Evaluation of the Allelic Variations in Vernalisation (VRN1) and Photoperiod (PPD1) Genes and Genetic Diversity in a Spanish Spelt Wheat Collection.

Allelic variation within genes controlling the vernalisation requirement (VRN1) and photoperiod response (PPD1) determines the adaptation of wheat to different environmental growing conditions as well as influences other traits related to grain yield. This study aimed to screen a Spanish spelt wheat collection using gene-specific molecular markers for VRN-A1, VRN-B1, VRN-D1, and PPD-D1 loci and to phenotype for heading date (HD) in both field and greenhouse experiments under a long photoperiod and without vernalisation. Fifty-five spelt genotypes (91.7%) exhibited a spring growth habit, and all of them carried at least one dominant VRN1 allele, whereas five (8.3%) genotypes had a winter growth habit, and they carried the triple recessive allele combination. The Vrn-D1s was the most frequent allele in the studied set of spelt accessions, and it was found in combination with both the dominant Vrn-A1b and/or Vrn-B1a alleles in 88.3% of the spelt accessions tested. All spelt accessions carried the photoperiod-sensitive Ppd-D1b allele, which may explain the late heading of spelt germplasm compared to the commercial spring bread wheat Setenil used as a control. The least significant difference test showed significant differences between allelic combinations, the earliest accessions being those carrying two or three dominant alleles, followed by the one-gene combinations. In addition, the genetic diversity was evaluated through capillary electrophoresis using 15 wheat simple sequence repeat (SSR) markers. Most markers had high levels of polymorphism, producing 95 different alleles which ranged between 53 and 279 bp in size. Based on the polymorphic information content values obtained (from 0.51 to 0.97), 12 out of the 15 SSRs were catalogued as informative markers (values > 0.5). According to the dendrogram generated, the spelt accessions clustered as a separate group from the commercial bread wheat Setenil. Knowledge of VRN1 and PPD1 alleles, heading time, and genetic variability using SSR markers is valuable for spelt wheat breeding programs.

Bread Wheat Biofortification for Grain Carotenoid Content by Inter-Specific Breeding.

Bread wheat has traditionally been selected for whitish derived flours. As a consequence, the current varieties carry carotenogenic alleles associated with low grain carotenoid. In contrast, high grain yellow pigment content (YPC) has been a major target in durum wheat programs since yellow colour is an important aesthetic factor for pasta production. Phytoene synthase 1 (Psy1) genes have an important role in the determination of the carotenoid content in wheat. In this work, we have transferred the genes Psy1-A1 and Psy1-B1 from durum to bread wheat by inter-specific hybridization in order to evaluate the combined effect of these genes for the improvement of grain carotenoid content, as well as the development of carotenoid-enriched bread wheat lines. Inter-specific breeding coupled with a MAS approach based on Psy1-A1 and Psy1-B1 alleles has allowed the development of bread wheat pre-breeding lines with enhanced grain carotenoid content (16-23% mean). These biofortified lines have the potential to become new varieties or to be used as recurrent parents in bread wheat breeding programs.

Correlación entre la glucosa salival con la glucosa de ayuno, la Hemoglobina glicada y el Péptido-C en personas con diabetes mellitus tipo 2

Objetivo : Determinar la correlación entre la glucosa salival con la glucosa en ayunas, HbA1c y el péptido C en personas con Diabetes Mellitus tipo 2 (DM2). Materiales y métodos : Estudio transversal llevado a cabo en el Centro de Investigación en Diabetes, Obesidad y Nutrición (CIDON) en Lima, Perú durante el año 2021. Se categorizó en buen control metabólico (HbA1c<7 %) y mal control metabólico (HbA1c≥7 %). Se midió la glucosa basal, HbA1c y el péptido C en sangre. La glucosa salival se midió con el método glucosa oxidasa. La correlación de Spearman fue usada para determinar la asociación entre la glucosa salival con la glucosa en ayunas, HbA1c y el péptido- C. Resultados : Participaron un total de 142 personas con DM2. La concentración de glucosa salival fue significativamente más elevada en DM2 con mal control metabólico (p<0.01). Se observó una correlación positiva débil significativa entre la glucosa salival y la glucosa basal (r=0.23, p=0.04) y HbA1c (r=0.26, p=0.02) en DM2 con mal control metabólico y una correlación negativa insignificante (r=-0.08; p=0.47) con el péptido C. Conclusiones : La glucosa salival presenta una asociación significativa y positiva con la glucosa en sangre y la HbA1c, pero no con el péptido C en personas con DM2 con mal control metabólico. Sin embargo, hay muchos factores que deben ser considerados y analizados más a fondo para determinar su posible uso.

