Study on the In Vitro Activity of Five Disinfectants against Nosocomial Bacteria

Abstract

Nosocomial infections cause significant morbidity and mortality worldwide, and the pathogenic organisms responsible for such infections can develop resistance to antimicrobial agents. Understanding the activity of disinfectants against clinical and environmental bacterial isolates is therefore crucial. We analysed the in vitro activity of five antimicrobial products (phenolic compounds, didecyldimethylammonium chloride (DDAC), sodium hypochlorite, isopropanol + ammonium compounds (IACs), hydrogen peroxide) against 187 bacterial strains comprising clinical isolates, as well as 30 environmental isolates of Pseudomonas aeruginosa from hospital water samples. Disk diffusion assays were employed to assess antimicrobial activity. Hydrogen peroxide was significantly more active (p < 0.0001) than the other disinfectants against all P. aeruginosa, Klebsiella pneumoniae, Enterococcus faecalis and Staphylococcus aureus strains. It was also the only disinfectant with activity against both clinical and environmental strains of P. aeruginosa. DDAC and IAC-based disinfectants were ineffective against Gram-negative strains, but showed significant activity (particularly IACs, p < 0.0001) against the Gram-positive strains. Compared with IACs, DDAC was significantly more active on E. faecalis and less active on S. aureus (p < 0.0001). Sodium hypochlorite and phenol compounds, by contrast, were inactive against all bacterial strains. The development of disinfection procedures that are effective against all microorganisms is essential for limiting the spread of nosocomial infections.

Potential application of novel technology developed for instant decontamination of personal protective equipment before the doffing step

“…Other studies have already demonstrated the effect of different biocidal agents against the microorganisms tested in this study, showing that the efficacy of the disinfection process varies with the type of disinfectant [ 99 , 100 ] or according to the application method used [ 101 , 102 ]. There are few reports in the scientific literature on the efficacy of PPE decontamination after exposure to pathogens, as was analyzed in this study.…”

Antimicrobial Susceptibility of Bovine Subclinical Mastitis and During Milk Separation Isolates and the Accompanying Hygienic Practices

“…The biocidal effect of hydrogen peroxide is attributable to the-OH radical, formed by the decomposition of peroxide in the presence of catalysts, such as iron and copper ions, commonly found in microorganisms. The radical acts via an oxidative mechanism against the membrane, DNA and other cellular constituents of the microorganism (Montagna et al, 2019).…”

The Role of Urban Wastewater in the Environmental Transmission of Antimicrobial Resistance: The Current Situation in Italy (2010–2019)

“…However, some alternatives for efficient ARG removal from effluent of wastewater treatment plants have been recently proposed, including the use of synthesized hydrated manganese oxide coupled with permanganate, the metal-free photocatalyst graphitic carbon nitride (g-C 3 N 4 ), and the natural zeolite clinoptilolite enriched with silver (AgNZ) [ 56 , 57 , 58 ]. In addition, bacterial resistance to commonly used disinfectants is often overlooked [ 59 ].…”