Lactococcus lactis and Lactococcus cremoris are Gram-positive lactic acid bacteria widely used as starter in milk fermentations. Lactococcal cells are covered with a polysaccharide pellicle (PSP) ...that was previously shown to act as the receptor for numerous bacteriophages of the
class. Thus, mutant strains lacking PSP are phage resistant. However, because PSP is a key cell wall component, PSP-negative mutants exhibit dramatic alterations of cell shape and severe growth defects, which limit their technological value. In the present study, we isolated spontaneous mutants with improved growth, from
PSP-negative mutants. These mutants grow at rates similar to the wild-type strain, and based on transmission electron microscopy analysis, they exhibit improved cell morphology compared to their parental PSP-negative mutants. In addition, the selected mutants maintain their phage resistance. Whole-genome sequencing of several such mutants showed that they carried a mutation in
, a gene encoding a penicillin-binding protein involved in peptidoglycan biosynthesis. Our results indicate that lowering or turning off PBP2b activity suppresses the requirement for PSP and ameliorates substantially bacterial fitness and morphology.
Lactococcus lactis and Lactococcus cremoris are widely used in the dairy industry as a starter culture. As such, they are consistently challenged by bacteriophage infections which may result in reduced or failed milk acidification with associated economic losses. Bacteriophage infection starts with the recognition of a receptor at the cell surface, which was shown to be a cell wall polysaccharide (the polysaccharide pellicle PSP) for the majority of lactococcal phages. Lactococcal mutants devoid of PSP exhibit phage resistance but also reduced fitness, since their morphology and division are severely impaired. Here, we isolated spontaneous, food-grade non-PSP-producing
mutants resistant to bacteriophage infection with a restored fitness. This study provides an approach to isolate non-GMO phage-resistant L. cremoris and L. lactis strains, which can be applied to strains with technological functionalities. Also, our results highlight for the first time the link between peptidoglycan and cell wall polysaccharide biosynthesis.
Our study aimed to assess perinatal outcomes and recurrence rate of Chronic Intervillositis of Unknown Etiology (CIUE). We conducted an observational retrospective study in a tertiary care university ...hospital in France from January 1, 1997 to July 31, 2018. 122 pregnancies (102 women) with CIUE were included. Cases of the Department of Histopathology placenta database were re-analysed independently by three pathologists specializing in fetal pathology. Diagnosis of CIUE was confirmed according to: (1) the presence of cellular infiltrate in the intervillous space, (2) ~ 80% of the mononuclear cells in the intervillous space positive for CD68, (3) infiltration occupying at least 5% of the intervillous space, and (4) no clinical or histopathological sign of infection. Outcomes of pregnancies with CIUE (miscarriages, stillbirths, terminations of pregnancy, live birth with or without prematurity or fetal growth restriction) and proportion of CIUE recurrence were analysed. The lost pregnancies comprised 17 (13.9%) miscarriages, 17 (13.9%) stillbirths, and 18 (14.8%) terminations of pregnancy. Of the 70 (57.4%) pregnancies that led to a live birth, 38 (54.3%) new-borns were premature and 50 (72.5%) exhibited fetal growth restriction. Among the 102 women, 23 subsequently became pregnant, half of whom (n = 11) developed recurrent CIUE. CIUE was associated with high rates of adverse perinatal outcomes, including pregnancy loss, fetal growth restriction, and preterm birth with a risk of recurrence nearly 50%.
Yarrowia lipolytica, a nonconventional oleaginous yeast species, has attracted attention due to its high lipid degradation and accumulation capacities. Y. lipolytica is used as a chassis for the ...production of usual and unusual lipids and lipid derivatives. While the genes involved in the intracellular transport and activation of fatty acids in different cellular compartments have been characterized, no genes involved in fatty acid transport from the extracellular medium into the cell have been identified thus far. In this study, we identified secreted proteins involved in extracellular fatty acid binding. Recent analysis of the Y. lipolytica secretome led to the identification of a multigene family that encodes four secreted proteins, preliminarily named UP1 to UP4. These proteins were efficiently overexpressed individually in wild-type and multideletant strain (Q4: DELAup1DELAup2DELAup3DELAup4) backgrounds. Phenotypic analysis demonstrated the involvement of these proteins in the binding of extracellular fatty acids. Additionally, gene deletion and overexpression prevented and promoted sensitivity to octanoic acid (C8) toxicity, respectively. The results suggested binding is dependent on aliphatic chain length and fatty acid concentration. 3D structure modeling supports the proteins' role in fatty acid assimilation at the molecular level. We discovered a family of extracellular-fatty-acid-binding proteins in Y. lipolytica and have proposed to name its members eFbp1 to eFbp4. The exact mode of eFbps action remains to be deciphered individually and synergistically; nevertheless, it is expected that the proteins will have applications in lipid biotechnology, such as improving fatty acid production and/or bioconversion.
