Identification of fungi from children's shoes and application of a novel antimicrobial agent on shoe insole

Abstract

13 strains of fungi were isolated from 12 shoes worn by children aged 6 to12 for a period of more than half a year consisting of 5 strains of yeasts and 8 strains of molds. Through morphological observation and 18SrDNA sequence analysis, the 5 strains of yeasts were identified as follows: Cryptococcus neoformans, Candida albicans, Cryptococcus albidus, Rhodotorula mucilaginosa and Candida utilis. While the 8 strains of molds characterized and classified by point cropping, insert method and imprint method were respectively Mucor (2 subspecies), Chain cell mold, Aspergillus (3 subspecies) and Penicillium (2 subspecies). In order to protect children's feet from being infected by the fungi, a novel nano antimicrobial composite containing nano ZnO and isothiazolinone was prepared and was used to treat the children’s insole by spraying. The inhibitory effects of the nano antimicrobial composite treated insole against yeasts and molds from children’s shoes were evaluated by the inhibition zone and the inhibition ratio method. The results show that the insole treated with 2% nano antimicrobial composite could inhibit the growth of tested microorganism effectively, which could also achieve more than 97% inhibition ratio against the entire tested fungi.

Key words: Children’s shoes, identification, fungi, nano antimicrobial composite.