Objetivo : To determine the correlation between salivary glucose levels with fasting blood glucose, HbA1c, and C-peptide in patients with type 2 diabetes mellitus (T2DM). Materials and methods : This is a cross-sectional study performed at the Centro de Investigación en Diabetes, Obesidad y Nutrición (CIDON) in Lima, Peru, during 2021. Patients were categorized as those with good metabolic control (HbA1c<7 %), and poor metabolic control (HbA1c≥7 %). Baseline fasting blood glucose, as well as blood HbA1c and C-peptide values were measured. Salivary glucose was measured using the glucose oxidase method. Spearman's correlation was used for determining an association between salivary glucose levels and fasting blood glucose, HbA1c, and C-peptide. Results : One-hundred and forty-two subjects with T2DM participated in the study. Salivary glucose was significantly higher in T2DM subjects with poor metabolic control (p<0.01). A weak positive correlation between salivary glucose and fasting blood glucose (r= 0.23, p= 0.04) and HbA1c (r= 0.26, p= 0.02) was observed in subjects with T2DM and poor metabolic control, and also a non-significant negative correlation (r=-0.08; p= 0.47) with C-peptide. Conclusions : Salivary glucose levels show significant and positive association with fasting blood glucose and HbA1c, but not with C-peptide in persons with T2DM and poor metabolic control. However, there are many factors that should be considered and analyzed in detail aiming to determine its potential use.

Analysis of Chromosome Associations during Early Meiosis in Wheat Lines Carrying Chromosome Introgressions from Agropyron cristatum.

Crested wheatgrass (Agropyron cristatum L. Gaertn., genome P), included in the Triticeae tribe (family Poaceae), is one of the most important grasses in temperate regions. It has been valued as a donor of important agronomic traits for wheat improvement, including tolerance to cold, drought, and high salinity, as well as resistance to leaf rust, stripe rust, and powdery mildew. For successful incorporation of beneficial alleles into wheat, it is essential that recombination between wheat and A. cristatum chromosomes occurs. In this work, we analysed chromosome associations during meiosis in wheat lines carrying chromosome introgressions from A. cristatum chromosomes 5P and 6P in the presence and absence of Ph1 locus using fluorescence in situ hybridisation. The results showed that the Ph1 locus does not affect chromosome associations between A. cristatum and wheat chromosomes because there were no interspecific chromosome associations; therefore, no recombination between chromosomes from wheat and Agropyron were observed in the absence of the Ph1 locus. The 5P and 6P A. cristatum chromosomes do not have a suppressor effect on the Ph1 locus. Wheat univalents in metaphase I suggest that Agropyron chromosomes might carry genes having a role in wheat homologous chromosome associations. Putative effect of the Agropyron genes on wheat chromosome associations does not interact with the Ph1 locus.

Large-Scale Transcriptome Analysis in Faba Bean (Vicia faba L.) under Ascochyta fabae Infection.

