EVIDENCE FOR PLASMID-MEDIATED BACTERIAL RESISTANCE TO INDUSTRIAL BIOCIDES

A total of 16 isolates of Pseudomonas strains that were cultured from biocide-treated kaolin slurries and. in one instance. from a water-based latex paint were studied with respect to their resistance to four industrial biocides. Many of the isolates showed multiple resistance patterns in that they were resistant to more than one biocide as well as to certain heavy metals and other antimicrobial agents; and. many of the isolates were resistant to agents to which they had no previous history of exposure. One to four plasmids were detected in each of the biocide-resistant isolates that were examined. These experimental data were highly suggestive that resistance to the industrial biocides Was due to plasmid-encoded mechanisms.