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RECOVERY OF HELICOBACTER PYLORI FROM WATER BY IMMUNOMAGNETIC CAPTURE
Citation:
McDaniels, A E. AND S G. Lynn. RECOVERY OF HELICOBACTER PYLORI FROM WATER BY IMMUNOMAGNETIC CAPTURE. Presented at American Society for Microbiology, Orlando, FL, May 20-24, 2001.
Description:
A few reports have been written stating that H. pylori can be found in waters. However, detection and identification of H. pylori from water samples remains a very difficult task. One method that seems to work successfully is immunomagnetic capture. Water samples were concentrated to low volumes without significant loss of the bacteria by stirred cells. This was followed by an indirect method of capture in which monoclonal mouse anti-H. pylori antibodies were added to H. pylori cells and incubated at 4 degrees C for approximately 18 h with gentle mixing. Goat anti-mouse IgG coated superparamagnetic beads were then added and mixed at 4 degrees C for 60 min. The bead-cell-antibody complex was separated from the supernatant by a magnet. The supernatant was removed and the bead complex gently rinsed. The bead complex and the supernatant were each filtered. A fluorescein isothiocyanate tagged rabbit anti-H. pylori was added to the filters which were incubated for 60 min. at room temperature. Detection and identification were by a solid phase cytometer where the presence of only one cell is counted. Validation of the counts was completed by microscopy. Capture of H. pylori cells ranged between 90% and 96%. Filters containing fluorescent antibody-antigen complexes were scanned by a solid phase cytometer within a 3 min. period. Another 15 min. were required to validate the presence of the bacteria. The immunomagnetic capture method was shown to reliably concentrate low numbers of H. pylori from water samples and to produce high recoveries. Solid phase cytometry is a rapid and efficient method to detect and identify targets labeled with a fluorescent tag that has an excitation wave length of 488nm.