Effect Of Temperature, Ph And Sodium Chloride Concentrations On Production Of Staphylococcal Enterotoxins A And B

Staphylococcus aureus strain S-6 was used to produce enterotoxins A (SEA) and B (SEB) by the sac culture technique using casein hydrolysate medium, NZ-Amine NAK, enriched with thiamine and niacine, under the following conditions: incubation temperatures of 20 to 45°C, pH values of 4.5 to 9.0 and NaCl concentrations of 0 to 125%. The highest enterotoxin production was obtained at the optimum growth conditions, 39.4°C and pH 7.0. Production of the two enterotoxins was completely inhibited at 20°C, above 45°C, at pH 4.5 and by 12% NaCl. Increases in the NaCl concentration resulted in a decrease in enterotoxin production, with a more pronounced effect on SEB production than on SEA production. Production of the enterotoxins in 4% NaCl was not observed at pH 6.0 and 6.5 after 18 h of incubation at 37Γ. The results show no major differences with those obtained using a different strain for each toxin, indicating that the behavior is inherent to the specific enterotoxin and not to the strain that produces it.45141306130

Production Of Staphylococcal Enterotoxin D In Foods By Low-enterotoxin-producing Staphylococci

The goal of this investigation was to determine whether staphylococcal strains producing enterotoxins at nanogram levels per milliliter in laboratory medium, not detectable by gel diffusion methods, could produce sufficient enterotoxin in foods to result in food poisoning. Three low-enterotoxin D (SED)-producing strains were selected for this research because this enterotoxin is produced in smaller amounts than the other enterotoxins. The foods used were cream pie and cooked ham, divided into two portions, sterile and non-sterile. Each portion was inoculated with known concentrations of the staphylococcal strains under study and incubated for 48 h at 25, 30, and 37°C. Samples were taken after 24 and 48 h. Enterotoxin was detectable in both sterilized and unsterilized cream and ham after 24 h at 37°C with an inoculum of 103/g. Some strains produced detectable amounts of enterotoxin in the sterilized foods after 24 h at 30°C and some produced detectable amounts of enterotoxin in the sterilized foods after 24 h at 25°C with inocula of 104/g. It can be concluded that staphylococcal strains producing enterotoxin at ng/ml levels in laboratory medium, not detectable by gel diffusion methods, can produce sufficient enterotoxin (ng/g) in foods to cause poisoning. © 1991.1411925Casman, Bennet, Dorsey, Stone, The microslide gel double diffusion test for the detection and assay of staphylococcal enterotoxins (1969) Health Lab. Sci., 6, pp. 185-197Evenson, Hinds, Bernstein, Bergdoll, Estimation of human dose of staphylococcal enterotoxin A from a large outbreak of staphylococcal food poisoning involving chocolate milk (1988) Int. J. Food Microbiol., 7, pp. 311-316Igarashi, Fujikawa, Shinagaki, Bergdoll, Latex agglutination test for staphylococcal toxic shock syndrome toxin-1 (1986) J. Clin. Microbiol., 23, pp. 509-512Kokan, Bergdoll, Detection of low-enterotoxin-producing Staphylococcus aureus (1987) Appl. Environ. Microbiol., 53, pp. 2675-2676Robbins, Gould, Bergdoll, Detecting the enterotoxigenicity of Staphylococcus aureus strains (1974) Appl. Microbiol., 28, pp. 496-950Wieneke, Enterotoxin production by strains of Staphylococcus aureus isolated from foods and human beings (1974) Journal of Hygiene, 73, pp. 155-16

Prevention Of Nonspecific Reactions On Reversed Passive Latex Agglutination Assay (rpla) For Detecting Low Amounts Of Staphylococcal Enterotoxins

