Microbiological analysis of the antibacterial effects of sprays applied to non-woven fabric masks

This study characterized the microbiota on lip-contact surfaces of worn non-woven fabric masks and evaluated the effects of commercially available mask sprays. Masks worn by six healthy volunteers were sampled, cultured anaerobically, and analyzed by 16S rRNA gene PCR-RFLP and sequence analysis, since anaerobic cultures are known to yield a larger and more diverse microbial community of the microbiota on worn non-woven fabric masks (Maruyama et al. 2022). The mean bacterial concentration on worn masks was (1.4 ± 0.9) × 10³ CFU/mL. Among 299 isolates, Cutibacterium (75.3%) and Staphylococcus (19.4%) were predominant. Several sprays markedly reduced bacterial counts (to 10¹-10² CFU/mL), whereas others showed limited effects. Overall, mask sprays variably reduced bacterial contamination on lip-contact surfaces of worn non-woven fabric masks.