Use of five probiotic strains to determine sensitivity in vitro on pathogenic bacteria growth isolated from sick fishes

ABSTRACT Ornamental aquaculture is an activity in clear economic growth, both globally and in Mexico where the development is particularly relevant to freshwater species. Infectious diseases produced by fungus, bacteria and virus are considered one of the principal limitations during the productive process. Between implemented strategies for reduction of antibiotic use, which are "living microorganisms that confer a health benefit to the host if they are given in adequate quantities"; lactic acid bacteria and yeast are among the most common used microorganism in aquaculture. This investigation, prove the effect of isolated probiotic bacteria from the digestive tract of healthy fish, belonging to specie: Bacillus sp., Bacillus laterosporus, Bacillus subtilis, Lactobacillus sp, and Lactococcus lactis, at different dilutions (10 9 ,10 8 , 10 7 ,10 6 , 10 5 and 10 4 ) in vitro growth of pathogenic bacteria: Citrobacter freundii, Enterobacter sakasakii, Klebsiella oxytoca, Proteus vulgaris, and Vibrio fluvialis, isolated from kidney of sick fish, cultured and purified through successive inoculations and identificated by the amplification of gene 16S of rRNA (PCR) using universal primers 8 for. (5'-AGACTTTGATCATGGCTCAG-3') and 1492 rev. (5'-TACGGCTACCTTGTTACGACTT-3') and comparison with GENEBANK sequences base. Probiotic strains were previously isolated from the digestive tract of different healthy fish in the laboratory. In order to perform in vitro challenge tests, pathogenic strains were inoculated three times each in BHI agar boxes at a concentration of 1x10 7 CFU mL -1 and subsequently using the well diffusion method, 70 µL from a suspension with each of the probiotic strains were added. Agar boxes were incubated 24 h at 30ºC to observe the formation of inhibition halos. Obtained values from inhibition halos were transformed to qualitative data with the following premise: halo diameter < 2.0 mm negative effect; halo diameter > 2.0 mm positive effect. In this study, it was determined that probiotic strains B. subtilis was the one that gave better results to inhibit the growth of pathogenic bacteria P. vulgaris, E. sakazakii, V. fluvialis, K. oxytoca and C. freundii in most of used dilutions. Making it a strain with high potential in aquaculture. Key words: Growth, halos, probiotics, bacteria, sensibility. RESUMEN La acuicultura de especies ornamentales es una actividad económica en franco crecimiento, tanto a nivel mundial como en México, en donde tiene particular desarrollo lo correspondiente a especies dulceacuícolas. Las enfermedades infeccionas producidas por hongos, bacterias y virus, están consideradas una de las limitantes principales durante el proceso productivo. Entre las estrategias implementadas para disminuir el uso de antibióticos para el control de patógenos, se encuentra el control biológico mediante el uso de organismos probióticos, los cuales son "microorganismos vivos los cuales, administrados en cantidades adecuadas, confieren un beneficio en la salud del hospedador"; entre los de uso más común en acuicultura se encuentran las lactobacterias y las levaduras. En el presente trabajo, se probó el efecto de bacterias probióticas aisladas del tracto digestivo de peces sanos, pertenecientes a las especies: Bacillus sp., Bacillus laterosporus, Bacillus subtilis, Lactobacillus sp, y Lactococcus lactis, a diferentes diluciones (10 9 ,10 8 , 10 7 ,10 6 , 10 5 y 10 4 ) en el crecimiento in vitro de las bacterias patógenas: Citrobacter freundii, Enterobacter sakasakii, Klebsiella oxytoca, Proteus vulgaris y Vibrio fluvialis, aisladas del riñón de peces enfermos, cultivadas y purificadas a través de resiembras sucesivas e identificadas mediante la amplificación del gen 16S del ARNr (PCR) utilizando los primers universales 8 for. 24 AGACTTTGATCATGGCTCAG-3') y 1492 rev. (5'-TACGGCTACCTTGTTACGACTT-3') y su comparación con la base de secuencias GENEBANK. Las cepas probióticos fueron aisladas previamente del tracto intestinal de diversos peces sanos en el laboratorio. Para llevar a cabo las pruebas de desafío in vitro, las cepas patógenas se sembraron por triplicado en cajas de agar BHI a una concentración de 1x10 7 UFC mL -1 y posteriormente, utilizando el método de difusión en pozos, se adicionaran 70 µL de una suspensión con cada una de las cepas probióticas Las placas se incubaron durante 24 h a 30ºC para observar la formación de halos de inhibición. Los valores obtenidos de los halos de inhibición fueron transformados a datos cualitativos con la siguiente premisa: diámetro halo < 2.0 mm efecto negativo; diámetro de halo > 2.0 mm efecto positivo. En este estudio, se determinó que la cepas probiótica B. subtilis fue la que dio mejores resultados al inhibir el crecimiento de las bacterias patógenas P. vulgaris, E. sakazakii, V. fluvialis, K. oxytoca y C. freundii en la mayoría de las diluciones utilizadas. Por lo que es una cepa con alto potencial en acuicultura