Depuis ces dernières années, les écoles francophones en Alberta, province de l’ouest canadien, sont marquées par une diversification ethnoculturelle importante de leur population scolaire, reflétant ...ainsi les changements migratoires récents au Canada. La population scolaire d’un conseil scolaire francophone situé dans une agglomération de l’Alberta reflète ces nouvelles tendances migratoires, puisqu’un portrait ethno-démographique partiel réalisé en 2003 dans six de ses écoles signale que 50 % des élèves sont issus de l’immigration et proviennent de 23 pays différents ; majoritairement des pays de l’Afrique subsaharienne. Cette réalité démographique, qui se confirme plus d’une décennie plus tard, représente un changement structurel majeur pour les écoles francophones. En Alberta, comme dans d’autres provinces canadiennes, l’inclusion est au cœur du discours et des pratiques éducatives. À visée transformative, elle entend favoriser la prise en compte de la diversité ethnoculturelle en salle de classe et l’égalité des chances par le biais de pratiques scolaires d’équité. Cet article se concentre sur la mise en place, en milieu francophone minoritaire, du dispositif des travailleurs en établissement en école (TEE) dans les établissements chargés de faire le lien entre les cultures familiales, communautaires et scolaires. L’analyse des entrevues de quatre de ces travailleurs éclaire, de leurs perspectives, les défis rencontrés par les élèves et les familles immigrantes dans leur processus d’adaptation à l’école franco-albertaine, ainsi que les stratégies de soutien qui leur sont apportées pour les relever.
In recent years, Francophone schools in Alberta, a province in western Canada, have seen significant ethno-cultural diversification of their school population, thus reflecting recent migratory changes in Canada. The school population of a Francophone school board located in an agglomeration of Alberta reflects these new migratory trends. A partial ethno-demographic portrait carried out in 2003 in six of its schools indicates that 50% of the pupils come from an immigrant background and come from 23 different countries; mostly from sub-Saharan African countries. This demographic reality, confirmed more than a decade later, represents a major structural change for Francophone schools. In Alberta, as in other Canadian provinces, inclusion is at the heart of discourse and educational practices. With a transformative aim, it intends to promote ethno-cultural diversity in the classroom and equal opportunities through school equity practices. This article focuses on the Settlement workers in schools responsible for bridging family, community and school cultures. The analysis of the interviews of the four workers sheds light on and questions both the institutional practices and the personal strategies put in place to face the challenges encountered in this tripartite collaboration.
Mycobacterium tuberculosis is the etiological agent of tuberculosis (TB), one of the deadliest infectious diseases. The alarming health context coupled with the emergence of resistant M. tuberculosis ...strains highlights the urgent need to expand the range of anti-TB antibiotics. A subset of anti-TB drugs in use are prodrugs that require bioactivation by a class of M. tuberculosis enzymes called Baeyer-Villiger monooxygenases (BVMOs), which remain understudied. To examine the prevalence and the molecular function of BVMOs in mycobacteria, we applied a comprehensive bioinformatic analysis that identified six BVMOs in M. tuberculosis, including Rv3083 (MymA), Rv3854c (EthA), Rv0565c, and Rv0892, which were selected for further characterization. Homology modeling and substrate docking analysis, performed on this subset, suggested that Rv0892 is closer to the cyclohexanone BVMO, while Rv0565c and EthA are structurally and functionally similar to MymA, which is by far the most prominent type I BVMO enzyme. Thanks to an unprecedented purification and assay optimization, biochemical studies confirmed that all four BVMOs display BV-oxygenation activity. We also showed that MymA displays a distinctive substrate preference that we further investigated by kinetic parameter determination and that correlates with
modeling. We provide insights into distribution of BVMOs and the structural basis of their substrate profiling, and we discuss their possible redundancy in M. tuberculosis, raising questions about their versatility in prodrug activation and their role in physiology and infection.
Tuberculosis (TB), caused by Mycobacterium tuberculosis, is one of the leading causes of death worldwide. The rise in drug resistance highlights the urgent need for innovation in anti-TB drug development. Many anti-TB drugs require bioactivation by Baeyer-Villiger monooxygenases (BVMOs). Despite their emerging importance, BVMO structural and functional features remain enigmatic. We applied a comprehensive bioinformatic analysis and confirmed the presence of six BVMOs in M. tuberculosis, including MymA, EthA, and Rv0565c-activators of the second-line prodrug ethionamide-and the novel BVMO Rv0892. Combining
characterization with
validation, we outlined their structural framework and substrate preference. Markedly, MymA displayed an enhanced capacity and a distinct selectivity profile toward ligands, in agreement with its catalytic site topology. These features ground the molecular basis for structure-function comprehension of the specificity in these enzymes and expand the repertoire of BVMOs with selective and/or overlapping activity for application in the context of improving anti-TB therapy.
