31 INTEGRANTES

GRUPLAC

DESCRIPCIÓN 

El grupo de investigación tiene como objetivo generar conocimiento en áreas relevantes para el país en temáticas relacionadas con la salud y producción animal, medicina de poblaciones, zoonosis y medicina de la conservación. Para el cumplimiento de este objetivo el grupo desarrolla proyectos de investigación enmarcado en cinco líneas de investigación las cuales son: Producción animal, Medicina de Poblaciones, Medicina de la Conservación, Zoonosis y Salud Animal. Los proyectos realizados en el campo de la medicina de la conservación han permitido la conservación de especies nativas tales como el pez capitán de la sabana y la Pacarana.

PRODUCTOS DESTACADOS

Using of Okara in diets for growing broilers

This study aimed to evaluate the effects of okara inclusion in diet for growing broilers on performance, carcass yield, blood and bone variables, quality and lipid oxidation of meat and economic viability. For that, 575 Cobb 21-days-old male broilers were distributed in a completely randomized design with four levels of okara inclusion (25, 50, 75 and 100 g of okara/kg diet) and a control group with five replicates and 23 birds each. There was no difference (P>0.05) in function of okara levels on the performance variables, carcass yield, bone variables and serum triglycerides, calcium and phosphorus at 42 days old. Serum cholesterol levels showed a quadratic response (P<0.05), in which the lowest value estimated was 65.3 g of okara/kg of diet. Okara can be included in diets for broilers up to the level of 100g/kg without affecting the performance, carcass yield, bone variables and lipid oxidation of meat. However, the best economic results were observed up to 50g of okara/kg of diet.

Plasmodium vivax in vitro continuous culture: The spoke in the wheel

Understanding the life cycle of Plasmodium vivax is fundamental for developing strategies aimed at controlling and eliminating this parasitic species. Although advances in omic sciences and high-throughput techniques in recent years have enabled the identification and characterization of proteins which might be participating in P. vivax invasion of target cells, exclusive parasite tropism for invading reticulocytes has become the main obstacle in maintaining a continuous culture for this species. Such advance that would help in defining each parasite protein’s function in the complex process of P. vivax invasion, in addition to evaluating new therapeutic agents, is still a dream. Advances related to maintenance, culture medium supplements and the use of different sources of reticulocytes and parasites (strains and isolates) have been made regarding the development of an in vitro culture for P. vivax; however, only some cultures having few replication cycles have been obtained to date, meaning that this parasite’s maintenance goes beyond the technical components involved. Although it is still not yet clear which molecular mechanisms P. vivax prefers for invading young CD71+ reticulocytes [early maturation stages (I-II-III)], changes related to membrane proteins remodelling of such cells could form part of the explanation. The most relevant aspects regarding P. vivax in vitro culture and host cell characteristics have been analysed in this review to explain possible reasons why the species’ continuous in vitro culture is so difficult to standardize. Some alternatives for P. vivax in vitro culture have also been described

On the evolution and function of Plasmodium vivax reticulocyte binding surface antigen (pvrbsa)

The RBSA protein is encoded by a gene described in Plasmodium species having tropism for reticulocytes. Since this protein is antigenic in natural infections and can bind to target cells, it has been proposed as a potential candidate for an anti-Plasmodium vivax vaccine. However, genetic diversity (a challenge which must be overcome for ensuring fully effective vaccine design) has not been described at this locus. Likewise, the minimum regions mediating specific parasite-host interaction have not been determined. This is why the rbsa gene’s evolutionary history is being here described, as well as the P. vivax rbsa (pvrbsa) genetic diversity and the specific regions mediating parasite adhesion to reticulocytes. Unlike what has previously been reported, rbsa was also present in several parasite species belonging to the monkey-malaria clade; paralogs were also found in Plasmodium parasites invading reticulocytes. The pvrbsa locus had less diversity than other merozoite surface proteins where natural selection and recombination were the main evolutionary forces involved in causing the observed polymorphism. The N-terminal end (PvRBSA-A) was conserved and under functional constraint; consequently, it was expressed as recombinant protein for binding assays. This protein fragment bound to reticulocytes whilst the C-terminus, included in recombinant PvRBSA-B (which was not under functional constraint), did not. Interestingly, two PvRBSA-A-derived peptides were able to inhibit protein binding to reticulocytes. Specific conserved and functionally important peptides within PvRBSA-A could thus be considered when designing a fully-effective vaccine against P. vivax. © 2018 Camargo-Ayala, Garzón-Ospina, Moreno-Pérez, Ricaurte-Contreras, Noya and Patarroyo.

