Avaliação das técnicas de imunodifusão em gel de ágar, ensaio imunoenzimático indireto e reação em cadeia da polimerase no diagnóstico da brucelose ovina / Evaluation of technical, immunodiffusion agar gel, enzyme-linked immunosorbent assay and polymerase chain reaction in the diagnosis of ovine brucellosis

A brucelose na espécie ovina tem recebido destaque, uma vez que se trata de uma enfermidade que acomete o sistema reprodutivo dos animais, provocando sério comprometimento no setor produtivo. Dessa forma, objetivou-se a avaliação de três métodos para o diagnóstico da brucelose ovina: o ensaio imunoenzimático indireto (ELISAi), a técnica imunodifusão em gel de ágar (IDGA) e a reação em cadeia da polimerase (PCR). Para tanto, utilizaram-se 211 amostras de sangue de ovinos oriundos de propriedades de nove municípios da microrregião homogênea de Teresina, Piauí. As 211 amostras de sangue foram submetidas aos testes sorológicos e à PCR, visando detectar anticorpos anti-B. ovis e DNA de Brucella ovis, respectivamente. Foram obtidos resultados positivos nos testes sorológicos, sendo 36 (17,06%) positivos no teste IDGA e sete (3,31%) positivos no teste ELISAi, contudo não houve resultados positivos na técnica de PCR. Dos métodos de diagnóstico utilizados neste estudo, o teste IDGA foi o que apresentou melhor desempenho na detecção de animais reagentes, quando comparado ao teste ELISAi e à PCR em amostras de sangue, e o percentual de animais soropositivos sugere uma ampla distribuição de ovinos infectados por Brucella ovis na região em estudo, o que pode causar prejuízos aos produtores.(AU)

Brucellosis in sheep has received a major focus, since it is a disease that affects the reproductive system of animals, causing serious impairment in the productive sector. Thus, three methods for the diagnosis of ovine brucellosis were evaluated as goal, the indirect Linked Immunosorbent Assay (ELISAi) test, the Immunodiffusion Agar Gel (AGID) technique and the Polymerase Chain Reaction (PCR). Therefore, we used 211 sheep blood samples from properties of nine municipalities of the homogeneous micro-region of Teresina, Piaui. The 211 blood samples were subjected to serologic testing and PCR to detect anti-B. ovis antibodies, and Brucella ovis DNA, respectively. Positive results in serological tests were obtained, 36 (17%) positive in the AGID test and seven (3.3%) positive to the ELISAi test, however, there were no positive results in the PCR technique. Of the diagnostic methods used in this study, the AGID test was the one that presented the best performance in the detection of reactive animals, when compared to ELISAi and PCR in blood samples and, the percentage of seropositive animals suggests a wide distribution of Brucella ovis infected sheep in the study region and could cause loss to producers.(AU)

Effectiveness of different methods for anti-Sm antibody identification. A multicentre study.

Methods for the measurement of autoantibodies frequently provide controversial results. The objective of the present study was to evaluate the performance of Spanish Clinical Laboratories in the measurement of anti-Sm antibodies. A total of 23 laboratories participated, analysing 30 serum samples from patients with systemic lupus erythematosus and other autoimmune and non-autoimmune diseases. The laboratories used four extractable nuclear antigen screens, eight enzyme-linked immunosorbent assays (ELISAs) specific for anti-Sm, one line-blot, one dot-blot and one double immunodiffusion assay, from 15 different manufacturers. A total of 871 results were obtained. In general, very good sensitivity was obtained (95-100%), but specificity was moderate (52-86%) and must be improved. Most ELISAs and the line-blot were valid assays for anti-Sm detection and could serve as tests both for analysis and/or confirmation. The likelihood ratios indicated that both methods can be considered very useful or useful for the determination of anti-Sm antibodies. Nevertheless, the analytical quality of the methods for the measurement of anti-Sm antibodies could probably be improved by standardisation of the methods and the participation of laboratories in external quality control programs.

Use of a recombinant Coccidioides immitis complement fixation antigen-chitinase in conventional serological assays.

The coccidioidal complement fixation (CF) antigen has been cloned previously, and the fusion protein has been expressed in Escherichia coli. The recombinant CF (rCF) antigen was affinity purified by adsorption-desorption to chitin, and its reactivity was studied by using sera containing coccidioidal antibodies. The affinity-purified rCF antigen formed a line of identity with an immunodiffusion (ID) CF reference antigen (coccidioidin) derived from mycelial-phase Coccidioides immitis and was reactive with human, canine, and equine sera containing coccidioidal antibody. The affinity-purified rCF antigen yielded no detectable reaction with Blastomyces of Histoplasma antiserum by ID. The affinity-purified rCF antigen fixed complement with positive human sera and, even when used at lower concentrations, yielded titers comparable to those obtained with the coccidioidin. The reactivity of the affinity-purified rCF antigen was further evaluated by enzyme immunoassay, in which it manifested good sensitivity (96.9%) and specificity (100%) when evaluated with 43 human patients' sera. Thus, the affinity-purified rCF antigen has yielded reactions comparable to those of crude coccidioidal antigens in conventional CF, IDCF, and enzyme immunoassay.

Relación entre anticuerpos circulantes y cantidad de Candida albicans en materia fecal / Relation betwen circulatory antibodies and quality of candida albicans in faecal materia

Se estudió la presencia de anticuerpos contra Candida albicans, en 42 pacientes a los cuales se solicitaba cultivo micológico y recuento de levaduras en materia fecal. Por métodos estandarizados se procesaron las muestras, se cuantificó la presencia de levadura por gramo de materia fecal y se identificó a Candida albicans. Se obtuvo suero de los pacientes en el momento de llevar las muestras de heces al laboratorio. La presencia de anticuerpos se determinó por tres técnicas serológicas: aglutinación en tubo, inmunodifusión en gel de agar e inmunofluorescencia indirecta frente a levaduras y a tubos germinativos. La correlación de las tres pruebas con los resultados de los cultivos y recuento de colonias fue determinada sólo después que todos los datos fueron acumulados. Los resultados muestran que no existe correlación entre la cantidad de levaduras presentes y los anticuerpos circulantes. Ninguno de los pacientes presentaba infección diseminada o superficial evidente; se tuvo como referencia, la colonización del hongo en intestino

[An evaluation of the Khramkova-Abelev immunodiffusion method for determining the lectin concentration in a solution]. / Otsenka immunodiffuzionnogo metods Khramkovoi--Abeleva dlia opredeleniia kontsentratsii lektinov v rastvore.

Using the method of double radial immunodiffusion with highly purified preparations of HRPO and lectins PSA, PNA, SNA the threshold sensitivity of precipitation in agar gel, 7.2 micrograms/ml, was established. The use of monospecific immunodiffusion test system for PNA helped increase the sensitivity of immunodiffusion analysis to 3.6 micrograms/ml.