Chloraminated drinking water does not generate bacterial resistance to antibiotics in Pseudomonas aeruginosa biofilms.

This study aimed to determine whether exposure of Pseudomonas aeruginosa biofilms to chloraminated drinking water can lead to individual bacteria with resistance to antibiotics. Biofilms of P. aeruginosa PA14 were grown in drinking water in a Kadouri drip-fed reactor; the biofilms were treated with either 0.5 mg l-1 or 1.0 mg l-1 of chloramine for 15 or 21 days; control biofilms were grown in water without chloramine. Under these test conditions, there was no detectable increase in antibiotic resistance in P. aeruginosa exposed as biofilms to disinfectant residues in chloraminated drinking water. Chloramine in drinking water, while unable to kill biofilm bacteria, does not increase the potential of P. aeruginosa to become resistant to antibiotics. Letters in Applied Microbiology. 2008;46(5):562.