Cross-resistance to antibiotics of Escherichia coli adapted to benzalkonium chloride or exposed to stress-inducers.

This study looked at the effects of adaptation and stress on the resistance to benzalkonium chloride (BAC) and cross-resistance to antibiotics. Exposure of E. coli to stress inducers (salicylate, chenodeoxycholate and methyl viologen) generally increased the tolerance to BAC and chloramphenicol (CHL). This indicated that adaptation to BAC could be partly attributed to stress responses. Enhanced efflux was one of the observed differences in adapted cells. The authors conclude that provided not taking due precautions, extensive use of disinfectants could lead to emergence of antibiotic-resistant isolates. J Appl Microbiol 2004;96:201-208.