Prenatal testicular torsion is a very rare morbid entity, described in the literature to occur when the testicle is intrascrotal, around the 34th week of gestation. Here we report a case of early ...testicular necrosis. This male fetus was the product of a medical abortion at 27 weeks. During evisceration, a left testicular nubbin free in the peritoneal cavity was found. Histologically, it was extensively necrotic. Because of the location, the size, and the histological features of this necrotic testicle, we conclude that it was the result of torsion of the pedicle that occurred around the 20th week of pregnancy.
Background
The objective of this retrospective study was to identify prognostic, diagnostic, and therapeutic disparities between younger (≤40 years) and older (>40 years) women with ductal carcinoma ...in situ (DCIS) of the breast.
Methods
From 1971 to 2001, all patients treated for DCIS at Institut Bergonié were included in our analyses. Follow-up data was collected over 10 years. We used univariate and multivariate analyses to investigate patient-, disease-, and treatment-related factors predictive of diagnostic, histological, therapeutic, and prognostic DCIS criteria.
Results
A total of 812 patients were eligible including 731 women aged >40 years and 81 women ≤40 years. Younger women with DCIS were more likely to receive a mastectomy and less likely to receive radiotherapy. Young age and initial surgical treatment (lumpectomy and especially nonfree margins) were revealed as predictive of recurrence in multivariate analyses.
Conclusions
Young age represents a recurrence risk independent of histological and clinical characteristics of the tumor. Initial treatment, especially for nonfree margins, is also a predictive factor. Appropriate initial surgery with particularly wide margins appears essential for the treatment of young women with DCIS.
Koolen-de Vries syndrome (MIM#610443) is a rare microdeletion syndrome involving the 17q21.31 region, which was first described by Koolen in 2006. Clinical and behavioral characteristics have been ...extensively reported from more than 100 postnatal cases including infants, children and young adults. The syndrome is highly clinically heterogeneous, but the main features associate characteristic cranio-facial dysmorphism, heart defects, limb, skeletal, genito-urinary anomalies, along with intellectual disability with early childhood epilepsy and behavioral disturbances. Central nervous system malformations usually consist in hydrocephalus and thin corpus callosum. We report herein an early fetal case with an apparently isolated abnormal corpus callosum diagnosed by ultrasonography, for which a medical termination of the pregnancy was achieved at 22 weeks of gestation. Postmortem examination displayed facial dysmorphism consisting of hypertelorism, short philtrum and flat and broad nose, cleft palate and left duplex ureter. Neuropathological examination revealed a mega corpus callosum that has never been reported so far in this syndrome. Array-CGH performed on thymic DNA tissue revealed a 17q21.31 microdeletion, which allowed for the confirmation of early occurring Koolen-de Vries syndrome.
Depuis ces dernières années, les écoles francophones en Alberta, province de l’ouest canadien, sont marquées par une diversification ethnoculturelle importante de leur population scolaire, reflétant ...ainsi les changements migratoires récents au Canada. La population scolaire d’un conseil scolaire francophone situé dans une agglomération de l’Alberta reflète ces nouvelles tendances migratoires, puisqu’un portrait ethno-démographique partiel réalisé en 2003 dans six de ses écoles signale que 50 % des élèves sont issus de l’immigration et proviennent de 23 pays différents ; majoritairement des pays de l’Afrique subsaharienne. Cette réalité démographique, qui se confirme plus d’une décennie plus tard, représente un changement structurel majeur pour les écoles francophones. En Alberta, comme dans d’autres provinces canadiennes, l’inclusion est au cœur du discours et des pratiques éducatives. À visée transformative, elle entend favoriser la prise en compte de la diversité ethnoculturelle en salle de classe et l’égalité des chances par le biais de pratiques scolaires d’équité. Cet article se concentre sur la mise en place, en milieu francophone minoritaire, du dispositif des travailleurs en établissement en école (TEE) dans les établissements chargés de faire le lien entre les cultures familiales, communautaires et scolaires. L’analyse des entrevues de quatre de ces travailleurs éclaire, de leurs perspectives, les défis rencontrés par les élèves et les familles immigrantes dans leur processus d’adaptation à l’école franco-albertaine, ainsi que les stratégies de soutien qui leur sont apportées pour les relever.
Multiple becomings in digital story creation Dagenais, Diane; Brisson, Geneviève; André, Gwénaëlle ...
Language and intercultural communication,
09/2020, Letnik:
20, Številka:
5
Journal Article
Recenzirano
Using ethnographic approaches, we document encounters of humans and materials in environments where a digital tool was used to create multilingual and multimodal stories. Thinking with theories of ...the sociomaterial and concepts of agencement and becoming (Deleuze & Guattari, 1987), we reflect on identity construction as a collective process of coming into being. To do so, we examine relationships formed among young children, adults, digital devices and platforms, language and literacy norms, as well as discourses about monolingualism, multilingualism and literacy instruction to better understand how they converge during story creation.
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