A Comparison of Cultural Methods used with Microcolony and Direct Fluorescent-Antibody Techniques to Detect Salmonellae

Abstract

A comparison of various cultural methods for use with microcolony and direct fluorescent-antibody (FA) techniques to detect salmonella was conducted using 102 naturally contaminated samples. The methods were: (a) a 27-h microcolony technique, (b) a 51-h selenite-F FA microcolony technique, (c) a 51-h tetrathionate brilliant green FA microcolony technique, and (d) a 53-h FA technique from a broth enrichment. All were compared to an F.D.A. approved modification of the AOAC method. The 51-h FA microcolony technique, which employed tetrathionate brilliant green broth and brilliant green agar plates, produced 4.9% false-positives and no false-negatives, and produced the greatest frequency of salmonellae detection.

Rapid detection of salmonellas in raw meats using a fluorescent antibody‐microcolony technique

“…A loopful of an enrichment culture was placed on the surface of a BGA plate and after incubation for 3 h an impression was made of the growth on a glass slide. This modification was found to be much superior to the simple FA technique (Insalata et al 1975;Thomason 1981) as lower background fluorescence and larger fluorescing cells were observed.…”

“…Fluorescein-antibody conjugates were described nearly fifty years ago (Coons et al 1941) and were later developed as a rapid method for detecting salmonellas in meat (Georgala & Boothroyd 1964;Georgala et al 1965) and eggs (Haglund et al 1964). The approach has been used successfully with a wide range of foods (Silliker et al 1966;Goepfert et al 1970;Insalata et al 1967Insalata et al , 1972Insalata et al , 1973Insalata et al , 1975 Fantasia 1979) and animal feeds (Gibbs et al. 1972; Early & Patterson 1982) and for the rapid detection of a range of other organisms (e.g.…”

Unified Classification of Bacterial Colonies on Different Agar Media Based on Hyperspectral Imaging and Machine Learning

“…The detection of foodborne pathogens is important for controlling foodborne diseases and many countries have initiated foodborne pathogen surveillance programs to improve food safety and to prevent outbreaks of foodborne diseases [4]. The existing food-borne pathogen detection methods mainly include traditional plate culture detection methods, immunological-based detection methods (including fluorescent antibody detection method [5] and enzyme-linked immunosorbent assays [6], etc. ), molecular biology-based detection methods (including 2 of 13 polymerase chain reaction [7] and biological gene chip methods [8], etc.).…”

Rapid detection of Salmonella spp. in food by use of the ISO-GRID hydrophobic grid membrane filter

“…Little information is available to date on the reliability of the radiometry or the enzymelinked immunology techniques; however, fluorescent antibody staining and enrichment serology are known to produce false-positive results (12). For example, false-positive rates of 4 to 17% have been reported in the literature for fluorescent antibody staining (7,8,14,21,22). It is essential, therefore, to confirm a presumptive screening result by isolating the Salmonella spp.…”