ANTIBIOTIC-RESISTANCE IN THE BACTERIA OF A REMOTE UPLAND RIVER CATCHMENT

The incidence of antibiotic resistance was determined in a total of 183 heterotrophic bacteria of non-faecal origin isolated from the catchment of a remote upland stream. Some 40% were sensitive to each of the eight antibiotics tested while more than 35% were resistant to at least two compounds. Three isolates each carried seven resistance determinants. Unsuccessful attempts were made, using two curing techniques, to demonstrate that resistance was plasmid-borne. The high incidence of antibiotic resistance, particularly amongst pseudomonads, in an environment virtually free from anthropogenic influence is surprising, and has implications for the assessment of the spread of antibiotic resistance amongst populations of environmental bacteria.