Evaluation of Antibacterial Activity of Three Quaternary Ammonium Disinfectants on Different Germs Isolated from the Hospital Environment

Abstract

Background. The microbiological risk of the hospital environment, including inert surfaces, medical devices, and equipment, represents a real problem. Objective. This study is aimed at demonstrating and assessing the antibacterial activity of three synthetic disinfectants classified as quaternary ammoniums on different bacterial strains (Gram-negative and Gram-positive like Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus aureus) isolated from the hospital environment. The reference strains included Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 29213, and Pseudomonas aeruginosa ATCC 27853 used as negative control strains. Method. Three quaternary ammonium disinfectants were tested: DDN9® (0.5%) which contains didecylmethylpolyoxyethylammonium propionate as an active substance, spray (0.4%) containing quaternary ammonium compounds, and Phagosurf ND® (0.4%) with didecyldimethylammonium chloride. Their effect was evaluated using the disk diffusion technique and the broth dilution methods, allowing the Minimum Inhibitory Concentration (MIC) and then the Minimum Bactericidal Concentration (MBC). Result. Only the growth of Gram-positive bacteria and some strains of Gram-negative bacteria were inhibited by the three synthetic disinfectants. NDD9® demonstrated an antibacterial effect only against the Gram-positive strains (S. aureus and S. aureus ATCC 29213) with a MIC of 0.25 mg/ml. The disinfectant spray showed effect against all four strains including E. coli (9), S. aureus, E. coli ATCC 25922, and P. aeruginosa ATCC 27853 with an inhibitory concentration of 4 mg/ml, while the growth of S. aureus ATCC 29213 was inhibited at 2 mg/ml. The third disinfectant, Phagosurf ND®, inhibited only the growth of S. aureus ATCC 29213 at a MIC of 4 mg/ml. Conclusion. This study is the first here in Morocco to evaluate the bacterial activity of products intended for the control of the healthcare environment. The results obtained on the three disinfectants tested reveal an ineffectiveness against some isolated strains from the hospital environment.

Kinetics of Bacterial Adaptation, Growth, and Death at Didecyldimethylammonium Chloride sub-MIC Concentrations

“…Didecyldimethylammonium chloride is antimicrobial acting on the bacterial membranes and showing bacteriostatic and bactericide activity depending on its concentration and the growth phase of the population (Yoshimatsu and Hiyama, 2007;Kampf, 2018a). The MIC values for DDAC vary among species and isolates but its application at the recommended dosage in commercial disinfectants seems to be not always enough to inactivate all types of pathogens (Ramzi et al, 2020). In general, most bacteria isolated from food have MIC values ranging from 0.5 to 6.0 mg L −1 (Kampf, 2018a).…”

Microbiological Monitoring of the Environment Using the “Association Rules” Approach and Disinfection Procedure Evaluation in a Hospital Center in Morocco

“…e contamination of operating theater is justified by the poor quality of disinfection and cleaning procedures between surgical operations, despite the limited access of patients and nursing staff, and by the multitude of surgical specialties in these departments. e most contaminated sites are the floor, door handles, and bed rails, due to their frequent use by patients and nursing staff, as these sites are close to the patient, and this has been justified by several studies [23,24]. e majority of bacteria isolated from the different studied services' surfaces are Gram-positive germs.…”

“…The most contaminated sites are the floor, door handles, and bed rails, due to their frequent use by patients and nursing staff, as these sites are close to the patient, and this has been justified by several studies [ 23 , 24 ].…”

In vitro Efficacy Testing of Some Commercial Disinfectants against Pathogenic Bacteria Isolated from Different Poultry Farms

“…Quaternary ammonium compounds are effective antimicrobial agents due to their significant biocide activity, compatibility with the environment, and long-term durability (Ramzi et al, 2020). It is a cationic surfactant whose bactericidal effect depends on lipophilicity, altering cell permeability and resulting in extravasation of the bacterial content.…”