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OBJECTIVE: In the present study, we evaluated the levels of MIP-1alpha and eotaxin and in vivo migration in the peritoneal cavity model, in mice inoculated with live yeast forms of Histoplasma capsulatum or the beta-glucan cell wall component of this fungus, and the influence of a leukotriene biosynthesis inhibitor, MK886, on the release of these chemokines in relation to cell recruitment. MATERIALS: Female outbred Swiss mice (N = 4-5 per group, 3-4 wk, were used. Mice were injected i.p. with 1 ml of the 6 x 10(5) live yeast form of the fungus or with 10 microg of beta-glucan from the cell wall fraction, and treated daily with MK886 (1 mg kg(-1), p.o.) or vehicle. RESULTS: The fungus induced rapid generation of high levels of MIP-1alpha, which remained elevated from 4-48 h whereas very little eotaxin was detected at any time point (Fig. 1A and B). In contrast, the beta-glucan induced a little MIP-1alpha but considerably higher concentrations of eotaxin within the first four hours; however, the level of neither chemokine was sustained (Fig. 2A and B). Treatment of animals with MK886 was effective in reducing the numbers of neutrophils, eosinophils and, to a lesser degree, mononuclear cells accumulating in the peritoneal cavity in response to both the live fungus (Fig. 1C-E) and the cell wall beta-glucan (Fig. 2C-E). CONCLUSIONS: The results suggest that chemokines and leukotrienes may play key roles in the inflammatory cell influx to H. capsulatum infection or to the inoculation of the beta-glucan cell wall component of this fungus

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Vibrio parahaemolyticus es una de las principales bacterias Gram-negativas causantes de toxiinfecciones alimentarias y gastroenteritis aguda en humanos. En peces causa septicemia hemorrágica y ulceraciones de la piel, conviertiéndose en una de las principales causas de pérdidas en las explotaciones piscícolas. El presente trabajo documenta el establecimeinto de un protocolo de identificación de Vibrio parahaemolyticus por la técnica de acción en cadena de la polimerasa (PCR). Se realizaron caracaterizaciones genómicas de 24 aislados de Vibrio sp. obtenidos del cepario del laboratorio de Bacteriología de Sanidad Animal CENIAP-INIA en Maracay, estado Aragua, Venezuela. En la identificación genética los aislados fueron caracterizaciones mediante la PCR, siguiendo la metodología descrita por Lee y col. (1) con modificaciones en la extracción del ADN, que se realizó con DNAzol. Los iniciadores utilizados para tal fin fueron: 5`-GCGAATTCGATAGGGTGTTAACC-3` y 5`-CGAATCCTTGAACATACGCAGC-3`. De los 24 aislados analizados por PCR se obtuvieron 7 amplificados, que se identificaron como V. parahaemolyticus

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Un importante patógeno humano es vibrio cholerae, causante de diarreas profusas (cólera) y otros desórdenes. Su transmisión está asociada con el consumo de alimentos marinos contaminados. En el presente estudio se realizaron caracterizaciones fenotípicas de 24 aislados de Vibrio sp. obtenidos por necropsia y del cepario del laboratorio de Bacteriología de Sanidad Animal CENIAP-INIA en Maracay, estado Aragua; entre los cuales fue aislado vibrio cholerae proveniente de lisas y tilapsias. Las técnicas de identificación bacteriana se basan en sus características fenotípicas y metabólicas, desarrollo de colonias en medios de cultivos, morfología microscópica y reacciones tintoriales y características bioquímicas basadas en la utilización de sustratos. En los ejemplares de tilapia estudiados se identificó vibrio cholerae no-O1 y en las lisas, predominaron vibrio parahaemolyticus y vibrio cholerae no-O1. Este hallazgo es de gran importancia sanitaria, ya que los peces son de consumo humano, lo que constituye un riesgo en salud pública

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Vibrio cholerae produce una potente toxina codificada por dos genes: el operón ctxAB. Los estudios epidemiológicos han sido limitados por las técnicas fenotípicas; por ello es necesrio establecer un protocolo para la detección del gen de la subnidad A (ctxA), que codifica la toxina de Vibrio cholerae, por lo cual se realizaron caracterizaciones genéticas de 24 horas aislados de la familia Vibrionaceae obtenidos del cepario del laboratorio de Bacteriología de Sanidad Animal-CENIAP-INIA, que provienen de lisas, tilapias y cachamas. Se siguió la metodología recomendada por Fields et al. (1992) con modificaciones, siendo la secuencia de los iniciadores: 5'-GGGCAGATTCTAGACCTCCTG-3' Y 5'-CGATGATCTTGGAGCATTCCCAC-3'. Los aislados de Vibrio cholerae no 01 analizados no poseen la toxina colérica. La investigación de la toxina colérica en aislados ambientales es necesaria, ya que en los peces en los que fueron aislados son de consumo humano, lo que constituye un riesgo en salud pública.

