Diagnóstico de pseudotuberculosis en ovinos patagónicos / Diagnosis of caseous lymphadenitis in sheep from Patagonia

La linfadenitis caseosa (LAC) es una enfermedad bacteriana supurativa crónica que afecta a ovinos. El agente etiológico es Corynebacterium pseudotuberculosis. El diagnóstico diferencial con otras afecciones que presentan manifestaciones clínicas similares sólo puede hacerse sobre la base del aislamiento y la identificación del agente etiológico. El objetivo de este trabajo fue caracterizar metabólica y genéticamente al agente causal de abscesos granulomatosos observados en ovinos en la región patagónica. En las muestras, se observó un contenido caseoso rodeado de una membrana fibrosa, y en el examen histopatológico, un centro de necrosis caseosa rodeado por células epitelioides, linfocitos y polinucleares. Mediante estudios microscópicos, bacteriológicos y moleculares fue confirmada la infección causada por C. pseudotuberculosis biovar ovis.

Caseous lymphadenitis (CLA) is a chronic bacterial, infectious and contagious disease caused by Corynebacterium pseudotuberculosis. It affects sheep and results in abscesses of the lymph nodes in subcutaneous tissue, as well as in internal organs such as lungs, liver and kidneys. Differential diagnosis of the disease is based on the isolation and biochemical identification of the etiological agent. The purpose of this study was to characterize the bacteria isolated from typical CLA lesions in sheep from Patagonia, Argentina, at metabolic and genetic levels. Macroscopic observations show a fibrous membrane containing caseous necrotic tissue. Histopathological analysis shows an eosinophilic necrotic area surrounded by epitheloid cells and polymorphonuclear infiltration. Other analyses performed such as microscopic observations, in vitro culture, biochemical tests and 16s rDNA sequencing confirmed diagnosis of caseous lymphadenitis due to C. pseudotuberculosis.

Contenido en algunos nutrientes del alga marina comestible Monostroma undulatum Wittrock de la costa patagónica argentina / Chemical composition and seasonal fluctuations of the edible green seaweed, Monostroma undulatum, Wittrock, from the Southern Argentina coast

The chemical composition of green seaweed, Monostroma undulatum, Wittrock, growing in the Southern Argentina coast, was studied. Samples were collected in Puerto Deseado, province of Santa Cruz (47 degrees 45'L.S., 65 degrees 55'L.W.), from October to December 1999 and 2000. It has been analyzed six sample during this period. Algae were washed with sea water and dried at room temperature for 24 hs. Moisture, nitrogen, lipids and ashes were determined according to AOAC; fiber (total, soluble and insoluble), according to Lahaye. After mineralization with nitric acid, sodium and potassium were determined by flame photometry, calcium by complexometric method, and phosphorus by Gomori's method. The ranges expressed per 100 g dry algae were: protein (Nx6.25): 12.89-21.85; ashes (g): 33.92-40.05; lipid (g): 0.32-1.47; total fiber (g): 14.36-19.6; digestible carbohydrates (calculated by difference) (g): 20.86-32.48; sodium (g): 7.39-13.11; potassium (g): 1.38-3.18; calcium (mg): 149-226; phosphorus (mg): 190-447; Vitamin C (mg): 159-455. These results show that this green seaweed is an important source for protein, fiber, macronutrients minerals and vitamin C, during the macroscopic period. There was an important fluctuation that must be taken into account to consider the commercial collection to use it in human nutrition.