Fast and Sensitive Multiplex Real-Time Quantitative PCR to Detect Cutibacterium Periprosthetic Joint Infections

Diagnosis of Cutibacterium periprosthetic joint infections (PJIs) is challenging due to a long cultivation time of up to 14 days. Faster culture-independent diagnosis would improve patient care with early and accurate treatment. Specific primers and probes were designed for Cutibacterium acnes, Cutibacterium avidum, and Cutibacterium granulosum and evaluated in a multiplex TaqMan real-time quantitative PCR (qPCR) format on 57 skin swabs and 20 culture-negative cerebrospinal fluid samples. The multiplex qPCR was tested in a PJI cohort of 41 sonication fluid samples from removed implants infected with different pathogens. All five culture-positive Cutibacterium PJIs were detected with the corresponding Cutibacterium-specific probe (100% positive percent agreement). The multiplex qPCR additionally detected C. avidum in two PJI sonication fluid samples that were diagnosed as Staphylococcus species infections according to culture (95% negative percent agreement). The new multiplex qPCR can provide a Cutibacterium PJI diagnosis within 1 day, allowing early and accurate antibiotic treatment. A prospective diagnostic trial in PJI with a high number of Cutibacterium species infections (shoulder PJI) is needed for further evaluation

Antimicrobial susceptibility testing is crucial when treating Finegoldia magna infections

Finegoldia magna is an anaerobic gram-positive bacterium that can cause invasive human infections. Recently, a 52-year-old patient suffering from a periprosthetic joint infection (PJI) due to F. magna was treated with cefepime on hemodialysis; however, treatment failed due to relapse caused by antibiotic-resistant strains. Reports on the antimicrobial susceptibility of F. magna clinical isolates are rare. We collected 57 clinical F. magna isolates from Zurich, Switzerland, between September 2019 and July 2020 and tested their antimicrobial susceptibility to investigate the local resistance pattern. Antimicrobial susceptibility testing (AST) was evaluated for nine antibiotics (benzylpenicillin, amoxicillin/clavulanic acid, cefuroxime, cefepime, levofloxacin, rifampicin, metronidazole, doxycycline, and clindamycin) by E-test according to CLSI guidelines. All F. magna strains were susceptible to benzylpenicillin, amoxicillin/clavulanic acid, and metronidazole, while 75% to clindamycin. F. magna isolates showed MIC values lower than species-unrelated breakpoints for cefuroxime, levofloxacin, and cefepime in 93%, 56%, and 32% of the cases, respectively. MIC values for rifampicin and doxycycline were lower than locally determined ECOFFs in 98% and 72% of the cases, respectively. In summary, we recommend the use of benzylpenicillin, amoxicillin/clavulanic acid, or metronidazole without prior AST as first-line treatment option against F. magna PJI infections. If cefuroxime, cefepime, levofloxacin, rifampicin, doxycycline, or clindamycin are used, AST is mandatory. Keywords: Antimicrobial susceptibility; Cefepime; Finegoldia magna; Periprosthetic joint infectio

Genetic diversity and structure of baobab (Adansonia digitata L.) in southeastern Kenya

Baobab (Adansonia digitata L.) is an iconic tree of African savannahs. Its multipurpose character and nutritional composition of fruits and leaves offer high economic and social potential for local communities. There is an urgent need to characterize the genetic diversity of the Kenyan baobab populations in order to facilitate further conservation and domestication programmes. This study aims at documenting the genetic diversity and structure of baobab populations in southeastern Kenya. Leaf or bark samples were collected from 189 baobab trees in seven populations distributed in two geographical groups, i.e. four inland and three coastal populations. Nine microsatellite loci were used to assess genetic diversity. Overall, genetic diversity of the species was high and similarly distributed over the populations. Bayesian clustering and principal coordinate analysis congruently divided the populations into two distinct clusters, suggesting significant differences between inland and coastal populations. The genetic differentiation between coastal and inland populations suggests a limited possibility of gene flow between these populations. Further conservation and domestications studies should take into consideration thegeographical origin of trees and more attention should be paid to morphological characterization of fruits and leaves of the coastal and inland populations to understand the causes and the impact of the differentiation

Burnout, depression and depersonalisation – Psychological factors and coping strategies in dental and medical students

Background: Previous studies found that stress, depression, burnout, anxiety, and depersonalisation play a significant role amongst dental and medical students. We wanted to examine if students of the University of Erlangen-Nuremberg also would report elevated values as can been found in similar publications. Furthermore, particularly coping strategies were investigated

The neurovascular unit as a selective barrier to polymorphonuclear granulocyte (PMN) infiltration into the brain after ischemic injury

