TwinsUK: The UK Adult Twin Registry Update.

TwinsUK is the largest cohort of community-dwelling adult twins in the UK. The registry comprises over 14,000 volunteer twins (14,838 including mixed, single and triplets); it is predominantly female (82%) and middle-aged (mean age 59). In addition, over 1800 parents and siblings of twins are registered volunteers. During the last 27 years, TwinsUK has collected numerous questionnaire responses, physical/cognitive measures and biological measures on over 8500 subjects. Data were collected alongside four comprehensive phenotyping clinical visits to the Department of Twin Research and Genetic Epidemiology, King's College London. Such collection methods have resulted in very detailed longitudinal clinical, biochemical, behavioral, dietary and socioeconomic cohort characterization; it provides a multidisciplinary platform for the study of complex disease during the adult life course, including the process of healthy aging. The major strength of TwinsUK is the availability of several 'omic' technologies for a range of sample types from participants, which includes genomewide scans of single-nucleotide variants, next-generation sequencing, metabolomic profiles, microbiomics, exome sequencing, epigenetic markers, gene expression arrays, RNA sequencing and telomere length measures. TwinsUK facilitates and actively encourages sharing the 'TwinsUK' resource with the scientific community - interested researchers may request data via the TwinsUK website (http://twinsuk.ac.uk/resources-for-researchers/access-our-data/) for their own use or future collaboration with the study team. In addition, further cohort data collection is planned via the Wellcome Open Research gateway (https://wellcomeopenresearch.org/gateways). The current article presents an up-to-date report on the application of technological advances, new study procedures in the cohort and future direction of TwinsUK.

Intestinal Dysbiosis Featuring Abundance of Ruminococcus gnavus Associates With Allergic Diseases in Infants.

BACKGROUND & AIMS: Dysbiosis of the intestinal microbiota has been associated with development of allergies in infants. However, it is not clear what microbes might contribute to this process. We investigated what microbe(s) might be involved in analyses of infant twins and mice. METHODS: We studied fecal specimens prospectively in a twin cohort (n = 30) and age-matched singletons (n = 14) born at National Taiwan University Children's Hospital, Taipei, Taiwan, from April 2011 to March 2013. Clinical parameters (gestational age, birth body weight, mode of delivery and feeding, immunizations, and medical events) were recorded. Fecal samples were collected beginning immediately after birth and for 1 year; the children were followed until 3 years of age and allergic symptoms (repetitive and continuous for at least 6 months) were noted. A skin prick test was used to ascertain atopy. Bacterial communities in fecal samples were profiled by 16S ribosomal RNA-based polymerase chain reaction-temporal temperature gradient gel electrophoresis and next-generation sequencing. BALB/c mice without and with ovalbumin sensitization/challenge were infected with candidate bacteria by oral gauge intragastric intubation. Fecal, serum, lung, and colon tissue samples were collected from mice and analyzed for mechanisms of allergy development. RESULTS: During the investigation period, 20 children (45.5%) developed allergic diseases, including respiratory (allergic rhinitis and asthma) and skin (atopic dermatitis and eczema) allergies. Lachnospiraceae were detected at significantly higher frequency in allergic infants than nonallergic infants (P < .004); the high fecal count of Lachnospiraceae in allergic subjects appeared at 2 months of age and persisted until 12 months of age. The enrichment of Lachnospiraceae in allergic infants was attributed to the overgrowth of Ruminococcus gnavus, which tended to have a low frequency in nonallergic subjects (P = .0004). Increased R gnavus was observed before the onset of allergic manifestations, and was associated with respiratory allergies (P < .002) or respiratory allergies coexistent with atopic eczema (P < .001). In mice, endogenous R gnavus grew rapidly after sensitization and challenge with ovalbumin. Mice gavaged with purified R gnavus developed airway hyper-responsiveness and had histologic evidence of airway inflammation (asthma). Expansion of R gnavus in mice stimulated secretion of cytokines (interleukin [IL] 25, IL33, and thymic stromal lymphopoietin) by colon tissues, which activated type 2 innate lymphoid cells and dendritic cells to promote differentiation of T-helper 2 cells and production of their cytokines (IL4, IL5, and IL13). This led to infiltration of the colon and lung parenchyma by eosinophils and mast cells. CONCLUSIONS: In a study of a twin cohort (some infants with, some without allergies), we associated development of allergies, particularly respiratory allergies, with increased fecal abundance of R gnavus. Mice fed R gnavus developed airway inflammation, characterized by expansion of T-helper 2 cells in the colon and lung, and infiltration of colon and lung parenchyma by eosinophils and mast cells.