Faba bean is an important food crop worldwide. However, progress in faba bean genomics lags far behind that of model systems due to limited availability of genetic and genomic information. Using the Illumina platform the faba bean transcriptome from leaves of two lines (29H and Vf136) subjected to Ascochyta fabae infection have been characterized. De novo transcriptome assembly provided a total of 39,185 different transcripts that were functionally annotated, and among these, 13,266 were assigned to gene ontology against Arabidopsis. Quality of the assembly was validated by RT-qPCR amplification of selected transcripts differentially expressed. Comparison of faba bean transcripts with those of better-characterized plant genomes such as Arabidopsis thaliana, Medicago truncatula and Cicer arietinum revealed a sequence similarity of 68.3%, 72.8% and 81.27%, respectively. Moreover, 39,060 single nucleotide polymorphism (SNP) and 3,669 InDels were identified for genotyping applications. Mapping of the sequence reads generated onto the assembled transcripts showed that 393 and 457 transcripts were overexpressed in the resistant (29H) and susceptible genotype (Vf136), respectively. Transcripts involved in plant-pathogen interactions such as leucine rich proteins (LRR) or plant growth regulators involved in plant adaptation to abiotic and biotic stresses were found to be differently expressed in the resistant line. The results reported here represent the most comprehensive transcript database developed so far in faba bean, providing valuable information that could be used to gain insight into the pathways involved in the resistance mechanism against A. fabae and to identify potential resistance genes to be further used in marker assisted selection.

A reference consensus genetic map for molecular markers and economically important traits in faba bean (Vicia faba L.).

BACKGROUND: Faba bean (Vicia faba L.) is among the earliest domesticated crops from the Near East. Today this legume is a key protein feed and food worldwide and continues to serve an important role in culinary traditions throughout Middle East, Mediterranean region, China and Ethiopia. Adapted to a wide range of soil types, the main faba bean breeding objectives are to improve yield, resistance to biotic and abiotic stresses, seed quality and other agronomic traits. Genomic approaches aimed at enhancing faba bean breeding programs require high-quality genetic linkage maps to facilitate quantitative trait locus analysis and gene tagging for use in a marker-assisted selection. The objective of this study was to construct a reference consensus map in faba bean by joining the information from the most relevant maps reported so far in this crop. RESULTS: A combination of two approaches, increasing the number of anchor loci in diverse mapping populations and joining the corresponding genetic maps, was used to develop a reference consensus map in faba bean. The map was constructed from three main recombinant inbreed populations derived from four parental lines, incorporates 729 markers and is based on 69 common loci. It spans 4,602 cM with a range from 323 to 1041 loci in six main linkage groups or chromosomes, and an average marker density of one locus every 6 cM. Locus order is generally well maintained between the consensus map and the individual maps. CONCLUSION: We have constructed a reliable and fairly dense consensus genetic linkage map that will serve as a basis for genomic approaches in faba bean research and breeding. The core map contains a larger number of markers than any previous individual map, covers existing gaps and achieves a wider coverage of the large faba bean genome as a whole. This tool can be used as a reference resource for studies in different genetic backgrounds, and provides a framework for transferring genetic information when using different marker technologies. Combined with syntenic approaches, the consensus map will increase marker density in selected genomic regions and will be useful for future faba bean molecular breeding applications.

Immunoglobulin domains in Escherichia coli and other enterobacteria: from pathogenesis to applications in antibody technologies.

The immunoglobulin (Ig) protein domain is widespread in nature having a well-recognized role in proteins of the immune system. In this review, we describe the proteins containing Ig-like domains in Escherichia coli and enterobacteria, reporting their structural and functional properties, protein folding, and diverse biological roles. In addition, we cover the expression of heterologous Ig domains in E. coli owing to its biotechnological application for expression and selection of antibody fragments and full-length IgG molecules. Ig-like domains in E. coli and enterobacteria are frequently found in cell surface proteins and fimbrial organelles playing important functions during host cell adhesion and invasion of pathogenic strains, being structural components of pilus and nonpilus fimbrial systems and members of the intimin/invasin family of outer membrane (OM) adhesins. Ig-like domains are also found in periplasmic chaperones and OM usher proteins assembling fimbriae, in oxidoreductases and hydrolytic enzymes, ATP-binding cassette transporters, sugar-binding and metal-resistance proteins. The folding of most E. coli Ig-like domains is assisted by periplasmic chaperones, peptidyl-prolyl cis/trans isomerases and disulfide bond catalysts that also participate in the folding of antibodies expressed in this bacterium. The technologies for expression and selection of recombinant antibodies in E. coli are described along with their biotechnological potential.

