The Marine Isolate <Emphasis Type="Italic">Novosphingobium</Emphasis> sp. PP1Y Shows Specific Adaptation to Use the Aromatic Fraction of Fuels as the Sole Carbon and Energy Source

Novosphingobium sp. PP1Y, isolated from a surface seawater sample collected from a closed bay in the harbour of Pozzuoli (Naples, Italy), uses fuels as its sole carbon and energy source. Like some other Sphingomonads, this strain can grow as either planktonic free cells or sessile-aggregated flocks. In addition, this strain was found to grow as biofilm on several types of solid and liquid hydrophobic surfaces including polystyrene, polypropylene and diesel oil. Strain PP1Y is not able to grow on pure alkanes or alkane mixtures but is able to grow on a surprisingly wide range of aromatic compounds including mono, bi, tri and tetracyclic aromatic hydrocarbons and heterocyclic compounds. During growth on diesel oil, the organic layer is emulsified resulting in the formation of small biofilm-coated drops, whereas during growth on aromatic hydrocarbons dissolved in paraffin the oil layer is emulsified but the drops are coated only if the mixtures contain selected aromatic compounds, like pyrene, propylbenzene, tetrahydronaphthalene and heterocyclic compounds. These peculiar characteristics suggest strain PP1Y has adapted to efficiently grow at the water/fuel interface using the aromatic fraction of fuels as the sole carbon and energy source.     

Microbial Deterioration of Artistic Tiles from the Façade of the Grande Albergo Ausonia &; Hungaria (Venice,Italy)

The Grande Albergo Ausonia &; Hungaria (Venice Lido, Italy) has an Art Nouveau polychrome ceramic coating on its façade, which was restored in 2007. Soon after the conservation treatment, many tiles of the façade decoration showed coloured alterations putatively attributed to the presence of microbial communities. To confirm the presence of the biological deposit and the stratigraphy of the Hungaria tiles, stereomicroscope, optical and environmental scanning electron microscope observations were made. The characterisation of the microbial community was performed using a PCR–DGGE approach. This study reported the first use of a culture-independent approach to identify the total community present in biodeteriorated artistic tiles. The case study examined here reveals that the coloured alterations on the tiles were mainly due to the presence of cryptoendolithic cyanobacteria. In addition, we proved that the microflora present on the tiles was generally greatly influenced by the environment of the Hungaria hotel. We found several microorganisms related to the alkaline environment, which is in the range of the tile pH, and related to the aquatic environment, the presence of the acrylic resin Paraloid B72® used during the 2007 treatment and the pollutants of the Venice lagoon.     

Multidrug-Resistant Enterococci in Animal Meat and Faeces and Co-Transfer of Resistance from an <Emphasis Type="Italic">Enterococcus durans</Emphasis> to a Human <Emphasis Type="Italic">Enterococcus faecium</Emphasis>

Forty-eight isolates resistant to at least two antibiotics were selected from 53 antibiotic-resistant enterococci from chicken and pig meat and faeces and analysed for specific resistance determinants. Of the 48 multidrug-resistant (MDR) strains, 31 were resistant to two antibiotics (29 to erythromycin and tetracycline, 1 to erythromycin and vancomycin, 1 to vancomycin and tetracycline), 14 to three (erythromycin, tetracycline and vancomycin or ampicillin) and 3 to four (erythromycin, vancomycin, ampicillin and gentamicin). erm(B), tet(M), vanA and aac (6′)-Ie aph (2′′)-Ia were the antibiotic resistance genes most frequently detected. All 48 MDR enterococci were susceptible to linezolid and daptomycin. Enterococcus faecalis (16), Enterococcus faecium (8), Enterococcus mundtii (2) and Enterococcus gallinarum (1) were identified in meat, and E. faecium (13) and Enterococcus durans (13) in faeces. Clonal spread was not detected, suggesting a large role of gene transfer in the dissemination of antibiotic resistance. Conjugative transfer of resistance genes was more successful when donors were enterococcal strains isolated from faeces; co-transfer of vanA and erm(B) to a human E. faecium occurred from both E. faecium and E. durans pig faecal strains. These data show that multidrug resistance can be found in food and animal species other than E. faecium and E. faecalis, and that these species can efficiently transfer antibiotic resistance to human strains in inter-specific matings. In particular, the occurrence of MDR E. durans in the animal reservoir could have a role in the emergence of human enterococcal infections difficult to eradicate with antibiotics.     

