Microbiological Analysis of Selected Washed and Unwashed Nose Masks and its Implication for Public Health

Abstract

The microbial loads of washed and unwashed medical and fabric nose masks were investigated.  Six nose masks were sampled from different sources and were subjected to microbial isolation and identification procedures using the serial dilution and pour plate method, and microbes found were identified using the several characteristics. Study revealed that the new medical nose mask had no microbial load while the used unwashed medical nose mask had microbial loads too numerous to count (TNTC) and the used washed medical nose mask had microbial load of 89 cfu/ml. The new and unwashed fabric masks had microbial loads too numerous to count (TNTC) while the washed fabric nose mask had 40cfu/ml. Nine organisms were identified including; Aspergillus spp and yeast (Fungi), Staphylococcus aureus, Salmonella typhi, Proteus bulgaris, Escherichia coli, Proteus mirabilis, Enterobacter cloacae, Micrococcus spp, Streptococcus canis and Pseudomonas aeruginosa.  They were subjected to antibiotic susceptibility test using the disk diffusion method. They were tested against standard gram +ve and gram -ve antibiotics. Antibiotics resistance profile of the isolates to standard antibiotics are as follows; Staphylococcus aureus was resistant to 86% of the antibiotic used and P. bulgaris was 64%, S. typhii was 86%.  The microbial load of new medical nose masks is significantly negligible while microbial load of the used nose masks was high, It reveals that washing reduces the microbial load but does not completely eliminate the presence of microorganisms. This study recommends that medical nose masks should only be used once and then properly discarded.