Biocidal activity of a bioactive glass–protected, preservative-free tattooing solution

Background The number of people obtaining a tattoo has increased markedly in recent years Tattooing is known to present a risk of transfer of bacterial/fungal pathogens and possibly also viral pathogens. Colorants used for tattooing purposes can be heavily contaminated with bacteria, thus presenting a risk for infections. Concerted efforts are being made to remove this threat, including the production and use of cleaner dyes and pigments with enhanced antimicrobial properties. Methods Challenge tests were used to assess the survival characteristics of bacteria, bacterial endospores, fungal hyphae/spores, and bacteriophage in tattooing colorants. Results Bacteria were able to grow to high numbers in some colorants. A recently marketed, preservative-free colorant was shown to have a good hygienic quality and rapidly inactivated added bacteria and fungal spores. Activity against bacterial endospores was also demonstrated. Bacteriophage survived in the product during the 28-day test period. Conclusion The present study is the first to document the survival characteristics of vegetative bacteria and endospores, fungi, and bacteriophage (as virus surrogate) in tattooing solutions. The results of the present study readily explain the previously reported high numbers of bacteria in some tattooing colorants. A preservative-free colorant, which was designed in response to recent recommendations of the European Council with respect to chemical content, was also adequately self-preserving with respect to bacterial and fungal growth.