Performance of the 2007 WHO Algorithm to diagnose Smear-negative Pulmonary Tuberculosis in a HIV prevalent setting

The 2007 WHO algorithm for diagnosis of smear-negative pulmonary tuberculosis (PTB) including Mycobacterium tuberculosis (MTB) culture was evaluated in a HIV prevalent area of Kenya

Radiographers supporting radiologists in the interpretation of screening mammography: a viable strategy to meet the shortage in the number of radiologists.

BackgroundAn alternative approach to the traditional model of radiologists interpreting screening mammography is necessary due to the shortage of radiologists to interpret screening mammograms in many countries.MethodsWe evaluated the performance of 15 Mexican radiographers, also known as radiologic technologists, in the interpretation of screening mammography after a 6 months training period in a screening setting. Fifteen radiographers received 6 months standardized training with radiologists in the interpretation of screening mammography using the Breast Imaging Reporting and Data System (BI-RADS) system. A challenging test set of 110 cases developed by the Breast Cancer Surveillance Consortium was used to evaluate their performance. We estimated sensitivity, specificity, false positive rates, likelihood ratio of a positive test (LR+) and the area under the subject-specific Receiver Operating Characteristic (ROC) curve (AUC) for diagnostic accuracy. A mathematical model simulating the consequences in costs and performance of two hypothetical scenarios compared to the status quo in which a radiologist reads all screening mammograms was also performed.ResultsRadiographer's sensitivity was comparable to the sensitivity scores achieved by U.S. radiologists who took the test but their false-positive rate was higher. Median sensitivity was 73.3 % (Interquartile range, IQR: 46.7-86.7 %) and the median false positive rate was 49.5 % (IQR: 34.7-57.9 %). The median LR+ was 1.4 (IQR: 1.3-1.7 %) and the median AUC was 0.6 (IQR: 0.6-0.7). A scenario in which a radiographer reads all mammograms first, and a radiologist reads only those that were difficult for the radiographer, was more cost-effective than a scenario in which either the radiographer or radiologist reads all mammograms.ConclusionsGiven the comparable sensitivity achieved by Mexican radiographers and U.S. radiologists on a test set, screening mammography interpretation by radiographers appears to be a possible adjunct to radiologists in countries with shortages of radiologists. Further studies are required to assess the effectiveness of different training programs in order to obtain acceptable screening accuracy, as well as the best approaches for the use of non-physician readers to interpret screening mammography

Transcriptome profiling of grapevine seedless segregants during berry development reveals candidate genes associated with berry weight

