Metatranscriptomics reveals metabolic adaptation and induction of virulence factors by Haemophilus parasuis during lung infection

International audienceAbstractHaemophilus parasuis is a common inhabitant of the upper respiratory tract of pigs, and the causative agent of Glässer’s disease. This disease is characterized by polyserositis and arthritis, produced by the severe inflammation caused by the systemic spread of the bacterium. After an initial colonization of the upper respiratory tract, H. parasuis enters the lung during the early stages of pig infection. In order to study gene expression at this location, we sequenced the ex vivo and in vivo H. parasuis Nagasaki transcriptome in the lung using a metatranscriptomic approach. Comparison of gene expression under these conditions with that found in conventional plate culture showed generally reduced expression of genes associated with anabolic and catabolic pathways, coupled with up-regulation of membrane-related genes involved in carbon acquisition, iron binding and pathogenesis. Some of the up-regulated membrane genes, including ABC transporters, virulence-associated autotransporters (vtaAs) and several hypothetical proteins, were only present in virulent H. parasuis strains, highlighting their significance as markers of disease potential. Finally, the analysis also revealed the presence of numerous antisense transcripts with possible roles in gene regulation. In summary, this data sheds some light on the scarcely studied in vivo transcriptome of H. parasuis, revealing nutritional virulence as an adaptive strategy for host survival, besides induction of classical virulence factors

Pancreaticojejunostomy Versus Pancreaticogastrostomy After Pancreaticoduodenectomy: An Up-to-date Meta-Analysis

Background: The reconstruction of the pancreas after pancreaticoduodenectomy (PD) is a crucial factor in preventing postoperative complications as pancreatic anastomosis failure is associated with a high morbidity rate and contributes to prolonged hospitalization and mortality. Several techniques have been described for the reconstruction of pancreatic digestive continuity in the attempt to minimize the risk of a pancreatic fistula. The aim of this study was to compare the results of pancreaticogastrostomy and pancreaticojejunostomy after PD. Methods: A systematic review and meta-analysis were conducted of randomized controlled trials (RCTs) published up to January 2015 comparing patients with pancreaticogastrostomy (PG group) versus pancreaticojejunostomy (PJ group). Two reviewers independently assessed the eligibility and quality of the studies. The meta-analysis was conducted using either the fixed-effect or the random-effect model. Results: Eight RCTs describing 1,211 patients were identified for inclusion in the study. The meta-analysis shows that the PG group had a significantly lower incidence rate of postoperative pancreatic fistulas [OR 0.64 (95% confidence interval 0.46–0.86), p =.003], intra-abdominal abscesses [OR 0.53 (95% CI, 0.33–0.85), p =.009] and length of hospital stay [MD −1.62; (95% CI 2.63–0.61), p =.002] than the PJ group, while biliary fistula, mortality, morbidity, rate of delayed gastric emptying, reoperation, and bleeding did not differ between the two groups. Conclusion: This meta-analysis suggests that the most effective treatment for reconstruction of pancreatic continuity after pancreatoduodenectomy is pancreaticogastrostomy. However, the advantage of the latter could potentially be demonstrated through further RCTs, including only patients at high risk of developing pancreatic fistulas

Nonnegative signal factorization with learnt instrument models for sound source separation in close-microphone recordings

Close-microphone techniques are extensively employed in many live music recordings, allowing for interference rejection and reducing the amount of reverberation in the resulting instrument tracks. However, despite the use of directional microphones, the recorded tracks are not completely free from source interference, a problem which is commonly known as microphone leakage. While source separation methods are potentially a solution to this problem, few approaches take into account the huge amount of prior information available in this scenario. In fact, besides the special properties of close-microphone tracks, the knowledge on the number and type of instruments making up the mixture can also be successfully exploited for improved separation performance. In this paper, a nonnegative matrix factorization (NMF) method making use of all the above information is proposed. To this end, a set of instrument models are learnt from a training database and incorporated into a multichannel extension of the NMF algorithm. Several options to initialize the algorithm are suggested, exploring their performance in multiple music tracks and comparing the results to other state-of-the-art approaches.This work was supported by the Andalusian Business, Science and Innovation Council under project P2010- TIC-6762, (FEDER) the Spanish Ministry of Economy and Competitiveness under the projects TEC2012-38142-C04-03 and TEC2012-37945-C02-0

CD4 cell response to antiretroviral therapy in children with vertically acquired HIV infection: Is it associated with age at initiation?

Background. Considerable uncertainty remains as to whether early initiation of antiretroviral therapy (ART) in children with vertically acquired human immunodeficiency virus (HIV) infection increases the benefit in terms of immunological response. Methods. The association between immunological outcome and early initiation of and/or more-potent ART was investigated, using age-standardized z scores for CD4 cell counts (hereafter, "CD4 z scores"), in 131 HIV-infected children enrolled in the European Collaborative Study, a birth cohort study. Results. Median age at initiation of the most-potent ART was 4 years (range, 0.1-15.5 years). Initiation of treatment after 5 months of age resulted in nonsignificantly lower CD4 z scores 6 months after initiation. Time to a 20% increase in CD4 z score was associated with age at initiation of the most-potent ART (adjusted hazard ratios [AHRs], 0.37 [P<.01] and 0.43 [P = .05] for 5 months-5 years of age and >5 years of age, respectively, compared with <5 months of age), ethnicity (AHR, 0.48 [P = .01], for black vs. white), and highly active ART (HAART) with or without prior ART (AHRs, 3.16 [P<.01] and 3.95 [P<.001], vs. mono or dual ART, respectively). The risk of subsequent deterioration of CD4 z score was similar for children who initiated ART in different age groups (\u3c72 = 0.824; P = .82). Conclusions. We confirm the effectiveness of HAART with respect to the recovery of CD4 cell count and suggest a benefit of initiating ART before the age of 5 months. Age at initiation of the most-potent ART was not associated with the likelihood of sustaining the recovery of CD4 cell count