Enteropathogens in paediatric gastroenteritis: comparison of routine diagnostic and molecular methods.

OBJECTIVES: Studies of acute gastroenteritis (AGE) are hampered by the lack of routine diagnostic methods with good sensitivity and specificity. Molecular methods are increasingly used for clinical purposes, but the clinical significance of a positive result remains a challenge. In this study we aimed to compare results of routine diagnostic methods and molecular methods in symptomatic children and asymptomatic controls. METHODS: Patients presenting to the pediatric emergency departments of two university hospitals in Brussels with AGE were recruited prospectively from May 2015 to October 2016; asymptomatic controls were recruited from the same hospitals. Stool analyses were performed for all participants for common pathogenic bacteria (culture), virus (immunochromatography) and parasites (microscopy). Stools were also analysed with the Luminex Gastrointestinal Pathogen Panel, a multiplex-PCR for common enteropathogens. RESULTS: Stools from 178 patients and 165 controls were analysed. An enteropathogen was detected in 62.4% (111/178) of cases when combining the two methods (56.2% (100/178) by Luminex, 42.7% (76/178) with routine methods) and 29.1% (48/165) of controls (24.2% (40/165) by Luminex and 10.3% (17/165) by routine methods). Some pathogens were detected more often with Luminex than with routine methods, such as Salmonella (16.3% (29/178) with Luminex and 3.9% (7/178) with routine method, p < 0.05), whereas others identified by culture methods, such as Campylobacter, Shigella, Yersinia, were missed by Luminex. CONCLUSIONS: Molecular tools seem attractive methods, providing high positivity and a rapid turn-around time for the diagnosis of AGE. However, high rates of positivity in both cases and controls highlight the difficulty in interpreting results. Pathogens missed by Luminex but detected by culture methods raise more questions about the true clinical interest of the technique for our patients.

Immunome differences between porcine ileal and jejunal Peyer's patches revealed by global transcriptome sequencing of gut-associated lymphoid tissues.

The epithelium of the intestinal mucosa and the gut-associated lymphoid tissues (GALT) constitute an essential physical and immunological barrier against pathogens. In order to study the specificities of the GALT transcriptome in pigs, we compared the transcriptome profiles of jejunal and ileal Peyer's patches (PPs), mesenteric lymph nodes (MLNs) and peripheral blood (PB) of four male piglets by RNA-Seq. We identified 1,103 differentially expressed (DE) genes between ileal PPs (IPPs) and jejunal PPs (JPPs), and six times more DE genes between PPs and MLNs. The master regulator genes FOXP3, GATA3, STAT4, TBX21 and RORC were less expressed in IPPs compared to JPPs, whereas the transcription factor BCL6 was found more expressed in IPPs. In comparison between IPPs and JPPs, our analyses revealed predominant differential expression related to the differentiation of T cells into Th1, Th2, Th17 and iTreg in JPPs. Our results were consistent with previous reports regarding a higher T/B cells ratio in JPPs compared to IPPs. We found antisense transcription for respectively 24%, 22% and 14% of the transcripts detected in MLNs, PPs and PB, and significant positive correlations between PB and GALT transcriptomes. Allele-specific expression analyses revealed both shared and tissue-specific cis-genetic control of gene expression.

[Management of vaccination in children receiving an allogeneic marrow transplant]. / Prise en charge de la vaccination chez les enfants receveurs d'une greffe de moelle allogénique.

Over the last decades, significant advances in the diagnosis and therapeutics have considerably improved success rate from bone marrow transplant in patients suffering from otherwise life-threatening diseases, allowing now for prolonged survival and better quality of life after an allograft. However, infectious diseases remain one of the most serious complication in this population, hence associated with a high morbidity and mortality. Prevention, in particular through vaccination, constitutes a cornerstone of the management of immunocompromised hosts, since this procedure aims to protect them once back to life in community after long periods of hospitalization. If the necessity of vaccinating immunocompromised patients as well as their family is unequivocally recognized among health care workers, some questions remain source of debate. Several famous societies edited guidelines, but those differ from each other and cannot be transposed from a country to another without considering their local epidemiology and implemented vaccination schedule. Moreover, development and availability of new vaccines render recommendations constantly susceptible to adaptations. After exhaustive literature review, this article aims to offer pragmatic answers to the main questions raised by healthcare workers when vaccinating children after a bone marrow transplant. We here review all vaccines available and discuss their modalities of administration considering the timing after transplant, the immunological residual status and the medical history of the child. We also offer clues to optimize vaccination of patients' siblings. In addition to highlight some interrogations about future vaccines formulations, we propose here a vaccination schedule tailored for pediatric bone marrow transplant recipients in Belgium in 2017.

Au cours des dernières années, les progrès faits dans les domaines thérapeutiques et diagnostiques ont permis d'améliorer les performances des traitements par greffes de moelle osseuse, allongeant ainsi significativement l'espérance de vie des patients souffrant de maladies jusqu'alors associées à un sombre pronostic. Cependant, aujourd'hui encore, les infections restent parmi les complications les plus redoutées en termes de morbidité et de mortalité chez ces patients. La prévention et particulièrement la vaccination occupe donc une place primordiale dans la prise en charge de ces hôtes fragiles, visant à les protéger une fois leur retour à la vie en communauté envisagé après de longues périodes d'immunosuppression. Si la nécessité de vacciner les patients transplantés et leur entourage fait l'unanimité au sein des soignants, les modalités de vaccination restent encore sujettes à de maintes interrogations dans la littérature. Plusieurs sociétés réputées font état de recommandations mais celles-ci varient entre elles et ne peuvent être transposées d'un pays à l'autre sans tenir compte de l'épidémiologie locale et du schéma vaccinal préalablement implémenté. Par ailleurs, la mise à disposition constante de nouveaux vaccins nécessite une adaptation perpétuelle des diverses recommandations établies. Sur base d'une revue exhaustive de la littérature, nous tenterons dans cet article d'apporter des réponses pragmatiques aux questions fréquemment soulevées par les soignants en charge des enfants greffés de moelle osseuse. Le document détaille les différents vaccins disponibles, en discute les critères d'administration selon le délai par rapport à la greffe et le statut immunologique du patient et revoit comment optimaliser la vaccination de l'entourage. En plus de souligner certaines interrogations à suivre concernant de nouvelles formulations vaccinales à venir, l'article ci-dessous offre un schéma pratique d'administration des différents vaccins chez les enfants receveurs d'une greffe de moelle en Belgique en 2017.

[The human gut microbiota: Interactions with the host and dysfunctions]. / Le microbiome digestif humain : interactions avec l'hôte et dysfonctions.

The human intestinal microbiota is composed of approximately 100,000 billion microorganisms with the average total number of different commensal bacterial species estimated at over 500 per individual. The human intestinal microbiota can be considered as an organ within another, which co-evolved with its host to achieve a symbiotic relationship leading to physiological homeostasis. The host provides an environment enriched in nutrients and the microbiota provides essential functions. Dysbiosis of the intestinal microbiota (changes in bacterial composition) has been associated with local dysfunctions of the gastrointestinal tract, such as inflammatory bowel disease or irritable bowel syndrome but also with obesity and metabolic diseases. However, a better understanding of the human intestinal ecosystem is still needed to understand the exact role of the microbiota in health and disease. Most intestinal bacteria are anaerobic and therefore, for the large majority, impossible to culture at present. Consequently, their function cannot be inferred from data on their composition. Today, with the help of a metagenomic approach, the bacterial genomic content of an ecosystem and the associated functions can be directly accessed from the environment without culture.

Baseline gut microbiota predicts clinical response and colitis in metastatic melanoma patients treated with ipilimumab.

BACKGROUND: Ipilimumab, an immune checkpoint inhibitor targeting CTLA-4, prolongs survival in a subset of patients with metastatic melanoma (MM) but can induce immune-related adverse events, including enterocolitis. We hypothesized that baseline gut microbiota could predict ipilimumab anti-tumor response and/or intestinal toxicity. PATIENTS AND METHODS: Twenty-six patients with MM treated with ipilimumab were prospectively enrolled. Fecal microbiota composition was assessed using 16S rRNA gene sequencing at baseline and before each ipilimumab infusion. Patients were further clustered based on microbiota patterns. Peripheral blood lymphocytes immunophenotypes were studied in parallel. RESULTS: A distinct baseline gut microbiota composition was associated with both clinical response and colitis. Compared with patients whose baseline microbiota was driven by Bacteroides (cluster B, n = 10), patients whose baseline microbiota was enriched with Faecalibacterium genus and other Firmicutes (cluster A, n = 12) had longer progression-free survival (P = 0.0039) and overall survival (P = 0.051). Most of the baseline colitis-associated phylotypes were related to Firmicutes (e.g. relatives of Faecalibacterium prausnitzii and Gemmiger formicilis), whereas no colitis-related phylotypes were assigned to Bacteroidetes. A low proportion of peripheral blood regulatory T cells was associated with cluster A, long-term clinical benefit and colitis. Ipilimumab led to a higher inducible T-cell COStimulator induction on CD4+ T cells and to a higher increase in serum CD25 in patients who belonged to Faecalibacterium-driven cluster A. CONCLUSION: Baseline gut microbiota enriched with Faecalibacterium and other Firmicutes is associated with beneficial clinical response to ipilimumab and more frequent occurrence of ipilimumab-induced colitis.

Intestinal microbiota contributes to individual susceptibility to alcoholic liver disease.

OBJECTIVE: There is substantial inter-individual diversity in the susceptibility of alcoholics to liver injury. Alterations of intestinal microbiota (IM) have been reported in alcoholic liver disease (ALD), but the extent to which they are merely a consequence or a cause is unknown. We aimed to demonstrate that a specific dysbiosis contributes to the development of alcoholic hepatitis (AH). DESIGN: We humanised germ-free and conventional mice using human IM transplant from alcoholic patients with or without AH. The consequences on alcohol-fed recipient mice were studied. RESULTS: A specific dysbiosis was associated with ALD severity in patients. Mice harbouring the IM from a patient with severe AH (sAH) developed more severe liver inflammation with an increased number of liver T lymphocyte subsets and Natural Killer T (NKT) lymphocytes, higher liver necrosis, greater intestinal permeability and higher translocation of bacteria than mice harbouring the IM from an alcoholic patient without AH (noAH). Similarly, CD45+ lymphocyte subsets were increased in visceral adipose tissue, and CD4(+)T and NKT lymphocytes in mesenteric lymph nodes. The IM associated with sAH and noAH could be distinguished by differences in bacterial abundance and composition. Key deleterious species were associated with sAH while the Faecalibacterium genus was associated with noAH. Ursodeoxycholic acid was more abundant in faeces from noAH mice. Additionally, in conventional mice humanised with the IM from an sAH patient, a second subsequent transfer of IM from an noAH patient improved alcohol-induced liver lesions. CONCLUSIONS: Individual susceptibility to ALD is substantially driven by IM. It may, therefore, be possible to prevent and manage ALD by IM manipulation.

Structural robustness of the gut mucosal microbiota is associated with Crohn's disease remission after surgery.

OBJECTIVES: Preventing postoperative recurrence after ileocolonic resection (ICR) for Crohn's disease (CD) is challenging. Defining the disturbances of the microbial composition and community structure after ICR and their link with early disease recurrence is crucial. DESIGN: Microbiota composition (fingerprinting and 16S rDNA sequencing) and community structure (correlation networks of bacterial species) were assessed from ileal mucosa sampled in 20 patients undergoing ICR and 6 months later during endoscopy from above (neoterminal ileum) and below (subanastomotic colon) the surgical anastomosis. RESULTS: ICR had a dramatic effect on gut microbial ecosystem. At surgery, CD mucosa harboured a dysbiotic microbiota with high proportions of α/ß Proteobacteria and Bacilli. Six months later, half of the patients had recurrent lesions at ileocolonoscopy and presented higher numbers of Lachnospiraceae. Recurrence of endoscopic lesions was associated with enrichment in Enterococcus durans while patients in remission had increased proportions of Dorea longicatena and Bacteroides plebeius. Structural differences were striking between recurrence and remission microbiota; while the microbiota of patients with CD recurrence exhibited a loose community structure, the microbiota of patients in remission displayed communities that were robustly correlated to each other. Microbiota colonising the neoterminal ileum and subanastomotic colon 6 months after ICR only differed in patients with recurrence. CONCLUSIONS: ICR modifies the gut microbiome. Remission after 6 months was associated with homogenous bacterial distribution around the anastomosis. Community structure and bacterial networks highlight target species, including Faecalibacterium prausnitzii and Ruminococcus gnavus, which may allow precise modulations of the overall microbial ecosystem towards remission pattern.

[Practical problems related to the management of febrile urinary tract infection in Vietnamese children]. / Difficultés de prise en charge des infections urinaires fébriles chez l'enfant vietnamien.

BACKGROUND: To describe the practical problems related to urinary tract infection (UTI) management in febrile Vietnamese children. METHODS: During a prospective 28-month inclusion period, 143 febrile children with significant bacteriuria were treated for UTI in the nephrology department of Nhi Dong 2 children's hospital in Ho Chi Minh City, Vietnam. Patients were treated after blood and urine samples had been taken for culture, according to a local antibiotic protocol, parenterally with ceftriaxone 75mg/kg/day. Oral treatment with cefixime 8mg/kg/day was started after 48h of apyrexia for 2 weeks. According to local protocol, antibiotic therapy was only changed if children did not respond clinically to treatment regardless of antibiogram results. RESULTS: Among these 143 children, 51% were girls and 80% of them had their first UTI before the age of 2 years. The commonest causative agent was Escherichia coli (80% of cases) with a high resistance rate to ampicillin (91%) and cotrimoxazole (74%). Extended-spectrum ß-lactamase (ESBL) production was observed in 52% of Enterobacteriaceae isolates. According to antibiotic susceptibility, the initial treatment with ceftriaxone was found to be inappropriate in 63% of cases. CONCLUSIONS: E. coli was responsible for 80% of UTIs in Vietnamese children with a high rate of resistance to first-line antibiotics. ESBL production was found to be extremely high in this study. Based on these data, we propose a new empiric treatment schedule for Vietnamese children suspected of UTI.

Gut microbiome and anticancer immune response: really hot Sh*t!

The impact of gut microbiota in eliciting innate and adaptive immune responses beneficial for the host in the context of effective therapies against cancer has been highlighted recently. Chemotherapeutic agents, by compromising, to some extent, the intestinal integrity, increase the gut permeability and selective translocation of Gram-positive bacteria in secondary lymphoid organs. There, anticommensal pathogenic Th17 T-cell responses are primed, facilitating the accumulation of Th1 helper T cells in tumor beds after chemotherapy as well as tumor regression. Importantly, the redox equilibrium of myeloid cells contained in the tumor microenvironment is also influenced by the intestinal microbiota. Hence, the anticancer efficacy of alkylating agents (such as cyclophosphamide) and platinum salts (oxaliplatin, cis-platin) is compromised in germ-free mice or animals treated with antibiotics. These findings represent a paradigm shift in our understanding of the mode of action of many compounds having an impact on the host-microbe mutualism.

Management of the neonate at risk for early-onset Group B streptococcal disease (GBS EOD): new paediatric guidelines in Belgium.

Despite group B streptococcal (GBS) screening in late pregnancy and intrapartum antimicrobial prophylaxis, early-onset sepsis in neonates remains a common source of neonatal morbidity and mortality especially in preterm neonates. The identification of neonates with early-onset sepsis is usually based on perinatal risk factors. Clinical signs are aspecific and laboratory tests are not sensitive. Therefore, many clinicians will overtreat at-risk infants. Inappropriate treatment with antibiotics increases the risk for late-onset sepsis, necrotizing enterocolitis, mortality, and prolongs hospitalisation and costs. In 2003, the Belgian Health Council published guidelines for the prevention of perinatal GBS infections. This report presents the Belgian paediatric management guidelines, which have been endorsed by the Belgian and Flemish societies of neonatology and paediatrics. The most imported changes in the 2014 guidelines are the following: recommendations for a lumbar puncture; clarification of normal spinal fluid parameters and blood neutrophil indices corrected for gestation age; specific timing for diagnostic testing after birth; no indication for diagnostic testing in asymptomatic newborns unless additional risk factors; a revised algorithm for management of neonates according to maternal and neonatal risk factors; and premature infants described as those below 35 weeks instead of 37 weeks. The guidelines were made on the basis of the best evidence and on expert opinion when inadequate evidence exists.

Harnessing the intestinal microbiome for optimal therapeutic immunomodulation.

Distinct cytotoxic agents currently used in the oncological armamentarium mediate their clinical benefit by influencing, directly or indirectly, the immune system in such a way that innate and adaptive immunity contributes to the tumoricidal activity. Now, we bring up evidence that both arms of anticancer immunity can be triggered through the intervention of the intestinal microbiota. Alkylating agents, such as cyclophosphamide, set up the stage for enhanced permeability of the small intestine, facilitating the translocation of selected arrays of Gram-positive bacteria against which the host mounts effector pTh17 cells and memory Th1 responses. In addition, gut commensals, through lipopolysaccharide and other bacterial components, switch the tumor microenvironment, in particular the redox equilibrium and the TNF production of intratumoral myeloid cells during therapies with platinum salts or intratumoral TLR9 agonists combined with systemic anti-IL10R Ab respectively. Consequently, antibiotics can compromise the efficacy of certain chemotherapeutic or immunomodulatory regimens.

[Infant botulism after honey exposure]. / Botulisme infantile après exposition à du miel.

Infant botulism is a rare neuroparalytic disease caused by the neurotoxin of Clostridium botulinum. Initial clinical features are constipation, poor feeding, descending hypotonia, drooling, irritability, weak crying and cranial nerve dysfunctions. We describe the clinical progression and the epidemiological investigation carried out in a 3-month-old infant. Better knowledge of the disease should allow faster diagnosis and adequate management. We emphasize the risks associated with honey exposure in children less than one year old and that honey should not be fed to infants under 12 months of age.

Whole exome sequencing unravels disease-causing genes in consanguineous families in Qatar.

Whole exome sequencing (WES) has greatly facilitated the identification of causal mutations for diverse human genetic disorders. We applied WES as a molecular diagnostic tool to identify disease-causing genes in consanguineous families in Qatar. Seventeen consanguineous families with diverse disorders were recruited. Initial mutation screening of known genes related to the clinical diagnoses did not reveal the causative mutations. Using WES approach, we identified the definitive disease-causing mutations in four families: (i) a novel nonsense homozygous (c.1034C>G) in PHKG2 causing glycogen storage disease type 9C (GSD9C) in a male with initial diagnosis of GSD3; (ii) a novel homozygous 1-bp deletion (c.915del) in NSUN2 in a male proband with Noonan-like syndrome; (iii) a homozygous SNV (c.1598C>G) in exon 11 of IDUA causing Hurler syndrome in a female proband with unknown clinical diagnosis; (iv) a de novo known splicing mutation (c.1645+1G>A) in PHEX in a female proband with initial diagnosis of autosomal recessive hypophosphatemic rickets. Applying WES as a diagnostic tool led to the unambiguous identification of disease-causing mutations in phenotypically complex disorders or correction of the initial clinical diagnosis in ˜25% of our cases.

[Is it necessary to vaccinate against varicella?]. / Faut-il vacciner contre la varicelle?

Varicella is a frequent viral disease, with a substantial medical and societal impact. For many years, various industrialized countries have adopted an universal mass vaccination against varicella, using a one-dose schedule. In these countries, the global incidence of varicella has decreased by about 90%. A significant reduction in hospitalizations, outpatient visits and medical costs due to varicella has also been observed. Recently, a 2-dose schedule has demonstrated an efficacy of about 98%, as well as herd immunity.

[Peripheral facial nerve palsy]. / La paralysie faciale périphérique.

Facial palsy can be defined as a decrease in function of the facial nerve, the primary motor nerve of the facial muscles. When the facial palsy is peripheral, it affects both the superior and inferior areas of the face as opposed to central palsies, which affect only the inferior portion. The main cause of peripheral facial palsies is Bell's palsy, which remains a diagnosis of exclusion. The prognosis is good in most cases. In cases with significant cosmetic sequelae, a variety of surgical procedures are available (such as hypoglossal-facial anastomosis, temporalis myoplasty and Tenzel external canthopexy) to rehabilitate facial aesthetics and function.

