Innovative Test Method for Antimicrobial Fabrics Presented

Recent studies have found high amounts of bacteria hitching a ride on healthcare worker uniforms.  While special antimicrobial fabrics are being developed to combat this problem, a team of scientists in Washington, D.C. is developing new test methods to evaluate the emerging technologies.

The American Society of Testing and Materials (ASTM) 32nd Symposium on Pesticide Formulation and Delivery: Innovating Legacy Products for New Uses, held in Tampa recently, invited a team from MedStar Health Research Institute to present its work titled, The Fabric Challenge Assays: a Novel Standard for the Evaluation of the Performance of Antimicrobial Textiles.

Antimicrobial textiles are gaining interest in healthcare settings, says Matthew Hardwick, PhD, director of laboratory of clinical investigations at MedStar Health who presented to the ASTM Committee.  New product categories, especially in healthcare, need to be vetted for safety and efficacy.

While there are several standard methods available for testing antimicrobial textile efficacy, each is limited due to the artificial nature of the testing method.  Our team at MedStar Health wanted to develop a test that showed the efficacy of these fabrics in terms of reducing bacterial load in real-world scenarios, explains Hardwick.

In the real world clinical environment, there are three primary means of transmission of bacteria: aqueous splatter such as urine or blood; aerosol such as a cough or sneeze; and direct contact with infected persons or environmental surfaces. The novel fabric challenge assay is designed to mimic each mode of transmission in order to test the efficacy of antimicrobial textiles in a more real-world simulation. 
 
Our results show that the test fabric, which was treated with Semeltec antimicrobial and provided by Vestex, reduced methicillin-resistant Staphylococcus aureus (MRSA) by different percentages for different contact simulations -- 99 percent for aerosol, 99.9 percent for direct contact and 99.9 percent for splatter conditions, Hardwick says.  The different inoculation simulations also had different kill-time curves the Semeltec antimicrobial fabric from Vestex worked immediately in all tests.  The control fabric did not have appreciable reductions in bacteria with any test method.

As technologies advance, our test methods must advance.  The closer we get in the lab to mimicking actual use conditions, the more useful the test, says Margaret Cotton, an author of the study.