The Mechanical Characterization of Welded Hybrid Joints Based on a Fast-Curing Epoxy Composite with an Integrated Phenoxy Coupling Layer.

The joining of composites mostly relies on traditional joining technologies, such as film or paste adhesives, or mechanical fasteners. This study focuses on the appealing approach of using standard thermoplastic welding processes to join thermosets. To achieve this, a thermoplastic coupling layer is created by curing with a thermoset composite part. This leads to a functional surface that can be utilized with thermoplastic welding methods. The thermoplastic coupling layer is integrated as a thin film, compatible with the thermoset resin in the sense that it can partially diffuse in a controlled way into the thermoset resin during the curing cycle. Recent studies showed the high affinity for the interphase formation of poly hydroxy ether (phenoxy) film as coupling layer, in combination with a fast-curing epoxy system that cures within 1 min at 140 °C. In this study, an investigation based on resistance and ultrasonic welding techniques with different testing conditions of single-lap shear samples (at room temperature, 60 °C, and 80 °C) was performed. The results showed strong mechanical strengths of 28.9 MPa (±0.7%) for resistance welding and 24.5 MPa (±0.1%) for ultrasonic welding, with only a minor reduction in mechanical properties up to the glass transition temperature of phenoxy (90 °C). The combination of a fast-curing composite material with an ultra-fast ultrasonic joining technology clearly demonstrates the high potential of this joining technique for industrial applications, such as automotive, sporting goods, or wind energy. The innovation allowing structural joining performance presents key advantages versus traditional methods: the thermoplastic film positioning in the mold can be automated and localized, joint formation requires only a fraction of a second, and the joining operation does not require surface preparation/cleaning or structure deterioration (drilling).

Enhanced antibacterial effect of the novel T4-like bacteriophage KARL-1 in combination with antibiotics against multi-drug resistant Acinetobacter baumannii.

The continuing rise of infections caused by multi-drug resistant bacteria has led to a renewed interest in bacteriophage therapy. Here we characterize phage vB_AbaM-KARL-1 with lytic activity against multi-drug resistant clinical isolates of Acinetobacter baumannii (AB). Besides genomic and phenotypic phage analysis, the objective of our study was to investigate the antibacterial outcome when the phage acts in concert with distinct antibiotics. KARL-1 belongs to the family of Myoviridae and is able to lyse 8 of 20 (40%) tested clinical isolates. Its double-stranded DNA genome consists of 166,560 bp encoding for 253 open reading frames. Genome wide comparison suggests that KARL-1 is a novel species within the subfamily Tevenvirinae, sharing 77% nucleotide identity (coverage 58%) with phage ZZ1. The antibacterial efficacy at various multiplicities of infection (MOI) was monitored either alone or in combination with meropenem, ciprofloxacin, and colistin. A complete clearance of liquid cultures was achieved with KARL-1 at an MOI of 10-1 and meropenem (>128 mg/l). KARL-1 was still effective at an MOI of 10-7, but antibacterial activity was significantly augmented with meropenem. While ciprofloxacin did generally not support phage activity, the application of KARL-1 at an MOI of 10-7 and therapeutic doses of colistin significantly elevated bacterial suppression. Hence, KARL-1 represents a novel candidate for use against multi-drug resistant AB and the therapeutic outcome may be positively influenced by the addition of traditional antibiotics.

Differential Effect of Newly Isolated Phages Belonging to PB1-Like, phiKZ-Like and LUZ24-Like Viruses against Multi-Drug Resistant Pseudomonas aeruginosa under Varying Growth Conditions.

In this study, we characterize three phages (SL1 SL2, and SL4), isolated from hospital sewage with lytic activity against clinical isolates of multi-drug resistant Pseudomonas aeruginosa (MDR-PA). The host spectrum ranged from 41% to 54%, with all three phages together covering 79% of all tested clinical isolates. Genome analysis revealed that SL1 (65,849 bp, 91 open reading frames ORFs) belongs to PB1-like viruses, SL2 (279,696 bp, 354 ORFs) to phiKZ-like viruses and SL4 (44,194 bp, 65 ORFs) to LUZ24-like viruses. Planktonic cells of four of five selected MDR-PA strains were suppressed by at least one phage with multiplicities of infection (MOIs) ranging from 1 to 10-6 for 16 h without apparent regrowth of bacterial populations. While SL2 was most potent in suppressing planktonic cultures the strongest anti-biofilm activity was observed with SL4. Phages were able to rescue bacteria-infected wax moth larvae (Galleria melonella) for 24 h, whereby highest survival rates (90%) were observed with SL1. Except for the biofilm experiments, the effect of a cocktail with all three phages was comparable to the action of the best phage alone; hence, there are no synergistic but also no antagonistic effects among phages. The use of a cocktail with these phages is therefore expedient for increasing host range and minimizing the development of phage resistance.

