[Inactivation of disinfectants by proteins and calcium ions as a function of their chemical constitution and bacterial species].
Activity of nine disinfectants was evaluated with interfering substances (albumin-yeast mixture and hard water), by two methods (NFT. 72 170, NFT. 72 171 and without interfering substance NFT. 72 150, NFT 72 151 respectively). Interference indexes were defined as the ratio of bactericidal concentration without interfering substances to bactericidal concentration with interfering substances. Five different ratings of interference effects were arbitrarily defined (no effect, moderate, average, strong, very strong). Proteins and hard water significantly inactivate aldehydes and quaternary ammonium salts : interference index is usually 25 but may reach 100-500. Inactivation of phenolic products by these two interfering substances is either lacking or inconsiderable. Conversely to Gram negative bacteria, activity of disinfectants on Gram positive bacteria is not significantly affected by proteins or hard water. P. aeruginosa can survive despite high concentrations of disinfectant in the presence of proteins and calcium ions. This finding may be a reason why this microorganism is difficult to eliminate from hospital wards.
D001419:Bacteria / Q000187:drug effects*; D002118:Calcium / Q000494:pharmacology*; D055598:Chemical Phenomena; D002621:Chemistry; D004202:Disinfectants / Q000037:antagonists & inhibitors*; D008826:Microbial Sensitivity Tests; D011506:Proteins / Q000494:pharmacology*; D013045:Species Specificity; D014867:Water / Q000032:analysis
D004202:Disinfectants; D011506:Proteins; D014867:Water; D002118:Calcium
Inactivation par les protéines et les ions calcium des désinfectants en fonction de leur nature chimique et des espèces bactériennes.