The migration of polymorphonuclear granulocytes (PMN) into the brain parenchyma and release of their abundant proteases are considered the main causes of neuronal cell death and reperfusion injury following ischemia. Yet, therapies targeting PMN egress have been largely ineffective. To address this discrepancy we investigated the temporo-spatial localization of PMNs early after transient ischemia in a murine transient middle cerebral artery occlusion (tMCAO) model and human stroke specimens. Using specific markers that distinguish PMN (Ly6G) from monocytes/macrophages (Ly6C) and that define the cellular and basement membrane boundaries of the neurovascular unit (NVU), histology and confocal microscopy revealed that virtually no PMNs entered the infarcted CNS parenchyma. Regardless of tMCAO duration, PMNs were mainly restricted to luminal surfaces or perivascular spaces of cerebral vessels. Vascular PMN accumulation showed no spatial correlation with increased vessel permeability, enhanced expression of endothelial cell adhesion molecules, platelet aggregation or release of neutrophil extracellular traps. Live cell imaging studies confirmed that oxygen and glucose deprivation followed by reoxygenation fail to induce PMN migration across a brain endothelial monolayer under flow conditions in vitro. The absence of PMN infiltration in infarcted brain tissues was corroborated in 25 human stroke specimens collected at early time points after infarction. Our observations identify the NVU rather than the brain parenchyma as the site of PMN action after CNS ischemia and suggest reappraisal of targets for therapies to reduce reperfusion injury after strok

Prediction of phenotype and gene expression for combinations of mutations

Molecular interactions provide paths for information flows. Genetic interactions reveal active information flows and reflect their functional consequences. We integrated these complementary data types to model the transcription network controlling cell differentiation in yeast. Genetic interactions were inferred from linear decomposition of gene expression data and were used to direct the construction of a molecular interaction network mediating these genetic effects. This network included both known and novel regulatory influences, and predicted genetic interactions. For corresponding combinations of mutations, the network model predicted quantitative gene expression profiles and precise phenotypic effects. Multiple predictions were tested and verified

Synthetic viability genomic screening defines Sae2 function in DNA repair.

DNA double-strand break (DSB) repair by homologous recombination (HR) requires 3' single-stranded DNA (ssDNA) generation by 5' DNA-end resection. During meiosis, yeast Sae2 cooperates with the nuclease Mre11 to remove covalently bound Spo11 from DSB termini, allowing resection and HR to ensue. Mitotic roles of Sae2 and Mre11 nuclease have remained enigmatic, however, since cells lacking these display modest resection defects but marked DNA damage hypersensitivities. By combining classic genetic suppressor screening with high-throughput DNA sequencing, we identify Mre11 mutations that strongly suppress DNA damage sensitivities of sae2∆ cells. By assessing the impacts of these mutations at the cellular, biochemical and structural levels, we propose that, in addition to promoting resection, a crucial role for Sae2 and Mre11 nuclease activity in mitotic DSB repair is to facilitate the removal of Mre11 from ssDNA associated with DSB ends. Thus, without Sae2 or Mre11 nuclease activity, Mre11 bound to partly processed DSBs impairs strand invasion and HR.We thank M.P. Longhese, R. Rothstein and J. Haber for providing strains and plasmids; Sir T. Blundell and T. Ochi for advice on structural biology and for providing comments to the manuscript. Research in the Jackson laboratory is funded by Cancer Research UK Programme Grant C6/A11224, the European Research Council and the European Community Seventh Framework Programme Grant Agreement No. HEALTH‐F2‐2010‐259893 (DDResponse). Core funding is provided by CRUK (C6946/A14492) and the Wellcome Trust (WT092096). SPJ receives his salary from the University of Cambridge, UK, supplemented by CRUK. TO, IG and FP were funded by Framework Programme Grant Agreement No. HEALTH‐F2‐2010‐259893 (DDResponse). FP also received funding from EMBO (Fellowship ALTF 1287‐2011); NG and IS are funded by the Wellcome Trust (101126/Z/13/Z). DJA and TMK were supported by Cancer Research UK and the Wellcome Trust (WT098051). PS and HN were supported by NIH grants RO1ES007061 and K99ES021441, respectively.This is the final version. It was first published by EMBO at http://emboj.embopress.org/content/early/2015/04/21/embj.201590973.lon

Lack of Neuronal IFN-β-IFNAR Causes Lewy Body- and Parkinson's Disease-like Dementia.

Neurodegenerative diseases have been linked to inflammation, but whether altered immunomodulation plays a causative role in neurodegeneration is not clear. We show that lack of cytokine interferon-β (IFN-β) signaling causes spontaneous neurodegeneration in the absence of neurodegenerative disease-causing mutant proteins. Mice lacking Ifnb function exhibited motor and cognitive learning impairments with accompanying α-synuclein-containing Lewy bodies in the brain, as well as a reduction in dopaminergic neurons and defective dopamine signaling in the nigrostriatal region. Lack of IFN-β signaling caused defects in neuronal autophagy prior to α-synucleinopathy, which was associated with accumulation of senescent mitochondria. Recombinant IFN-β promoted neurite growth and branching, autophagy flux, and α-synuclein degradation in neurons. In addition, lentiviral IFN-β overexpression prevented dopaminergic neuron loss in a familial Parkinson's disease model. These results indicate a protective role for IFN-β in neuronal homeostasis and validate Ifnb mutant mice as a model for sporadic Lewy body and Parkinson's disease dementia.Support to S.I.-N. was from Danish Council For Independent Research (DFF)-Medical Sciences, Alzheimer-forskningsfonden, Danish Multiple Sclerosis Society, Danish Cancer Society and Lundbeck Foundation. D.C.R. is a Wellcome Trust Principal Research Fellow.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.cell.2015.08.06