Preliminary survey of local bacteriophages with lytic activity against multi-drug resistant bacteria.

Bacteriophages (phages) represent a potential alternative for combating multi-drug resistant bacteria. Because of their narrow host range and the ever emergence of novel pathogen variants the continued search for phages is a prerequisite for optimal treatment of bacterial infections. Here we performed an ad hoc survey in the surroundings of a University hospital for the presence of phages with therapeutic potential. To this end, 16 aquatic samples of different origins and locations were tested simultaneously for the presence of phages with lytic activity against five current, but distinct strains each from the ESKAPE-group (i.e., Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter cloacae). Phages could be isolated for 70% of strains, covering all bacterial species except S. aureus. Apart from samples from two lakes, freshwater samples were largely devoid of phages. By contrast, one liter of hospital effluent collected at a single time point already contained phages active against two-thirds of tested strains. In conclusion, phages with lytic activity against nosocomial pathogens are unevenly distributed across environments with the prime source being the immediate hospital vicinity.

Drinking water treatment with ultraviolet light for travelers -- Evaluation of a mobile lightweight system.

BACKGROUND: The SteriPEN(®) is a handheld device for disinfecting water with ultraviolet (UV) radiation. The manufacturer claims a reduction of at least 99.9% of bacteria, viruses, and protozoa. The present study intends to verify the general effectiveness of the device. Furthermore, the influence of bottle geometry and water movement is examined and the issue of user safety with regard to UV-C radiation is addressed. METHODS: The device was applied on water containing a known number of microorganisms (Escherichia coli, Staphylococcus aureus, and the spore of Geobacillusstearothermophilus) and the survival rate was examined. Three different types of bottles commonly used among travelers served as test containers. All tests were conducted with and without agitating the water during irradiation. Furthermore, a spectral analysis was performed on the light of the device. RESULTS: The SteriPEN(®) reached a mean reduction of more than 99.99% of bacteria and 99.57% of the spores when applied correctly. However, the results of the trials without agitating the water only yielded a 94.98% germ reduction. The device's maximal radiation intensity lies at 254 nm which is the wavelength most efficient in inactivating bacteria. The UV-C fraction is filtered out completely by common bottle materials. However, when applied in larger containers a portion of the UV-C rays exits the water surface. CONCLUSIONS: If applied according to the instructions the device manages a satisfactory inactivation of bacteria. However, it bears the danger of user errors relevant to health. Therefore, education on the risks of incorrect application should be included in the travel medical consultation. Also there are still aspects that need to be subject to further independent research.

Viruses versus bacteria-novel approaches to phage therapy as a tool against multidrug-resistant pathogens.

Bacteriophage therapy (the application of phages to treat bacterial infections) has a tradition dating back almost a century, but interest in phage therapy slowed down in the West when antibiotics were discovered. With the emerging threat of infections caused by multidrug-resistant bacteria and scarce prospects of newly introduced antibiotics in the future, phages are currently being reconsidered as alternative therapeutics. Conventional phage therapy uses lytic bacteriophages for treatment and recent human clinical trials have revealed encouraging results. In addition, several other modern approaches to phages as therapeutics have been made in vitro and in animal models. Dual therapy with phages and antibiotics has resulted in significant reductions in the number of bacterial pathogens. Bioengineered phages have overcome many of the problems of conventional phage therapy, enabled targeted drug delivery or reversed the resistance of drug-resistant bacteria. The use of enzymes derived from phages, such as endolysin, as therapeutic agents has been efficient in the elimination of Gram-positive pathogens. This review presents novel strategies for phage-related therapies and describes our current knowledge of natural bacteriophages within the human microbiome. Our aim is to provide an overview of the high number of different methodological concepts, thereby encouraging further research on this topic, with the ultimate goal of using phages as therapeutic or preventative medicines in daily clinical practice.

Early muscle and brain ultrastructural changes in polymerase gamma 1-related encephalomyopathy.

