Agricultural biowaste based disinfectant formulation mitigates drug resistant nosocomial pathogens

Proper disinfection is one of the essential ways to prevent the transmission of pathogens, as hospital surfaces act as a reservoir of microorganisms. The existing commercial disinfectant possesses disadvantages like a high carbon footprint and toxic by-product emissions, thereby creating an urgent need for the development of renewable and environmentally friendly disinfectants. The present study deals with the formulation of a disinfectant using the aqueous phase (AQ) produced during the pyrolysis of wheat straw biomass. Results indicate a high rate of the killing ability of the notorious nosocomial pathogens, namely Methicillin Resistant Staphylococcus aureus, Acinetobacter baumannii and Candida auris when cultured alone and as a co-culture. The efficacy of the formulated disinfectant was then assessed using the phenol coefficient test. The formulated disinfectant had good efficacy as it had a phenol coefficient value greater than 1. Further, a CDC biofilm reactor model to mimic the biofilms formed in clinical settings was used to assess the efficacy of the formulation against the multi-species biofilms of the above pathogens formed on stainless steel 316 coupons, a widely used material in hospital settings. The formulation was not only effective against the planktonic cells but also effective in disrupting the mature biofilms. The formulated disinfectant showed a phenol coefficient greater than one and resulted in 6 log reductions to biofilm cells. The live/dead fluorescence staining showed that in the control coupons, the biofilm cells were alive, and in the treated coupons, the biofilm cells were dead. The toxicity of the formulation was further assessed using the earthworm as a biological model. This study thus demonstrates the potential of wheat straw, which is discarded as agricultural waste, into a value-added product like a disinfectant.