Innovative textile technology with antimicrobial activity: preliminary tests

Abstract

The prevalence of urinary tract infections (UTI) and antibiotic resistance prompts researchers to develop strategies for bacterial containment, such as antiseptic-active textiles. We verified the in vitro antimicrobial effect of innovative Nexus Energy Fiber compared to conventional cotton fabrics. The analytical procedure is performed in accordance with ASTM E-2180-07 document. Tests are realized both against clinical and reference UTI-responsible microorganisms by comparing CFUs declines on the two textiles, at different contact times (0, 6, 24, 48 hours) and at different distances between the fabrics and the microbial strains (0, 0.5-1 cm). Results show that Nexus Energy Fiber has a measurable bactericidal effect which depends on the distances and is directly proportional to the contact time on most of the tested microbial strains. IntroductionThe prevalence of urinary tract infections (UTI) and the problem of antibiotic resistance prompt researchers to develop innovative strategies for bacterial containment. The usage of textiles with intrinsic antiseptic properties can be an interesting solution to obtain containment of colonizing microorganisms (2). The innovative fabric Nexus Energy Fiber® (NEF), Italy shows excellent static-eliminating properties due to its far infrared radiation physical activity added to the presence of silver compounds (3). Purpose of this study is to verify whether NEF has an in vitro antimicrobial effect compared to conventional pure cotton fabrics. Type of the studyOn top, its antimicrobial activity is evaluated on microorganisms responsible for UTI: particularly, E. coli, P. aeruginosa, E. faecalis and S. saprophyticus isolated from urine cultures of hospitalized patients. The reference microorganisms belong instead to the ATTC collection: S.aureus ATCC 6538 and K. pneumoniae ATCC 4352. All the analysis are performed in triplicate in accordance with the document ASTM E-2180-07 Determining the activity of antimicrobial agents incorporated into polymeric or hydrophobic materials (1). Specifically, the test took place in two rounds. Round 1 (direct contact conditions) involved the evaluation of the antimicrobial response when the fabric is at direct contact with microbial cultures in exponential growth phase. A slurry agar was used (4). If any antimicrobial effect is measured, round 2 (remote conditions) was performed: the fabrics were placed 0.5-1 cm away from the microbial culture. For both tests, positive and negative control references were set up to demonstrate media reliability and to exclude possible contaminations. The antimicrobial response was tested at different contact times: 0, 6, 24 and 48 hours.The bactericidal effect was estimated by comparing the different decline in the CFUs on pure cotton and on NEF. Antimicrobial effect percentages of NEF versus conventional pure cotton were calculated as indicated in paragraph 9 of the ASTM E-2180-07 (1).Results are reported in Tables 1 and 2. Direct contact tests proved that NEF has no antimicrobial effect against wild strains ...

4 Proofs, Defenses, and the Determination of Guilt or Innocence

“…We find the practice in Bologna and Venice, where formal opinions, consilia, written by medical professionals survive in abundance.65 Smaller towns such as Imola and Forlì near Bologna, probably influenced by the practice of larger cities, used them too. 66 The physicians who offered professional advice were selected by the court. In thirteenth-century Bologna, the selection was made randomly when the Podestà withdrew one of four names from a bag,67 working with a relatively small number of experts.68 In Reggio, it seems doubtful that there were many medical professionals to choose from.…”