Fingerprinting of Salmonella enterica subsp. enterica serovar Enteritidis by ribotyping

Objective: To carry out an epidemiologic evaluation of Salmonella enterica subsp. enterica serovar Enteritidis outbreaks in households and small communities by means of rRNA gene restriction pattern analysis (ribotyping).
Method: One hundred Enteritidis isolates dating from 1989 to 1994 which could be allocated epidemiologically to different sources or to small community outbreaks were investigated with ribotyping, a fingerprinting method in which bacterial DNA is hybridized with the biotin-labeled plasmid pKK 3535 containing a ribosomal RNA operon of Escherichia coli to determine the ribosomal RNA gene restriction patterns.
Results: Four different ribotyping patterns were found with the restriction endonuclease Sma I and nine with Sph I. Ribotypes of isolates which could be allocated epidemiologically to a common source usually corresponded. Almost 60% of the Enteritidis infections had the ribotyping pattern Sph I-A. In contrast, this pattern was not found in any of the five Enteritidis strains isolated in 1989. The suspicion that Enteritidis phage type 4 infections are caused by consumption of insufficiently heated eggs is supported by the fact that the ribotyping pattern Sph 1-A was found in isolates from eggs and from human specimens.
Conclusions: As patterns Sph I-A and Sma I-J appeared in 58% and 75% of the isolates, respectively, ribotyping cannot be used for the differentiation between various outbreaks with these two patterns. In cases where the Enteritidis strains showed less frequent patterns, ribotyping seems to be a practical tool for the identification of infection chains. In addition newly appearing ribotyping patterns can give information about the epidemiologic development of Enteritidis infection.     

Molecular cloning and sequencing of general odorant-binding proteins GOBP1 and GOBP2 from the tobacco hawk moth Manduca sexta: comparisons with other insect OBPs and their signal peptides.

Odorant-binding proteins (OBPs) are small, water-soluble proteins uniquely expressed in olfactory tissue of insects and vertebrates. OBPs are present in the aqueous fluid surrounding olfactory sensory dendrites and are thought to aid in the capture and transport of hydrophobic odorants into and through this fluid. OBPs may represent the initial biochemical recognition step in olfaction, because they transport odorants to the receptor neurons. Insect OBPs are represented by multiple classes: pheromone-binding proteins (PBPs) and general odorant-binding proteins (GOBP1 and GOBP2). PBPs associate with pheromone-sensitive neurons, while GOBPs associate with general odorant-sensitive neurons. Analysis of N-terminal amino acid sequences of 14 insect OBPs isolated from six species indicated that the PBPs were variable and the GOBPs were highly conserved. However, inferred properties of these proteins were based only on partial sequence data. We now report the full-length sequences of a GOBP1 and GOBP2 from the moth Manduca sexta and compare these sequences with those of PBPs from three species, including M. sexta, Antheraea polyphemus, and A. pernyi. We also compare these with a GOBP2 of A. pernyi, previously identified only as a novel OBP. These comparisons fully support our N-terminal analysis. The signal peptide sequences of seven insect OBPs reveal conserved sequences within OBP classes, but not between OBP classes even within the same animal species. This suggests that multiple OBPs may be coexpressed in the same cell type, but differentially processed in a class-specific manner. Properties of the GOBPs suggest that general olfaction is broadly receptive at the periphery. Properties of the PBPs suggest that pheromone olfaction is discriminatory at the periphery, and that the initial biochemical steps in pheromone detection may play an active role in odor perception.     

