Evaluation of new enzyme-linked immunosorbent assay based on a supernatant containing Staphylococcus aureus alpha-toxin produced by Bacillus subtilis.

1993 ◽  
Vol 31 (11) ◽  
pp. 3036-3039 ◽  
Author(s):  
P Egnell ◽  
B Christensson ◽  
R Möllby ◽  
J I Flock
2012 ◽  
Vol 25 (5) ◽  
pp. 607-619 ◽  
Author(s):  
Thacianna Barreto da Costa ◽  
Natália Gomes de Morais ◽  
Thays Miranda de Almeida ◽  
Maiara Santos Severo ◽  
Célia Maria Machado Barbosa de Castro

OBJETIVO: Avaliar a influência da desnutrição neonatal sobre a produção de Interferon gama, Interleucina-12 e Interleucina-10 em cultura de macrófagos alveolares e linfócitos infectados, in vitro, com Staphylococcus aureus sensível/resistente à meticilina. MÉTODOS: Ratos machos Wistar foram amamentados por mães cuja dieta, durante a lactação, continha 17% de proteína no grupo nutrido e 8% no grupo desnutrido. Após desmame, ambos os grupos receberam a dieta normoproteica. Os macrófagos foram obtidos após traqueostomia, através da coleta do lavado broncoalveolar. Para obtenção dos linfócitos, foi realizado o procedimento cirúrgico de punção cardíaca. Após o isolamento dos diferentes tipos celulares, procedeuse à realização dos estímulos com as cepas de estudo. A dosagem das citocinas foi realizada pelo método de Enzyme-Linked Immunosorbent Assay, a partir de amostras coletadas do sobrenadante das culturas após 24 horas de incubação. RESULTADOS: A desnutrição acarretou diminuição do crescimento ponderal, redução na produção de Interferon gama em cultura de macrófagos alveolares e linfócitos e diminuição na produção de Interleucina-12 em cultura de macrófagos alveolares. Apenas a produção de Interferon gama e Interleucina-10 em cultura de macrófagos alveolares apresentou diferença entre as cepas analisadas, em ambos os grupos estudados. CONCLUSÃO: O modelo de desnutrição neonatal produziu sequela no peso corporal e reduziu a produção de citocinas próinflamatórias (Interleucina-12 e Interferon gama), indicando que esse modelo de desnutrição pode comprometer a resolução de um processo infeccioso. A cepa de Staphylococcus aureus resistente à meticilina estimulou uma maior produção de Interferon gama e Interleucina-10 por macrófagos alveolares, o que sugeriu estimulação imunológica mais intensa, por essa cepa, nesse tipo celular especificamente.


1996 ◽  
Vol 59 (1) ◽  
pp. 6-10 ◽  
Author(s):  
PAUL C. BARTLETT ◽  
RONALD J. ERSKINE ◽  
PATRICK GASTON ◽  
PHILIP M. SEARS ◽  
HENDRICUS WILHELMUS HOUDIJK

Recent reports have indicated that the relative sensitivity and specificity of the ELISA test for detection of intramammary infection of cows with Staphylococcus aureus is not as high as originally reported. It has been suggested that antibodies measured by enzyme-linked immunosorbent assay (ELISA) more closely reflect previous infection status rather than current infection status, and that the delay in antibody formation following infection and the persistence of antibodies after elimination of infection may be responsible for some of the discrepancy observed between ELISA and bacterial culture results conducted on the same milk sample. This study (n = 209 cows) was undertaken to determine if an ELISA for S. aureus intramammary infection more closely reflects previous infection status than it does current infection status, and to ascertain whether correction of this time-delay factor substantially improves calculated values of ELISA relative sensitivity and specificity. Receiver-operator curves were constructed to compare different time-related definitions of microbiologic culture results used for comparison with ELISA results. A greater degree of curvature in receiver-operator curves indicated that ELISA results did more closely reflect culture results performed on milk samples taken 1 and 3 weeks previously. Insignificant improvement in sensitivity and specificity occurred when the database was limited to cows (n = 140) with milk production greater than 13.6 kg/day. However, values of sensitivity were all less than or equal to 90%, and values of specificity were all less than 54%.


1999 ◽  
Vol 54 (2) ◽  
pp. 423-427
Author(s):  
Yukiko SAKAITANI ◽  
Norikatsu YUKI ◽  
Yoko TAGAMI ◽  
Masami MOROTOMI

1994 ◽  
Vol 57 (3) ◽  
pp. 184-189 ◽  
Author(s):  
TSUNG C. CHANG ◽  
SU H. HUANG

A sandwich enzyme-linked immunosorbent assay (ELISA) was developed for the rapid detection of Staphylococcus aureus in foods. The assay was based on the detection of protein A which is a specific protein secreted by S. aureus. Following a 24-h incubation in a staphylococcal selective broth containing mannitol as the carbon source, the culture supematant was added to the microtiter plate coated with anti-protein A immunoglobulin G (IgG). After incubation, peroxidase-labeled anti-protein A IgG was used to produce the signal of antigen-antibody reaction. The sensitivity of the assay for protein A was 0.1 ng/ml. For 37 strains of S. aureus studied, all produced protein A, and the amount (13-1,100 ng/ml) of protein A secreted by different strains varied to a large degree. For another 57 strains (including 19 Staphylococcus spp.) of bacteria tested, two strains (5. capilis subsp. capitis CCRC 12161 and S. lentus CCRC 12926) produced very low amounts of protein A (0.6-1 ng/ml) after 24-h incubation. Staphylococcus aureus was detected by the ELISA in all of six samples of precooked foods naturally contaminated with the bacterium. Twenty-two processed foods artificially inoculated with S. aureus at levels of < 2 CFU/g and 10 to 20 CFU/g, respectively, were all positive by the ELISA. As compared to the conventional culture methods which take 5 to 6 days to complete, the ELISA can detect low numbers of S. aureus in processed foods with a total analytical time of only 28 h.


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