Textile Treatment Keeps Microbes at Bay

By Jan Suszkiw
June 8, 1999

A textile treatment that has improved thermal adaptability, absorbency and other desirable properties in fabric may offer yet another benefit, scientists say.

In lab tests, coating cotton, polyester and other fabrics with nontoxic polymers called polyethylene glycols (PEG) reduced by almost 100 percent the growth of several common fungi and bacteria. Most, like odor-causing Brevibacterium epidermidis bacteria, grow in socks and other clothing by forming biofibrils.

The PEGs apparently mar the fibers’ surface so that the biofibrils can’t attach. The substances may also dehydrate the microbes, rupturing their cell membranes, according to Agricultural Research Service chemist Tyrone Vigo and University of Georgia professor Karen Leonas. ARS is the U.S. Department of Agriculture’s chief scientific agency.

ARS’ Vigo and colleagues originally developed the PEG treatments several years ago to improve comfort, wear and other properties of textiles like cotton. Commercial applications--from licensee Wisconsin Global Technologies Ltd.--include sportswear and apparel that retain or release body heat as needed. Another licensee, Bayshore Holding, Inc., uses the technology for health care products like underpads for incontinence.

Last year, as part of a CRADA, the group decided to confirm and explain earlier observations that PEG treatments also impart antimicrobial properties, a trait clothing and textile manufacturers are keen to exploit, says Vigo, with ARS’ Cotton Textile Chemistry Research Unit in New Orleans.

The scientists found a nearly complete decrease in microbe and fungal growth after lab tests in which swaths of cotton-polyester bedsheets were inoculated with spores of Brevibacterium, Staphylococcus epideremidis bacteria, and Aspergillus fumigatus and Microsporum cookel fungi. Both fungi can cause allergies and asthma. Staph bacteria can cause skin, wound and other infections.

In untreated fabrics, scientists observed minor reductions, most likely from additives briefly present after processing. A fifth pathogen, the yeast Candida albicans, was unaffected by the PEG-treated fabrics.

Another benefit: scientists believe PEGs’ antimicrobial action is more physical than chemical, so fabric-infecting germs should be less apt to develop resistance.

Scientific contact: Tyrone Vigo, ARS Southern Regional Research Center, New Orleans, La., phone (504) 286-4487, fax (504) 286-4271, tvigo@commserver.srrc.usda.gov.