Microbial contamination of tattoo and permanent makeup inks marketed in the US: a follow‐up study

In a 2018 survey, U.S. Food and Drug Administration (FDA) identified microbial contamination in 42 (49%) of 85 unopened tattoo and permanent makeup (PMU) inks purchased from 13 manufacturers in the US between November 2015 and April 2016. To confirm the results of our previous survey, we evaluated the level of microbial contamination in an additional 27 samples from 10 manufacturers from September 2017 to December 2017, including 21 unopened tattoo and PMU inks which were selected based on our previous survey results and 6 ink diluents that were not previously analysed. Aerobic plate count and enrichment culture methods from the FDA’s Bacteriological Analytical Manual revealed 11 (52%) out of 21 inks, from six manufacturers, were contaminated with micro‐organisms, with contamination levels up to 3·6 × 108 CFU per gram, consistent with our previous survey results. We identified 25 bacterial strains belonging to nine genera and 19 species. Strains of Bacillus sp. (11 strains, 44%) were dominant, followed by Paenibacillus sp. (5 strains, 20%). Clinically relevant strains, such as Kocuria rhizophila and Oligella ureolytica, were also identified, as similar to the findings in our previous survey. No microbial contamination was detected in any of the six ink diluents. Significance and Impact of the Study: Risks of infection associated with tattoo and permanent makeup (PMU) inks contaminated with microorganisms continues to be a public health concern. This study confirms the results from our previous study showing that a high portion of tattoo and PMU inks were contaminated with micro‐organisms, including pathogenic bacteria. The results of this survey highlight the safety concerns associated with intradermal injection of microbially contaminated tattoo inks. Furthermore, this study shows the importance of continuously monitoring the levels of microbial contamination of tattoo and PMU inks marketed in the US.