Development of a lateral flow immunochromatography test for the rapid detection of bovine tuberculosis.

Detection of specific antibodies would be a useful test strategy for bovine tuberculosis (bTB) as a complement to the single skin test. We developed a lateral flow immunochromatography (LFIC) test for rapid bTB detection based on the use of a conjugate of gold nanoparticles with a recombinant G protein. After evaluating 3 Mycobacterium bovis (MB) antigens: ESAT-6, CFP-10 and MPB83 for the control line, we selected MPB83 given it was the most specific. The performance of the test was analyzed with 820 bovine sera, 40 sera corresponding to healthy animals, 5 sera from animals infected with Mycobacterium avium subsp. paratuberculosis (MAP) and 775 sera of animals from herds with bTB. All these sera were also submitted to a validated bTB-ELISA using whole-cell antigen from MB. From the 775 sera of animals from herds with bTB, 87 sera were positive by the bTB-ELISA, 45 were positive by LFIC and only 5 animals were positives by skin test (TST). To confirm bTB infection in the group of TST (-), bTB-ELISA (+) and LFIC (+) animals, we performed postmortem examination in 15 randomly selected animals. Macroscopically, these 15 animals had numerous small and large yellow-white granulomas, characteristic of bTB, and the infection was subsequently confirmed by PCR in these tissues with lesions (gold standard). No false positive test result was detected with the developed LFIC either with the sera from healthy animals or from animals infected with MAP demonstrating that it can be a useful technique for the rapid identification of animals infected with bTB.

Immunohistochemical detection of pro-inflammatory and anti-inflammatory cytokines in granulomas in cattle with natural Mycobacterium bovis infection.

Cellular immune response was evaluated in lymph nodes and lung with different granulomatous lesions from cattle naturally infected with Mycobacterium bovis. For this purpose, we assessed pro-inflammatory and anti-inflammatory cytokines by immunohistochemical assays. Immunoreaction was observed for all the cytokines analyzed. Fourteen animals displayed advanced stage IV granulomas, with intense immunoreactivity to IFN-γ and TGF-ß in areas of caseous necrosis, macrophages and lymphocytes. Seven animals showed stage III granuloma, with high immunoreactivity to IFN-γ (average of 44.5% immunoreactive cells) and moderate to TNF-α and to the anti-inflammatory cytokines IL-10 and TGF-ß, in relation to the proliferation of fibroblasts in granuloma periphery We found satellite stage I granulomas in 4 bovines and stage II granulomas in 2 bovines, which exhibited low immunostaining response (-13%). Cytokine expression in stage III and IV granulomas was significant, with predominance of immunoreactivity to IFN-γ, thus suggesting a strong, longstanding local immune response mediated by macrophages and epithelioid cells. In addition, these two stages displayed lower reactivity to IL-10; which suggests a deficit of anti-inflammatory cytokines, suppressed immunity and persistence of the infection. High expression of TGF-ß could indicate a chronic process with greater tissue damage and fibrosis. Numerous bacilli observed in necrotic areas in stage III and IV granulomas with low expression of IL-1ß suggest failure in the immune response with bacterial multiplication. In this study, evidence of in situ presence of cytokines demonstrates these cytokines are involved in the development and evolution of bovine tuberculosis granulomas.

Mycobacterium intracellulare infection in a capybara (Hydrochoerus hydrochaeris).

This report describes the first case of Mycobacterium intracellulare infection with typical granulomatous lesions of mycobacteriosis in a capybara (Hydrochoerus hydrochaeris). The individual was a captive-bred young female, part of the control group of an experimental study on stress. Multiple granulomatous lesions were detected in a mesenteric lymph node of this young female. Mycobacterial infection was confirmed by bacteriologic culture and molecular identification methods. Clinical lesions were characterized by histopathology.

Polycystic ovarian syndrome: temporal characterization of the induction and reversion process in an experimental model

Numerosos modelos experimentais têm sido desenvolvimos para o estudo da síndrome do ovário policístico em ratos. No presente estudo, a síndrome foi inducida por exposição à luz constante. O processo foi avaliado durante sua indução e inclusive durante sua reversão. O ciclo estral foi analisado através de citologia vaginal; parámetros reprodutivos foram avaliados por acasalamento, bem como a morfologia ovariana. Todos animais desenvolveram a síndrome depois de 13 semanas de luz permanente. As características histológicas dos ovários, na semana 15, foram similares àquelas observadas na síndrome do ovário policístico em humanos e outras espécies. Após a regressão da síndrome, não houve diferenta em nenhum dos parámetros reprodutivos avaliados, quando comparados com o grupo controle.

Histochemical study of the extracellular matrix components in the follicular wall of induced polycystic ovaries

Numerous models have been developed to study polycystic ovarian syndrome in rats. In the present study, the syndrome was induced by exposure to constant light. The histological structure and differential distribution of extracellular matrix (ECM) fibers as well as the glycosaminoglycans (GAGs) content and composition of the ovarian follicular wall of rats with polycystic syndrome were evaluated. Histochemical differences were observed in the graunlosa and theca externa of follicular cysts when compared to normal preovulatory follicles. The colagen content of the theca externa of follicular cysts, quantified by the picrosirius method, was higher than in the controls. The neural carbohydrate and acidic GAC levels were lower in the granulosa and higher in the theca externa of cyst follicles than in control ovaries. Histomorphometrically, the follicular diameter was both a convenient and appropriate measurement for describing the cyst status; there were no differences in the thickness of each follicular layer. In conclusion, differences in the components of ECM were observed in the follicular wall of ovarian cysts compared eith normal preovulatory follicles. Howere, sinde these changes did not occur uniformly in all layers of the follicular wall, their role in cyst development remains to be established.

Identificación de hongos en tejidos y cultivos: importancia de sustancias argirófilas en su estructura / Identification of fungi in tissues and cultures: the importance of argirophilic substances on its cellular walls

Se presenta un método basado en la combinación de la acción de microondas con uno de los métodos de impregnación argéntica de Del Río Hortega. Se estudiaron materiales de tejidos patológicos y cultivos de hongos. Además del análisis morfológico, se consideran las causas de la reducción de la plata iónica a metálica, algunas características del reactivo argéntico y su relación con la constitución histoquímica de las paredes celulares. Se destaca la rapidez en la demostración de los hongos, la definición satisfactoria de los tejidos afectados, las ventajas de trabajar con un reactivo estable, la omisión de sustancias carcinogenéticas, la posibilidad de impregnar estructuras fúngicas en preparados previamente teñidos con técnica anilínica y la extensión del método a materiales de cultivo sin necesidad de fijación formólica previa.

Identificación de hongos en tejidos y cultivos: importancia de sustancias argirófilas en su estructura / Identification of fungi in tissues and cultures: the importance of argirophilic substances on its cellular walls

Se presenta un método basado en la combinación de la acción de microondas con uno de los métodos de impregnación argéntica de Del Río Hortega. Se estudiaron materiales de tejidos patológicos y cultivos de hongos. Además del análisis morfológico, se consideran las causas de la reducción de la plata iónica a metálica, algunas características del reactivo argéntico y su relación con la constitución histoquímica de las paredes celulares. Se destaca la rapidez en la demostración de los hongos, la definición satisfactoria de los tejidos afectados, las ventajas de trabajar con un reactivo estable, la omisión de sustancias carcinogenéticas, la posibilidad de impregnar estructuras fúngicas en preparados previamente teñidos con técnica anilínica y la extensión del método a materiales de cultivo sin necesidad de fijación formólica previa. (Au)