ISOLATION AND CHARACTERIZATION OF COLIFORMS FROM GLACIAL ICE AND WATER IN CANADA HIGH ARCTIC

Ellesmere Island is the northern most member of the Canadian Arctic Ar chipelago with over one-third of the land mass covered by ice. A joint services expedition to the island's Blue Mountains offered a unique o pportunity for microbiological studies of resident bacteria in an envi ronment uninhabited by man. Over 100 samples of water and ice were col lected from stream, lake and glacier and the filtrate cultured under c anvas. Bacterial growth was harvested onto swabs for transport back to the UK and 50 coliforms chosen at random for identification and antib iotic susceptibility testing. Most of the glacial strains were capsula ted, pigmented and some over 2000 years old. Genera such as Serratia, Enterobacter, Klebsiella and Yersinia were found; speciation was incon clusive and some organisms remain unidentified. Ampicillin resistance was evident in 80% of water isolates as opposed to 30% of the glacial organisms, but the isolates were generally exquisitely susceptible to antibiotics. The facility for ampicillin resistance did not appear to be transferable. Plasmid DNA was found in 33% of the glacial organisms and over 50% of the water isolates. Similar profiles were identified within and apparently between species and required plasmid restriction analysis to help establish identity. Plasmid-free Serratia spp. were subjected to genomic fingerprinting. Indistinguishable patterns were f ound within sets of isolates both widely spaced by distance and collec tion date and it was postulated that coliforms able to survive an Arct ic environment had spread extensively throughout the expedition area. In conclusion, this study contributes towards knowledge of naturally o ccurring antibiotic resistance, confirms the presence of plasmids and genotypic data provided evidence that potentially ancient organisms fr om glaciers can be cultured from water samples significantly distant.