Biotic factor does not limit operational pH in packed-bed bioreactor for ferrous iron biooxidation.

Ferrous ion biooxidation is a process with many promising industrial applications: mainly regeneration of ferric ion as an oxidizing reagent in bioleaching processes and depuration of acid mine drainage. The flooded packed-bed bioreactor (FPB) is the design that leads to the highest biooxidation rate. In this bioreactor, biomass is immobilized in a biofilm that consists of an inorganic matrix, formed by precipitated ferric compounds, in the pores of which cells are attached. This biofilm covers the surface of particles (siliceous stone) that form the bed. The chemical stability of this inorganic matrix defines the widest possible pH range in FPBs. At pH below 1, ferric matrix is dissolved and cells are washed out. At pH higher than 2, ferric ion precipitates massively, greatly hindering mass transfer to cells. Thus, among other parameters, pH is recognised as a key factor for operational control in FPBs. This paper aims to explain the effect of pH on FPB operation, with an emphasis on microbial population behaviour. FPBs seeded with mixed inocula were assayed in the pH range from 2.3 to 0.8 and the microbial population was characterised. The microbial consortium in the bioreactor is modified by pH; at pH above 1.3 Acidithiobacillus ferrooxidans is the dominant microorganism, whereas at pH below 1.3 Leptospirillum ferrooxidans dominates. Inoculum can be adapted to acidity during continuous operation by progressively decreasing the pH of the inlet solution. Thus, in the pH range from 2.3 to 1, the biotic factor does not compromise the bioreactor performance.

Translocase and major signal peptidase malfunctions affect aerial mycelium formation in Streptomyces lividans.

Deficiency in the translocase complex (SecG mutant strain) or in the major type I signal peptidase (SipY mutant strain) function in Streptomyces lividans resulted, as expected, in a drastic reduction of secretory protein production and in a bald phenotype. The transcriptional profiling of both strains showed that the expression of a set of genes involved in the morphological differentiation process was down regulated in both mutant strains (bldG, bldN and bldM), whereas bldA and bldH were only down-regulated in the SipY mutant strain. Consistently, low temperature scanning electron microscopy revealed that the disruption of sipY had a more noticeable effect in the growth/morphological aspect of the mycelium than that of secG, suggesting that in the sipY mutant, the blockage of the export process might have more severe consequences than in the secG mutant. In both cases, the likely degradation of the proteins that cannot be secreted might provide nutrients that might be responsible for the lack of induction of the bald cascade, which is thought to be triggered under conditions of nutritional limitation.

Certified reference materials for analytical mercury speciation in biological and environmental matrices: do they meet user needs?; a review.

The usefulness of a certified reference material (CRM) for analytical method validation and quality control purposes is attributed mainly to its key properties, namely homogeneity and stability. However, it is also advisable to select suitable CRMs in terms of representativeness. To assess the representativeness of a CRM for analytical mercury speciation, a number of aspects must be considered in regard to the routine samples analyzed: the origin of the matrix, the type of mercury species and the level of concentration. This review critically analyzes the availability of current CRMs for mercury speciation analysis in environmental and biological fields. The characteristics of the CRMs are compared with the matrices and samples covered in papers published in the last five years on mercury speciation, mainly in water, soils, sediments, sewage sludge, seafood, blood, urine and hair.

The fimbrial usher FimD follows the SurA-BamB pathway for its assembly in the outer membrane of Escherichia coli.