Mutations affecting the mitochondrial DNA-polymerase gamma 1 (POLG1) gene have been shown to cause Alpers-Huttenlocher disease. Ultrastructural data on brain and muscle tissue are rare. We report on ultrastructural changes in brain and muscle tissue of two sisters who were compound heterozygous for the c.2243G>C and c.1879C>T POLG1 mutations. Patient 1 (16 years) presented with epilepsia partialis continua that did not respond to antiepileptic treatment. Neuroimaging showed right occipital and bithalamic changes. Light microscopy from a brain biopsy performed after 3 weeks suggested chronic encephalitis showing astro- and microgliosis as well as perivascular CD8-positive T-cells. However, immunosuppressive therapy failed to improve her condition. When her 17-year-old sister (patient 2) also developed epilepsy, an intensified search for metabolic diseases led to the diagnosis. On electron microscopy mitochondrial abnormalities mainly affecting neurons were detected in the brain biopsy of patient 1, including an increase in number and size, structural changes and globoid inclusions. In patient 2, light and electron microscopy on a muscle biopsy confirmed a mitochondrial myopathy, also revealing an increase in mitochondrial size and number, as well as globoid inclusions. Neurons may be the primary target of mitochondrial dysfunction in brains of patients with Alpers disease related to POLG1 mutations. During early disease stages, brain histopathology may be misleading, showing reactive inflammatory changes.

Invasive group A streptococcal disease and association with varicella in Germany, 1996-2009.

A nationwide laboratory-based surveillance study was conducted to analyse the epidemiology of varicella-associated invasive group A streptococcal (iGAS) infections in Germany. A total of 1342 iGAS samples were collected between 1 January 1996 and 22 September 2009. For 21 of these isolates, an association with varicella was observed. The median age of this subgroup was 4.2 years (mean 12.1). Most of these patients presented with sepsis (42.9%), streptococcal toxic shock syndrome (23.8%) and necrotizing fasciitis (19.0%). The most common complications among patients with underlying varicella were hypotensive shock and soft-tissue necrosis (38.1% each), disseminated intravascular coagulopathy (33.3%) and renal impairment (28.6%). The overall rate of complications was higher among the patients with underlying varicella than among those without. In the varicella-positive group, emm types 1 (38.1%), 12 (19.0%) and 4 (14.3%) were predominant, while among the varicella-negative isolates, emm types 1 (32.5%), 28 (14.0%) and 3 (8.3%) were found most often. Among the varicella-positive group, the rate of ssa-positive isolates was considerably higher than that among the varicella-negative group (28.6% vs. 12.6%), as well as the coexistence of speC and ssa (14.3% vs. 3.6%).

Real-time PCR assay and a synthetic positive control for the rapid and sensitive detection of the emerging resistance gene New Delhi Metallo-ß-lactamase-1 (bla(NDM-1)).

Carbapenems are important last-line antibiotics for the treatment of hospital infections. Enterobacteriaceae (such as Klebsiella pneumoniae or Escherichia coli) expressing the "New Delhi Metallo-ß-lactamase" gene bla(NDM-1) are resistant to carbapenems and were predicted to become a major global health problem. To cope with this emerging threat, there is a need for rapid and sensitive molecular assays to detect bla(NDM-1) in carbapenem-resistant Enterobacteriaceae from clinical isolates. In diagnostic laboratories, real-time PCR is the current gold standard for the sensitive and rapid detection of pathogens. We describe a real-time PCR assay as well as two conventional PCR assays to detect bla(NDM-1). Only minute amounts of total DNA extracted from one bacterial colony are sufficient to allow detection of bla(NDM-1) by real-time PCR within less than 1 h. We also introduce a chemically synthesized bla(NDM-1) gene as a convenient positive control for those laboratories wishing to setup in-house assays for bla(NDM-1) detection. Importantly, our study represents a proof of principle for the usefulness of rapidly synthesized genes serving as positive controls for novel diagnostic PCR assays of emerging pathogens during the initial phase after their discovery when biological isolates are still rare and not commonly available.

Association between respiratory and herpes viruses on pulmonary exacerbations in cystic fibrosis patients.

Respiratory viruses discovered in the 21st century and human herpes viruses (N=13) were seldom (4/50) detected in our cystic fibrosis patients although exacerbation frequency (7.75+/-2.9/a versus 4.45+/-2.1/a; p=0.03) and colonization with Aspergillus fumigatus (RR: 2.6; CI95: 1.8-3.7), Pseudomonas aeruginosa (RR: 1.84; CI95: 1.4-2.4), and Staphylococcus aureus (RR: 1.5; CI95: 1.2-1.9) including MRSA (RR: 4.6; CI95: 1.3-16.6) were associated with virus positivity. Further studies should clarify whether this finding reflects non-specific colonization (human Bocavirus) or reactivation (Epstein-Barr virus) or rather an acceleration of lung tissue inflammation.

