Diagnostic aspects of infections with Chlamydia trachomatis, Neisseria gonorrhoeae and herpes simplex virus

The sexually transmitted diseases (STOs) constitute a worldwide problem of major significance in terms of health. economic and social consequences. The most important STOs are Ihe bacterial infections syphilis (causative agent Treponema pal/idum sub·species pallidum), gonorrhoea (causative agent Neisseria gonorrllOeae, N. gOllorrhoeae), infections caused by Chlamydia trachomatis (C. trachomatis) and the viral infections herpes genitalis (causative agent herpes simplex virus, HSV), condylomata acuminata (causative agent human papilloma virus, HPV) and human immunodeficiency virus infections including AIDS. In addition, donovanosis (causative agent Calymmatobacterium grallulomatis) and chancroid (causative agent Haemophilus ducrep) are important in the developing countries. The combat against STOs is aimed at disrupting the infectious cascade. Attempts have been made to achieve this via education (for instance: safe sex campaigns), contact tracing, the screening of high-risk groups and treatment of patients. It was expected that this would decrease the spread of STOs in the community and prevent the development of complications and sequela in the individual patient.

Stapling of Peptides Potentiates the Antibiotic Treatment of Acinetobacter baumannii In Vivo

The rising incidence of multidrug resistance in Gram-negative bacteria underlines the urgency for novel treatment options. One promising new approach is the synergistic combination of antibiotics with antimicrobial peptides. However, the use of such peptides is not straightforward; they are often sensitive to proteolytic degradation, which greatly limits their clinical potential. One approach to increase stability is to apply a hydrocarbon staple to the antimicrobial peptide, thereby fixing them in an α-helical conformation, which renders them less exposed to proteolytic activity. In this work we applied several different hydrocarbon staples to two previously described peptides shown to act on the outer membrane, L6 and L8, and tested their activity in a zebrafish embryo infection model using a clinical isolate of Acinetobacter baumannii as a pathogen. We show that the introduction of such a hydrocarbon staple to the peptide L8 improves its in vivo potentiating activity on antibiotic treatment, without increasing its in vivo antimicrobial activity, toxicity or hemolytic activity

Nuclear trafficking, histone cleavage and induction of apoptosis by the meningococcal App and MspA autotransporters

Neisseria meningitidis, a major cause of bacterial meningitis and septicaemia, secretes multiple virulence factors, including the adhesion and penetration protein (App) and meningococcal serine protease A (MspA). Both are conserved, immunogenic, type Va autotransporters harbouring S6-family serine endopeptidase domains. Previous work suggested that both could mediate adherence to human cells, but their precise contribution to meningococcal pathogenesis was unclear. Here, we confirm that App and MspA are in vivo virulence factors since human CD46-expressing transgenic mice infected with meningococcal mutants lacking App, MspA or both had improved survival rates compared with mice infected with wild type. Confocal imaging showed that App and MspA were internalized by human cells and trafficked to the nucleus. Cross-linking and enzyme-linked immuno assay (ELISA) confirmed that mannose receptor (MR), transferrin receptor 1 (TfR1) and histones interact with MspA and App. Dendritic cell (DC) uptake could be blocked using mannan and transferrin, the specific physiological ligands for MR and TfR1, whereas in vitro clipping assays confirmed the ability of both proteins to proteolytically cleave the core histone H3. Finally, we show that App and MspA induce a dose-dependent increase in DC death via caspase-dependent apoptosis. Our data provide novel insights into the roles of App and MspA in meningococcal infection

Construction of synthetic carbonate plugs: A review and some recent developments

Plugs are cylindrical rocks with known dimensions that are extracted typically from reservoir formations with representative mineralogical compounds, petrophysical properties and oilfield fluids. They are used in the laboratory to understand the behaviour of oil in reservoirs. One of their applications is to study the screening of chemicals, such as surfactants and polymers, for enhanced oil recovery research before being applied in the reservoir. Many of Brazil’s pre-salt basins are located in ultra-deep waters, and the high heterogeneities of its offshore carbonate reservoirs make the extraction of representative rock samples difficult, risky and expensive. The literature reports the construction of synthetic plug samples that reproduce rocks as an alternative and viable solution for this issue. However, there is a lack of publications that focus on the construction of representative carbonate plugs that considers both the mineralogical composition and petrophysics properties, such as porosity and permeability. In this work, the construction of synthetic plugs is studied, using a combination of published methodologies to achieve an alternative construction of synthetic carbonate plugs for laboratory scale studies. Using a procedure based on the use of pulverized rock matrices with known particle sizes, uniaxial compaction, and probable CaCO3 solubility control by changing temperature and pH, it was possible to obtain synthetic carbonate plugs with a similar mineralogy to the natural carbonate reservoir. However, further studies are necessary to obtain more controlled petrophysical properties of such samples

Physiotherapy for Children with Functional Constipation:A Pragmatic Randomized Controlled Trial in Primary Care