Establishment of Recombinant Trisegmented Mopeia Virus Expressing Two Reporter Genes for Screening of Mammarenavirus Inhibitors

Highly pathogenic Arenaviruses, like the Lassa Virus (LASV), pose a serious public health threat in affected countries. Research and development of vaccines and therapeutics are urgently needed but hampered by the necessity to handle these pathogens under biosafety level 4 conditions. These containment restrictions make large-scale screens of antiviral compounds difficult. Therefore, the Mopeia virus (MOPV), closely related to LASV, is often used as an apathogenic surrogate virus. We established for the first time trisegmented MOPVs (r3MOPV) with duplicated S segments, in which one of the viral genes was replaced by the reporter genes ZsGreen (ZsG) or Renilla Luciferase (Rluc), respectively. In vitro characterization of the two trisegmented viruses (r3MOPV ZsG/Rluc and r3MOPV Rluc/ZsG), showed comparable growth behavior to the wild type virus and the expression of the reporter genes correlated well with viral titer. We used the reporter viruses in a proof-of-principle in vitro study to evaluate the antiviral activity of two well characterized drugs. IC₅₀ values obtained by Rluc measurement were similar to those obtained by virus titers. ZsG expression was also suitable to evaluate antiviral effects. The trisegmented MOPVs described here provide a versatile and valuable basis for rapid high throughput screening of broadly reactive antiviral compounds against arenaviruses under BSL-2 conditions.     

Neurological Sequelae in Adults After E coli O104: H4 Infection-Induced Hemolytic-Uremic Syndrome

In an outbreak of shiga toxin-producing Escherichia coli infections and associated hemolytic-uremic syndrome (STEC O104:H4) in Germany in the year 2011 neurological complications in adult patients occurred unexpectedly frequent, ranging between 48% and 100% in different patient groups. Few is known about the long-term effects of such complications and so we performed follow-up exams on 44 of the patients treated for STEC-HUS at Hannover Medical Scool in this observational study. Standardized follow-up exams including neurological and neuropsychological assessments, laboratory testing, magnetic resonance imaging (MRI), and EEG were carried out. Subgroups were examined 2 (n = 34), 7 (n = 22), and 19 (n = 23) months after disease onset. Additionally, at the 19-month follow-up, quality of life, sleep quality, and possible fatigue were assessed.Nineteen months after disease onset 31 patients were reassessed, 22 of whom still suffered from symptoms such as fatigue, headache, and attention deficits. In the neuropsychological assessments only 39% of the patients performed normal, whereas 61% scored borderline pathological or lower. Upon reviewal, the follow-up data most prominently showed a secondary decline of cognitive function in about one-quarter of the patients. Outcome was not related to treatment or laboratory data in the acute phase of the disease nor length of hospitalization. Prognosis of STEC-HUS associated brain dysfunction in adults with regard to severity of symptoms is mostly good; some patients however still have not made a full recovery. Patients’ caretakers have to be aware of possible secondary decline of brain function as was observed in this study.     

Genetic and Environmental Influences on Self-Control: Assessing Self-Control with the ASEBA Self-Control Scale

This study used a theoretically-derived set of items of the Achenbach System of Empirically Based Assessment to develop the Achenbach Self-Control Scale (ASCS) for 7–16 year olds. Using a large dataset of over 20,000 children, who are enrolled in the Netherlands Twin Register, we demonstrated the psychometric properties of the ASCS for parent-, self- and teacher-report by examining internal and criterion validity, and inter-rater and test–retest reliability. We found associations between the ASCS and measures of well-being, educational achievement, and substance use. Next, we applied the classical twin design to estimate the genetic and environmental contributions to self-control. Genetic influences accounted for 64–75% of the variance in self-control based on parent- and teacher-report (age 7–12), and for 47–49% of the variance in self-control based on self-report (age 12–16), with the remaining variance accounted by non-shared environmental influences. In conclusion, we developed a validated and accessible self-control scale, and show that genetic influences explain a majority of the individual differences in self-control across youth aged 7–16 years.     