Fimbrial ushers are the largest ß-barrel outer membrane proteins (OMPs) known to date, which function in the polymerization of fimbriae and their translocation to the bacterial surface. Folding and assembly of these complex OMPs are not characterized. Here, we investigate the role of periplasmic chaperones (SurA, Skp, DegP, and FkpA) and individual components of the ß-barrel assembly machinery (BAM) complex (BamA, BamB, BamC, and BamE) in the folding of the Escherichia coli FimD usher. The FimD level is dramatically reduced (∼30-fold) in a surA null mutant, but a strong cell envelope stress is constitutively activated with upregulation of DegP (∼10-fold). To demonstrate a direct role of SurA, FimD folding was analyzed in a conditional surA mutant in which SurA expression was controlled. In this strain, FimD is depleted from bacteria in parallel to SurA without significant upregulation of DegP. Interestingly, the dependency on SurA is higher for FimD than for other OMPs. We also demonstrate that a functional BAM complex is needed for folding of FimD. In addition, FimD levels were strongly reduced (∼5-fold) in a mutant lacking the accessory lipoprotein BamB. The critical role of BamB for FimD folding was confirmed by complementation and BamB depletion experiments. Similar to SurA dependency, FimD showed a stronger dependency on BamB than OMPs. On the other hand, folding of FimD was only marginally affected in bamC and bamE mutants. Collectively, our results indicate that FimD usher follows the SurA-BamB pathway for its assembly. The preferential use of this pathway for the folding of OMPs with large ß-barrels is discussed.

Estudio de las alteraciones tiroideasen el embarazo en cuatro zonas básicas de salud de Toledo / Study of the thyroid alterations in pregnancy in four basic health zones in Toledo, Spain

Objetivo: Describir la prevalencia de alteraciones tiroideas en las embarazadas de cuatro zonas básicas de salud (ZBS), así como las características de las gestantes con alteraciones tiroideas respecto de laseutiroideas. Material y métodos: Estudio observacional, descriptivo y transversal, realizado en embarazadas de cuatro ZBS de Toledo. A las gestantes seles pasó un cuestionario al inicio del estudio, y se determinaron las hormonas tiroideas y la tiroperoxidasa (TPO) en la analítica del primer trimestre. No se inició suplementación con yodo hasta la realización de la analítica. Se remitió a las mujeres con alteraciones tiroideas a su médico de familia para efectuar el tratamiento correspondiente. Resultados: Participaron un total de 113 mujeres, con una media de edad (± desviación estándar) de 31,1 ± 5,25 años. Un 17% presentaba alteraciones tiroideas (un 11,7% hipotiroidismo subclínico, un 5,8%hipotiroidismo franco, un 41,1% hipertiroidismo subclínico y un 41,1% elevaciones aisladas de TPO). Observamos alteraciones en el 35% de las mujeres con Rh(–) frente al 12,9% de las Rh(+) (PeF= 0,042). Rozanla significación estadística las siguientes variables: mujeres del grupo AB0 (alteraciones tiroideas en el 30,6% del grupo A frente al12,5% en el grupo 0; p= 0,056), consumo de anticonceptivos orales (el28,6 frente al 12,7% en no consumo; p= 0,059) y edad de la menarquia(14,87 años en las que presentaban hipertiroidismo frente a 12,84 años en las que no lo presentaban; p= 0,056) (AU)

Aim: To describe the prevalence of thyroid alterations in the pregnant women in four basic health zones (BHZ), as well as the characteristics of the women with thyroid alterations compared with healthy women. Material and methods: Observational, descriptive, cross-sectional study of pregnant women of four BHZ in Toledo, Spain. All women were interviewed in the first pregnancy consultation. Athyroid hormones and TPO antibodies determination was carried out in the first trimester analytical. Iodine supplementation was not initiated until the analytical determination. Women found to present thyroid function alterations were derived to their familyphysicians. Results: 113 women, mean age (± standard deviation) 31.1 ± 5.25 years old. 17% thyroid alterations (11.7% subclinical hypothyroidism, 5.8% overt hypothyroidism, 41.1% subclinical hyperthyroidism,41.1% only elevated TPO antibodies). We observed these alterations in 35% of Rh(–) women vs 12.9% of Rh(+) ones (FeT=0.042). There were almost statistically significative differences in AB0 blood group (30.6% thyroid alterations in A group vs 12.5% in0 group; p= 0.056), the intake of oral contraceptives (28.6% vs12.7% in no consumers; p= 0.059) and the age of menarche (14.87years old in hyperthyroidism vs 12.84 years old in no hyperthyroidism;p= 0.056) (AU)