Sepsis-induced alterations in sleep of rats

Sepsis is a systemic immune response to infection that may result in multiple organ failure and death. Polymicrobial infections remain a serious clinical problem, and in the hospital, sepsis is the number-one noncardiac killer. Although the central nervous system may be one of the first systems affected, relatively little effort has been made to determine the impact of sepsis on the brain. In this study, we used the cecal ligation and puncture (CLP) model to determine the extent to which sepsis alters sleep, the EEG, and brain temperature (Tbr) of rats. Sepsis increases the amount of time rats spend in non-rapid eye movement sleep (NREMS) during the dark period, but not during the light period. Rapid eye movements sleep (REMS) of septic rats is suppressed for about 24 h following CLP surgery, after which REMS increases during dark periods for at least three nights. The EEG is dramatically altered shortly after sepsis induction, as evidenced by reductions in slow-frequency components. Furthermore, sleep is fragmented, indicating that the quality of sleep is diminished. Effects on sleep, the EEG, and Tbr persist for at least 84 h after sepsis induction, the duration of our recording period. Immunohistochemical assays focused on brain stem mechanisms responsible for alterations in REMS, as little information is available concerning infection-induced suppression of this sleep stage. Our immunohistochemical data suggest that REMS suppression after sepsis onset may be mediated, in part, by the brain stem GABAergic system. This study demonstrates for the first time that sleep and EEG patterns are altered during CLP-induced sepsis. These data suggest that the EEG may serve as a biomarker for sepsis onset. These data also contribute to our knowledge of potential mechanisms, whereby infections alter sleep and other central nervous system functions.     

Detecting common copy number variants in high-throughput sequencing data by using JointSLM algorithm

The discovery of genomic structural variants (SVs), such as copy number variants (CNVs), is essential to understand genetic variation of human populations and complex diseases. Over recent years, the advent of new high-throughput sequencing (HTS) platforms has opened many opportunities for SVs discovery, and a very promising approach consists in measuring the depth of coverage (DOC) of reads aligned to the human reference genome. At present, few computational methods have been developed for the analysis of DOC data and all of these methods allow to analyse only one sample at time. For these reasons, we developed a novel algorithm (JointSLM) that allows to detect common CNVs among individuals by analysing DOC data from multiple samples simultaneously. We test JointSLM performance on synthetic and real data and we show its unprecedented resolution that enables the detection of recurrent CNV regions as small as 500 bp in size. When we apply JointSLM to analyse chromosome one of eight genomes with different ancestry, we identify 3000 regions with recurrent CNVs of different frequency and size: hierarchical clustering on these regions segregates the eight individuals in two groups that reflect their ancestry, demonstrating the potential utility of JointSLM for population genetics studies.     

Significant differences in gene expression of GABA receptors in peripheral blood leukocytes of migraineurs

Migraine is a debilitating neurovascular disorder, with a substantial genetic component. The exact cause of a migraine attack is unknown; however cortical hyperexcitability is thought to play a role. As Gamma-aminobutyric Acid (GABA) is the major inhibitory neurotransmitter in the brain, malfunctioning of this system may be a cause of the hyperexcitability. To date, there has been limited research examining the gene expression or genetics of GABA receptors in relation to migraine. The aim of our study was to determine if GABA receptors play a role in migraine by investigating their gene expression using profile in migraine affected individuals and non-affected controls by Q-PCR. Gene expression of GABA(A) receptor subunit isoforms (GABRA3, GABRB3, GABRQ) and GABA(B) receptor 2 (GABBR2) was quantified in mRNA obtained from peripheral blood leukocytes from 28 migraine subjects and 22 healthy control subjects. Analysis of results showed that two of the tested genes, GABRA3 and GABBR2, were significantly down regulated in migraineurs (P=0.018; P=0.017), compared to controls. Results from the other tested genes did not show significant gene expression variation. The results indicate that there may be specific GABA receptor gene expression variation in migraine, particularly involving the GABRA3 and GABBR2 genes. This study also identifies GABRA3 and GABBR2 as potential biomarkers to select migraineurs that may be more responsive to GABA agonists with future investigations in this area warranted.     

