Susceptibility patterns of bacteria isolated from the hospital environment towards disinfectants commonly used for surfaces and medical devices

This study aimed to evaluate the bactericidal activity of common disinfectants used for surfaces and medical devices. Sodium hypochlorite (D1), disinfectant (D2) composed of N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine, chloride de didecyldimethylammonium, and disinfectant (D3) composed of Didecyldimethylammonium chloride and Polyhexamethylene biguanide hydrochloride, were tested against 15 strains isolated from the hospital environment and four reference bacteria. The microdilution method was performed to assess antimicrobial activity. The susceptibility was evaluated by comparing the minimum inhibitory dilution with the dilution of disinfectant recommended by the manufacture. D1 and D2 were active against Staphylococcus epidermidis , Staphylococcus saprophyticus, Enterobacter cloacae, Escherichia coli, Pseudomonas fluorescens, Methicillin-resistant Staphylococcus aureus, Bacillus spp, Corynebacterium spp, Gram-positive bacillus, Escherichia coli ATCC 25922, Bacillus subtilis ATCC 3366, and Pseudomonas aeruginosa ATCC 27853 strains but not active against Micrococcus spp, and Staphylococcus aureus ATCC 29213. D3 was ineffective against Micrococcus spp, Bacillus Gram Positive, Staphylococcus epidermidis , and Escherichia coli ATCC 25922. Therefore, D1 and D2 can eliminate most pathogenic bacteria in hospitals, in comparison to D3. It is necessary to monitor the antibacterial activity of disinfectants against reference strains but also against those usually present on surfaces. The obtained results could have promising applications in controlling the emergence of nosocomial infections.