Indexación: Web of Science; PubMedBackground Berry size is considered as one of the main selection criteria in table grape breeding programs. However, this is a quantitative and polygenic trait, and its genetic determination is still poorly understood. Considering its economic importance, it is relevant to determine its genetic architecture and elucidate the mechanisms involved in its expression. To approach this issue, an RNA-Seq experiment based on Illumina platform was performed (14 libraries), including seedless segregants with contrasting phenotypes for berry weight at fruit setting (FST) and 6–8 mm berries (B68) phenological stages. Results A group of 526 differentially expressed (DE) genes were identified, by comparing seedless segregants with contrasting phenotypes for berry weight: 101 genes from the FST stage and 463 from the B68 stage. Also, we integrated differential expression, principal components analysis (PCA), correlations and network co-expression analyses to characterize the transcriptome profiling observed in segregants with contrasting phenotypes for berry weight. After this, 68 DE genes were selected as candidate genes, and seven candidate genes were validated by real time-PCR, confirming their expression profiles. Conclusions We have carried out the first transcriptome analysis focused on table grape seedless segregants with contrasting phenotypes for berry weight. Our findings contributed to the understanding of the mechanisms involved in berry weight determination. Also, this comparative transcriptome profiling revealed candidate genes for berry weight which could be evaluated as selection tools in table grape breeding programs.http://bmcplantbiol.biomedcentral.com/articles/10.1186/s12870-016-0789-

New approaches to measuring anthelminthic drug efficacy: parasitological responses of childhood schistosome infections to treatment with praziquantel

By 2020, the global health community aims to control and eliminate human helminthiases, including schistosomiasis in selected African countries, principally by preventive chemotherapy (PCT) through mass drug administration (MDA) of anthelminthics. Quantitative monitoring of anthelminthic responses is crucial for promptly detecting changes in efficacy, potentially indicative of emerging drug resistance. Statistical models offer a powerful means to delineate and compare efficacy among individuals, among groups of individuals and among populations.; We illustrate a variety of statistical frameworks that offer different levels of inference by analysing data from nine previous studies on egg counts collected from African children before and after administration of praziquantel.; We quantify responses to praziquantel as egg reduction rates (ERRs), using different frameworks to estimate ERRs among population strata, as average responses, and within strata, as individual responses. We compare our model-based average ERRs to corresponding model-free estimates, using as reference the World Health Organization (WHO) 90 % threshold of optimal efficacy. We estimate distributions of individual responses and summarize the variation among these responses as the fraction of ERRs falling below the WHO threshold.; Generic models for evaluating responses to anthelminthics deepen our understanding of variation among populations, sub-populations and individuals. We discuss the future application of statistical modelling approaches for monitoring and evaluation of PCT programmes targeting human helminthiases in the context of the WHO 2020 control and elimination goals

Diversity of isoprene-degrading bacteria in phyllosphere and soil communities from a high isoprene-emitting environment: a Malaysian oil palm plantation

Background: Isoprene is the most abundantly produced biogenic volatile organic compound (BVOC) on Earth, with annual global emissions almost equal to those of methane. Despite its importance in atmospheric chemistry and climate, little is known about the biological degradation of isoprene in the environment. The largest source of isoprene is terrestrial plants, and oil palms, the cultivation of which is expanding rapidly, are among the highest isoprene-producing trees. Results: DNA stable isotope probing (DNA-SIP) to study the microbial isoprene-degrading community associated with oil palm trees revealed novel genera of isoprene-utilising bacteria including Novosphingobium, Pelomonas, Rhodoblastus, Sphingomonas and Zoogloea in both oil palm soils and on leaves. Amplicon sequencing of isoA genes, which encode the α-subunit of the isoprene monooxygenase (IsoMO), a key enzyme in isoprene metabolism, confirmed that oil palm trees harbour a novel diversity of isoA sequences. In addition, metagenome assembled genomes (MAGs) were reconstructed from oil palm soil and leaf metagenomes and putative isoprene degradation genes were identified. Analysis of unenriched metagenomes showed that isoA-containing bacteria are more abundant in soils than in the oil palm phyllosphere. Conclusion: This study greatly expands the known diversity of bacteria that can metabolise isoprene and contributes to a better understanding of the biological degradation of this important but neglected climate-active gas