Epstein-Barr virus BDLF2-BMRF2 complex affects cellular morphology.

Herpesvirus glycoproteins often form specific heterodimers that can fulfil functions that cannot be carried out by either of the partners acting alone. This study showed that interactions between the Epstein-Barr virus (EBV) multi-spanning transmembrane envelope protein BMRF2 and type II membrane protein BDLF2 influence the way in which these proteins are trafficked in the cell, and hence the subcellular compartment in which they accumulate. When expressed transiently in mammalian cells, BDLF2 accumulated in the endoplasmic reticulum (ER), whereas BMRF2 accumulated in the ER and Golgi apparatus. However, when the two proteins were co-expressed, BDLF2 was transported with BMRF2 to the Golgi apparatus and from there to the plasma membrane, where the proteins co-localized extensively. The distribution of the two proteins at the plasma membrane was reproducibly associated with dramatic changes in cellular morphology, including the formation of enlarged membrane protrusions and cellular processes whose adhesion extremities were organized by the actin cytoskeleton. A dominant-active form of the small GTPase RhoA was epistatic to this morphological phenotype, suggesting that RhoA is a central component of the signalling pathway that reorganizes the cytoskeleton in response to BDLF2-BMRF2. It was concluded that EBV produces a glycoprotein heterodimer that induces changes in cellular morphology through reorganization of the actin cytoskeleton and may facilitate virion spread between cells.

Low to medium WU-virus titers in young children with lower respiratory tract infections.

The WU-virus (WUV), a novel polyomavirus, has recently been recovered from respiratory tract samples. Within a study collective of children with severe lower respiratory tract disease, 3% of the patients tested WUV positive. Viral loads ranged from 5 x 10(2) copies/ml to 1 x 10(4) copies/ml. The WUV genome-positive patients did not display specific clinical or radiological characteristics to be distinguished from other respiratory tract infections.

Myocarditis in newborn wild-type BALB/c mice infected with the murine gamma herpesvirus MHV-68.

OBJECTIVES: Animal models of human Epstein-Barr virus (EBV) infection include EBV infection of primates and infection of mice with MHV-68, a further gamma herpesvirus (gamma-HV). We aimed at extending the MHV-68 model to study gamma-HV-related cardiac disease. METHODS: Newborn wild-type BALB/c- (n=107), wild-type C57BL/6- (n=17) and immunodeficient B6-(Rag1) mice (n=18) were infected by nasal inoculation and evaluated for histopathological changes as well as tissue viral loads. RESULTS: From day 5 on BALB/c mice showed myocardial viral replication. Whereas focal inflammation occurred simultaneously, necrosis was first observed 9 days post-infection. The maximum rates of necrosis (40%) and of focal inflammation (33%) were found after 10 to 12 and 33 to 35 days, respectively. Some animals developed persistent viral activity and inflammation throughout the observation period of three months. Inflammation was mainly related to T cell infiltrates. Although C57BL/6 mice also showed myocardial inflammation, necrosis was not found suggesting differences in the susceptibility to the virus in distinct mouse strains. In immunodeficient animals higher myocardial viral loads were observed compared to wild-type mice but no cardiac lesions, which suggests that the antiviral immune response contributed to the lesions. CONCLUSIONS: The model system presented here is the first to allow detailed studies on cardiac disease caused by gamma-HV infections and may facilitate the development of more specific treatment options for human cardiac EBV infection.

High prevalence of human bocavirus detected in young children with severe acute lower respiratory tract disease by use of a standard PCR protocol and a novel real-time PCR protocol.

The human bocavirus (HBoV) was recently isolated from respiratory tract samples. Within a study collective of children with severe lower respiratory tract disease, the patients testing positive for HBoV (12.8%) had a higher rate of underlying cardiopulmonary disease. Viral loads in respiratory tract specimens varied from 10(2) to 10(10) genome equivalents/ml.

Intrathecal synthesis of anti-viral antibodies in pediatric patients.