Group B streptococcal disease in infants in the first year of life: a nationwide surveillance study in Japan, 2011-2015.

PURPOSE: This study aimed to describe the epidemiology of childhood group B streptococcus (GBS) disease including late late-onset disease (LLOD) and to clinically characterize recurrent cases and twin-sibling cases in Japan. METHODS: We collected information on infants (<1 year of age) with invasive GBS disease and institutional information about births and transfers through a nationwide questionnaire between 2011 and 2015. RESULTS: We identified 133 infants with early-onset disease (EOD), 274 late-onset disease (LOD), and 38 LLOD from 149 institutes. The case fatality rate (CFR) of EOD, LOD, and LLOD was 4.5, 4.4, and 0%, respectively. CFR in EOD was significantly (P < 0.001) associated with preterm birth, but not that in LOD and LLOD. Twenty-nine percent of infants with meningitis (49/169) had neurologic sequelae. We showed clinical details of 12 recurrent cases that accounted for 2.8% of the total patients, and 4 sets of both twins affected; 4 of 12 recurrent cases and 3 of 4 twin-sibling sets were also associated with preterm birth. Based on the livebirth number of 581,488, the instituted-based incidence of EOD, LOD, and LLOD was estimated as 0.09 (95% CI 0.06-0.11), 0.12 (95% CI 0.11-0.14), and 0.01 (95% CI 0.01-0.02) per 1000 livebirths, respectively. CONCLUSIONS: CFR of EOD and LOD in Japan is comparable with that in high-income European countries or the United States, and their incidence is much lower. Our findings also describe the clinical details of LLOD, recurrent infections, and infections in twin siblings. This study is the largest among Asian childhood GBS studies ever reported.

Isolation of Separate Ureaplasma Species From Endotracheal Secretions of Twin Patients.

Isolation of Ureaplasma spp. from preterm neonates and the association with development of bronchopulmonary dysplasia has been previously investigated. However, few studies have contrasted the nature of infection in twins. In this article, we report that dizygotic twins (1 girl, 1 boy) born at 24 weeks gestation both yielded culturable Ureaplasma from endotracheal secretions. The samples were part of a serial blind collection cohort of ventilated premature neonates, and analysis of repeat cultures showed stable, separate infections over a period of 17 and 21 days, respectively. Immunoblot and probe-specific quantitative polymerase chain reaction analysis determined that Twin 1 was solely infected with Ureaplasma parvum (specifically, serovar 6 by gene sequencing), whereas Twin 2 was solely infected with Ureaplasma urealyticum (specifically, genotype A- serovars 2, 5, and 8 by gene sequencing). Immunoblot analysis found that the major surface antigen (multiple-banded antigen) altered relative mass for both strains during the course of infection. Quantitative polymerase chain reaction analysis of extracted endotracheal aspirates confirmed no evidence of mixed infection for either twin. Failure of sentinel ventilated preterm infants on the same ward to acquire Ureaplasma infection after the first week of birth suggests no cot-to-cot transfer of Ureaplasma infection occurred. This study demonstrated not only a contrasting clinical outcome for a set of twins infected with 2 separate species of Ureaplasma, but also the first real-time demonstration of multiple-banded antigen alteration and evolution of Ureaplasma over the course of a clinical infection.

Pyrosequencing of Plaque Microflora In Twin Children with Discordant Caries Phenotypes.

Despite recent successes in the control of dental caries, the mechanism of caries development remains unclear. To investigate the causes of dental decay, especially in early childhood caries, the supragingival microflora composition of 20 twins with discordant caries phenotypes were analyzed using high-throughput pyrosequencing. In addition, the parents completed a lifestyle questionnaire. A total of 228,789 sequencing reads revealed 10 phyla, 84 genera, and 155 species of microflora, the relative abundances of these strains varied dramatically among the children, Comparative analysis between groups revealed that Veillonella, Corynebacterium and Actinomyces were presumed to be caries-related genera, Fusobacterium, Kingella and Leptotrichia were presumed to be healthy-related genus, yet this six genera were not statistically significant (P>0.05). Moreover, a cluster analysis revealed that the microbial composition of samples in the same group was often dissimilar but that the microbial composition observed in twins was usually similar. Although the genetic and environmental factors that strongly influence the microbial composition of dental caries remains unknown, we speculate that genetic factors primarily influence the individual's susceptibility to dental caries and that environmental factors primarily regulate the microbial composition of the dental plaque and the progression to caries. By using improved twins models and increased sample sizes, our study can be extended to analyze the specific genetic and environmental factors that affect the development of caries.