Using a limited mapping strategy to identify major QTLs for resistance to grapevine powdery mildew (Erysiphe necator) and their use in marker-assisted breeding

A limited genetic mapping strategy based on simple sequence repeat (SSR) marker data was used with five grape populations segregating for powdery mildew (Erysiphe necator) resistance in an effort to develop genetic markers from multiple sources and enable the pyramiding of resistance loci. Three populations derived their resistance from Muscadinia rotundifolia ‘Magnolia’. The first population (06708) had 97 progeny and was screened with 137 SSR markers from seven chromosomes (4, 7, 9, 12, 13, 15, and 18) that have been reported to be associated with powdery or downy mildew resistance. A genetic map was constructed using the pseudo-testcross strategy and QTL analysis was carried out. Only markers from chromosome 13 and 18 were mapped in the second (04327) and third (06712) populations, which had 47 and 80 progeny, respectively. Significant QTLs for powdery mildew resistance with overlapping genomic regions were identified for different tissue types (leaf, stem, rachis, and berry) on chromosome 18, which distinguishes the resistance in ‘Magnolia’ from that present in other accessions of M. rotundifolia and controlled by the Run1 gene on chromosome 12. The ‘Magnolia’ resistance locus was termed as Run2.1. Powdery mildew resistance was also mapped in a fourth population (08391), which had 255 progeny and resistance from M. rotundifolia ‘Trayshed’. A locus accounting for 50% of the phenotypic variation mapped to chromosome 18 and was named Run2.2. This locus overlapped the region found in the ‘Magnolia’-based populations, but the allele sizes of the flanking markers were different. ‘Trayshed’ and ‘Magnolia’ shared at least one allele for 68% of the tested markers, but alleles of the other 32% of the markers were not shared indicating that the two M. rotundifolia selections were very different. The last population, 08306 with 42 progeny, derived its resistance from a selection Vitis romanetii C166-043. Genetic mapping discovered a major powdery mildew resistance locus termed Ren4 on chromosome 18, which explained 70% of the phenotypic variation in the same region of chromosome 18 found in the two M. rotundifolia resistant accessions. The mapping results indicate that powdery mildew resistance genes from different backgrounds reside on chromosome 18, and that genetic markers can be used as a powerful tool to pyramid these loci and other powdery mildew resistance loci into a single line

Characterising the KMP-11 and HSP-70 recombinant antigens' humoral immune response profile in chagasic patients

11 pages, 6 figures.-- The pre-publication history for this paper can be accessed here: http://www.biomedcentral.com/1471-2334/9/186/pre pubBackground: Antigen specificity and IgG subclass could be significant in the natural history of Chagas' disease. The relationship between the different stages of human Chagas' disease and the profiles of total IgG and its subclasses were thus analysed here; they were directed against a crude T. cruzi extract and three recombinant antigens: the T. cruzi kinetoplastid membrane protein-11 (rKMP-11), an internal fragment of the T. cruzi HSP-70 protein192-433, and the entire Trypanosoma rangeli HSP-70 protein. Methods: Seventeen Brazilian acute chagasic patients, 50 Colombian chronic chagasic patients (21 indeterminate and 29 cardiopathic patients) and 30 healthy individuals were included. Total IgG and its subtypes directed against the above-mentioned recombinant antigens were determined by ELISA tests. Results: The T. cruzi KMP-11 and T. rangeli HSP-70 recombinant proteins were able to distinguish both acute from chronic chagasic patients and infected people from healthy individuals. Specific antibodies to T. cruzi crude antigen in acute patients came from IgG3 and IgG4 subclasses whereas IgG1 and IgG3 were the prevalent isotypes in indeterminate and chronic chagasic patients. By contrast, the specific prominent antibodies in all disease stages against T. cruzi KMP-11 and T. rangeli HSP-70 recombinant antigens were the IgG1 subclass.This work was supported by Colciencias Research project No. 1203-333- 18692. IDF was supported by Colciencias and the Universidad Javeriana's Young Researcher 2008 Programme (Bogotá, Colombia). MCT and MCL were supported by P06-CTS-02242 Grant from PAI (Junta de Andalucia) and RICET-RD06/0021-0014, Spain. MS received financial support from the Brazilian agency - CNPq.Peer reviewe

