Genetic diversity and relatedness of uropathogenic Escherichia Coli with non-clinical isolates in Grenada

OBJECTIVE: To compare genetic profiles of uropathogenic E.coli (UPEC) to strains isolated from freshwater, seawater and iguanas in Grenada. DESIGN AND METHODS: Eighty-five E. coli strains were isolated using double streak-plating on eosin methylene blue (EMB) and MacConkey agar from human urine, iguanas, fresh and marine water. Species identification was confirmed using API20E. Genomic DNA was extracted from individual pure cultures of E. coli and amplified using the oligonucleotide (GTG5) and BOX primers. The DNA fingerprints were separated by electrophoresis, normalized using reference American Test Culture collection (ATCC) E.coli and compared using DendroUPGMA, the FigTreeO, dominance and co-clustering analyses. RESULTS: Both DNA fingerprinting methods targeted extragenic DNA and demonstrated enormous intra-species diversity within the population of studied 85 E. coli isolated from four major eco-habitats. DNA fingerprinting based on BOX-PCR was less discriminating than the (GTG)5-PCR. The BOX analysis correlated better with the ecotype distribution. The combination of dominance and co-clustering analyses allowed us to trace the relatedness of strains among and between the four different ecotypes. CONCLUSIONS: The (GTG5) PCR based co-clustering analysis indicated that the clinical isolates had a closer relationship to iguana E. coli isolates than to fresh and marine water isolates. However, in accordance with the BOX analysis, clinical isolates were most similar to marine, followed by freshwater and iguanas.