title: Electron microscope study of effect of benzalkonium chloride and edetate disodium on cell envelope of Pseudomonas aeruginosa.
abstract: Electron micrographs of Pseudomonas aeruginosa grown in nutrient broth or broth containing subinhibitory concentrations of benzalkonium chloride indicate that benzalkonium chloride at 50 and 100 mug/ml strips off the outer cell membrane. Cells grown in the presence of edetate disodium, 50-100 mug/ml had convoluted surfaces (wavy in cross section). Cells damaged by growing on nutrient agar containing benzalkonium (200 mug/ml), when subsequently grown for 16 hr in nutrient broth, produced cells with apparently normal outer lavers. Similar cells grown on nutrient agar plus benzalkonium (500 mug/ml) when grown for 16 hr in nutrient broth had normal resistance to edetate disodium lysis, but cells grown overnight in broth plus benzalkonium (500 mug/ml) showed increased sensitivity to edetate disodium lysis. Cells grown on nutrient agar in the presence of benzalkonium (800 mug/ml) grew in broth plus benzalkonium (10 mug/ml) without stripping of their external membrane, but replicate inocula into broth plus benzalkonium (10 mug/ml) and edetate disodium (50 mug/ml) produced cells with structural damage to the outer lavers of the cell envelope.
mesh_terms: D001548:Benzalkonium Compounds / Q000494:pharmacology*; D002473:Cell Wall / Q000187:drug effects / Q000648:ultrastructure*; D003470:Culture Media; D004492:Edetic Acid / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000166:cytology*; D013997:Time Factors
chemical_list: D001548:Benzalkonium Compounds; D003470:Culture Media; D004492:Edetic Acid