New insights about phenotypic heterogeneity within Propionibacterium freudenreichii argue against its division into subspecies

Propionibacterium freudenreichii is widely used in Swiss-type cheese manufacture, where it contributes to flavour and eye development. It is currently divided into two subspecies, according to the phenotype for lactose fermentation and nitrate reduction (lac+/nit- and lac-/nit+ for P. freudenreichii subsp. shermanii and subsp. freudenreichii, respectively). However, the existence of unclassifiable strains (lac+/nit+ and lac-/nit-) has also been reported. The aim of this study was to revisit the relevance of the subdivision of P. freudenreichii into subspecies, by confirming the existence of unclassifiable strains. Relevant conditions to test the ability of P. freudenreichii for lactose fermentation and nitrate reduction were first determined, by using 10 sequenced strains, in which the presence or absence of the lactose and nitrate genomic islands were known. We also determined whether the subdivision based on lac/nit phenotype was related to other phenotypic properties of interest in cheese manufacture, in this case, the production of aroma compounds, analysed by gas chromatography-mass spectrometry, for a total of 28 strains. The results showed that a too short incubation time can lead to false negative for lactose fermentation and nitrate reduction. They confirmed the existence of four lac/nit phenotypes instead of the two expected, thus leading to 13 unclassifiable strains out of the 28 characterized (7 lac+/nit+ and 6 lac-/nit-). The production of the 15 aroma compounds detected in all cultures varied more within a lac/nit phenotype (up to 20 times) than between them. Taken together, these results demonstrate that the division of P. freudenreichii into two subspecies does not appear to be relevant.Fil: de Freitas, Rosangela. Universidade Federal de Viçosa. Departamento de Tecnologia de Alimentos; Brasil. Institut National de la Recherche Agronomique; Francia. Science et Technologie du Lait et de l; FranciaFil: Madec, Marie Noelle. Institut National de la Recherche Agronomique; Francia. Science et Technologie du Lait et de l; FranciaFil: Chuat, Victoria. Institut National de la Recherche Agronomique; Francia. Science et Technologie du Lait et de l; FranciaFil: Maillard, Marie Bernadette. Institut National de la Recherche Agronomique; Francia. Science et Technologie du Lait et de l; FranciaFil: Abeijon Mukdsi, Maria Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Centro de Referencia para Lactobacilos (i); Argentina. Institut National de la Recherche Agronomique; Francia. Science et Technologie du Lait et de l; FranciaFil: Falentin, Hélène. Institut National de la Recherche Agronomique; Francia. Science et Technologie du Lait et de l; FranciaFil: Carvalho, Antonio Fernandes de. Universidade Federal de Viçosa. Departamento de Tecnologia de Alimentos; BrasilFil: Valence, Florence. Institut National de la Recherche Agronomique; Francia. Science et Technologie du Lait et de l; FranciaFil: Thierry, Anne. Institut National de la Recherche Agronomique; Francia. Science et Technologie du Lait et de l; Franci

A Temporal -omic Study of Propionibacterium freudenreichii CIRM-BIA1T Adaptation Strategies in Conditions Mimicking Cheese Ripening in the Cold

Propionibacterium freudenreichii is used as a ripening culture in Swiss cheese manufacture. It grows when cheeses are ripened in a warm room (about 24°C). Cheeses with an acceptable eye formation level are transferred to a cold room (about 4°C), inducing a marked slowdown of propionic fermentation, but P. freudenreichii remains active in the cold. To investigate the P. freudenreichii strategies of adaptation and survival in the cold, we performed the first global gene expression profile for this species. The time-course transcriptomic response of P. freudenreichii CIRM-BIA1T strain was analyzed at five times of incubation, during growth at 30°C then for 9 days at 4°C, under conditions preventing nutrient starvation. Gene expression was also confirmed by RT-qPCR for 28 genes. In addition, proteomic experiments were carried out and the main metabolites were quantified. Microarray analysis revealed that 565 genes (25% of the protein-coding sequences of P. freudenreichii genome) were differentially expressed during transition from 30°C to 4°C (P<0.05 and |fold change|>1). At 4°C, a general slowing down was observed for genes implicated in the cell machinery. On the contrary, P. freudenreichii CIRM-BIA1T strain over-expressed genes involved in lactate, alanine and serine conversion to pyruvate, in gluconeogenesis, and in glycogen synthesis. Interestingly, the expression of different genes involved in the formation of important cheese flavor compounds, remained unchanged at 4°C. This could explain the contribution of P. freudenreichii to cheese ripening even in the cold. In conclusion, P. freudenreichii remains metabolically active at 4°C and induces pathways to maintain its long-term survival

