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 ◽  
Vol 2 (1) ◽  
pp. 35-45 ◽  
Author(s):  
J. W. KOPER ◽  
A. M. HAGENAARS ◽  
S. NOTERMANS
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%.


2008 ◽  
Vol 15 (12) ◽  
pp. 1788-1795 ◽  
Author(s):  
A-Rum Shin ◽  
Sung Jae Shin ◽  
Kil-Soo Lee ◽  
Sun-Ho Eom ◽  
Seung-Sub Lee ◽  
...  

ABSTRACT Tuberculosis (TB) is the leading cause of death from a single infectious agent in Korea. In this study, we compared the proteins present in culture filtrates from Mycobacterium tuberculosis strain K, which is the dominant clinical isolate in Korea, with those present in culture filtrates from M. tuberculosis H37Rv. Several differences in expression were detected between the two strains for those proteins with a molecular mass of <20 kDa. ESAT-6, HSP-X, and CFP-10 were found to be abundantly expressed in the strain K culture filtrates by liquid chromatography-electrospray ionization-time of flight mass spectrometry. The serodiagnostic potentials of recombinant antigens rESAT-6, rHSP-X, and rCFP-10 and two native antigens (Ag85 and PstS1) were evaluated by Western blot analysis and enzyme-linked immunosorbent assay (ELISA) using sera collected from 46 TB patients with active disease and 46 healthy controls. As for our ELISA results, HSP-X was superior to the other antigens in terms of sensitivity when a single antigen was employed. The results of a receiver operator characteristic analysis revealed that a cocktail ELISA using all five antigens was significantly more sensitive (77.8%) than the use of a single antigen and offered equivalent specificity; moreover, it produced the largest area under the curve (0.91 versus 0.55 to 0.87). Therefore, a cocktail ELISA containing abundantly expressed antigens enhances the sensitivity of a single antigen and can be a useful diagnostic tool for the detection of active TB.


2001 ◽  
Vol 8 (1) ◽  
pp. 52-57 ◽  
Author(s):  
Fedoua Echahidi ◽  
Gaëtan Muyldermans ◽  
Sabine Lauwers ◽  
Anne Naessens

ABSTRACT Ureaplasma urealyticum comprises 14 serotypes. The existing serotyping methods all use polyclonal antibodies. These methods are time-consuming and labor-intensive, and they cannot always be performed on primary isolates; in addition, the results are difficult to interpret. We developed a new enzyme-linked immunosorbent assay (ELISA) method using serotype-specific monoclonal antibodies (MAbs) to enable the serotyping of U. urealyticum isolates from primary broth cultures. Each of the 14 serotype reference strains was tested against 14 selected MAbs. Homologous reactions were very strong, while heterologous reactions were negligible. Three cross-reactions were observed: MAb 5 cross-reacted with serotype 2, MAb 14 cross-reacted with serotype 3, and MAb 8 cross-reacted with serotype 13. Despite the cross-reactions observed, all the serotype reference strains ofU. urealyticum could be identified and differentiated using a combination of MAbs. Reproducibility was analyzed with a fractionated antigenic preparation and with several freshly prepared antigens of the same strain. No significant interrun variation was found with the fractionated antigen, but significant variations in optical density (OD) values were found when freshly prepared antigens were tested. However, the variation in OD values did not influence the overall interpretation of the ELISA: reactions with homologous MAbs were always prominent compared to those of the negative controls. This newly developed ELISA using MAbs seems promising for serotyping of U. urealyticum clinical isolates.


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