Prevalence of Multidrug‐Resistant Bacteria on Hospital Face Masks: A Surveillance Report

ABSTRACT Background Nosocomial infections have become a major concern, with the COVID‐19 pandemic leading to increased utilization of face masks. Masks act as a barrier to ensure the safety against the respiratory threat; continued use enables the bacteria to fester, which raises the risk of contamination. The aim of this study was to investigate the bacteria from masks worn by hospital staff and evaluate their implications. Methods A total of 10 masks worn by intensive care unit staff for 20–24 h were collected. A novel mask‐press technique was used to isolate bacteria on selective agar media. Morphological and biochemical characterizations and then antibiotic susceptibility testing using the Kirby‐Bauer Disc‐Diffusion method were performed against 11 antibiotics. The most resistant isolate underwent molecular identification via 16S rDNA sequencing and phylogenetic analysis. Results Among 10 masks, 8 exhibited bacterial growth, and 400 bacterial colonies were obtained. Samples 1 and 6 showed very low bacterial burden, almost negligible and were excluded. Isolated genera were Bacillus , Streptococcus , Staphylococcus , Klebsiella , and Enterococcus . The highly resistant strain was identified as Klebsiella michiganensis (GenBank Accession No. PP854651.1), a rarely documented nosocomial pathogen that was found to be resistant to 10 of 11 tested antibiotics, including cefotaxime, methicillin and ciprofloxacin. On the contrary, the Viridans group Streptococci showed susceptibility to all antibiotics except cloxacillin. Conclusions The intensive care unit face mask may harbor multidrug‐resistant Klebsiella michiganensis over a long period, even posing a risk of transmission to immunocompromised patients. The mask–press technique proved to be effective in the full recovery of bacteria. The findings indicate that more effort is needed to enhance mask decontamination procedures, standardize disposal practices, and conduct larger surveillance studies to evaluate the clinical significance of mask‐associated bacterial reservoirs in healthcare settings.