Low efficacy of three non-alcohol-based hand disinfectants utilizing silver polymer, lactic acid and benzalkonium chloride on inactivation of bacteria in healthcare workers’ fingertips

Knowledge, attitudes, and practice of medical students towards the use of benzalkonium chloride in hand sanitization from the perspective of environmental sustainability

Control measures for disinfectant pollution and related anthropogenic behaviors are required. Benzalkonium chloride (BAC) with widespread use especially in hand sanitization is highlighted as a representative disinfectant emerging contaminant. This cross-sectional survey was conducted to assess the knowledge, attitudes, practice regarding BAC use for hand hygiene among medical students from the perspective of environmental sustainability. Of the 703 responding students, only 3.7% had never used hand sanitizer products containing BAC. But few students paid attention to the "environmental friendliness" property of products when consumption. Mean knowledge test score was 1.90 out of 5, suggesting poor knowledge regarding BAC use. Most students had positive attitudes toward source control of BAC pollution and strong intentions to learn more about environmental knowledge related to BAC and other disinfectants. Data indicated that medical students had positive attitudes but lacked knowledge and practices towards eco-friendly disinfectant use, thus further training and practice standards are required.

Rapid-killing efficacy substantiates the antiseptic property of the synergistic combination of carvacrol and nerol against nosocomial pathogens

Globally, new classes of synthetic and natural antibiotics and antivirulents have continuously been validated for their potential broad-spectrum antagonistic activity with the aim of identifying an effective active molecule to prevent the spread of infectious agents in both food industry and medical field. In view of this, present study is aimed at evaluating the rapid killing efficacy of bioactive molecules Carvacrol (C) and Nerol (N) through British Standard European Norm 1276: phase2/step1 (EN1276) protocol. Active molecules C and N showed broad-spectrum antimicrobial activity against the test strains Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus hirae at concentration range of 78.125, 625, 156.25 and 312.5 μg/mL, respectively, for C, and 625 μg/mL for N. Whereas, combinatorial approach showed efficient activity with four times reduced concentration of C and N at 78.125 and 156.25 µg/mL, respectively, against test strains. Further, EN1276 results proved the rapid killing efficacy of test strains in 1 min of contact time with significant (> 5 log) growth reduction at 100X concentration of actives. SEM analysis and reduced concentration of protease, lipids and carbohydrate contents of treated group biofilm components ascertained preformed biofilm disruption potential of C + N on polystyrene and nail surfaces. C + N at synergistic concentration exhibited no adverse effect on HaCaT cells at 78.125 µg/mL (C) + 156.25 µg/mL (N). Taken together, based on the observed experimental results, present study evidence the antiseptic/disinfectant ability of C + N and suggest that the combination can preferentially be used in foam-based hand wash formulations.