Traditional vs Innovative Sanitizers: In Vitro and In Situ Challenge in Multidrug-Resistant Bacteria

Multidrug-resistant (MDR) bacteria pose a threat to public
health
worldwide. In this context, disinfectants are used to prevent and
control the spread of these pathogens in hospital and industrial environments.
The objective of this study was to determine minimum bactericidal
concentrations (MBC) for 10 traditional and innovative active ingredients
against 11 bacterial species. At the same time, the efficiency test
was applied in vitro and the effect on hospital surfaces
was analyzed in situ. The most promising compounds
were selected to determine their mechanism of action in the Gram-positive
bacterium (Staphylococcus aureusMRSA)
and the Gram-negative bacterium (Pseudomonas aeruginosaPA) by metabolomic analysis. Resistance to 50% of the active
ingredients was observed in the five strains, and PA was resistant
to 70% of them. Peracetic acid, chlorhexidine digluconate, and neem
extract eliminated all strains within 1 min in MBC. In efficiency
tests, traditional products killed bacteria, with an average reduction
of 7.07 ± 0.331 log cycles. Neem extract achieved an average
reduction of 6.60 ± 0.33 log across all strains. In situ, peracetic acid did not allow bacterial growth, while biguanide,
neem extract, tea tree oil, and orange oil achieved a reduction of
more than 4 cycles of bacterial control on the surface. The exposure
of MRSA and PA to the most promising compounds promoted distinct alterations
in intra- and extracellular metabolism, which were modulated by the
bacterial cell wall structure. The study highlights the importance
of evaluating the practical efficacy of disinfectants, emphasizing
the diversity of approaches including natural compounds as alternatives
in critical environments.