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AN EFFICIENT IMMUNOMAGNETIC CAPTURE SYSTEM FOR ENTEROCOCCUS FAECALIS AND ENTEROCOCCUS FAECIUM
Citation:
AzconaOlivera, J. I. AND B G. Smith. AN EFFICIENT IMMUNOMAGNETIC CAPTURE SYSTEM FOR ENTEROCOCCUS FAECALIS AND ENTEROCOCCUS FAECIUM. Presented at Water Quality Technology Conference, Nashville, TN, November 14, 2001.
Impact/Purpose:
The goal of this research project is to evaluate and compare methods that rapidly (less than 2 hours) measure fecal contamination of water with respect to accuracy, specificity, and ease of use.
Description:
Enterococci detection is one of the two approved procedures by the US Environmental Protection Agency (EPA) used for the assessment of the microbiological quality of recreational waters. The action levels established by the EPA for enterococci are 35 pr 100 ml in marine recreational waters and 33 per 100 ml in fresh water. Turn-around time of the method is over 24 hr, and thus there is a clear need to reduce that time to allow a faster and reliable assessment of the safety/quality of the waters. The most abundant and prevalent species among the fecal enterococci (>90%) are E. faecalis and E. faecium. Our objective is to devise an efficient bacterial capture/concentration system in conjunction with a rapid detection method that will make possible the assessment of very low levels of fecal enterococci within a working day. In the first phase of our project described in this paper our objectives have been twofold (1) the procurement and/or production of antibodies able to capture efficiently the above mentioned microorganisms and (2) the evaluation of varoius tagging alternatives (nucleic acid based generic dyes, specific antibody fluorochrome-conjugates, etc) for the detection of enterococci with the RBD2000, a specialized flow cytometer designed for bacterial detection. This initial part of the project has been done in clean samples spiked with various bacterial loads. The next phase of our project is to test the reagents produced and the methods developed in real samples, being our final goal the full development and validation of a flow cytometry based method that will enable the detection and enumeration of low levels of fecal enterococci in recreational waters in less than 8 hr.