Programa de Microbiología

Programa por bolillas del curso de Microbiología, correspondiente al Segundo Año de la Carrera de Medicina Veterinaria de la Facultad de Ciencias Veterinarias de la Universidad Nacional de La Plata.Dado que no se cuenta con la fecha de aprobación y publicación por el Honorable Consejo Directivo, se asigna la fecha de su primer ciclo lectivo: 1° de marzo de 1967.Facultad de Ciencias Veterinaria

In vivo knockdown of Brachyury results in skeletal defects and urorectal malformations resembling caudal regression syndrome

The T-box transcription factor BRACHYURY (T) is a key regulator of mesoderm formation during early development. Complete loss of T has been shown to lead to embryonic lethality around E10.0. Here we characterize an inducible miRNA-based in vivo knockdown mouse model of T, termed KD3-T, which exhibits a hypomorphic phenotype. KD3-T embryos display axial skeletal defects caused by apoptosis of paraxial mesoderm, which is accompanied by urorectal malformations resembling the murine uro-recto-caudal syndrome and human caudal regression syndrome phenotypes. We show that there is a reduction of T in the notochord of KD3-T embryos which results in impaired notochord differentiation and its subsequent loss, whereas levels of T in the tailbud are sufficient for axis extension and patterning. Furthermore, the notochord in KD3-T embryos adopts a neural character and loses its ability to act as a signaling center. Since KD3-T animals survive until birth, they are useful for examining later roles for T in the development of urorectal tissues

Murine expression and mutation analyses of the prostate androgen-regulated mucin-like protein 1 (Parm1) gene, a candidate for human epispadias.

Background Epispadias is the mildest phenotype of the human bladder exstrophy–epispadias complex (BEEC), and presents with varying degrees of severity. This urogenital birth defect results from a disturbance in the septation process, during which separate urogenital and anorectal components are formed through division of the cloaca. This process is reported to be influenced by androgen signaling. The human PARM1 gene encodes the prostate androgen-regulated mucin-like protein 1, which is expressed in heart, kidney, and placenta. Methods We performed whole mount in situ hybridization analysis of Parm1 expression in mouse embryos between gestational days (GD) 9.5 and 12.5, which are equivalent to human gestational weeks 4–6. Since the spatio-temporal localization of Parm1 corresponded to tissues which are affected in human epispadias, we sequenced PARM1 in 24 affected patients. Results We found Parm1 specifically expressed in the region of the developing cloaca, the umbilical cord, bladder anlage, and the urethral component of the genital tubercle. Additionally, Parm1 expression was detected in the muscle progenitor cells of the somites and head mesenchyme. PARM1 gene analysis revealed no alterations in the coding region of any of the investigated patients. Conclusions These findings suggest that PARM1 does not play a major role in the development of human epispadias. However, we cannot rule out the possibility that a larger sample size would enable detection of rare mutations in this gene

Isolated bladder exstrophy associated with a de novo 0.9 Mb microduplication on chromosome 19p13.12.

The exstrophy-epispadias complex (BEEC) is a urogenital birth defect of varying severity. The causes of the BEEC are likely to be heterogeneous, with individual environmental or genetic risk factors still being largely unknown. In this study, we aimed to identify de novo causative copy number variations (CNVs) that contribute to the BEEC. METHODS Array-based molecular karyotyping was performed to screen 110 individuals with BEEC. Promising CNVs were tested for de novo occurrence by investigating parental DNAs. Genes located in regions of rearrangements were prioritized through expression analysis in mice to be sequenced in the complete cohort, to identify high-penetrance mutations involving small sequence changes. RESULTS A de novo 0.9 Mb microduplication involving chromosomal region 19p13.12 was identified in a single patient. This region harbors 20 validated RefSeq genes, and in situ hybridization data showed specific expression of the Wiz gene in regions surrounding the cloaca and the rectum between GD 9.5 and 13.5. Sanger sequencing of the complete cohort did not reveal any pathogenic alterations affecting the coding region of WIZ. CONCLUSIONS The present study suggests chromosomal region 19p13.12 as possibly involved in the development of CBE, but further studies are needed to prove a causal relation. The spatiotemporal expression patterns determined for the genes encompassed suggest a role for Wiz in the development of the phenotype. Our mutation screening, however, could not confirm that WIZ mutations are a frequent cause of CBE, although rare mutations might be detectable in larger patient samples

Whole exome resequencing reveals recessive mutations in TRAP1 in individuals with CAKUT and VACTERL association

