Immunomagnetic separation and DNA hybridization for detection of enterotoxigenic Escherichia coli in a piglet model.

摘要: Enterotoxigenic Escherichia coli (ETEC) strains were detected by stool blot hybridization assays using different oligonucleotide probes for the colonization fimbrial antigen F4, heat-stable enterotoxin I (ST I), and heat-labile (LT I) genes. Forty-eight fecal samples seven of intestinal content from ETEC-challenged newborn piglets processed in two ways: (i) direct inoculation bacterial suspension onto nylon membranes overlaying blood agar (ii) immunomagnetic enrichment F4+ ETEC magnetic beads coated with F4 monoclonal antibodies before membranes. In obtained nondiarrheic pre- postchallenge, E. genes ST I, LT could be only after enrichment. No difference between methods detection these was observed when blots diarrheic examined. By separation, it easy to decrease background flora, cells, debris thus produce purer specimens. The method evaluated this animal model appeared simple quick increased sensitivity 100-fold compared assays. Prior isolation identification not necessary.