In Vitro Activity of Disinfectants against Mold Fungi Isolated from Different Environments of the Children’s Medical Center Hospital, Tehran, Iran

Introduction: Fungal aerosols cause life-threatening infections in patients hospitalized in critical wards. Antiseptics and disinfectants have broad-spectrum antimicrobial activity against the living tissue and inert surfaces microorganisms; hence, they have an essential role in controlling and preventing nosocomial infections. This study aimed to evaluate in vitro antifungal activity of benzalkonium chloride (BAC), chlorhexidine digluconate (CHX), and sodium hypochlorite (SH) against isolated fungal aerosols from the hospital environment. Materials and Methods: The susceptibility tests were performed on fungal aerosols isolated from various wards of Children’s Medical Center, based on broth microdilution antifungal susceptibility testing of filamentous fungi approved by the Clinical and Laboratory Standards Institute (CLSI) M38-A2 document. The isolates included Aspergillus (Aspergillus flavus (n = 14), Aspergillus niger complex (n = 12), Penicillium spp. (n = 14), and Cladosporium spp. (n = 14). Results: The geometric means (GM) of the Minimum Inhibitory Concentrations (MICs) of the biocides across all isolates were as follows: BAC, 3.56 µg/ml, CHX, 9.45 µg/ml, and SH, 810.35 µg/ml. The highest range of MICs was found for SH (50-12800 µg/ml), while the lowest range was for BAC (1-16 µg/ml) against all fungal isolates. Generally, BAC showed the highest in vitro activity among disinfectants tested. The lowest MIC50 and MIC90 values were 4 and 8 µg/ml for BAC, followed by 16 and 32 µg/ml for CHX, and 800 and 6400 µg/ml for SH, respectively. Conclusion: The findings showed that BAC was an effective disinfectant, which can  prevent resistant species and fungal pathogens and be used an alternative to other disinfectants and antiseptics.