Rapid detection of enterotoxigenic Escherichia coli O6 in water by using monoclonal antibody and a photon-counting television camera.
Monoclonal antibodies (MAbs) raised against Escherichia coli O6:H16 were screened against 15 strains of E. coli and 19 non-E. coli bacteria. A MAb-luminescence assay using MAb-5.8, which shows no cross-reactions with non-E. coli bacteria, and a photon-counting television camera were developed for rapid enumeration of E. coli O6:H16 in water. The membrane filter that retained bacteria was boiled for 5 min in a buffer and incubated with biotinylated MAb-5.8. After incubation with streptavidin-peroxidase conjugate, it was reacted with luminol-based reaction mixture. Luminous image and light intensity of the filter was recorded with a Biocell Counter. Levels of E. coli O6 higher than 7 x 10(3) CFU were detected by the MAb-luminescence assay when E. coli O6 was spotted onto the membrane filter. The sample that contained E. coli O6:H16 was filtered through a membrane filter, and the filter that retained bacteria was incubated on a filter paper soaked with nutrient broth supplemented with 0.5% NaCl at 37 degrees C for 6 h. The number of light emission points on the filter correlated well with initial E. coli O6:H16 counts within the range of 1 to 3 x 10(2) CFU. The correlation coefficient was 0.89.
Trevanich
S
S
Food Science and Technology, Faculty of Agriculture, Kyushu University, Fukuoka, Japan.
Miyamoto
T
T
Harada
Y
Y
Honjoh
K
K
Hatano
S
S
D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D001427:Bacterial Toxins / Q000302:isolation & purification*; D004768:Enterotoxins / Q000302:isolation & purification*; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli; D005374:Filtration; D007124:Immunoenzyme Techniques; D008165:Luminol; D017785:Photons; D013690:Television; D014871:Water Microbiology
D000911:Antibodies, Monoclonal; D001427:Bacterial Toxins; D004768:Enterotoxins; D008165:Luminol