EVALUATION OF THE ANTIMICROBIAL EFFECTS OF NEW HETEROCYCLIC BIS-QUATERNARY AMMONIUM COMPOUNDS ON BIOFILMS
OANA E. CONSTANTIN 1, BIANCA FURDUI 2*, GABRIELA BAHRIM 1, RODICA M. DINICă 2 1. Dunărea de Jos University of Galati, Faculty of Food Science and Engineering, 111 Domnească Street, 800201, Galati, Romania
2. Dunărea de Jos University of Galati, Faculty of Sciences and Environment, 111 Domnească Street, 800201, Galati, Romania
*Corresponding author: bfurdui@ugal.ro
Considering the well-known mechanism of adaptable resistance of microorganisms to chemical compounds through biofilms formation and the widespread use of N-heterocyclic quaternary ammonium salts (QAC) as disinfectants, in this study we have evaluate the effect of 8 newly synthesized symmetrical and unsymmetrical diquaternary ammonium salts of 1,2-bis-(4-pyridil)-ethane on bacterial biofilms produced by three different bacterial strains. The effect of the exposure to quaternary ammonium salts on biofilm communities was investigated within biofilms obtained in a conventional testing system, on stainless steel and glass surfaces. Differential plate counts were used to characterize the developed communities and the effects of QAC exposure and the results were correlated with epifluorescence microphotographs. The data obtained revealed a significant reduction of bacterial cells in the biofilms tested with 4-7 log CFU for all the QAC.