Objective: To determine the effectiveness of physiotherapy plus conventional treatment compared with conventional treatment alone for the treatment of functional constipation in children age 4-17 years in primary care. Study design: Pragmatic randomized controlled trial with 8 months follow-up. Primary care physicians recruited children diagnosed with functional constipation (n = 234), and pediatricians recruited newly referred children with a diagnosis of functional constipation (n = 11). Conventional treatment comprised toilet training, nutritional advice, and laxative prescribing, whereas physiotherapy focused on resolving dyssynergic defecation. The primary outcome was treatment success over 8 months, defined as the absence of functional constipation (Rome III criteria) without laxative use. Secondary outcomes included the absence of functional constipation irrespective of continuation of laxative use and global perceived treatment effect. Results: Children were allocated to conventional treatment plus physiotherapy or conventional treatment alone (67 per group), mean (SD) age was 7.6 (3.5) years. Results of longitudinal analyses in the intention-to-treat population showed that the treatment success percentage was not statistically improved by adding physiotherapy to conventional treatment (adjusted relative risk [aRR] 0.80, 95% CI 0.44-1.30). At 4 months, fewer children receiving physiotherapy had treatment success (17%) than children receiving conventional treatment alone (28%), but this had equalized by 8 months (42% and 41%, respectively). The percentage of children without functional constipation, irrespective of continuation of laxative use, was not statistically different between groups over 8 months (aRR 1.12, 95% CI 0.82-1.34). Notably, parents reported significantly more global symptom improvement after physiotherapy than after conventional treatment (aRR 1.40; 95% CI 1.00-1.73). Conclusions: We find no evidence to recommend physiotherapy for all children with functional constipation in primary care. Trial registration: Netherlands Trial Registry: NTR4797

Virulence Evolution of the Human Pathogen Neisseria meningitidis by Recombination in the Core and Accessory Genome

Joseph B, Schwarz RF, Linke B, et al. Virulence Evolution of the Human Pathogen Neisseria meningitidis by Recombination in the Core and Accessory Genome. PLoS ONE. 2011;6(4): e18441.Background: Neisseria meningitidis is a naturally transformable, facultative pathogen colonizing the human nasopharynx. Here, we analyze on a genome-wide level the impact of recombination on gene-complement diversity and virulence evolution in N. meningitidis. We combined comparative genome hybridization using microarrays (mCGH) and multilocus sequence typing (MLST) of 29 meningococcal isolates with computational comparison of a subset of seven meningococcal genome sequences. Principal Findings: We found that lateral gene transfer of minimal mobile elements as well as prophages are major forces shaping meningococcal population structure. Extensive gene content comparison revealed novel associations of virulence with genetic elements besides the recently discovered meningococcal disease associated (MDA) island. In particular, we identified an association of virulence with a recently described canonical genomic island termed IHT-E and a differential distribution of genes encoding RTX toxin-and two-partner secretion systems among hyperinvasive and non-hyperinvasive lineages. By computationally screening also the core genome for signs of recombination, we provided evidence that about 40% of the meningococcal core genes are affected by recombination primarily within metabolic genes as well as genes involved in DNA replication and repair. By comparison with the results of previous mCGH studies, our data indicated that genetic structuring as revealed by mCGH is stable over time and highly similar for isolates from different geographic origins. Conclusions: Recombination comprising lateral transfer of entire genes as well as homologous intragenic recombination has a profound impact on meningococcal population structure and genome composition. Our data support the hypothesis that meningococcal virulence is polygenic in nature and that differences in metabolism might contribute to virulence

Physiotherapy plus conventional treatment versus conventional treatment only in the treatment of functional constipation in children:Design of a randomized controlled trial and cost-effectiveness study in primary care

BACKGROUND: Our aim was to design a study to evaluate the effectiveness and cost-effectiveness of adding physiotherapy to conventional treatment for children with functional constipation in primary care. Physiotherapy is focusing on improving the coordination between the pelvic floor and abdominal musculature during bowel movement, while conventional treatment is mainly focusing on symptomatic relief of symptoms, therefore, we expect the effects of physiotherapy will be more sustainable than the effects of conventional treatment. In this paper we describe the final study design and how the design was adapted, to overcome recruitment problems. METHODS: We designed a randomized controlled trial of children aged 4-17 years with functional constipation diagnosed by a general practitioner or pediatrician. Children in the intervention group received physiotherapy plus conventional treatment, and those in the control group received conventional treatment only. Follow-up measurements took place at 4 and 8 months. The primary outcome was treatment success defined according to the Rome-III criteria as the absence of functional constipation, with no laxative use. Secondary outcomes were absence of functional constipation irrespective of laxative use, quality of life, global perceived effect, and costs. Children were recruited from September 2014 to February 2017. Initially, we aimed to include children with recent symptom onset. However, in the first phase of enrollment we were confronted with an unforeseen recruitment problem: many children and their parents refused randomization because physiotherapy was considered too burdensome for the stage of disease. Therefore, we decided to also include children with a longer duration of symptoms. In total 134 children were included. DISCUSSION: The target number of participants is achieved. Therefore, the results may change thinking about the management of functional constipation in children. TRAIL REGISTRATION: Netherlands Trial Register ( NTR4797 ), registered 8 September 2014

An Outer Membrane Receptor of Neisseria meningitidis Involved in Zinc Acquisition with Vaccine Potential

Since the concentration of free iron in the human host is low, efficient iron-acquisition mechanisms constitute important virulence factors for pathogenic bacteria. In Gram-negative bacteria, TonB-dependent outer membrane receptors are implicated in iron acquisition. It is far less clear how other metals that are also scarce in the human host are transported across the bacterial outer membrane. With the aim of identifying novel vaccine candidates, we characterized in this study a hitherto unknown receptor in Neisseria meningitidis. We demonstrate that this receptor, designated ZnuD, is produced under zinc limitation and that it is involved in the uptake of zinc. Upon immunization of mice, it was capable of inducing bactericidal antibodies and we could detect ZnuD-specific antibodies in human convalescent patient sera. ZnuD is highly conserved among N. meningitidis isolates and homologues of the protein are found in many other Gram-negative pathogens, particularly in those residing in the respiratory tract. We conclude that ZnuD constitutes a promising candidate for the development of a vaccine against meningococcal disease for which no effective universal vaccine is available. Furthermore, the results suggest that receptor-mediated zinc uptake represents a novel virulence mechanism that is particularly important for bacterial survival in the respiratory tract