Evaluierung des spezifischen Targetings von EBV und EBV-miRNA zur Entwicklung einer neuen gene-silencing-basierten Therapiestrategie

Das Epstein-Barr-Virus (EBV) gehört mit einer Prävalenz von ca. 95% bei Erwachsenen zu den erfolgreichsten Viren weltweit. Nach Erstinfektion persistiert das Virus lebenslang im Wirt und reaktiviert unter bestimmten Umständen. Neben symptomlosen Verläufen oder leichten grippalen Infekten kann EBV aber auch schwerwiegende Erkrankungen, wie lymphoproliferative Störungen oder Tumore auslösen. Ein wichtiger Pathogenitätsfaktor dabei sind microRNAs (kurz miRNAs). Diese kleinen RNAs regulieren Proliferation, Apoptose oder Reifung von Immunzellen und stehen deshalb bei EBV-induzierten Tumoren im Fokus der Forschung. Die Expressionsprofile für Erstinfektion, Persistenz oder Reaktivierung wurden hingegen kaum untersucht. In dieser Arbeit wurde im Rahmen einer Studie mit 122 Probanden die Expression der einzelnen Infektionsphasen analysiert. Dafür wurden zunächst verschiedene quantitative PCR-Methoden validiert. Die Analysen erfolgten mittels Normalisierung zu einer Kontrollgruppe aus EBV-seronegativen Patienten, um falsch-positive Signale zu reduzieren. miR-BHRF1-1 war während der Erstinfektion besonders stark exprimiert und würde sich damit als molekularer Marker für diese Phase eignen. Für die Reaktivierungen konnte keine spezifische miRNA ermittelt werden, da die Expressionslevel der miRNAs sehr gering und vergleichbar mit denen in der Persistenz waren. Da miRNA potentielle Ansatzpunkte für eine neuartige EBV-Therapie sind, wurden Experimente zum gene silencing mit zielgerichteten siRNAs in EBV-immortalisierten B-Zellen durchgeführt. Dafür wurde intelligente siRNA verwendet, die durch die Kopplung eines Peptides nur in Zellen aktiviert wird, welche eine bestimmte EBV-Protease produzieren. In den Vorversuchen mit einer solchen siRNA konnte jedoch kein gene silencing erzielt werden, da die transfizierte siRNA nicht ausreichend aktiviert wurde. Ein selektives gene silencing auf Basis der EBV-kodierten Protease scheint somit kein erfolgversprechender Ansatz

Biocide Susceptibility and Antimicrobial Resistance of Escherichia coli Isolated from Swine Feces, Pork Meat and Humans in Germany

Phenotypic susceptibility testing of Escherichia (E.) coli is an essential tool to gain a better understanding of the potential impact of biocide selection pressure on antimicrobial resistance. We, therefore, determined the biocide and antimicrobial susceptibility of 216 extended-spectrum β-lactamase-producing (ESBL) and 177 non-ESBL E. coli isolated from swine feces, pork meat, voluntary donors and inpatients and evaluated associations between their susceptibilities. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of benzalkonium chloride, chlorhexidine digluconate (CHG), chlorocresol (PCMC), glutaraldehyde (GDA), isopropanol (IPA), octenidine dihydrochloride and sodium hypochlorite (NaOCl) showed unimodal distributions, indicating the absence of bacterial adaptation to biocides due to the acquisition of resistance mechanisms. Although MIC95 and MBC95 did not vary more than one doubling dilution step between isolates of porcine and human origin, significant differences in MIC and/or MBC distributions were identified for GDA, CHG, IPA, PCMC and NaOCl. Comparing non-ESBL and ESBL E. coli, significantly different MIC and/or MBC distributions were found for PCMC, CHG and GDA. Antimicrobial susceptibility testing revealed the highest frequency of resistant E. coli in the subpopulation isolated from inpatients. We observed significant but weakly positive correlations between biocide MICs and/or MBCs and antimicrobial MICs. In summary, our data indicate a rather moderate effect of biocide use on the susceptibility of E. coli to biocides and antimicrobials

The World Federation of ADHD International Consensus Statement:208 Evidence-based conclusions about the disorder

Background: Misconceptions about ADHD stigmatize affected people, reduce credibility of providers, and prevent/delay treatment. To challenge misconceptions, we curated findings with strong evidence base. Methods: We reviewed studies with more than 2000 participants or meta-analyses from five or more studies or 2000 or more participants. We excluded meta-analyses that did not assess publication bias, except for meta-analyses of prevalence. For network meta-analyses we required comparison adjusted funnel plots. We excluded treatment studies with waiting-list or treatment as usual controls. From this literature, we extracted evidence-based assertions about the disorder. Results: We generated 208 empirically supported statements about ADHD. The status of the included statements as empirically supported is approved by 80 authors from 27 countries and 6 continents. The contents of the manuscript are endorsed by 366 people who have read this document and agree with its contents. Conclusions: Many findings in ADHD are supported by meta-analysis. These allow for firm statements about the nature, course, outcome causes, and treatments for disorders that are useful for reducing misconceptions and stigma.</p

