Intra- and Interspecies Genomic Transfer of the Enterococcus faecalis Pathogenicity Island

Enterococci are the third leading cause of hospital associated infections and have gained increased importance due to their fast adaptation to the clinical environment by acquisition of antibiotic resistance and pathogenicity traits. Enterococcus faecalis harbours a pathogenicity island (PAI) of 153 kb containing several virulence factors including the enterococcal surface protein (esp). Until now only internal fragments of the PAI or larger chromosomal regions containing it have been transfered. Here we demonstrate precise excision, circularization and horizontal transfer of the entire PAI element from the chromosome of E. faecalis strain UW3114. This PAI (ca. 200 kb) contained some deletions and insertions as compared to the PAI of the reference strain MMH594, transferred precisely and integrated site-specifically into the chromosome of E. faecalis (intergenic region) and Enterococcus faecium (tRNAlys). The internal PAI structure was maintained after transfer. We assessed phenotypic changes accompanying acquisition of the PAI and expression of some of its determinants. The esp gene is expressed on the surface of donor and both transconjugants. Biofilm formation and cytolytic activity were enhanced in E. faecalis transconjugants after acquisition of the PAI. No differences in pathogenicity of E. faecalis were detected using a mouse bacteraemia and a mouse peritonitis models (tail vein and intraperitoneal injection). A 66 kb conjugative pheromone-responsive plasmid encoding erm(B) (pLG2) that was transferred in parallel with the PAI was sequenced. pLG2 is a pheromone responsive plasmid that probably promotes the PAI horizontal transfer, encodes antibiotic resistance features and contains complete replication and conjugation modules of enterococcal origin in a mosaic-like composition. The E. faecalis PAI can undergo precise intra- and interspecies transfer probably with the help of conjugative elements like conjugative resistance plasmids, supporting the role of horizontal gene transfer and antibiotic selective pressure in the successful establishment of certain enterococci as nosocomial pathogens

New insights into perinatal testicular torsion

Perinatal testicular torsion is a relatively rare event that remains unrecognized in many patients or is suspected and treated accordingly only after an avoidable loss of time. The authors report their own experience with several patients, some of them quite atypical but instructive. Missed bilateral torsion is an issue, as are partial torsion, possible antenatal signs, and late presentation. These data are discussed together with the existing literature and may help shed new light on the natural course of testicular torsion and its treatment. The most important conclusion is that a much higher index of suspicion based on clinical findings is needed for timely detection of perinatal torsion. It is the authors’ opinion that immediate surgery is mandatory not only in suspected bilateral torsions but also in cases of possible unilateral torsions. There is no place for a more fatalistic “wait-and-see” approach. Whenever possible, even necrotic testes should not be removed during surgery because some endocrine function may be retained

Amyloids - A functional coat for microorganisms

Amyloids are filamentous protein structures ~10 nm wide and 0.1–10 µm long that share a structural motif, the cross-β structure. These fibrils are usually associated with degenerative diseases in mammals. However, recent research has shown that these proteins are also expressed on bacterial and fungal cell surfaces. Microbial amyloids are important in mediating mechanical invasion of abiotic and biotic substrates. In animal hosts, evidence indicates that these protein structures also contribute to colonization by activating host proteases that are involved in haemostasis, inflammation and remodelling of the extracellular matrix. Activation of proteases by amyloids is also implicated in modulating blood coagulation, resulting in potentially life-threatening complications.

The creatine kinase system and pleiotropic effects of creatine

The pleiotropic effects of creatine (Cr) are based mostly on the functions of the enzyme creatine kinase (CK) and its high-energy product phosphocreatine (PCr). Multidisciplinary studies have established molecular, cellular, organ and somatic functions of the CK/PCr system, in particular for cells and tissues with high and intermittent energy fluctuations. These studies include tissue-specific expression and subcellular localization of CK isoforms, high-resolution molecular structures and structure–function relationships, transgenic CK abrogation and reverse genetic approaches. Three energy-related physiological principles emerge, namely that the CK/PCr systems functions as (a) an immediately available temporal energy buffer, (b) a spatial energy buffer or intracellular energy transport system (the CK/PCr energy shuttle or circuit) and (c) a metabolic regulator. The CK/PCr energy shuttle connects sites of ATP production (glycolysis and mitochondrial oxidative phosphorylation) with subcellular sites of ATP utilization (ATPases). Thus, diffusion limitations of ADP and ATP are overcome by PCr/Cr shuttling, as most clearly seen in polar cells such as spermatozoa, retina photoreceptor cells and sensory hair bundles of the inner ear. The CK/PCr system relies on the close exchange of substrates and products between CK isoforms and ATP-generating or -consuming processes. Mitochondrial CK in the mitochondrial outer compartment, for example, is tightly coupled to ATP export via adenine nucleotide transporter or carrier (ANT) and thus ATP-synthesis and respiratory chain activity, releasing PCr into the cytosol. This coupling also reduces formation of reactive oxygen species (ROS) and inhibits mitochondrial permeability transition, an early event in apoptosis. Cr itself may also act as a direct and/or indirect anti-oxidant, while PCr can interact with and protect cellular membranes. Collectively, these factors may well explain the beneficial effects of Cr supplementation. The stimulating effects of Cr for muscle and bone growth and maintenance, and especially in neuroprotection, are now recognized and the first clinical studies are underway. Novel socio-economically relevant applications of Cr supplementation are emerging, e.g. for senior people, intensive care units and dialysis patients, who are notoriously Cr-depleted. Also, Cr will likely be beneficial for the healthy development of premature infants, who after separation from the placenta depend on external Cr. Cr supplementation of pregnant and lactating women, as well as of babies and infants are likely to be of benefit for child development. Last but not least, Cr harbours a global ecological potential as an additive for animal feed, replacing meat- and fish meal for animal (poultry and swine) and fish aqua farming. This may help to alleviate human starvation and at the same time prevent over-fishing of oceans