INTRODUCTION: Detection of intrathecal synthesis of specific antibodies (antibody index (AI)) is an established method to prove cerebral viral infection. Experience on its clinical application in large patient groups, however, is sparse. METHODS: Retrospective analysis of pediatric patients with positive viral AI treated at RWTH Aachen University Hospital between 1999 and 2005. RESULTS: 63 patients were studied, including 14 with encephalitis, 12 with neuritis, nine with cerebral vasculitis, six with multiple sclerosis (MS), five with severe cephalgia, five with psychiatric symptoms, three with hearing loss, two with seizures, three with white matter diseases, two with movement disorders, one with meningococcal meningitis and one with sinus venous thrombosis. Seven had several positive AI among them only one patient with MS. Of the 51 patients with a single positive AI and not having MS, 16 showed a positive AI for herpes simplex-, 13 for varicella zoster-, nine for Epstein-Barr-, four for cytomegalo-, four for mumps-, three for rubella- and two for measles virus. Frequent combinations were varicella zoster virus (VZV) and vasculitis (n = 8), herpes simplex virus (HSV) and neuritis (n = 6), Epstein-Barr virus (EBV) (n = 5), respectively, VZV (n = 4) and encephalitis as wells as mumps virus (n = 2) and hearing loss. Matched polymerase chain reaction (PCR) and AI data were available in 25 patients. PCR was simultaneously positive in three cases only. DISCUSSION: AI testing identifies a similar spectrum of pathogens as known from cerebrospinal fluid (CSF) PCR studies. It complements the PCR and increases the chance for adequate diagnosis and treatment of patients with assumed cerebral viral infections.

Reactivation of the Epstein-Barr virus from viral latency by an S-adenosylhomocysteine hydrolase/14-3-3 zeta/PLA2-dependent pathway.

The S-adenosylhomocysteine hydrolase (SAH) and 14-3-3 zeta/phospholipase A2 (PLA2) are transcriptionally activated in parallel to the induction of the Epstein-Barr virus (EBV) lytic cycle by the ganglioside IV(3)NeuAc-nLcOse(4)Cer. For analysis of the initiation of the viral reactivation, SAH and 14-3-3 zeta/PLA2 were overexpressed. Expression of EA-D, BZLF1, and BHRF1 was increased in response to both, SAH- and 14-3-3 zeta/PLA2 overexpression indicating the initiation of the EBV lytic cycle. Expression of 14-3-3 zeta/PLA2 was shown to be increased in SAH overexpressing cells. Additionally, SAH-triggered initiation of viral reactivation could be inhibited by PLA2-specific inhibitors. The phosphorylation status of protein kinase C (PKC) was shown to be increased in SAH-overexpressing cells. PKC-specific inhibitors arrested SAH-triggered initiation of viral reactivation. Surprisingly, 14-3-3 zeta/PLA2-induced initiation of viral reactivation did not correlate with PKC activation. PKC-specific inhibitors were of no influence. SAH initiated EBV reactivation via the BZLF1-Zp and the BZLF1-Rp promoter, whereas 14-3-3 zeta/PLA2 was connected to the promoter Rp only. Our results suggest two routes of viral reactivation involving SAH, one associated with PKC and BZLF1-Zp, the other associated with 14-3-3 zeta/PLA2 and BZLF1-Rp.

Sensitivity of the Enzygnost anti-EBV/IgG for the determination of the Epstein-Barr virus immune status in pediatric patients.

The Enzygnost Anti-EBV/IgG shows good performance for populations not defined by age. Samples from 349 pediatric outpatients were screened with the assay and with immunofluorescence assay (IFA) as the gold standard. The Enzygnost assay showed a sensitivity of 85%. Ten and one-tenth percent of EBV seropositive samples were classified as intermediate, and 4.9% were falsely determined as seronegative when compared to the standard IgG anti-virus capsid antigen (VCA) IFA. Our data suggest a limited sensitivity of the assay with samples from pediatric patients.

Murine gammaherpesvirus-68 infection of mice: A new model for human cerebral Epstein-Barr virus infection.

Epstein-Barr virus infection may cause severe neurological complications that are not mirrored by animal models. Here, we show that nasal inoculation of newborn BALB/c wild-type mice with MHV-68, a murine gammaherpesvirus, causes cerebral infection with inflammation in 50% of the animals. The inflammatory patterns are strikingly similar to those known from Epstein-Barr virus, including hydrocephalus, meningitis, cerebellitis, focal or diffuse encephalitis, and temporal lobe encephalitis. This offers a new powerful tool to study the virological and immunological characteristics of cerebral gammaherpesvirus infections.