The use of random amplified polymorphic dna (rapd) markers for discrimination and verification among rabbit escherichia coli isolates

DNA heterogeneity among four local strains of E. coli belonging to serogroups O26, O119, O127, and O128 isolated from rabbits suffering from diarrhea was demonstrated with the arbitrary primed polymerase chain reaction (AP-PCR) method. Bacterial genomic DNA was extracted and reproducible DNA fragments of four different E. coli isolates were generated with two arbitrary chosen primers. The E. coli isolates were distinguished according to the banding patterns of their amplified DNA on agarose gel and the differences were characteristic for each isolates. High polymorphism was observed between the severely pathogenic strain O26 and the rest of the strains where more polymorphic bands were obtained. This polymorphism was confirmed by the calculated wide genetic distance between O26 strain and the rest of the strains expressed as low similarity coefficient (51.7 %-57.7 %). In addition, the RAPD pattern of the moderate pathogenic strain, O119, revealed high similarity (77.7 %) to the high pathogenic strain O128, while lower similarity (73.3 %) to the low pathogenic strain O127, was obtained. So the arbitrary primed PCR was able to differentiate between high and low pathogenic serotypes of E. coli and the obtained DNA fingerprints would help in the selection of the most suitable serotypes of E. coli for future vaccine Production.