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There was a spontaneous outbreak of mycobacteriosis in fancy veiltail guppies, Lebistes reticulatus, raised on an ornamental fish farm in Venezuela. The clinical signs included listlessness, emaciation, spinal curvature, sunken eyes and loss of colour. Numerous acid-fast bacteria, identified as Mycobacterium species, were detected in smears from the kidneys, liver, mesentery and spleen of the fish, from fresh faecal material, and from the unborn embryos of infected gravid females. The bacteria were eradicated by the addition of kanamycin sulphate to the water at a concentration of 50 ppm, the dose being repeated on four occasions with 48 hours between each dose. Fifteen days after the treatment, none of the clinical signs described were detected in any of the treated fish. The offspring born to treated females were healthy and normal, and did not harbour acid-fast bacteria.

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Blood eosinophilia and tissue infiltration by eosinophils are frequently observed in allergic inflammation and parasitic infections. This selective accumulation of eosinophils suggested the existence of endogenous eosinophil-selective chemoattractants. We have discovered a novel eosinophil-selective chemoattractant which we called eotaxin in an animal model of allergic airways disease. Eotaxin is generated in both allergic and non-allergic bronchopulmonary inflammation. The early increase in eotaxin paralleled eosinophil infiltration in the lung tissue in both models. An antibody to IL-5 suppressed lung eosinophilia, correlating with an inhibition of eosinophil release from bone marrow, without affecting eotaxin generation. This suggests that endogenous IL-5 is important for eosinophil migration but does not appear to be a stimulus for eotaxin production. Constitutive levels of eotaxin observed in guinea-pig lung may be responsible for the basal lung eosinophilia observed in this species. Allergen-induced eotaxin was present mainly in the epithelium and alveolar macrophages, as detected by immunostaining. In contrast there was no upregulation of eotaxin by the epithelial cells following the injection of sephadex beads and the alveolar macrophage and mononuclear cells surrounding the granuloma were the predominant positive staining cells. Eotaxin and related chemokines acting through the CCR3 receptor may play a major role in eosinophil recruitment in allergic inflammation and parasitic diseases and thus offer and attractive target for therapeutic intervention.

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Rapamycin is a macrolide antibiotic whose potent immunosuppressor activity was recently described in vivo and in vitro. The aim of the present work was to determine if rapamycin could affect an established inflammatory response. Conscious pathogen-free Dunkin-Hartley guinea pigs (300-400 g) were injected intravenously with Sephadex beads (G50, superfine, 10 to 40 microns, 24 mg/kg) to induce lung inflammation and bronchial hyperreactivity. Bronchoalveolar lavage (BAL) fluid was collected 2, 12 and 24 h after Sephadex administration and the cells were counted. Bronchial tissue was used to construct dose-response (contraction, g) curves to histamine and acetylcholine 24 h after the Sephadex injection, using a cascade system. Results are presented as area under the log dose-response curves. Test animals were injected with rapamycin (5 mg/kg) or its vehicle by the intramuscular route either 2 or 12 h after Sephadex injection and BAL fluid collected 24 h after Sephadex administration. Rapamycin administration 2 h after Sephadex reduced eosinophil and lymphocyte numbers in BAL by 52 and 55%, respectively, but not ex vivo bronchial hyperreactivity induced by Sephadex injection. However, rapamycin administration 12 h after Sephadex reduced BAL eosinophil and lymphocyte numbers (55 and 62%, respectively) and bronchial hyperreactivity. The increase in neutrophil numbers in BAL induced by Sephadex injection was not modified by rapamycin. Since lymphocyte numbers in BAL were significantly increased in Sephadex-treated animals at 12 h but not at 2 h after Sephadex injection, the present results suggest that the inhibition of bronchial hyperreactivity by rapamycin may be dependent on the presence of lymphocytes elicited into the airways by Sephadex injection.

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Rapamycin is a macrolide antibiotic whose potent immunosuppressor activity was recently described in vivo and in vitro. The aim of the present work was to determine if rapamycin could affect an established inflammatory response. Conscious pathogen-free Dunkin-Hartley guinea pigs (300-400 g) were injected intravenously with Sephadex beads (G50, superfine, 10 to 40 microns, 24 mg/kg) to induce lung inflammation and bronchial hyperreactivity. Bronchoalveolar lavage (BAL) fluid was collected 2, 12 and 24 h after Sephadex administration and the cells were counted. Bronchial tissue was used to construct dose-response (contraction, g) curves to histamine and acetylcholine 24 h after the Sephadex injection, using a cascade system. Results are presented as area under the log dose-response curves. Test animals were injected with rapamycin (5 mg/kg) or its vehicle by the intramuscular route either 2 or 12 h after Sephadex injection and BAL fluid collected 24 h after Sephadex administration. Rapamycin administration 2 h after Sephadex reduced eosinophil and lymphocyte numbers in BAL by 52 and 55 per cent , respectively, but not ex vivo bronchial hyperreactivity induced by Sephadex injection. However, rapamycin administration 12 h after Sephadex reduced BAL eosinophil and lymphocyte numbers (55 and 62 per cent , respectively) and bronchial hyperreactivity. The increase in neutrophil numbers in BAL induced by Sephadex injection was not modified by rapamycin. Since lymphocyte numbers in BAL were significantly increased in Sephadex-treated animals at 12 h but not at 2 h after Sephadex injection, the present results suggest that the inhibition of bronchial hyperreactivity by rapamycin may be dependent on the presence of lymphocytes elicited into the airways by Sephadex injection

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