Stachybotrys chartarum : its identification and response to antimicrobial treatment and prevention

BACKGROUND: Stachybotrys chartarum is mostly associated with water intrusion in the indoor environment. It is known as a species complex fungus and it can often be misidentified with its closely related species. Fungal resilience is a challenging problem when attempting to eradicate it from the envi...

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Bibliographic Details
Main Author: Binti Mohamad, Zuraifah Asrah
Other Authors: Ciric, L. ; Kibbler, C.
Published: University College London (University of London) 2018
Online Access:https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.756209
Description
Summary:BACKGROUND: Stachybotrys chartarum is mostly associated with water intrusion in the indoor environment. It is known as a species complex fungus and it can often be misidentified with its closely related species. Fungal resilience is a challenging problem when attempting to eradicate it from the environment and several studies have documented the ineffectiveness of antimicrobials when applied in real-life settings. OBJECTIVES: This study aims to: a) evaluate various identification methods to characterise Stachybotrys species; and b) determine the effects of antimicrobial agents on S. chartarum. METHODS: Current identification methods; a) Culture characteristics and microscopy; b) Polymerase chain reaction (PCR); and c) Matrix assisted desorption ionisation- time of flight (MALDI-TOF), were employed. The effects of antimicrobial agents consisting of bleach, aerosolised hydrogen peroxide, peracetic acid and organosilane (OS) on S. chartarum were evaluated a) in vitro; b) On building material and; c) By using a proteomic approach. RESULTS: The methods of culture and microscopy are useful for early stage screening. A universal PCR primer set is suitable for identification at the genus level. However, tri5 primers provide a quick and specific method for identifying S. chartarum and S. chlorohalonata. MALDI-TOF could differentiate both species but could not provide reliable identification for other Stachybotrys species. The in vitro and environmental studies of antimicrobial agents show that bleach and OS appeared to be effective as treatment and prevention strategies, respectively. Differences in protein changes towards bleach and OS suggest that a combination of antimicrobial agents with different modes of action might provide a more effective way to eliminate fungal growth. CONCLUSION: Confirmatory methods are important to obtain the correct identification especially for less commonly studied moulds such as S. chartarum. More research with regard to an effective application strategy or delivery method is required to complement the antimicrobial agents that are currently available on the market.