Pathotyping Escherichia coli by using miniaturized DNA microarrays

Abstract

The detection of virulence determinants harbored by pathogenic Escherichia coli is important for establishing the pathotype responsible for infection. A sensitive and specific miniaturized virulence microarray containing 60 oligonucleotide probes was developed. It detected six E. coli pathotypes and will be suitable in the future for high-throughput use.

FIG. 1.

Optimization of the genomic concentration used in this study. The optimal concentration of genomic DNA from EDL933 used for the detection of genes on the virulence oligonucleotide miniaturized microarray chip was assessed using (a) 2 μg, (b) 1 μg, (c) 0.5 μg, (d) 0.1 μg, and (e) 0.05 μg of DNA. The six biotinylated marker spots (C) are visible in all arrays. A concentration of 0.135 μM per primer in the stock solution and 200 pg/μl of poly-horseradish peroxidase-streptavidin conjugate were used for these assays.