Fabric Challenge Assays: New Standards for the Evaluation of the Performance of Textiles Treated with Antimicrobial Agents

Abstract

Textiles treated with antimicrobial agents are emerging as new strategies to reduce acquisition of healthcare-associated infections (HAIs). Essential to development/validation of these textiles are standard methods for the testing antimicrobial textile efficacy. Our laboratory has developed new testing methods, the fabric challenge assays, to recapitulate each transmission method and test the efficacy of antimicrobial textiles in a more “real world” simulation. 5 × 105 colony-forming units/ml (CFU/ml) MRSA suspensions were grown. 15 × 15 cm2 swatches of control, antimicrobial, hydrophobic barrier, and VTT003 fabric were inoculated with MRSA either by aerosol, splatter, or direct contact. Inoculated fabric was left at room temperature for 0, 30, or 60 min. Fabric was then transferred to buffer and shaken for 3 min at 400 rpm. A liquid suspension (0.1 ml) was then plated onto blood agar, grown overnight at 37°C, and colonies were counted. In the aerosol test, at 0 min, VTT003 significantly reduced MRSA by 78.52 ± 10.26 % compared to control fabric. At 30 min, antimicrobial reduced MRSA levels by 91.48 ± 8.52 %. In the splatter test, at 0 min, antimicrobial, hydrophobic barrier, and VTT003 fabrics reduced MRSA levels by 98.56 ± 1.44, 83.91 ± 13.16, and 100.00 ± 0.03 %, respectively. At 30 min, hydrophobic barrier and VTT003 reduced levels by 82.63 ± 17.37 and 100.00 ± 0.00 %, respectively. At 60 min, hydrophobic barrier and VTT003 abrogated MRSA levels. In the contact test, at 0 min, hydrophobic barrier and VTT003 reduced MRSA levels by 99.06 ± 0.94 and 97.08 ± 2.92 %, respectively. At 30 min, hydrophobic barrier and VTT003 reduced MRSA levels by 100.00 ± 0.03 and 19.38 ± 19.38 %, respectively. At 60 min, hydrophobic barrier and VTT003 abrogated MRSA levels. The fabric challenge assays are a novel method for evaluation of antimicrobial textile performance and should be considered in the development of standards and testing methods for all antimicrobial textiles intended for use in healthcare infection control strategies.

Role of healthcare apparel and other healthcare textiles in the transmission of pathogens: a review of the literature

“…Technical or engineered fabrics have reduced MRSA surface levels to near 0% in splatter, spray and contact challenge tests within 5 min. 99 In addition, Bearman et al documented four-to seven-log reductions for MRSA on technical or engineered fabrics with fluid repellency and antimicrobial properties compared with traditional control scrubs, both at the beginning and end of the nurse work shift. 32 They concluded that the use of an antimicrobial hydrophobic barrier is highly effective in reducing the microbial bioburden on the surface of HCWs' scrubs.…”

Making the Case for Textiles with a Dual Mechanism of Action

“…It is also important to note that Bearman’s findings in the clinical setting were validated in the laboratory findings of Hardwick et al 3 Dr. Hardwick and colleagues described the dual mechanism of action of breathable, antimicrobial, fluid barrier fabrics in their published laboratory “Fabric Challenge” test method. Hardwick noted that the combination of an organo-silane antimicrobial agent and a hydrophobic barrier chemistry provides an additive effect when combined and results in a higher reduction of MRSA on the fabric than does either the antimicrobial or the fluid barrier alone.…”

Pediatrik Ayaktan Tedavide Enfeksiyon Önleme ve Kontrol

“…Hasta çarşaf ve önlükler tekrar kullanılıyorsa, çevre kirlenmesini en aza indirecek biçimde dikkatle kullanılması önemlidir. Dıştan sıvı geçirmez ve antimikrobiyal ajanlar eklenmiş olarak tasarlanan yeni bir "aktif bariyer" kumaş sınıfı mevcuttur (73)(74)(75). Kirli nevresimler, kullanım yerinde kirli çamaşır kapına konulmalıdır (3).…”