Multilocus fragment analysis of Cryptosporidium parvum from pre-weaned calves in Colombia

The intra-species genetic diversity of Cryptosporidium parvum in dairy cattle farms in the central area of Colombia was investigated using a multilocus fragment typing approach with nine variable-number tandem-repeat (VNTR) loci and the gp60 gene. Genomic DNA of 70 C. parvum isolates from pre-weaned calves in 32 farms was analysed. Most markers showed two (ML1, MSB, CP47, and MSC6-7) or three alleles (5B12, Cgd2_3850, and Cgd6_5400), although they exhibited a major allele accounting for more than 69% of specimens, which explains their low discriminatory index. The TP14 microsatellite was monomorphic while a total of six alleles were found at the ML2 microsatellite. The two novel allelic variants (219bp, 245bp) exhibited by more than 36% of specimens at the latter locus were a remarkable finding. The 10-markers typing tool provided a Hunter-Gaston discriminatory value of 0.940 (95% CI, 0.918 – 0.961) and differentiated 22 multilocus subtypes (MLTs). Nevertheless, the combination of the three most informative markers (ML2, gp60, and Cgd2_3850) differentiated 68% of MLTs and hardly impaired the discriminatory index. The fact that many MLTs (13/22) were distinctive for individual farms provides evidence for the endemic nature of the infection and the major role played by transmission within farms. The eBURST algorithm suggested a low degree of genetic divergence. All but three MLTs were clustered in a clonal complex with a star-like topology typical of clonal expansion, however linkage analysis did not find evidence of linkage disequilibrium. Bayesian analysis also identified a genetic structure with K = 3 being the best estimation of ancestral clusters, although a large proportion of isolates (35%) could not be allocated to a single population, which indicates their mixed origin. The results confirm the genetic distinctiveness of C. parvum in cattle farms in this geographical area. This is the first multilocus analysis on the intra-specific variability of Cryptosporidium from calves in South America.

Multilocus fragment analysis of Cryptosporidium parvum from pre-weaned calves in Colombia

The intra-species genetic diversity of Cryptosporidium parvum in dairy cattle farms in the central area of Colombia was investigated using a multilocus fragment typing approach with nine variable-number tandem-repeat (VNTR) loci and the gp60 gene. Genomic DNA of 70 C. parvum isolates from pre-weaned calves in 32 farms was analysed. Most markers showed two (ML1, MSB, CP47, and MSC6-7) or three alleles (5B12, Cgd2_3850, and Cgd6_5400), although they exhibited a major allele accounting for more than 69% of specimens, which explains their low discriminatory index. The TP14 microsatellite was monomorphic while a total of six alleles were found at the ML2 microsatellite. The two novel allelic variants (219bp, 245bp) exhibited by more than 36% of specimens at the latter locus were a remarkable finding. The 10-markers typing tool provided a Hunter-Gaston discriminatory value of 0.940 (95% CI, 0.918 – 0.961) and differentiated 22 multilocus subtypes (MLTs). Nevertheless, the combination of the three most informative markers (ML2, gp60, and Cgd2_3850) differentiated 68% of MLTs and hardly impaired the discriminatory index. The fact that many MLTs (13/22) were distinctive for individual farms provides evidence for the endemic nature of the infection and the major role played by transmission within farms. The eBURST algorithm suggested a low degree of genetic divergence. All but three MLTs were clustered in a clonal complex with a star-like topology typical of clonal expansion, however linkage analysis did not find evidence of linkage disequilibrium. Bayesian analysis also identified a genetic structure with K = 3 being the best estimation of ancestral clusters, although a large proportion of isolates (35%) could not be allocated to a single population, which indicates their mixed origin. The results confirm the genetic distinctiveness of C. parvum in cattle farms in this geographical area. This is the first multilocus analysis on the intra-specific variability of Cryptosporidium from calves in South America

GALERÍA