socks on each test day. Individual scoring sheets were used by the judges and new sheets were used everyday of the evaluation. The odor grading scale was 0 to 10 ( no odor to very intense and disagreeable odor ). Two-day average odor scores were uses to compare unwashed treated and control socks to washed treated and control socks. The Wilcoxon matched pairs test indicated that there was no difference in odor scores between the unwashed treated and control socks at the 95 percent confidence level. There was a significant reduction in odor of washed treated socks compared to washed control socks at the 99% significance level. The difference in results between washed and unwashed treated socks when compared to controls is explained by the presence of non substantive process chemical such as dye carriers, softeners and wetting agents which are removed upon washing. The presence of these chemicals may: 1) Impart a hydrophobic character to the socks which inhibit intimate contact of micro- organisms with the textile surface, thus reducing effectiveness. 2) Impart a pleasant, new-clothing odor which can mask unpleasant odors and is similar in action to a deodorant. 3) Impart a temporary, leachable antimicrobial activity, usually due to the quaternary nature of most textile finishes such as softeners and antistats. The results of this comparative evaluation show that the ÆGIS antimicrobial agent is bonded to the textile (sock) and is not removed by repeated laundering. In contrast to untreated controls, repeated washing does not destroy the antimicrobial activity nor odor reduction of the treated socks.

4 BactiBarrier Testing and Analysis - 4 Figure 2. Results: AATCC Method 30; AEM 5700 Treatment, Conventional Antimicrobial Treatment, and Untreated Control. Washed and Unwashed. Antimicrobial Treatment, and Untreated Control. Was Quaternary Silsesquioxane: A Developmental Toxicity Study in Rats 3 Results There was no maternal mortality during the study. No clinical signs or behavioral changes were observed among dams that could be related with the administration of Quat- Silsesquioxane. Mean body weight gains and feed consumption in treated animals were not affected during the study when compared to those of the control group (Table 1). Mean corrected body weights (terminal body weight minus gravid uterine weight) were comparable between the treated and the control groups. A slight but significant increase in relative liver- to-body-weight ratio was observed at the 1000 mg/kg/day dose level and was considered treatment-related (Table 1)....no malformations among litters of dosed rates at an incidence which was significantly different from the control (Table 3). Discussion In conclusion, it has been demonstrated that Quat-Silsesquioxane administered orally up to 1000 mg/kg/day once a day during major organogenesis produced no developmental toxicity in Sprague-Dawley rats. The no observable adverse effect level of Quat- Silsesquioxane in rats was considered to be 300 mg/kg/day for maternal toxicity based on the slightly increased relative liverto-body-weight ratio and greater than 1000 mg/kg/day for developmental toxicity.

5 BactiBarrier Testing and Analysis - 5 The Nature of Antimicrobials 4 The ÆGIS Microbe Shield Is bound to the product requiring microbes to contact it Is affixed to the product surface Modifies the surface Is not consumed by microorganisms Mechanically interrupts (stabs) the cell wall Remains functional for the life of the product Will not create the environment for adaptive microorganisms Summary of Toxicity Data Pertaining to AEM 5700 / ÆGIS Antimicrobial 5 Skin Contact Acute Dermal Toxicity - Albino Rabbits...does not appear to present a problem from skin absorption under ordinary industrial handling conditions. Human Repeated Insult Patch Test (HRIPT) with AEM 5700 Antimicrobial There was no evidence of skin sensitization noted with any of the subjects. Percutaneous Absorption of AEM 5700 Antimicrobial in Rabbits None was detected in tissues of animals treated dermally. The results showed that the absorption of AEM 5700 Antimicrobial through the skin of the rabbit was essentially zero. The potential hazard of the use of this antimicrobial in contact with the skin is, therefore, considered to be insignificant. Three-Week Vaginal Irritation Study with Panty Hose Fabric Treated with AEM 5700 Antimicrobial in Beagle Dogs A 3-week vaginal irritation study with treated panty hose fabrics* (cotton and nylon) was conducted using sexually mature, purebred beagle dogs. Each test animal (four with treated cotton fabric, four with treated nylon fabric) received 15 intravaginal applications, each of which allowed a 24-hour exposure period. Each treated control animal (four with untreated cotton fabric, four with untreated nylon fabric) received the same type of application procedure. Two untreated control animals were utilized during the study for purposes of comparison. Vaginal examinations performed during the course of the study and gross and histologic examinations conducted at its termination revealed no significant differences between test and treated control animals exposed to either the cotton or nylon fabrics. *Application was by conventional technique and actual deposition of the antimicrobial was in the range of 0.2% based upon garment weight.

6 BactiBarrier Testing and Analysis Day Human Wear Test with Socks Treated with AEM 5700 Antimicrobial Various sock materials (wool, cotton, nylon, ORLON and SPANDEX ) were treated with AEM 5700 Antimicrobial at 0.35% owf (on weight of fiber) for safety evalua tions of skin irritation and skin sensitization properties. The antimicrobial(aem5700) treated socks were evaluated on 23 male subjects for a total of 32 continuous days. The results of the investigation showed the antimicrobial treated socks to be free from any observable skin irritation or skin sensitization. Three-Month Wear Test for Treated Athletic Socks with AEM 5700 Antimicrobial Various sock materials (wool, cotton, nylon, ORLON and SPANDEX) were treated with AEM 5700 Antimicrobial at 0.35% owf (on weight of fiber) for safety evaluation of potential hazard to skin under normal wear conditions. The antimicrobial (AEM 5700) treated socks were evaluated for skin irritating and skin sensitizing properties on 44 young male subjects for an entire football season (approximately 90 continuous days). The results of the investigation showed the male subjects to be free from any observable skin irritation or skin sensitization at the end of the test period. Technical Brief - Understanding the Silver Based Antimicrobials Mode of Action & Testing Methods 6 Resistance & Adaptation Resistance to Silver is well documented in the scientific literature. The ability to adapt is transferred from bacteria to bacteria via a DNA plasmid. This adaptation mechanism not only includes an inactivating protein but also turns on two active efflux pumps which rid the cells of Silver. The original resistant organism was isolated from a hospital burn ward. This is certainly a potentially serious real world problem and deserving of additional research work. Conclusions Products containing Silver as the active antimicrobial agent readily leach into the environment. Understanding the implications of this mode of action and the delivery of the active ingredient to the target cell are critical when making safe, sound antimicrobial choices.

7 BactiBarrier Testing and Analysis - 7 Works Cited Full documents available upon request. 1 ÆGIS Microbe Shield Program: A History of Confidence Form #1A1 Rev 05/ A New, Durable Antimicrobial Finish for Textiles Richard L. Gettings, Dow Corning Corporation, Midland, Michigan Benny L. Triplett, Burlington Industries Inc., Greensboro, North Carolina Form #4A1 3 Quaternary Silsesquioxane: A Developmental Toxicity Study in Rats Waheed H. Siddiqui and Raymond G. York Dow Corning Corporation, Toxicology Laboratory, 2200W. Salzburg Road, Midland, Michigan Received May 13, 1992; accepted March 5, 1993 Form #4A4 4 The Nature of Antimicrobials Form #6A1 Rev 3/ Summary of Toxicity Data Pertaining to AEM 5700 / ÆGIS Antimicrobial Form #7A 6 Technical Brief - Understanding the Silver Based Antimicrobials Mode of Action & Testing Methods Prepared by: Robert A. Monticello, Ph.D. Reviewed by: W. Curtis White Date: Form #7B12 Rev 4/2003