Characterization of the InSTEC’s low-background gamma spectrometer for environmental radioactivity studies / Caracterización del espectrómetro gamma de bajo fondo del INSTEC para estudios de radioactividad ambiental

ABSTRACT The capabilities of the LowBackground Gamma Spectrometer (LBGS) at InSTEC were studied for environmental purposes. Fifty three glines were identified in the LBGS background spectrum. The Minimum Detectable Activity for , , , , and were calculated using the detector’s volumetric efficiency simulated by Monte Carlo method. Validation was performed by absolute and relative analysis of radionuclide activities present in a marine sediment certified material.

RESUMEN Se determinan las potencialidades del Espectrómetro Gamma de Bajo Fondo del InSTEC con fines ambientales. Se identificaron 53 líneas gamma en el espectro de fondo natural del espectrómetro. Se calculan las actividades mínimas detectables para los radionucleidos , , , , and empleando la eficiencia volumétrica del detector simulada por Monte Carlo. Como validación se determinan, por vía absoluta y relativa, las actividades de los radionucleidos presentes en un estándar de sedimento marino.

Integration of new CAPS and dCAPS-RGA markers into a composite chickpea genetic map and their association with disease resistance.

A composite linkage map was constructed based on two interspecific recombinant inbred line populations derived from crosses between Cicer arietinum (ILC72 and ICCL81001) and Cicer reticulatum (Cr5-10 or Cr5-9). These mapping populations segregate for resistance to ascochyta blight (caused by Ascochyta rabiei), fusarium wilt (caused by Fusarium oxysporum f. sp. ciceris) and rust (caused by Uromyces ciceris-arietini). The presence of single nucleotide polymorphisms in ten resistance gene analogs (RGAs) previously isolated and characterized was exploited. Six out of the ten RGAs were novel sequences. In addition, classes RGA05, RGA06, RGA07, RGA08, RGA09 and RGA10 were considerate putatively functional since they matched with several legume expressed sequences tags (ESTs) obtained under infection conditions. Seven RGA PCR-based markers (5 CAPS and 2 dCAPS) were developed and successfully genotyped in the two progenies. Six of them have been mapped in different linkage groups where major quantitative trait loci conferring resistance to ascochyta blight and fusarium wilt have been reported. Genomic locations of RGAs were compared with those of known Cicer R-genes and previously mapped RGAs. Association was detected between RGA05 and genes controlling resistance to fusarium wilt caused by races 0 and 5.

Influence of a Streptomyces lividans SecG functional analogue on protein secretion.

The membrane protein complex translocase mediates the translocation of bacterial proteins. In this complex, the SecY, SecE, and SecG proteins constitute an integral membrane domain. Sequence comparison revealed a potential secG-like gene in the gram-positive soil bacterium Streptomyces lividans. Chromosomal deletion of this gene resulted in a sporulation defect and an overall deficiency in secretion. The SecG-depleted strain was able to overproduce and secrete alpha-amylase, but the appearance of the oversynthesized protein outside the cell was delayed compared to the protein produced by the wildtype strain. SecG deficiency was found to result in more pronounced effects in S. lividans than in Bacillus subtilis or Escherichia coli.

Specific residues in the N-terminal domain of FimH stimulate type 1 fimbriae assembly in Escherichia coli following the initial binding of the adhesin to FimD usher.

Type 1 fimbriae are assembled by the chaperone-usher pathway where periplasmic protein complexes formed between fimbrial subunits and the FimC chaperone are recruited by the outer membrane protein FimD (the usher) for their ordered polymerization and export. FimH adhesin initiates and stimulates type 1 fimbriae polymerization by interacting with FimD. Previously we showed that the N-terminal lectin domain of FimH (N-FimH) is necessary for binding of the adhesin to FimD. In this work, we have selected mutants in N-FimH that reduce the levels of adhesin and type 1 fimbriae displayed in Escherichia coli without altering the levels of FimH in the periplasm. The selected mutations are mostly concentrated in residues G15, N46 and D47. In contrast to other mutations isolated that simply affect binding of FimH to FimD (e.g. C3Y), these variants associate to FimD and alter its susceptibility to trypsin digestion similarly to wild-type FimH. Importantly, their mutant phenotype is rescued when FimD is activated in vivo by the coexpression of wild-type FimH. Altogether, these data indicate that residues G15, N46 and D47 play an important role following initial binding of FimH to FimD for efficient type 1 fimbriae polymerization by this outer membrane usher.

