| class 1 and class 2 integrons in multidrug-resistant gram-negative bacteria isolated from the salmon river, british columbia. | using an enrichment protocol, we isolated 16 gram-negative, multidrug-resistant strains of known or opportunistic bacterial pathogens from the salmon river in south-central british columbia from 2005 to 2009, and investigated the genetic basis of their resistance to a variety of antibiotics. of the 16 strains, 13 carried class 1 integrons and three carried class 2 integrons. genes found in cassettes associated with the integrons included those for dihydrofolate reductases (dfra1, dfra12, dfra17, ... | 2011 | 21627486 |