The SET-RPLA, from Denka Seiken Co. Ltd., Tokio, a commercial reversed passive latex agglutination test kit, has been recommended to establish the enterotoxicity capacity of some staphylococcal strains, implicated in food poisoning outbreaks that produce low levels of enterotoxins (SE). Despite the RPLA specificity, the occurrence of nonspecific reactions when testing low- SE-producing is common. In order to control these nonspecific reactions the addition of purified normal rabbit IgG purified was applied on approximately 350 staphylococcal isolates from human milk and anatomic sites of healthy dental student carriers. The results indicated that addition of 5% (v/v) of purified normal rabbit IgG (0.74 mg/mL) to the culture supernatant fluid is a simple and reliable tool for the controlling of nonspecific reactions in the RPLA assay.3901/02/155763Adesyin, A.A., Esbach, M., Lenz, W., Schall, K.P., Detection of enterotoxigenicity of Staphylococcus aureus strains: A comparative use of the modified Outcherlony precipitation test, reversed passive latex agglutination test, and avidin-biotin ELISA (1992) Can. J. Microbiol., 38, pp. 1097-1101Bergdoll, M.S., Staphylococcus aureus (1989) Foodborne Bacterial Pathogens., pp. 463-523. , Doyle, M.P. (ed.) INC, New YorkBergdoll, M.S., Importance of staphylococci that produce nanogram quantities of enterotoxin (1995) Zbl. Bakt., 282, pp. 1-6Ey, P.L., Prowsa, S.J., Jenken, C.R., Isolation of pure IgG1, IgG2a, and IgG2b immunoglobulins from mouse serum using protein A-Sepharose (1987) Biochem., 15, pp. 429-436Evenson, M.L., Hinds, M.W., Bernstein, R.S., Bergdoll, M.S., Estimation of human dose of staphylococcal enterotoxin A from a large outbreak involving chocolate milk (1988) Int. J. Food Microbiol., 7, pp. 311-316Foster, T.J., McDevitt, D., Surface associated proteins of Staphylococcus aureus: Their possible roles in virulence (1994) FEMS Microbiol. Letters, 118, pp. 199-206Halander, H., Production of large quantities of enterotoxin B and other staphylococcal toxins on solid media (1965) Acta. Pathol. Microbiol. Scand., 63, pp. 299-305Igasashi, H., Figikawa, H., Shingaki, M., Bergdoll, M.S., Latex agglutination test for staphylococcal toxic shock syndrome toxin-1 (1986) J. Clin. Microbiol., 23, pp. 509-512Jarvis, A.W., Lawrence, R.C., Production of high titers of enterotoxins for the routine testing of staphylococci (1970) Appl. Microbiol., 19, pp. 698-699Koper, J.W., Hagenaars, A.M., Notermans, S., Prevention of cross-reactions in the enzyme linked immunosorbent assay (ELISA) for the detection of Staphylococcus aureus enterotoxin type B in culture filtrates and foods (1980) J. Food Safety, 2, pp. 35-45Park, C.E., Szabo, R., Evaluation of the reversed passive latex agglutination (RPLA) test kit for detecting of staphylococcal enterotoxins A, B, C, and D in foods (1986) Can. J. Microbiol., 32, pp. 723-727Pereiera, J.P., Salsberg, S.P., Bergdoll, M.S., Production of staphylococcal enterotoxin D in foods by low-enterotoxin-producing staphylococci (1991) Int. J. Food Microbiol., 14, pp. 19-26Pereira, M.L., Carmo, L.S., Santos, E.J., Sellos, I.T., Bergdoll, M.S., Staphylococci in breast milk from women with and without mastitis (1995) Rev. Microbiol., 26, pp. 117-120Pereira, M.L., Carmo, L.S., Santos, E.J., Souki, M.Q., Carvalho, M.A.R., Bergdoll, M.S., Staphylococci from healthy dental student (1996) Braz. Dent. J., , in pressPereira, M.L., Heneine, L.G., Pereira, J.L., Bergdoll, M.S., Controlling of nonspecific reactions on reversed passive latex agglutination (RPLA) for detecting nanogram quantities of staphylococcal enterotoxins (1996) Arq. Bras. Med. Vet. Zootec., , in pressPereira, M.L., Carmo, L.S., Santos, E.J., Pereira, J.L., Bergdoll, M.S., Enterotoxin H in staphylococcal food poisoning (1995) J. Food Protect., 5, pp. 559-561Oda, T., Ohkubo, T., Nagai, M., Nishimoto, Y., Ohmaru, K., Detection of staphylococcal enterotoxins in foods by reversed passive agglutination test (1979) Ann. Rep. Fakuoka City Hyg. Lab., 4, pp. 33-37Robbins, R., Gould, S., Bergdoll, M.S., Detecting the enterotoxigenicity of Staphylococcus aureus strains (1974) Appl. Microbiol., 28, pp. 946-950Salomon, L.L., Tew, R.W., Assay of enterotoxin B by latex agglutination (1968) Proc. Soc. Exp. Biol. Med., 129, pp. 539-554Shingaki, M., Igarashi, H., Fugikawa, H., Ushioda, H., Tereyama, T., Sakai, Study on reversed passive agglutination for the detection of staphylococcal enterotoxins A, B, and C (1981) Ann. Rep. Fakuoka City Hyg. Lab., 32, pp. 128-131Valle, J., Gómez-Lucia, E., Piriz, S., Goyache, J., Orden, J.A., Vadillo, S., Enterotoxin production by staphylococci isolated from healthy goats (1990) Appl. Environ. Microbiol., 56, pp. 1323-1326Vanderzant, C., Spillitoesser, D.F., (1992) Compendium for the Microbiological Examination of Foods, , American Public Health Association. 3ed. Washington,DC., 1219