Fluorescent markers appropriately conjugated to antibody proteins provide the basis for a method to visualize those antibodies as they participate in antigen-antibody reactions. The method is referred to as the fluorescent antibody (FA) or immunofluorescence (IF) technique; it has been in widespread and successful use in medical microbiology and in pathology as a highly sensitive and specific cytochemical staining procedure for many years. Most current applications of the technique are for the localization of cellular and viral antigens in tissues and for the rapid detection and identification of infectious agents.

https://www.ctahr.hawaii.edu/bnf/Downloads/Bibliography/Immunofluorescence%20in%20Microbial%20Ecology,%20Bohlool%20and%20Schmdt,%201980.pdf?origin=publication_detail

The Immunofluorescence Approach in Microbial Ecology

The faecal streptococci are the most commonly used alternative or adjunct to coliform bacteria as faecal pollution indicators. They are a group of coccoid bacteria, naturally inhabiting the gut of warm‐blooded animals and humans. Their potential as faecal pollution indicators was recognised in the 1890s, but it was 50 years before the accumulated knowledge of their taxonomy and sanitary significance, together with the development of isolation and enumeration methods, allowed their practical application in water pollution research and management. There is still much disagreement over the classification of the group. Many workers now place some species in a separate genus, Enterococcus, and it is likely that this revised nomenclature will be incorporated into the next edition of Bergey ‘s Manual. Of the enumeration methods available (plate count, MPN, and membrane filtration), the mE‐EIA membrane filtration method, which recovers enterococci (a subset of faecal streptococci) is probably the most im...

https://www.tandfonline.com/doi/pdf/10.1080/00288330.1993.9516549

Faecal streptococci as faecal pollution indicators: A review. Part I: Taxonomy and enumeration

A most-probable-number (MPN) technique was evaluated for detecting and enumerating Pseudomonas aeruginosa in water and wastewater. Both the presumptive and confirmatory media, as described in the 13th edition of Standard Methods for the Examination of Water and Wastewater, as well as modifications of these media were included in evaluations. Various samples of water were tested, namely chlorinated tap water, creek water, and influent to a wastewater treatment plant. Modified media repeatedly gave higher estimated MPNs of P. aeruginosa than media listed in Standard Methods. P. aeruginosa was detected and recovered from all creek water and wastewater samples, but not from tap water samples tested. This organism was determined to be present in as large numbers as the fecal coliforms and in even greater quantities than the fecal streptococci in all samples, whenever MPN estimations were determined from those positive tubes containing the modified confirmatory medium.

Evaluation of a Most-Probable-Number Technique for the Enumeration of Pseudomonas aeruginosa

A new fluorescent sandwich method for the detection of Escherichia coli O157:H7 in ground beef was developed. Immunomagnetic beads (IMBs) precoated with anti-E. coli O157:H7 antibody were used to capture and concentrate E. coli O157:H7 present in ground beef. Streptavidin-coated fluorescent beads with anti-E. coli O157:H7 to form immunofluorescent beads (IFBs) were used to detect the E. coli O157:H7 captured by the IMBs by forming IMBM–E. coli O157:H7N–IFBO sandwich complexes, where the subscripts M, N and O were variable but integral numbers. This sandwich technique was able to detect 500 cfu of the bacteria in a 0.5-mL sample taken from a quantified and diluted broth culture. The method was then applied to detect E. coli O157:H7 in artificially contaminated ground beef. Known quantities of freshly cultured E. coli O157:H7 cells were added to 25-g ground beef patties held in sterile bags with filters. The inoculated patties were stored at 7C overnight; 75 mL of E. coli broth was added to each sample, and the bags were incubated at 40C with shaking at 160 rpm for 4.5 h. After the enrichment, E. coli O157:H7 in the filtrate was captured and concentrated with IMBs and further conjugated with IFBs for detection. The results demonstrate that, after a 4.5-h enrichment period, the developed procedure can detect the presence of E. coli O157:H7 in ground beef previously spiked with 1 cfu/g.

Detection of escherichia coli o157:h7 through the formation of sandwiched complexes with immunomagnetic and fluorescent beads†

A fluorescent antibody method for detection of fecal coliform pollution in water is reported. Detection of Escherichia coli of fecal origin by this method was compared to IMVIC typing and to detect...

Rufus K Guthrie

Papers

The use of fluorescent antibody techniques for detection of streptococcus faecalis as an indicator of fecal pollution of water