Leptospirosis is a neglected zoonosis with worldwide distribution. The causative agents are spirochete bacteria of the Leptospira genus, displaying huge diversity of serovars, the identity of which is critical for effective diagnosis and vaccination purposes. Among many other mammalian species, Leptospira infects cattle, eliciting acute signs in calves, and chronic disease in adult animals often leading to abortions. In South America, and including in Uruguay, beef and dairy export are leading sources of national income. Despite the importance of bovine health, food safety, and bovine-related dissemination of leptospirosis to humans, extremely limited information is available as to the identity of Leptospira species and serovars infecting cattle in Uruguay and the South American subcontinent. Here we report a multicentric 3-year study resulting in the isolation and detailed characterization of 40 strains of Leptospira spp. obtained from infected cattle. Combined serologic and molecular typing identified these isolates as L. interrogans serogroup Pomona serovar Kennewicki (20 strains), L. interrogans serogroup Canicola serovar Canicola (1 strain), L. borgpetersenii serogroup Sejroe serovar Hardjo (10 strains) and L. noguchii (9 strains). The latter showed remarkable phenotypic and genetic variability, belonging to 6 distinct serogroups, including 3 that did not react with a large panel of reference serogrouping antisera. Approximately 20% of cattle sampled in the field were found to be shedding pathogenic Leptospira in their urine, uncovering a threat for public health that is being largely neglected. The two L. interrogans serovars that we isolated from cattle displayed identical genetic signatures to those of human isolates that had previously been obtained from leptospirosis patients. This report of local Leptospira strains shall improve diagnostic tools and the understanding of leptospirosis epidemiology in South America. These strains could also be used as new components within bacterin vaccines to protect against the pathogenic Leptospira strains that are actually circulating, a direct measure to reduce the risk of human leptospirosis.
Clostridium haemolyticum causes bacillary hemoglobinuria (BH), an infectious and usually fatal disease that occurs mostly in cattle, which is clinically characterized by jaundice, hemoglobinuria, and anemia. The trematode Fasciola hepatica has been commonly reported as the main predisposing factor that triggers this condition. The authors evaluated 20 naturally occurring cases of bovine BH to characterize the pathology and pathogenesis of the disease. Grossly, the most consistent finding was a large, frequently single focus of necrosis surrounded by a red to purple halo, observed most frequently on the parietal surface of the right and left hepatic lobes. Other findings were jaundice, dark-brown discoloration of kidneys, and red urine in the urinary bladder. Microscopically, characteristic lesions were locally extensive, necrotizing hepatitis with thrombosis and numerous intralesional Gram-positive rod-shaped bacteria, and acute renal tubular necrosis. By immunohistochemistry, many hepatocytes outside the necrotic focus in the liver were positive for activated caspase 3, suggesting that those cells were undergoing apoptosis. Ultrastructural evaluation revealed hepatocyte necrosis, hemolysis, and clumps of vegetative and sporulating bacilli within the liver. Polymerase chain reaction for the C. haemolyticum beta toxin gene was positive in randomly selected liver samples. No gross or microscopic lesions indicative of fascioliasis were detected in the liver of any animal, suggesting that other yet undetermined predisposing factors were associated with these cases of BH.
The biotechnological production of dicarboxylic acids (C4) from renewable carbon sources represents an attractive approach for the provision of these valuable compounds by green chemistry means. Glycerol has become a waste product of the biodiesel industry that serves as a highly reduced carbon source for some microorganisms. Escherichia coli is capable of consuming glycerol to produce succinate under anaerobic fermentation, but with the deletion of some tricarboxylic acid (TCA) cycle genes, it is also able to produce succinate and malate in aerobiosis. In this study, we investigate possible rate-limiting enzymes by overexpressing the C-feeding anaplerotic enzymes Ppc, MaeA, MaeB, and Pck in a mutant that lacks the succinate dehydrogenase (Sdh) enzyme. The overexpression of the TCA enzyme Mdh and the activation of the glyoxylate shunt was also examined. Using this unbiased approach, we found that phosphoenol pyruvate carboxylase (Ppc) overexpression enhances an oxidative pathway that leads to increasing succinate, while phosphoenol pyruvate carboxykinase (Pck) favors a more efficient reductive branch that produces mainly malate, at 57.5% of the theoretical maximum molar yield. The optimization of the culture medium revealed the importance of bicarbonate and pH in the production of malate. An additional mutation of the ppc gene highlights its central role in growth and C4 production.