The Complete Genome of Propionibacterium freudenreichii CIRM-BIA1T, a Hardy Actinobacterium with Food and Probiotic Applications

Background: Propionibacterium freudenreichii is essential as a ripening culture in Swiss-type cheeses and is also considered for its probiotic use [1]. This species exhibits slow growth, low nutritional requirements, and hardiness in many habitats. It belongs to the taxonomic group of dairy propionibacteria, in contrast to the cutaneous species P. acnes. The genome of the type strain, P. freudenreichii subsp. shermanii CIRM-BIA1 (CIP 103027T), was sequenced with an 11-fold coverage. Methodology/Principal Findings: The circular chromosome of 2.7 Mb of the CIRM-BIA1 strain has a GC-content of 67% and contains 22 different insertion sequences (3.5% of the genome in base pairs). Using a proteomic approach, 490 of the 2439 predicted proteins were confirmed. The annotation revealed the genetic basis for the hardiness of P. freudenreichii, as the bacterium possesses a complete enzymatic arsenal for de novo biosynthesis of aminoacids and vitamins (except panthotenate and biotin) as well as sequences involved in metabolism of various carbon sources, immunity against phages, duplicated chaperone genes and, interestingly, genes involved in the management of polyphosphate, glycogen and trehalose storage. The complete biosynthesis pathway for a bifidogenic compound is described, as well as a high number of surface proteins involved in interactions with the host and present in other probiotic bacteria. By comparative genomics, no pathogenicity factors found in P. acnes or in other pathogenic microbial species were identified in P. freudenreichii, which is consistent with the Generally Recognized As Safe and Qualified Presumption of Safety status of P. freudenreichii. Various pathways for formation of cheese flavor compounds were identified: the Wood-Werkman cycle for propionic acid formation, amino acid degradation pathways resulting in the formation of volatile branched chain fatty acids, and esterases involved in the formation of free fatty acids and esters. Conclusions/Significance: With the exception of its ability to degrade lactose, P. freudenreichii seems poorly adapted to dairy niches. This genome annotation opens up new prospects for the understanding of the P. freudenreichii probiotic activity

Infection of Semen-Producing Organs by SIV during the Acute and Chronic Stages of the Disease

International audienceBACKGROUND: Although indirect evidence suggests the male genital tract as a possible source of persistent HIV shedding in semen during antiretroviral therapy, this phenomenon is poorly understood due to the difficulty of sampling semen-producing organs in HIV+ asymptomatic individuals. METHODOLOGY/PRINCIPAL FINDINGS: Using a range of molecular and cell biological techniques, this study investigates SIV infection within reproductive organs of macaques during the acute and chronic stages of the disease. We demonstrate for the first time the presence of SIV in the testes, epididymides, prostate and seminal vesicles as early as 14 days post-inoculation. This infection persists throughout the chronic stage and positively correlates with blood viremia. The prostate and seminal vesicles appear to be the most efficiently infected reproductive organs, followed by the epididymides and testes. Within the male genital tract, mostly T lymphocytes and a small number of germ cells harbour SIV antigens and RNA. In contrast to the other organs studied, the testis does not display an immune response to the infection. Testosteronemia is transiently increased during the early phase of the infection but spermatogenesis remains unaffected. CONCLUSIONS/SIGNIFICANCE: The present study reveals that SIV infection of the macaque male genital tract is an early event and that semen-producing organs display differential infection levels and immune responses. These results help elucidate the origin of HIV in semen and constitute an essential base to improving the design of antiretroviral therapies to eradicate virus from semen

Antiretroviral-naive and -treated HIV-1 patients can harbour more resistant viruses in CSF than in plasma