Specific Marking of hESCs-Derived Hematopoietic Lineage by WAS-Promoter Driven Lentiviral Vectors

Genetic manipulation of human embryonic stem cells (hESCs) is instrumental for tracing lineage commitment and to studying human development. Here we used hematopoietic-specific Wiskott-Aldrich syndrome gene (WAS)-promoter driven lentiviral vectors (LVs) to achieve highly specific gene expression in hESCs-derived hematopoietic cells. We first demonstrated that endogenous WAS gene was not expressed in undifferentiated hESCs but was evident in hemogenic progenitors (CD45−CD31+CD34+) and hematopoietic cells (CD45+). Accordingly, WAS-promoter driven LVs were unable to express the eGFP transgene in undifferentiated hESCs. eGFP+ cells only appeared after embryoid body (EB) hematopoietic differentiation. The phenotypic analysis of the eGFP+ cells showed marking of different subpopulations at different days of differentiation. At days 10–15, AWE LVs tag hemogenic and hematopoietic progenitors cells (CD45−CD31+CD34dim and CD45+CD31+CD34dim) emerging from hESCs and at day 22 its expression became restricted to mature hematopoietic cells (CD45+CD33+). Surprisingly, at day 10 of differentiation, the AWE vector also marked CD45−CD31low/−CD34− cells, a population that disappeared at later stages of differentiation. We showed that the eGFP+CD45−CD31+ population generate 5 times more CD45+ cells than the eGFP−CD45−CD31+ indicating that the AWE vector was identifying a subpopulation inside the CD45−CD31+ cells with higher hemogenic capacity. We also showed generation of CD45+ cells from the eGFP+CD45−CD31low/−CD34− population but not from the eGFP−CD45−CD31low/−CD34− cells. This is, to our knowledge, the first report of a gene transfer vector which specifically labels hemogenic progenitors and hematopoietic cells emerging from hESCs. We propose the use of WAS-promoter driven LVs as a novel tool to studying human hematopoietic development

Chagas Cardiomyopathy Manifestations and Trypanosoma cruzi Genotypes Circulating in Chronic Chagasic Patients

Chagas disease caused by Trypanosoma cruzi is a complex disease that is endemic and an important problem in public health in Latin America. The T. cruzi parasite is classified into six discrete taxonomic units (DTUs) based on the recently proposed nomenclature (TcI, TcII, TcIII, TcIV, TcV and TcVI). The discovery of genetic variability within TcI showed the presence of five genotypes (Ia, Ib, Ic, Id and Ie) related to the transmission cycle of Chagas disease. In Colombia, TcI is more prevalent but TcII has also been reported, as has mixed infection by both TcI and TcII in the same Chagasic patient. The objectives of this study were to determine the T. cruzi DTUs that are circulating in Colombian chronic Chagasic patients and to obtain more information about the molecular epidemiology of Chagas disease in Colombia. We also assessed the presence of electrocardiographic, radiologic and echocardiographic abnormalities with the purpose of correlating T. cruzi genetic variability and cardiac disease. Molecular characterization was performed in Colombian adult chronic Chagasic patients based on the intergenic region of the mini-exon gene, the 24Sα and 18S regions of rDNA and the variable region of satellite DNA, whereby the presence of T.cruzi I, II, III and IV was detected. In our population, mixed infections also occurred, with TcI-TcII, TcI-TcIII and TcI-TcIV, as well as the existence of the TcI genotypes showing the presence of genotypes Ia and Id. Patients infected with TcI demonstrated a higher prevalence of cardiac alterations than those infected with TcII. These results corroborate the predominance of TcI in Colombia and show the first report of TcIII and TcIV in Colombian Chagasic patients. Findings also indicate that Chagas cardiomyopathy manifestations are more correlated with TcI than with TcII in Colombia