Cytochrome P-450 3A13 and endothelin jointly mediate ductus arteriosus constriction to oxygen in mice

The fetal ductus arteriosus (DA) contracts to oxygen, and this feature, maturing through gestation, is considered important for its closure at birth. We have previously obtained evidence of the involvement of cytochrome P-450, possibly of the 3A subfamily (CYP3A), in oxygen sensing and have also identified endothelin (ET)-1 as the attendant effector for the contraction. Here, we examined comparatively wild-type (WT) and CYP3A-null (Cyp3a(-/-)) mice for direct validation of this concept. We found that the CYP3A subfamily is represented only by CYP3A13 in the WT DA. CYP3A13 was also detected in the DA by immunofluorescence microscopy, being primarily colocalized with the endoplasmic reticulum in both endothelial and muscle cells. However, a distinct signal was also evident in the plasma membrane. Isolated DAs from term WT animals developed a sustained contraction to oxygen with transient contractions superimposed. Conversely, no tonic response occurred in Cyp3a(-/-) DAs, whereas the phasic response persisted unabated. Oxygen did not contract the preterm WT DA but caused a full-fledged contraction after retinoic acid (RA) treatment. RA also promoted an oxygen contraction in the Cyp3a(-/-) DA. However, responses of RA-treated WT and Cyp3a(-/-) mice differed in that only the former abated with ET-1 suppression. This implies the existence of an alternative target for RA responsible for the oxygen-induced contraction in the absence of CYP3A13. In vivo, the DA was constricted in WT and Cyp3a(-/-) newborns, although with a tendency to be less narrowed in the mutant. We conclude that oxygen acts primarily through the complex CYP3A13 (sensor)/ET-1 (effector) and, in an accessory way, directly onto ET-1. However, even in the absence of CYP3A13, the DA may close postnatally thanks to the contribution of ET-1 and the likely involvement of compensating mechanism(s) identifiable with an alternative oxygen-sensing system and/or the withdrawal of relaxing influence(s) operating prenatally.     

Heart rate reduction with ivabradine prevents the global phenotype of left ventricular remodeling

The aim of this study was to investigate the effect of chronic heart rate (HR) reduction with the hyperpolarization-activated current inhibitor ivabradine on the global phenotype of left ventricular (LV) remodeling in a ligated rat model. Seven days after coronary artery ligation, Wistar rats received ivabradine (10 mg · kg(-1) · day(-1) administered in drinking water) [myocardial infarction + ivabradine (MI+IVA), n = 22] or vehicle only (drinking water) (MI, n = 20) for 90 days. A sham group (n = 20) was included for model validation. MI+IVA rats had 12% lower HR (P < 0.01), improved LV volumes, 15% higher LV ejection fraction (LVEF, P < 0.01) than MI rats, and 33% reductions in both plasma atrial natriuretic peptide (ANP, P = 0.052) and cardiac hydroxyproline. Using patch-clamp, action potential duration was reduced and transient outward current density increased (P < 0.05). Cardiac energy metabolism was also improved (+33% creatine phosphate, P < 0.001; +15% ATP; and +9% energy charge, P < 0.05). Significant correlations were found between HR and parameters of cardiac metabolism, ANP, and LVEF (all P < 0.05). The HR-reducing properties of ivabradine prevent changes in the global phenotype of LV remodeling in the rat, optimize energy consumption, and avoid electrophysiological and structural remodeling.     

Increased arginine-vasopressin response to hypertonic stimulation and upright posture in idiopathic hyperprolactinemia

To evaluate the possible influence of idiopathic hyperprolactinemia on the arginine-vasopressin (AVP) response to osmotic and pressure-volumetric stimuli, 14 idiopathic hyperprolactinemic women and 13 normoprolactinemic women were studied during a hypertonic saline infusion test (0.51M NaCl infusion for 2h) and an orthostatic test (standing upright and maintaining an orthostatic position for 20min). In both experimental conditions, the AVP response was significantly higher in women with idiopathic hyperprolactinemia than in normal normoprolactinemic women. These results indicate that in women hyperprolactinemia influences the AVP response to hyperosmotic and hypovolemic stimuli.