Objectives The neurological disorders in HIV-1-infected patients remain prevalent. The HIV-1 resistance in plasma and CSF was compared in patients with neurological disorders in a multicentre study. Methods Blood and CSF samples were collected at time of neurological disorders for 244 patients. The viral loads were >50 copies/mL in both compartments and bulk genotypic tests were realized. Results On 244 patients, 89 and 155 were antiretroviral (ARV) naive and ARV treated, respectively. In ARV-naive patients, detection of mutations in CSF and not in plasma were reported for the reverse transcriptase (RT) gene in 2/89 patients (2.2%) and for the protease gene in 1/89 patients (1.1%). In ARV-treated patients, 19/152 (12.5%) patients had HIV-1 mutations only in the CSF for the RT gene and 30/151 (19.8%) for the protease gene. Two mutations appeared statistically more prevalent in the CSF than in plasma: M41L (P = 0.0455) and T215Y (P = 0.0455). Conclusions In most cases, resistance mutations were present and similar in both studied compartments. However, in 3.4% of ARV-naive and 8.8% of ARV-treated patients, the virus was more resistant in CSF than in plasma. These results support the need for genotypic resistance testing when lumbar puncture is performe

Outcome after allogeneic stem cell transplantation with haploidentical versus HLA-matched donors in patients with higher-risk MDS.

peer reviewedAllogeneic hematopoietic stem cell transplantation remains the best curative option for higher-risk myelodysplastic syndrome. The presence of monosomal karyotype and/or complex karyotype abnormalities predicts inferior survival after allo-SCT in MDS patients. Haploidentical allo-SCT has been increasingly used in acute leukemia (AL) and has similar results as using HLA-matched donors, but data on higher-risk MDS is sparse. We compared outcomes in 266 patients with higher-risk MDS after HLA-matched sibling donor (MSD, n = 79), HLA-matched unrelated donor (MUD, n = 139) and HLA haploidentical donor (HID, n = 48) from 2010 to 2019. Median donor age differed between the three groups (p < 0.001). The overall survival was significantly different between the three groups with a better OS observed in the MUD group (p = 0.014). This observation could be explained by a higher progression-free survival with MUD (p = 0.014). The cumulative incidence of grade 2-4 acute GvHD was significantly higher in the HID group (p = 0.051). However, in multivariable analysis, patients transplanted using an HID had comparable mortality to patients transplanted using a MUD (subdistribution hazard ratio [sHR]: 0.58 [0.32-1.07]; p = 0.080) and a MSD ([sHR]: 0.56 [0.28-1.11]; p = 0.094). MUD do not remain a significant positive predictor of survival, suggesting that beyond the donor-recipient HLA matching, the donor age might impact recipient outcome

LA TRANSHUMANCE BOVINE EN BEARN, ASPECTS SOCIO-ECONOMIQUES ET SANITAIRES

La transhumance bovine, pratique ancestrale qui consiste à mener les troupeaux vers les estives de haute-montagne, connaît une récente reprise. C'est le cas notamment en Béarn dans l'est des Pyrénées Atlantiques où, chaque année, des vaches, Blondes d'Aquitaine pour la majorité, sont préparées et guidées jusqu'aux pâturages de montagne. Si la transhumance permet aux éleveurs de réaliser des économies de fourrages et de main d'oeuvre, elle n'est pas sans risques pour les troupeaux. Ceux-ci sont liés au milieu montagnard, plus hostile qu'en plaine ou encore au mélange de microbismes d'animaux d'origines différentes. Vétérinaires, municipalités et organismes départementaux et nationaux sont autant de protagonistes qui interviennent auprès des éleveurs afin de les aider à gérer les difficultés rencontrées en estive. Mais la transhumance présente aussi un intérêt pour l'économie des vallées ainsi que pour le maintien de l'équilibre d'un écosystème fragile.MAISONS-ALFORT-Ecole Vétérin (940462302) / SudocSudocFranceF

La mise au travail des intuitions dans la conduite d’entretiens de bilan de compétences

International audienc

Infections sévères à pyogènes chez les patients traités par Infliximab

DIJON-BU Médecine Pharmacie (212312103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Facteurs de risque cardiovasculaire au cours du lupus érythémateux systémique (à propos de 262 patients)

LILLE2-BU Santé-Recherche (593502101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF