Oyster hemolymph is a complex and dynamic ecosystem hosting bacteria, protists and viruses.

BACKGROUND: The impact of the microbiota on host fitness has so far mainly been demonstrated for the bacterial microbiome. We know much less about host-associated protist and viral communities, largely due to technical issues. However, all microorganisms within a microbiome potentially interact with each other as well as with the host and the environment, therefore likely affecting the host health. RESULTS: We set out to explore how environmental and host factors shape the composition and diversity of bacterial, protist and viral microbial communities in the Pacific oyster hemolymph, both in health and disease. To do so, five oyster families differing in susceptibility to the Pacific oyster mortality syndrome were reared in hatchery and transplanted into a natural environment either before or during a disease outbreak. Using metabarcoding and shotgun metagenomics, we demonstrate that hemolymph can be considered as an ecological niche hosting bacterial, protist and viral communities, each of them shaped by different factors and distinct from the corresponding communities in the surrounding seawater. Overall, we found that hemolymph microbiota is more strongly shaped by the environment than by host genetic background. Co-occurrence network analyses suggest a disruption of the microbial network after transplantation into natural environment during both non-infectious and infectious periods. Whereas we could not identify a common microbial community signature for healthy animals, OsHV-1 µVar virus dominated the hemolymph virome during the disease outbreak, without significant modifications of other microbiota components. CONCLUSION: Our study shows that oyster hemolymph is a complex ecosystem containing diverse bacteria, protists and viruses, whose composition and dynamics are primarily determined by the environment. However, all of these are also shaped by oyster genetic backgrounds, indicating they indeed interact with the oyster host and are therefore not only of transient character. Although it seems that the three microbiome components respond independently to environmental conditions, better characterization of hemolymph-associated viruses could change this picture.

First case of Mycobacterium marseillense lymphadenitis in a child.

BACKGROUND: Nontuberculous mycobacteria (NTM) are pathogens that commonly affect the paediatric population and its most frequent manifestation is a cervicofacial lymphadenopathy. With the improvement of technologies, new species have been recently identified. CASE PRESENTATION: We report the first case of NMT lymphadenitis in a child caused by Mycobacterium marseillense, a newly described species belonging to Mycobacterium avium complex. CONCLUSIONS: Improving the identification of these newly discovered mycobacteria, further information will be available about their clinical involvement and their best treatment.

Brain abscesses in children: an Italian multicentre study.

Brain abscess is uncommon in paediatric population, but of clinical importance because of significant long-term morbidity and mortality. In this multicentre study, promoted by the Italian Society for Paediatric Infectious Diseases, we retrospectively collected patients aged 0-18 years, with a diagnosis of 'brain abscess'. Seventy-nine children were included; the median age was 8·75 years. As predisposing factor, 44 children had preceding infections. The Gram-positive cocci were mostly isolated (27 cases). Sixty (76%) children underwent a surgical intervention. Intravenous antibiotic therapy was administered in all patients, then switched to oral treatment. Clinical sequelae were recorded in 31 (39·2%) children. Twenty-one of them had a single sequela, of which, the most represented, was epilepsy in nine of them. This study focus the attention on the need to have standardized national guidelines or adequate recommendations on type and duration of antibiotic treatment.

Factors associated with severity in invasive community-acquired Staphylococcus aureus infections in children: a prospective European multicentre study.

Staphylococcus aureus is the main pathogen responsible for bone and joint infections worldwide and is also capable of causing pneumonia and other invasive severe diseases. Panton-Valentine leukocidin (PVL) and methicillin-resistant S. aureus (MRSA) have been studied as factors related with severity in these infections. The aims of this study were to describe invasive community-acquired S. aureus (CA-SA) infections and to analyse factors related to severity of disease. Paediatric patients (aged 0-16 years) who had a CA-SA invasive infection were prospectively recruited from 13 centres in 7 European countries. Demographic, clinical and microbiological data were collected. Severe infection was defined as invasive infection leading to death or admission to intensive care due to haemodynamic instability or respiratory failure. A total of 152 children (88 boys) were included. The median age was 7.2 years (interquartile range, 1.3-11.9). Twenty-six (17%) of the 152 patients had a severe infection, including 3 deaths (2%). Prevalence of PVL-positive CA-SA infections was 18.6%, and 7.8% of the isolates were MRSA. The multivariate analysis identified pneumonia (adjusted odds ratio (aOR) 13.39 (95% confidence interval (CI) 4.11-43.56); p 0.008), leukopenia at admission (<3000/mm(3)) (aOR 18.3 (95% CI 1.3-259.9); p 0.03) and PVL-positive infections (aOR 4.69 (95% CI 1.39-15.81); p 0.01) as the only factors independently associated with severe outcome. There were no differences in MRSA prevalence between severe and nonsevere cases (aOR 4.30 (95% CI 0.68- 28.95); p 0.13). Our results show that in European children, PVL is associated with more severe infections, regardless of methicillin resistance.

Transcriptional changes in Crassostrea gigas oyster spat following a parental exposure to the herbicide diuron.

The Pacific oyster Crassostrea gigas is the main oyster species produced in the world, and a key coastal economic resource in France. High mortalities affect Pacific oysters since 2008 in France and Europe. Their origins have been attributed to a combination of biotic and abiotic factors, underlining the importance of environment quality. The impact of water pollution has been pointed out and one of the pollutants, the genotoxic herbicide diuron, occurs at high concentrations all along the French coasts. Previous work has revealed that a parental exposure to diuron had a strong impact on hatching rates and offspring development even if spats were not exposed to diuron themselves. In this study, we explored for the first time the transcriptional changes occurring in oyster spats (non exposed) originating from genitors exposed to an environmentally relevant concentration of diuron during gametogenesis using the RNAseq methodology. We identified a transcriptomic remodeling revealing an effect of the herbicide. Different molecular pathways involved in energy production, translation and cell proliferation are particularly disturbed. This analysis revealed modulated candidate genes putatively involved in response to oxidative stress and mitochondrial damage in offspring of genitors exposed to diuron. Complementary measures of the activity of enzymes involved in these latter processes corroborate the results obtained at the transcriptomic level. In addition, our results suggested an increase in energy production and mitotic activity in 5-month-spats from diuron-exposed genitors. These results could correspond to a "catch-up growth" phenomenon allowing the spats from diuron-exposed genitors, which displayed a growth delay at 3 months, to gain a normal size when they reach the age of 6 months. These results indicate that exposure to a concentration of diuron that is frequently encountered in the field during the oyster's gametogenesis stage can impact the next generation and may result in fitness disturbance.

Skin prick test results to artesunate in children sensitized to Artemisia vulgaris L.

Artemisia vulgaris L and Artemisia annua L (Chinese: qinghao) are similar plants of the Asterbaceae family. Artesunate, a semi-synthetic derivate of artemisin which is the active principle extract of the plant qinghao, has antimalarial properties. Some cases of severe allergic reactions to artesunate have been described. The purpose of this study was to evaluate the association between positive skin tests to Artemisia vulgaris L allergen and a preparation of injectable artesunate. A total of 531 children were skin prick tested with inhalants (including Artemisia vulgaris L), foods, and artesunate. Among the 59 patients positive to Artemisia vulgaris L only one child was also positive to artesunate. No child was positive to artesunate in those negative to Artemisia vulgaris L. We conclude that Artemisia vulgaris L sensitization is not associated with sensitization to artesunate; consequently, skin test to artesunate should not be carried out before using the drug considering the rare allergic reactions.

Treating paediatric community-acquired pneumonia in the era of antimicrobial resistance.

UNLABELLED: Increasing levels of paediatric community-acquired pneumonia (CAP), caused by drug-resistant bacteria and antimicrobial resistance, vary with age and countries and, in some cases, serotypes. When empirical first-line treatment administration fails, paediatricians should consider second-line treatments based on the prevalence of local resistance. A more judicious use of antimicrobial agents is also required. CONCLUSION: Knowledge of local epidemiology and an appropriate use of antimicrobial drugs are necessary to treat CAP in this era of antimicrobial resistance.

Macrophage activation syndrome in a child affected by malaria: the choice of steroid.

Macrophage activation syndrome is a potentially fatal clinical syndrome caused by an excessive activation and proliferation of macrophages and T cells, leading to an exaggerated inflammatory reaction. It is well known that it can complicate the course of different conditions, especially autoimmune, lympho-proliferative, infectious diseases and drugs. Many infective pathogens can trigger the syndrome but the association with malaria has rarely been described, especially in children. We report a child with severe malaria complicated by MAS, in whom the clinical appearance of this syndrome could be considered as worsening of malaria itself. Furthermore, the use of steroids as first choice drugs in this complication, but arguable in malaria, has been highlighted. Clinicians should be aware of this syndrome when malaria does not respond to conventional therapy, since early diagnosis and prompt treatment may dramatically reduce the mortality associated with this condition.

Evidence of transmission of a Panton-Valentine leukocidin-positive community-acquired methicillin-resistant Staphylococcus aureus clone: a family affair.

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) may represent a serious public health problem, owing to the spread of toxin-producing lineages. The presence of genes encoding for Panton-Valentine leukocidin (PVL) is an important virulence marker, as the clinical sequelae of PVL-positive infections are often described as more severe than those of PVL-negative S. aureus infections. To date, the presence of PVL has not appeared to be common in Italy; we describe the intrafamilial transmission of an epidemic PVL-producing CA-MRSA lineage, Southwest Pacific clone (SWP). Our data suggested that the strain circulated from the father, who was recurrently affected by a soft tissue infection, to the mother, who showed nasal colonization, and to their child, who was hospitalized with symptoms of necrotizing pneumonia. In this case, we found that a recurrent skin infection that is not normally taken into account may represent a serious threat if caused by a PVL-producing strain. Our findings may have considerable implications for strategies for infection control and treatment of methicillin-resistant S. aureus infections.

Pmarg-pearlin is a matrix protein involved in nacre framework formation in the pearl oyster Pinctada margaritifera.

The shell of pearl oysters is organized in multiple layers of CaCO(3) crystallites packed together in an organic matrix. Relationships between the components of the organic matrix and mechanisms of nacre formation currently constitute the main focus of research into biomineralization. In this study, we characterized the pearlin protein from the oyster Pinctada margaritifera (Pmarg); this shares structural features with other members of a matrix protein family, N14/N16/pearlin. Pmarg pearlin exhibits calcium- and chitin-binding properties. Pmarg pearlin transcripts are distinctively localized in the mineralizing tissue responsible for nacre formation. More specifically, we demonstrate that Pmarg pearlin is localized within the interlamellar matrix of nacre aragonite tablets. Our results support recent models for multidomain matrix protein involvement in nacreous layer formation. We provide evidence here for the existence of a conserved family of nacre-associated proteins in Pteriidae, and reassess the evolutionarily conserved set of biomineralization genes related to nacre formation in this taxa.

Cg-IkappaB, a new member of the IkappaB protein family characterized in the pacific oyster Crassostrea gigas.

Inhibitors of NF-kappaB (IkappaBs) have been implicated as major components of the Rel/NF-kappaB signaling pathway, which is an important mediator of immune responses throughout much of the animal kingdom. Here we report the first characterization of a bivalve mollusc cDNA that encodes a novel IkappaB member called Cg-IkappaB showing the conservation of most IkappaB protein characteristics. Sequences as well as phylogenetic analyses reveal a high level of identity between not only Cg-IkappaB and other mollusc and insect IkappaB-like proteins but also similarities to vertebrate IkappaB-alpha and -epsilon isoforms. Expression analyses demonstrated that the transcript is widely expressed in all oyster tissues. This work is consistent with our previous discovery of several members of an NF-kappaB pathway in Crassostrea gigas and further sustains the hypothesis of a conserved scheme of immune gene regulation through most of the metazoans.

First evidence of the activation of Cg-timp, an immune response component of Pacific oysters, through a damage-associated molecular pattern pathway.

In a previous work, we characterized a Crassostrea gigas cDNA (Cg-timp) encoding a protein which presents all the features of vertebrate tissue inhibitor of metalloproteinase (TIMP). The expression pattern of this gene led us to propose that Cg-timp is an important factor in oyster wound healing and defense mechanisms. Here we describe the analysis of Cg-timp expression in oysters challenged by live or dead bacteria as well as by bacterial secretory/excretory products and metalloproteinase. Surprisingly, bacterial secretory/excretory products activate Cg-timp gene expression whereas heat-inactivated ones do not. To address the question of the signal transduction pathway involved in Cg-timp gene activation, we isolated and sequenced Cg-timp promoter and upstream region. A 1-kb genomic DNA fragment flanking the 5'-end of the gene contains several regulatory elements and notably three NF-kappaB binding sites. The potential involvement of these motifs in Cg-timp gene regulation is discussed.

Cg-Rel, the first Rel/NF-kappaB homolog characterized in a mollusk, the Pacific oyster Crassostrea gigas.

We report here the identification and functional characterization of Cg-Rel, a gene encoding the Crassostrea gigas homolog of Rel/NF-kappaB transcription factors found in insects and mammals. Sequence and phylogenetic analysis showed that Cg-Rel shares the structural organization of Rel/NF-kappaB transcription factors of class II. It includes a Rel homology domain as well as a C-terminal transactivation domain (TD). Overexpression of Cg-Rel in the Drosophila S2 cell line activated the expression of a NF-kappaB-dependent reporter gene, whereas transfection with a Cg-Rel construct containing a C-terminal deletion of the TD or using a reporter gene with mutated kappaB binding sites failed to activate expression. These results suggest that Cg-Rel is a functional member of the Rel family of transcription factors, making this the sixth structurally homologous component of the Rel/NF-kappaB pathway characterized in C. gigas. Based on homology to other invertebrates' Rel/NF-kappaB cascade, the function of the oyster pathway may serve to regulate genes involved in innate defense and/or development. These findings serve to highlight a potentially important regulatory pathway to the study of oyster immunology, hence allowing comparison of the immune system in vertebrates and invertebrates, an important key issue to understand its evolution.

Cg-TIMP, an inducible tissue inhibitor of metalloproteinase from the Pacific oyster Crassostrea gigas with a potential role in wound healing and defense mechanisms(1).

We have cloned and characterized a cDNA encoding Cg-TIMP, the first tissue inhibitor of metalloproteinase identified in mollusks. The isolated cDNA encodes a protein of 221 residues that has a domain organization similar to that of vertebrate TIMPs including a signal sequence, and the 12 cysteines characteristic of the TIMP signature. Analysis of Cg-TIMP expression in adult oyster tissues, by Northern blot and in situ hybridization, indicates that Cg-TIMP was only expressed in hemocytes which are the key components of defense mechanisms in mollusks. We also observed that Cg-TIMP mRNA accumulated during shell damage and bacterial challenge. This pattern of expression suggests that Cg-TIMP may be an important factor in wound healing and defense mechanisms.

Oyster IKK-like protein shares structural and functional properties with its mammalian homologues.

In our search for genes involved in oyster immunity we isolated a cDNA encoding a polypeptide closely related to the mammalian IkappaB kinase (IKK) family. IKK proteins play a central role in cell signaling by regulating nuclear factor-kappaB (NF-kappaB) activation. We report here the cloning of an oyster IKK-like protein (oIKK) which possesses the characteristic organization of the mammalian IKK proteins, namely an amino-terminal kinase domain followed by a leucine zipper region and a carboxyl-terminal helix-loop-helix motif. When transfected into human cell lines, oIKK activated the expression of NF-kappaB-controlled reporter gene, whereas transfections with mutants of oIKK deleted within the kinase domain or within the helix-loop-helix motif respectively abolished and greatly reduced reporter gene activation. These results indicate that oIKK can replace the hIKK-alpha in catalyzing NF-kappaB nuclear translocation, and in triggering gene expression. Our results sustain the concept of an evolutionarily conserved signaling machinery in which IKK plays a major role.

Estradiol and progesterone during exercise in healthy untrained women.

Ten eumenorrheic nonathletic women, aged 21-25, were studied on the 8th day following the LH peak in three consecutive cycles. Plasma level and metabolic clearance rate (MCR) of estradiol (E2) and progesterone (P) were measured before and during a 2-h continuous treadmill test at a speed corresponding to 70% of their running speed at anaerobic threshold on three separate occasions. A significant decrease of plasma level of the hormones (-30% and -40%, respectively, P less than 0.01; mean) from resting values was found, while their metabolic clearance rate increased significantly [E2-MCR from 1017 l.d-1 to 1312 l.d-1 (+29%), P less than 0.001; mean; P-MCR from of 2061 l.d-1 to 2988 l.d-1 (+45%), P less than 0.003; mean]. The increase in MCR of the two hormones was significantly correlated with the increase in heart rate and systolic blood pressure accompanying the beginning of the exercise test.

Functional reconstruction of exstrophied bladder. Timing and technique. Follow-up of 39 cases.

Thirty-nine cases of functional reconstruction of exstrophied bladder are reviewed. There were 20 females and 19 males. In a first group of 31 staging was planned and carried out in 26 while 3 are awaiting a second stage. In a second group of 8 a single operation was performed. Out of the 31 early cases there were 2 deaths and 10 failures, 16 show good or very good functional result. All 16 show moderate renal scarring from reflux pyelonephritis which occurred between I and II stage. Single operation consisted of innominate osteotomy, bladder and bladder neck and urethral reconstruction and anti-reflux procedure (osteotomy was omitted in a 3 days old baby). Three, operated upon when aged 8 mths., 1 year and 4 years, were breakdowns of previous closure. They are incontinent and will need further surgery at the bladder outlet. Four are dry in the morning and suffer from occasional stress incontinence and enuresis. One, now aged 4 years, still wears pads. These last 5 are awaiting final assessment of and eventually further surgery to improve continence. In all 8 cases pyelo-calyceal cavities are normal except for a moderate right dilatation in one because of kinking of the reimplanted ureter. Delay in bladder closure (mean age 5 mths.) and severe changes to the bladder wall and possibly staging seems to be responsible for most of the failures and for renal damage occurring, after closure, in bladders showing moderate compliance. Single operation allows full protection of upper tract and kidney and should be preferred in patients aged over 2 months. Better functional results may be obtained if operation is performed soon after birth.

Pediatric surgery in Islamic medicine from the Middle Ages to the Renaissance.

Albucasis lived throughout the tenth century, practicing medicine for more than 40 years in Zahra at the outskirts of Cordoba. This was the period of the greatest splendour of Arab domination of Spain. Albucasis taught medicine at the university of Cordoba and published an encyclopedia of medicine comprising 30 volumes, the last one dealing with surgery. This work was translated into all civilized languages and was the standard medical textbook right till the eighteenth century. This paper deals with many pediatric surgical conditions as described in Albucasis' 30th volume. The pathology and treatment of harelip, hydrocephalus, the adenoids, ranula, gynecomastia, imperforated external urinary meatus, circumcision, hermaphrodites, imperforate anus, and supernumerary and webbed finger were all described by Albucasis, and his remarks are discussed here in some detail.

One stage functional reconstruction of exstrophied bladder: report of two cases with six-year follow-up.

Two female babies aged 8 and 13 mo., affected with bladder exstrophy, were submitted to a single-stage functional reconstruction of the bladder. Innominate osteotomy, bladder closure, anti-reflux procedure and narrowing of the bladder outlet followed by pubic reapproximation and easy closure of the abdominal wall were performed in one session. Bladder enlargment and a steadily improving continence occurred in the first case with no reflux and no urinary infection. Further surgery may not be needed if full urinary control can be achieved through active cooperation by the patient. Postoperative continence was achieved in the second patient with a secondary operation on the bladder outlet and pedicled muscle transplant. The absence of reflux, infection and pyelonephritis dis warrant a safe and definite bladder enlargement, with a very satisfactory functional result. An anti-reflux procedure should always be performed at the time of bladder reconstruction in babies older than 3 or 4 months.