[Nasal polyposis and olfactory function: results of the surgical treatment]. / La polypose nasosinusienne et l'odorat: intérêt de la chirurgie.

INTRODUCTION: Hyposmia is a common cause of functional complaint in patients with nasal polyposis. The aim of the current study was to report the olfactory functional results after sinus surgery. MATERIALS AND METHODS: A systematic review of the scientific literature was achieved in the Pubmed database. RESULTS: Overall, 10 series published between 1989 and 2013, involving 959 patients, were selected. The surgery for nasal polyposis, adjuvant medical treatment, may allow olfactory improvement. The results are even better than surgery is as wide as possible and the evolutionary stage is low.

[Diagnosis and therapeutic pathways in head and neck cancers]. / Parcours de soins du patient présentant un carcinome epidermoïdes des voies aéro-digestives supérieures.

BACKGROUND: Cancers of uppers aero-digestives tracts represent, infrequency, the 5th cancer in the French population. Most of them (about 70%) are diagnosed at an advanced stage (stage III or IV) while they are associated with a poor prognosis (only 40% five year survival). The objective of our study was to analyze the care pathway of patients with cancers of uppers aero-digestives tracts in order to target efforts to improve the survival of these patients. METHODS: It was a descriptive and retrospective study, on medical files, on the health care pathway of patients with cancers of uppers aero-digestives tracts cared in the Head and Neck surgery department of Val de Grâce in Paris and Percy in Clamart between January 2004 and December 2006. The patients were adults with squamous cell carcinoma of uppers aero-digestives tracts. RESULTS: One hundred thirty-eight files of patients were analyzed. Fifty-five percent of patients were diagnosed at an advanced stage. On average patients have waited two months and twenty-one days before consulting a doctor for the first time. The time interval between the specialist consultation and the start of treatment was on average 7 weeks. The overall 5-year survival rate was 61%. CONCLUSION: Squamous cell carcinoma of uppers aero-digestives tracts remains serious and has a poor diagnosis, even in a population with a high social-cultural level. The long time interval before the first consultation may be reduced by improving health education among the general practitioner (primary and secondary prevention), and by establishing health care public campaigns. This would allow earlier diagnosis, more conservative therapeutic opportunities and therefore a better prognosis.

Involvement of tissue bacteria in the onset of diabetes in humans: evidence for a concept.

AIMS/HYPOTHESIS: Evidence suggests that bacterial components in blood could play an early role in events leading to diabetes. To test this hypothesis, we studied the capacity of a broadly specific bacterial marker (16S rDNA) to predict the onset of diabetes and obesity in a general population. METHODS: Data from an Epidemiological Study on the Insulin Resistance Syndrome (D.E.S.I.R.) is a longitudinal study with the primary aim of describing the history of the metabolic syndrome. The 16S rDNA concentration was measured in blood at baseline and its relationship with incident diabetes and obesity over 9 years of follow-up was assessed. In addition, in a nested case-control study in which participants later developed diabetes, bacterial phylotypes present in blood were identified by pyrosequencing of the overall 16S rDNA gene content. RESULTS: We analysed 3,280 participants without diabetes or obesity at baseline. The 16S rDNA concentration was higher in those destined to have diabetes. No difference was observed regarding obesity. However, the 16S rDNA concentration was higher in those who had abdominal adiposity at the end of follow-up. The adjusted OR (95% CIs) for incident diabetes and for abdominal adiposity were 1.35 (1.11, 1.60), p = 0.002 and 1.18 (1.03, 1.34), p = 0.01, respectively. Moreover, pyrosequencing analyses showed that participants destined to have diabetes and the controls shared a core blood microbiota, mostly composed of the Proteobacteria phylum (85-90%). CONCLUSIONS/INTERPRETATION: 16S rDNA was shown to be an independent marker of the risk of diabetes. These findings are evidence for the concept that tissue bacteria are involved in the onset of diabetes in humans.