Equine pythiosis is an ulcerative and granulomatous disease of the skin, caused by the oomycete Pythium insidiosum (Pythiaceae). The objective of this study was to describe seven cases of equine pythiosis that occurred from 2012 to 2017 in the eastern region of Uruguay. Six of the seven cases occurred in the eastern wetland ecosystems of the Merin basin, and the remaining case occurred in the wetland fluvial plains of the Tacuarembó River. Lesions consisted of a large, rapidly growing ulcerated tumor with abundant granulation tissue, serosanguineous secretion, and fistulous tracts containing large concretions or kunkers. The animals presented intense pruritus, claudication and loss of body condition, with death or euthanasia in extremis in six cases. The main histological lesions consisted of an eosinophilic and pyogranulomatous inflammatory process, with numerous foci of eosinophilic necrosis (kunkers), collagenolysis, and a Splendore-Hoeppli reaction. In all cases, silver coloration (Grocott) showed intralesional hyphae compatible with P. insidiosum, which was confirmed by immunohistochemistry in three cases. A horse in the terminal phase of the disease was treated with triamcinolone acetonide (50mg IM every 15 days), and fully recovered after 1 year. It is concluded that equine pythiosis is prevalent in the wetland ecosystems of eastern Uruguay and that treatment with triamcinolone is auspicious.
Genetic disorders in Holstein cattle are a health problem that has grown worldwide in recent years, compromising the sustainability of modern dairy production. In Uruguay, Holstein-based milk production is one of the most important sectors of the country’s economy, but high levels of inbreeding have decreased the breed’s fertility in recent decades. This study investigated the presence and diffusion of lethal and semi-lethal alleles causing embryo death, abortions, fetal malformations, and neonatal diseases in Holstein calves. Using the GeneSeek® Genomic Profiler™ Bovine 50K BeadChip, we genotyped 383 calves (1-30 days-old) from 27 farms located in the main dairy region of Uruguay. Results showed a high prevalence of farms (85%) and carrier calves (21%), including one or more of the following semi-lethal or lethal alleles: Syndactylism (4.18%), brachyspina (3.39%), cholesterol deficiency haplotype (2.61%), complex vertebral malformation (2.09%), bovine leukocyte adhesion deficiency (1.04%s), and Holstein haplotypes HH1 (4.44%), HH3 (3.13%), HH4 (1.04%), and HH5 (0.26%). Most of these alleles had not been recognized previously in Uruguay. We concluded that lethal and semi-lethal mutations are widespread in the Holstein breed in Uruguay. More studies are required to determine their impact on dairy cattle fertility.
In this study, the epidemiological and pathological features of an outbreak of squamous cell carcinoma (SCC) in adult female sheep and a young ram, Friesian Milchschaf breed or crossbreed is described. Seven adult females belonging to an original flock nucleus of 20 animals were affected, as well as a young ram belonging to the same nucleus was affected in other establishment. Multiple verrucous neoplastic masses of several months of evolution were evident in the head region, with local invasion and regional lymph node metastases. Histological studies revealed a cancerous stage of invasion of the dermis and neoplastic proliferation characteristic of invasive SCC, and a pre-cancerous stage with solar elastosis and chronic solar keratosis lesions induced by sunlight. Decrease in latitude, increased level of solar radiation with long exposure to sunlight, and the phenotypic characteristics of the breed are the main factors responsible for the high prevalence of SCC, showing the susceptibility of the Friesian Milchschaf breed and crossbreed in temperate zones as Uruguay.
Las universidades interculturales en México surgen con la finalidad de favorecer el acceso a la educación superior de la población indígena, que historicamente ha experimentado un rezago. En el año 2003 se crea a nivel del gobierno federal la Coordinación General de Educación Intercultural y Bilingüe (CGEIB) con el objetivo de generar propuestas que incorporaran los conocimientos, lenguas y cultura de los pueblos indígenas a los procesos educativos oficiales. En el año 2014 se cuenta con diez instituciones de educación superior (IES), las cuales se encuentran agrupadas en la Red de Universidades Interculturales (Redui), y se ubican en estados con significativa presencia de pueblos indígenas. El presente escrito busca analizar tres grandes momentos: a) la génesis de las universidades interculturales en México, b) su evolución y desarrollo y c) evaluación y situación actual. Finalmente se analizarán los alcances, dificultades y problemas que ha
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