Age‐related changes in skin mechanical properties: a quantitative evaluation of 120 female subjects

Background/purpose: The most commonly used method to determine the mechanical ability of skin is the creep test using suction chamber devices. Until now, there is no scientific consensus upon which skin deformation parameters and which body sites are particularly suitable to describe age‐related changes in human skin mechanics. The aim of this study was to find those mechanical skin parameters best representing influence of aging at five different body sites. Methods: A total of 120 healthy women aged 18–65, divided into four similar age groups, were included in this study. The biomechanical properties of the skin were measured using the Cutometer^® MPA 580 on five body sites: cheek, neck, cleavage, volar forearm and back of the hand. In order to analyze parameters referred to 1 mm skin thickness, we also used 20 MHz sonography (DUB 20). Results: A high average correlation with age was found for the parameters U_a/U_f, U_r/U_e, U_r, U_r/U_f and U_a. Only low correlation with age was found for the parameters U_v/U_e, U_f‐U_a, U_f5/U_f, U_d/U_f and U_a5. The localizations cheek, forearm and neck showed the highest correlation with age, while cleavage showed only low correlation. Conclusion: According to the results of our study, we recommend the parameter ratio of elastic recovery to distensibility (U_r/U_f) as well as the gross elasticity (U_a/U_f) for evaluation of aging effects on the mechanical properties of skin. Their high correlation with age makes them particularly applicable to represent the influence of aging onto skin mechanical properties. Most suitable localizations to evaluate skin aging are cheek, forearm and neck.     

Sleep and resting‐state functional magnetic resonance imaging connectivity in middle‐aged adults and the elderly: A population‐based study

Sleep problems increase with ageing. Increasing evidence suggests that sleep problems are not only a consequence of age‐related processes, but may independently contribute to developing vascular or neurodegenerative brain disease. Yet, it remains unclear what mechanisms underlie the impact sleep problems may have on brain health in the general middle‐aged and elderly population. Here, we studied sleep's relation to brain functioning in 621 participants (median age 62 years, 55% women) from the population‐based Rotterdam Study. We investigated cross‐sectional associations of polysomnographic and subjectively measured aspects of sleep with intrinsic neural activity measured with resting‐state functional magnetic resonance imaging on a different day. We investigated both functional connectivity between regions and brain activity (blood‐oxygen‐level‐dependent signal amplitude) within regions, hierarchically towards smaller topographical levels. We found that longer polysomnographic total sleep time is associated with lower blood‐oxygen‐level‐dependent signal amplitude in (pre)frontal regions. No objective or subjective sleep parameters were associated with functional connectivity between or within resting‐state networks. The findings may indicate a pathway through which sleep, in a ‘real‐life’ population setting, impacts brain activity or regional brain activity determines total sleep time.     

Acidified seawater impacts sea urchin larvae pH regulatory systems relevant for calcification

Calcifying echinoid larvae respond to changes in seawater carbonate chemistry with reduced growth and developmental delay. To date, no information exists on how ocean acidification acts on pH homeostasis in echinoderm larvae. Understanding acid–base regulatory capacities is important because intracellular formation and maintenance of the calcium carbonate skeleton is dependent on pH homeostasis. Using H⁺-selective microelectrodes and the pH-sensitive fluorescent dye BCECF, we conducted in vivo measurements of extracellular and intracellular pH (pH_e and pH_i) in echinoderm larvae. We exposed pluteus larvae to a range of seawater CO₂ conditions and demonstrated that the extracellular compartment surrounding the calcifying primary mesenchyme cells (PMCs) conforms to the surrounding seawater with respect to pH during exposure to elevated seawater pCO₂. Using FITC dextran conjugates, we demonstrate that sea urchin larvae have a leaky integument. PMCs and spicules are therefore directly exposed to strong changes in pH_e whenever seawater pH changes. However, measurements of pH_i demonstrated that PMCs are able to fully compensate an induced intracellular acidosis. This was highly dependent on Na⁺ and HCO₃⁻, suggesting a bicarbonate buffer mechanism involving secondary active Na⁺-dependent membrane transport proteins. We suggest that, under ocean acidification, maintained pH_i enables calcification to proceed despite decreased pH_e. However, this probably causes enhanced costs. Increased costs for calcification or cellular homeostasis can be one of the main factors leading to modifications in energy partitioning, which then impacts growth and, ultimately, results in increased mortality of echinoid larvae during the pelagic life stage.