BACKGROUND: To isolate bacterial pathogens from environments, foods, or clinical specimens, we commonly apply methods that utilize selective media or antimicrobial resistance. Even so, these methods cannot completely isolate pathogenic bacteria from commensal bacteria. In addition, these classical techniques require a lot of time, cost, and effort for the separation of pathogenic bacteria.
METHODOLOGY/RESULTS: This study attempted to isolated Shiga Toxin-producing Escherichia coli (STEC) using the Immunomagnetic Separation (IMS) method. Monoclonal antibodies of Shiga toxin 1 and 2, which were excreted by STEC, were produced and then attached to the magnetic beads. Afterwards, STEC isolation from non-pathogenic E. coli was examined. In terms of detection limit, isolation ratio was higher than 80% at 102 CFU . But 1~10 CFU of STEC could not be isolated. The isolation ratio of STEC from other enteric pathogens (Salmonella, Vibrio spp., Shigella spp., EIEC, EPEC and ETEC) was higher than 80% on average. In particular, E. coli O157:H7 strain EDL933 was isolated by over 90%. These findings demonstrated that a magnetic bead-based method is effective in isolating pathogenic microorganisms.
CONCLUSION: The process described above resulted on the effective isolation of the pathogenic bacteria through the IMS method. In addition, it would be helpful in preventing the spread of the bacteria through the reduction of diagnosis time for pathogenic bacteria.
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