Influence of a Streptomyces lividans SecG functional analogue on protein secretion

The membrane protein complex translocase mediates the translocation of bacterial proteins. In this complex, the SecY, SecE, and SecG proteins constitute an integral membrane domain. Sequence comparison revealed a potential secG-like gene in the gram-positive soil bacterium Streptomyces lividans. Chromosomal deletion of this gene resulted in a sporulation defect and an overall deficiency in secretion. The SecG-depleted strain was able to overproduce and secrete alpha-amylase, but the appearance of the oversynthesized protein outside the cell was delayed compared to the protein produced by the wildtype strain. SecG deficiency was found to result in more pronounced effects in S. lividans than in Bacillus subtilis or Escherichia coli (AU)

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The Streptomyces lividans cytoplasmic signal recognition particle receptor FtsY is involved in protein secretion.

The bacterial version of the mammalian signal recognition particle (SRP) and its receptor alpha-subunit (FtsY) is well conserved and essential to all known bacteria. In gram-negative bacteria, the SRP pathway mediates a co-translational targeting of most inner membrane proteins. Additionally, in Streptomyces lividans, a gram-positive bacterium, SRP also targets secretory proteins to the translocon. The role of S. lividans FtsY has been assessed in this work. Co-immunoprecipitation studies confirmed that FtsY is associated with the S. lividans SRP in the cytoplasm and that this complex also co-immunoprecipitated with pre-agarase, suggesting that the SRP receptor is involved in SRP-mediated targeting of secretory proteins in S. lividans. Furthermore, the SRP remains attached for the most part to the cellular membrane when the cleavage of pre-secretory proteins is severely reduced in a strain lacking the gene coding for the major type-I signal peptidase.

Tratamiento comparativo de la infección por Bastocystis horminis con Metronidazol y Secnidazol / Comparative treatment of the infection for Blastocystis hominis with metronidazol and Secnidazol

Para evaluar el efecto de metronidazol y secnidazol en el tratamiento de la infección por Blastocystis hominis, se realizó un estudio prospectivo en 60 pacientes con tal diagnóstico. El diagnóstico fue establecido clínicamente y confirmado con examen parasitológico seriado en heces. Se tuvo subgrupos de estudio: A, B y C. A: Recibieron metronidazol 250 mg. desayuno, almuerzo y comida por cinco días. B: Recibieron metronidazol 750 mg. desayuno, almuerzo y comida por siete días. C: Recibieron secnidazol 2 gramos como dosis única. Al mes de tratamiento se hizo control de examen parasitológico seriado de heces y varios controles clínicos posterapia. Los síntomas clínicos más frecuentemente encontrados fueron: flatulencia, dolor abdominal, dispepsia, malestar general, diarrea. En cuanto a la evolución después de la terapia: Fue favorable en la mayoría de casos: 75 por ciento en el grupo A, 80 por ciento en el grupo B y C. Se encontró negativización del examen en: 60 por ciento (A), 50 por ciento (B), 65 por ciento (C). Hubo disminución de la población de Blastocystis hominis en el examen de heces 20 por ciento (A), 30 por ciento (B), 20 por ciento (C). Los efectos adversos más frecuentes fueron: dolor epigástrico, disbacteriosis, naúsea, diarrea. Podemos plantear que si se presenta infección por Blastocystis hominis sintomática esta puede ser tratada con Secnidazol o Metronidazol, pués se ha encontrado mejoría en los grupos sometidos a tratamiento. Deben realizarse o llevarse a cabo estudios prospectivos a doble ciego para poder reforzar este hallazgo.