Congenital abnormalities of the kidney and urinary tract (CAKUT) account for approximately half of children with chronic kidney disease and they are the most frequent cause of end-stage renal disease in children in the US. However, its genetic etiology remains mostly elusive. VACTERL association is a rare disorder that involves congenital abnormalities in multiple organs including the kidney and urinary tract in up to 60% of the cases. By homozygosity mapping and whole exome resequencing combined with high-throughput mutation analysis by array-based multiplex PCR and next-generation sequencing, we identified recessive mutations in the gene TNF receptor-associated protein 1 (TRAP1) in two families with isolated CAKUT and three families with VACTERL association. TRAP1 is a heat shock protein 90-related mitochondrial chaperone possibly involved in antiapoptotic and endoplasmic reticulum-stress signaling. Trap1 is expressed in renal epithelia of developing mouse kidney E13.5 and in the kidney of adult rats, most prominently in proximal tubules and in thick medullary ascending limbs of Henle’s loop. Thus, we identified mutations in TRAP1 as highly likely causing CAKUT or CAKUT in VACTERL association

Genome-wide association study and mouse expression data identify a highly conserved 32 kb intergenic region between WNT3 and WNT9b as possible susceptibility locus for isolated classic exstrophy of the bladder

Bladder exstrophy-epispadias complex (BEEC), the severe end of the urorectal malformation spectrum, has a profound impact on continence as well as sexual and renal functions. It is widely accepted that for the majority of cases the genetic basis appears to be multifactorial. Here, we report the first study which utilizes genome-wide association methods to analyze a cohort comprising patients presenting the most common BEEC form, classic bladder exstrophy (CBE), to identify common variation associated with risk for isolated CBE. We employed discovery and follow-up samples comprising 218 cases/865 controls and 78 trios in total, all of European descent. Our discovery sample identified a marker near SALL1, showing genome-wide significant association with CBE. However, analyses performed on follow-up samples did not add further support to these findings. We were also able to identify an association with CBE across our study samples (discovery: P = 8.88 × 10−5; follow-up: P = 0.0025; combined: 1.09 × 10−6) in a highly conserved 32 kb intergenic region containing regulatory elements between WNT3 and WNT9B. Subsequent analyses in mice revealed expression for both genes in the genital region during stages relevant to the development of CBE in humans. Unfortunately, we were not able to replicate the suggestive signal for WNT3 and WNT9B in a sample that was enriched for non-CBE BEEC cases (P = 0.51). Our suggestive findings support the hypothesis that larger samples are warranted to identify association of common variation with CBE

Relaciones entre el peso, la cantidad de globulos rojos y de hemoglobina, en los embriones de pollo en condiciones normales e infectados con virus "A" de influenza

Fil: Pennimpede, Francisco C. Ministerio del Interior; Instituto Bacteriológico "Dr. Carlos G. Malbrán"; ArgentinaSe estudian las relaciones entre el peso, cantidad de glóbulos rojos y de moglobina en los embriones de pollo nomrales y se comparan con otros grupos de determinaciones realizadas sobre embriones infectados con virus "A" de Influenza, entre el 11º y 16º dia de incubación; presentandose como valores normales para esos dias de desarrollo las medidas obtenidas. la relacion entre el peso del embrión y el contenido de glóbulos rojos es siempre superior en los normales, otro tanto aunque mas acentuado, ocurre entre el contenido hemoglobina y de glóbulos rojos. En cambio, los índices hemoglobina son prácticamente idénticos en ambos grupos, evidenciando que la infección con virus "A" de Influenza no altera esta relación

Cambios producidos en el hemograma y mielograma de los embriones de pollo infectados con virus "A" de influenza

Fil.: Pennimpede, F.C. Ministerio de Salud Pública de la Nación; Instituto Bacteriológico "Dr. Carlos G. Malbrán"; ArgentinaSe ha inoculado el virus A de influenza en huevos fértiles de once días de incubación, estudiándose paralelamente con huevos fértiles normales, la cantidad de hematíes y de hemoglobina, el hemograma y el mielograma. Se hicieron las comprobaciones siguientes : 1° Reducción del contenido de hematíes y de hemoglobina en la sangre de los embriones infectados, con Modificaciones cualicuantitativas en las series roja primitiva y definitiva, en el hemograma y mielograma. 3° Modificaciones citoplasmáticas en las células eritroblásticas, periféricas y centrales, consistiendo en la presencia de "vacuolas" únicas o múltiples. 4° Gran reacción mieloide central (médula ósea) y aumento consecutivo en la sangre periférica. 5° Notable aumento de las mitosis (sangre y médula ósea). Se 'discuten los resultados

La encefalomielitis equina en la República Argentina. Estudio epizootologico

Fil: Pennimpede, Francisco C. Ministerio del Interior; Instituto Bacteriológico "Dr. Carlos G. Malbrán"; Argentin