Aims: The purpose of the present investigation is to fill the current gap in information regarding the microbiological quality of toys containing aqueous media and the related risks for users.
Methods: Over 18 years, a total of 491 sealed toys containing aqueous media were analysed using conventional microbial culture methods. In addition, molecular methods (PCR/nested RT-PCR, followed by Sanger sequencing) were employed to test for enteric viruses (enteroviruses and adenoviruses) in a subset of toys; subsequently, the infectivity of the positive samples was tested on cell cultures.
Results: Of the examined toys, 23.8% were noncompliant with the limits of the European guideline. The most frequently exceeded limits were those for Aerobic bacteria (84.6%), and Pseudomonas aeruginosa (29.9%). Other opportunistic bacterial species that were frequently detected were Stenotrophomonas maltophilia, Pseudomonas fluorescens, Burkholderia cepacia, Sphingomonas paucimobilis and Comamonas acidovorans. In a subset of 28 samples, adenovirus (25%) and enterovirus (11%) genome was also found to be present, although the samples with viral positivity did not show infectivity after inoculation on appropriate cell monolayers.
Conclusions: The results indicate a condition of microbial exposure related to the use of toys containing aqueous media.
Significance and impact of study: The investigation highlights the need for more stringent monitoring during the production, packaging and storage of toys containing aqueous matrices in order to safeguard children's health.
Keywords: aqueous media; microbiological hazard; safety; soap bubbles; toys.
© 2022 Society for Applied Microbiology.