ANTIMICROBIAL EFFICACY OF QUATERNARY BISAMMONIUM SALTS AND THE EFFECTOF THEIR SUB-MICS ON PSEUDOMONAS-AERUGINOSA VIRULENCE FACTORS

Antipseudomonadal activity of homologous series of six quaternary bisa mmonium salts (QBAS) xo-3,8-dioxadekan-1,1-[bis(alkyldimethyldiammoniu m dibromide)] as well as the effect of their subinhibitory concentrati ons (sub-MICs) on Pseudomonas aeruginosa virulence factors was studied . Antibacterial activity of QBAS increased up to a certain length of t he chain and then decreased with further elongation. All the tested su b-MICs of QBAS caused a significant suppression of phospholipase C act ivity (to 0-41 %). Elastase and proteinase activity were less efficien tly reduced. A more effective decrease of these activities was only fo und after treatment with one-fourth of the MICs of the tested substanc es. QBAS caused only an erratic decrease of alginate production.