Detection of Salmonella in Eggs and Egg Products With Fluorescent Antibody1

Abstract

Salmonella in eggs and egg products with fluorescent antibody. Appl. Microbiol. 12:447-450. 1964.-Organisms of the genus Salmonella are detected in eggs and egg products within 24 hr in the presence of Pseudomonadaceae and other Enterobacteriaceae by combining selective cultural methods with fluorescentantibody techniques. These techniques are specific for Salmonella when H antibodies are used. Absorption techniques are necessary before the 0 antibodies give specific reactions for Salmonella. No cross-reactions appear when H antiserum is used. Absorption and interference techniques indicate the test is specific for Salmonella. Salmonellosis is one of the important food-borne infections in the world today; the United States alone reported almost 19,000 cases in 1963 (U.S. Department of Health, Education, and Welfare, 1964). Conventional methods for the isolation and identification of Salmonella are tedious and time-consuming. The development of a rapid and accurate test would be an invaluable aid toward controlling these organisms in dried eggs and egg products. Coons et al. (1942) introduced the fluorescent-antibody (FA) technique and made possible a new and rapid serological method of detecting microorganisms. In principle, this technique is an immunological staining procedure which uses homologous antibody conjugated with suitable fluorochromes. FA technique is now a common tool in microbiology and has generally been proved satisfactory. Thomason, Cherry, and Moody (1957) applied this method for the detection of several serotypes of Salmonella in pure culture. Later, Thomason, Cherry, and Edwards (1959) found that the value of the method for the rapid detection of Salmonella in feces was impaired by nonspecific staining.

Control of nonspecific staining in the fluorescent antibody technique for the detection of salmonellae in foods

“…The six conjugates were evaluated for their specific and NSS characteristics on smears prepared from broth cultures of egg white samples inoculated with motile salmonellae, nonmotile salmonellae, and other organisms. Egg white was selected as the menstruum because it has been implicated in NSS (18). H IgG gave the highest staining intensities with all seven serotypes of motile salmonellae (Table 2).…”

“…The use of a conjugate prepared from flagellar antiserum for the detection of salmonellae in foods has been criticized on the basis that it does not adequately cover Salmonella 0 groups either qualitatively or quantitatively (6). However, several research workers have obtained satisfactory results with FITC-conjugated Salmonella polyvalent H antiserum (15,18,20,36). Cross-reactions did not occur when H antibodies were used in the indirect FA technique (18).…”

“…However, several research workers have obtained satisfactory results with FITC-conjugated Salmonella polyvalent H antiserum (15,18,20,36). Cross-reactions did not occur when H antibodies were used in the indirect FA technique (18). A conjugate prepared from Salmonella polyvalent H antiserum gave a higher degree of agreement (95.7%) with the cultural technique than did two commercially purchased FA conjugates prepared from globulin fractions of OH antiserum (25).…”

A fluorescent‐antibody technique for the rapid detection of Salmonellae in foodstuffs

“…This procedure produced suitably thin smears but those prepared from selenite cultures exhibited more non-specific background fluorescence than those prepared from mannitol cultures. The preparation of smears for fluorescence microscopy at the pre-enrichment stage of a Salmonella investigation results in a greater saving of time than if the preparation is at the selenite enrichment stage and, as observed by Haglund et al (1964), cultures grown in the presence of mannitol exhibit brighter fluorescence than cultures grown in the presence of glucose or lactose.…”

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

“…One approach that has received considerable attention uses fluorescently labelled antibodies (FA) with visual detection by epifluorescence microscopy. 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.…”