Purification of Staphylococcal enterotoxins B and C2, by dye ligand chromatography - production of antisera

As enterotoxinas estafilocócicas B e C2 foram purificadas a partir do sobrenadante de culturas, através de cromatografia de troca catiônica em resina Amberlite CG-50 e cromatografia de afinidade com o corante Red A. Cem mililitros de sobrenadante de culturas contendo 270 mg de SEB/ml e 150 ml de sobrenadante contendo 93 mg de SEC2/ml proporcionaram uma recuperaçäo final de 59 por cento e 42 por cento, respectivamente. As toxinas purificadas apresentaram-se homogêneas quando analisadas por eletroforese em gel de poliacrilamida dodecil-sulfato de sódio. A imunizaçäo de coelhos com as enterotoxinas purificadas forneceram títulos máximos de 80 para a enterotoxina B e 40 para a enterotoxina C2. A metodologia descrita neste trabalho mostrou-se adequada para a purificaçäo de enterotoxinas B e C2, visando a obtençäo de reagentes e produçäo de anticorpos específicos, utilizando pequenos volumes iniciais de sobrenadante de culturas

Characterization of enterococcus strains isolated from ready-to-eat foods

Treze estirpes de Enterococcus faecalis e 5 de E. faecium isoladas a partir de alimentos foram estudadas em relaçäo a produçäo de termonuclease (TNase), atividade hemolítica em sangue humano e de coelho e sensibilidade a antimicrobianos. Näo foi observada a produçäo de TNase e ß-lactamase, reastência a vancomicina e a altos níveis de aminoglicosídeos

Purification of Staphylococcal enterotoxin a by dye ligand chromatography

A purificaçäo de enterotoxina A foi obtida a partir de 400 ml de cultura de Staphylococcus aureus FRI-722. O método de cultura em saco de diálise foi utilizado para a produçäo da enterotoxina. Foram recuperados 10 mg presentes do sobrenadante da cultura. A enterotoxina purificada apresentou-se homogênia quando analisada por eletroforese em gel de poliacrilamida dodecil-sulfato de sódio. A metodologia descrita neste trabalho mostrou-se adequada para purificar uma quantidade satisfatória de enterotoxina e pode ser utilizada em laboratórios onde näo existem equipamentos necessários para manipular grandes volumes de sobrenadante de cultura

Selective Enterotoxin Production in Foods by Staphylococcus aureus Strains That Produce More Than One Enterotoxin.

Staphylococcus aureus strain S-6, producer of enterotoxins A and B; strain FRI-913, producer of enterotoxins A, C, and E; and strain FRI-196E, producer of enterotoxins A and D, were grown in milk (pH 6.8), potato salad with mayonnaise, and boiled egg white (pH 8.0-8.5). Enterotoxins were detectable in milk incubated at 26°C when colony counts were less than 106. Enterotoxin production by strain S-6 was detectable in potato salad at 106 CFU at both 26 and 37°C. Enterotoxin A production by strain FRI-913 was detectable at approximately 106 CFU/g, whereas enterotoxin C was detectable only when growth reached approximately 108 CFU/g. Production of enterotoxins A and D by strain FRI-196E was detectable when growth was greater than 107 CFU/g. Production of enterotoxins A and B by strain S-6 in boiled egg white was detectable at greater than 106 CFU/g. In most experiments, enterotoxins A and C from strain FRI-913 were detectable when cell counts were greater than 107 CFU/g, whereas enterotoxin A and enterotoxin D production by strain FRI-196E was detectable at counts between 105 and 106 CFU/g. It can be concluded that enterotoxin production is influenced by the time of incubation and the composition and pH of the food.

Production of Staphylococcal Enterotoxins A, D, and E by Sac Culture.

The use of the sac culture method for production of relatively large amounts of enterotoxins A (SEA), D (SED), and E (SEE) for use in purification of the enterotoxins was investigated. One-hundred milliliters of medium per sac, made from Union Carbide sausage casing, with a shaking speed of 150 rpm was chosen as the optimum condition for the enterotoxin production. Brain heart infusion (BHI) broth was the medium of choice for production of SEA by strain FRI-722, with over 100 µg/ml being produced. Strain 1151m produced 20 µg/ml of SED in BHI medium which was 10 times that produced in shake flasks. The production of SEE was best in the Biosate + yeast extract medium, with adequate amounts being produced for purification.

Sensibilidade a antimicrobianos de Yersinia spp isoladas de alimentos na cidade do Rio de Janeiro / Antimicrobial susceptibility of Yersinia spp isolated from foods in Rio de Janeiro

Resumo: Cento e trinta e cinco culturas de Yersinia spp isoladas de alimentos foram testadas em relaçäo a 17 agentes antimicrobianos pelo método de difusäo simples em plca. Entre os antimicrobianos testados cloranfenicol, polimixina B, gentamicina, canamicina, tetraciclina, ácido nalidixico e colistina foram os que apresentaram maior atividade inibitória sobre Yersinia. Todas as amostras de Y. enterocolitica, Y. intermedia, Y. frederiksenii e Y. kristensenii produziram B-lactamase, detectada pelo método da cefolosporina cromogênica (au)

Outbreak of staphylococcal enterotoxin B food poisoning

Um surto por intoxicaçäo estafilocócica acometeu 61 pessoas. A partir de carne assada recheada com paio, foram isoladas culturas de Staphylococcus aureus produtores de enterotoxina B. O período de incubaçäo variou de 2 a 7 horas e 6 pessoas foram hospitalizadas

Incidence of Yersinia Species in Meat Samples Purchased in Rio de Janeiro, Brazil.

Twenty-five samples of several types of meat purchased at supermarkets in Rio de Janeiro were analyzed for presence of Yersinia . Species were isolated from 80% of beef and chicken giblets, 60% of ground beef and beef liver and 20% of pork, Fifteen strains were identified as Yersinia intermedia , 9 as Yersinia enterocolitica , 4 as Yersinia kristensenii and 1 as Yersinia frederiksenii . Two strains of Y. intermedia , serotype 0:13,7 were positive in both the autoagglutination and calcium-dependency tests. Two strains of atypical Y. intermedia (serotype 0:29 and one not typable) and one strain of atypical Y. enterocolitica , serotype 0:16; were positive only in the auto-agglutination test. Seventeen strains isolated from meat produced heat stable enterotoxin.

Occurrence of Yersinia Species in Raw and Pasteurized Milk in Rio de Janeiro, Brazil.

Thirty-seven (16.9%) of 219 raw milk samples and 38 (13.7%) of 280 pasteurized milk samples were positive for Yersinia sp. The isolates from raw milk samples include Yersinia enterocolitica (32.4%) comprising biotype 1 (0:5, 10.8%), and biotype 2 (0:10 K1, 1.6%); Yersinia intermedia (64.9%) comprising 0:18 (40.5%), 0:7,8 (8.1%), 0:16 (2,7%) and non-typable (13.5%) and Yersinia frederiksenii (0:22, 2.7%). The isolates from pasteurized milk samples include Y. enterocolitica (41.5%) comprising 0:5 (31.7%), 0:13 (2.4%), 0:7,8 (2.4%) and 0:16 (4.8%); Y. frederiksenii (56.1%) comprising 0:27 (7.3%), 0:25,35 (12.2%), non-typable (36.6%) and Y. intermedia (non-typable, 2.4%). Most Y. enterocolitica and about one third of non- Y. enterocolitica strains produce heat-stable toxin (ST). Antibiotic susceptibility, autoagglutination capacity and calcium-dependency of strains also were investigated.