MoWa: A Disinfectant for Hospital Surfaces Contaminated With Methicillin-Resistant Staphylococcus aureus (MRSA) and Other Nosocomial Pathogens.

Tyler V Gregory,Ana G Jop Vidal,Xueqing Wu,Babek Alibayov,Jorge E Vidal,Karen Ellis,Landon Murin,Faidad Khan,Renzo Valeriani,Tong Zhao

doi:10.3389/fcimb.2021.676638

Abstract

Introduction Staphylococcus aureus strains, including methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA), are a main cause of nosocomial infection in the world. The majority of nosocomial S. aureus-infection are traced back to a source of contaminated surfaces including surgery tables. We assessed the efficacy of a mixture of levulinic acid (LA) and sodium dodecyl sulfate (SDS), hereafter called MoWa, to eradicate nosocomial pathogens from contaminated surfaces.Methods and ResultsA dose response study demonstrated that MoWa killed 24 h planktonic cultures of S. aureus strains starting at a concentration of (LA) 8.2/(SDS) 0.3 mM while 24 h preformed biofilms were eradicated with 32/1.3 mM. A time course study further showed that attached MRSA bacteria were eradicated within 4 h of incubation with 65/2 mM MoWa. Staphylococci were killed as confirmed by bacterial counts, and fluorescence micrographs that were stained with the live/dead bacterial assay. We then simulated contamination of hospital surfaces by inoculating bacteria on a surface prone to contamination. Once dried, contaminated surfaces were sprayed with MoWa or mock-treated, and treated contaminated surfaces were swabbed and bacteria counted. While bacteria in the mock-treated samples grew at a density of ~104 cfu/cm2, those treated for ~1 min with MoWa (1.0/0.04 M) had been eradicated below limit of detection. A similar eradication efficacy was obtained when surfaces were contaminated with other nosocomial pathogens, such as Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, or Staphylococcus epidermidis.ConclusionsMoWa kills planktonic and biofilms made by MRSA and MSSA strains and showed great efficacy to disinfect MRSA-, and MSSA-contaminated, surfaces and surfaces contaminated with other important nosocomial pathogens.

Highlights

Staphylococcus aureus strains, including methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA), are a main cause of nosocomial infection in the world
A mid-log phase culture of methicillin resistant (MRSA) strain NRS384 was inoculated into a 24-well plate containing fresh brain heart infusion (BHI) broth and incubated for 24 h
Given that MoWa can be utilized to remove MSSA and MRSA strains from surfaces contaminated with a lower density to that obtained in 24 h cultures, we further investigated the timing and concentration required to eradicate MRSA bacteria that had attached to the substratum after being cultured for 4 h

Summary

Introduction

Staphylococcus aureus strains, including methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA), are a main cause of nosocomial infection in the world. Staphylococcus aureus, including methicillin resistant (MRSA) strains, have remained the main cause of hospital-acquired infection (HAI), i.e., nosocomial, in the United States and throughout the world (Magill et al, 2014; Magill et al, 2018). In hospitals where MRSA strains are endemic, bacteria have been isolated from 40% of overbed tables, 27% from beds or siderails, and >20% from door handles (Dancer, 2008) This high prevalence of contamination has placed S. aureus strains as the most prevalent etiology in bloodstream infection in the USA (Diekema et al, 2019), and a very common cause of HAI in burn patients (Pangli and Papp, 2019). Other Gram-positive and Gram-negative bacteria that cause a high burden of hospital acquired infections include Klebsiella pneumoniae, Staphylococcus epidermidis, and Acinetobacter baumannii (Magill et al, 2014; Magill et al, 2018; Cruz-Lopez et al, 2020)

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