Meckel’s diverticulum in paediatric practice on Crete (Greece): A 10-year review

Background: Although Meckel’s diverticulum (MD) is the most prevalent congenital abnormality of the gastrointestinal tract, it has varied presentations and often becomes a diagnostic challenge. The purpose ofthis study was to review the diverse presentations of MD, record the epidemiologic features for Crete and review the detection techniques and the treatment options.Patients and Methods: This was a review of the records of all children who underwent surgery for MD in the department of Paediatric Surgery of the University Hospital of Crete (Greece) between January 1999 and January 2009. Result: A total of 45 patients (32 male and 13 female) aged 1 to 13 years (median 10 years) with a diagnosis of MD were retrospectively reviewed. The collected data were analysed, looking at age, gender, clinical features, investigations, histopathological findings and surgical interventions. In 25 patients, MD was an incidental finding at laparotomy because of  appendicitis. The remaining 20 patients were symptomatic and presented with various clinical features. Nine patients (19.9%) had clinical features of peritonitis; of these, three had perforated MD and six had Meckel’s diverticulitis at laparotomy. Four patients were diagnosed with intestinal obstruction. Seven patients (15.5%) presented with lower gastrointestinal bleeding. Ultrasound scans revealed intussusception in three patients, requiring open reduction. The remaining four patients with bleeding per rectum underwent a Meckel’s Tc99 scan that showed a positive tracer.Conclusion: All patients with MD underwent Meckel’s diverticulectomy with appendicectomy. MD has an incidence of approximately 1 to 2% in our population. It is necessary to maintain a high index of suspicion in the in the diagnosis of MD paediatric age group because it can be easily misdiagnosed

Ischemia modified albumin, high-sensitivity c-reactive protein and natriuretic peptide in patients with coronary atherosclerosis

Background: Ischemia modified albumin (IMA), is a new biomarker of oxidative processes involved with coronary artery disease (CAD). We determined serum IMA, high-sensitivity C-reactive protein (hsCRP), and natriuretic peptide (NT-proBNP), and evaluated their correlation with severity of coronary atherosclerosis in patients undergoing coronary angiography (CA). Cardiac troponin T (cTnT), CK-MB mass, albumin and Total Antioxidant Status (TAS) were also evaluated. Methods: The study included 114 patients (88 men and 30 women) aged 43-80 years with documented CAD without evidence of acute coronary syndrome undergoing CA and 163 controls (131 men and 32 women) similarly aged. Results: IMA, hsCRP and NT-proBNP were higher (p < 0.001 and p = 0.008 for NT-proBNP) while TAS was lower (p < 0.001) in patients than in controls. IMA and TAS were negatively correlated in all subjects (p < 0.01). Among patients, there was no correlation between IMA and the number of diseased vessels. For CAD diagnosis the best cut-off point for IMA was 101.5 KU/L with a sensitivity and a specificity of 87.7% and a negative predictive value of 83.3%. IMA was associated with an increased risk for CAD (OR = 1.23, 95% CI: 1.16-1.31; p < 0.001). Conclusions: IMA determination may provide earlier information of CAD presence before hsCRP or NT-proBNP elevation, contributing to early assessment of overall patient risk. © 2009 Elsevier B.V. All rights reserved

Ultra-smooth lithium niobate photonic micro-structures by surface tension reshaping

Annealing of micro-structured lithium niobate substrates at temperatures close to, but below the melting point, allows surface tension to reshape preferentially melted surface zones of the crystal. The reshaped surface re-crystallizes upon cooling to form a single crystal again as it is seeded by the bulk which remains solid throughout the process. This procedure yields ultra-smooth single crystal superstructures suitable for the fabrication of photonic micro-components with low scattering loss