Anti-tumor necrosis factor antibody impairs the therapeutic effect of ceftriaxone in murine pneumococcal pneumonia

Treatments aimed at inhibition of tumor necrosis factor (TNF) in patients with sepsis have been unsuccessful. Up to 50% of such patients suffer from pneumonia. To determine the effect that treatment with anti-TNF has on pneumococcal pneumonia, mice were intranasally inoculated with Streptococcus pneumoniae and, 25 h later, treated with 1 of the following: (1) control antibody, (2) anti-TNF, (3) ceftriaxone (CEF) with control antibody, or (4) CEF with anti-TNF. In the absence of treatment with CEF, mice displayed high bacterial loads in lungs, and all of these mice died within 5 days after inoculation. Anti-TNF did not influence these outcomes. In contrast, 60% of mice treated with CEF alone survived. Anti-TNF administered together with CEF reduced survival to 40% and was associated with enhanced bacterial outgrowth. These data suggest that treatment with anti-TNF impairs the therapeutic efficacy of CEF during pneumococcal pneumoni

EBV miRNA expression profiles in different infection stages: A prospective cohort study.

The Epstein-Barr virus (EBV) produces different microRNAs (miRNA) with distinct regulatory functions within the infectious cycle. These viral miRNAs regulate the expression of viral and host genes and have been discussed as potential diagnostic markers or even therapeutic targets, provided that the expression profile can be unambiguously correlated to a specific stage of infection or a specific EBV-induced disorder. In this context, miRNA profiling becomes more important since the roles of these miRNAs in the pathogenesis of infections and malignancies are not fully understood. Studies of EBV miRNA expression profiles are sparse and have mainly focused on associated malignancies. This study is the first to examine the miRNA profiles of EBV reactivation and to use a correction step with seronegative patients as a reference. Between 2012 and 2017, we examined the expression profiles of 11 selected EBV miRNAs in 129 whole blood samples from primary infection, reactivation, healthy carriers and EBV seronegative patients. Three of the miRNAs could not be detected in any sample. Other miRNAs showed significantly higher expression levels and prevalence during primary infection than in other stages; miR-BHRF1-1 was the most abundant. The expression profiles from reactivation differed slightly but not significantly from those of healthy carriers, but a specific marker miRNA for each stage could not be identified within the selected EBV miRNA targets

ESBL colonization and acquisition in a hospital population: The molecular epidemiology and transmission of resistance genes.

A prospective cohort study (German Clinical Trial Registry, No. 00005273) was performed to determine pre-admission colonization rates, hospital acquisition risk factors, subsequent infection rates and colonization persistence including the respective molecular epidemiology and transmission rates of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae (EPE). A total of 342 EPEs were isolated from rectal swabs of 1,334 patients on admission, at discharge and 6 months after hospitalization. Inclusion criteria were patients' age > 18 years, expected length of stays > 48 hours, external referral. The EPEs were characterized by routine microbiological methods, a DNA microarray and ERIC-PCR. EPE colonization was found in 12.7 % of admitted patients, with the highest rate (23.8 %) in patients from nursing homes. During hospitalization, 8.1 % of the patients were de novo EPE colonized, and invasive procedures, antibiotic and antacid therapies were independent risk factors. Only 1/169 patients colonized on admission developed a hospital-acquired EPE infection. Escherichia coli was the predominant EPE (88.9 %), and 92.1% of the ESBL phenotypes could be related to CTX-M variants with CTX-M-1/15 group being most frequent (88.9%). A corresponding β-lactamase could not be identified in five isolates. Hospital-acquired EPE infections in patients colonized before or during hospitalization were rare. The diversity of the EPE strains was much higher than that of the underlying plasmids. In seven patients, transmission of the respective plasmid across different species could be observed indicating that the current strain-based surveillance approaches may underestimate the risk of inter-species transmission of resistance genes

Lipopolysaccharide (LPS)-binding protein mediates LPS detoxification by chylomicrons

Chylomicrons have been shown to protect against endotoxin-induced lethality. LPS-binding protein (LBP) is involved in the inactivation of bacterial toxin by lipoproteins. The current study examined the interaction among LBP, chylomicrons, and bacterial toxin. LBP was demonstrated to associate with chylomicrons and enhance the amount of LPS binding to chylomicrons in a dose-dependent fashion. In addition, LBP accelerated LPS binding to chylomicrons. This LBP-induced interaction of LPS with chylomicrons prevented endotoxin toxicity, as demonstrated by reduced cytokine secretion by PBMC. When postprandial circulating concentrations of chylomicrons were compared with circulating levels of low density lipoprotein, very low density lipoprotein, and high density lipoprotein, chylomicrons exceeded the other lipoproteins in LPS-inactivating capacity. Furthermore, highly purified lipoteichoic acid, an immunostimulatory component of Gram-positive bacteria, was detoxified by incubation with LBP and chylomicrons. In conclusion, our results indicate that LBP associates with chylomicrons and enables chylomicrons to rapidly bind bacterial toxin, thereby preventing cell activation. Besides a role in the detoxification of bacterial toxin present in the circulation, we believe that LBP-chylomicron complexes may be part of a local defense mechanism of the intestine against translocated bacterial toxi