Gut-Microbiota-Metabolite Axis in Early Renal Function Decline.

INTRODUCTION: Several circulating metabolites derived from bacterial protein fermentation have been found to be inversely associated with renal function but the timing and disease severity is unclear. The aim of this study is to explore the relationship between indoxyl-sulfate, p-cresyl-sulfate, phenylacetylglutamine and gut-microbial profiles in early renal function decline. RESULTS: Indoxyl-sulfate (Beta(SE) = -2.74(0.24); P = 8.8x10-29), p-cresyl-sulfate (-1.99(0.24), P = 4.6x10-16), and phenylacetylglutamine(-2.73 (0.25), P = 1.2x10-25) were inversely associated with eGFR in a large population base cohort (TwinsUK, n = 4439) with minimal renal function decline. In a sub-sample of 855 individuals, we analysed metabolite associations with 16S gut microbiome profiles (909 profiles, QIIME 1.7.0). Three Operational Taxonomic Units (OTUs) were significantly associated with indoxyl-sulfate and 52 with phenylacetylglutamine after multiple testing; while one OTU was nominally associated with p-cresyl sulfate. All 56 microbial members belong to the order Clostridiales and are represented by anaerobic Gram-positive families Christensenellaceae, Ruminococcaceae and Lachnospiraceae. Within these, three microbes were also associated with eGFR. CONCLUSIONS: Our data suggest that indoxyl-sulfate, p-cresyl-sulfate and phenylacetylglutamine are early markers of renal function decline. Changes in the intestinal flora associated with these metabolites are detectable in early kidney disease. Future efforts should dissect this relationship to improve early diagnostics and therapeutics strategies.

[Late-onset Group B Streptococcus disease in twins delivered by caesarean section]. / Infección tardía por estreptococo grupo B en gemelos nacidos mediante cesárea.

Group B Streptococcus (GBS) is a commensal pathogen of the gut microflora with a well-established role in the aetiology of early and late onset GBS infections in the newborn. The incidence of early onset infections by vertical transmission has been drastically reduced in recent decades with the use of intravenous intrapartum prophylaxis. Progress in risk factor detection and prophylaxis of late-onset infection has however remained static. The ongoing modifications and improvements of the guidelines regarding prophylaxis, risk factors and prevention of the early-onset GBS disease have not addressed late-onset GBS infection in detail. The following cases illustrate the presence of grey areas in current guidelines and in the knowledge of the pathogenesis of late-onset disease.

Toxic bovine mastitis caused by Staphylococcus aureus in twin cows.

In this report, we describe two cases of bovine toxic mastitis associated with S. aureus and we provide DNA microarray based characterization data of the strain causing the disease. Both cows had recently calved and suffered from anorexia, pyrexia, and an elevated heart rate. In both animals, at least one mammary gland was swollen, hardened, sensitive to touch, and produced brownish or bloody secretions. The clinical state of the animals deteriorated quickly and both cows had to be euthanized within 48 hours after presentation. The S. aureus strain, which was isolated from the mastitis milk of both cows, was assigned to spa type t267, agr type I, capsule type 5 and CC97, a clonal complex recently identified as the evolutionary origin of two emerging clones of human epidemic community-associated methicillin-resistant S. aureus. The strain did not harbour any genes conferring resistance to antimicrobial agents and we did not detect any genes coding for enterotoxins, toxic shock syndrome toxin, or exfoliative toxins. Taking into consideration that twin cows were affected by this rare disease, we suggest that host factors may play a crucial role in toxic mastitis associated with S. aureus.

Bacteremia caused by Rhizobium radiobacter in a preterm neonate.

The authors report a case of bacteremia due to Rhizobium radiobacter in a preterm neonate. Although the baby recovered from the septic episode following therapy with appropriate antibiotics he succumbed to complications, mainly associated with prematurity. This case highlights a rare manifestation of R.radiobacter infection in a neonate in whom the source of the organism remained undiscovered.

Gut microbiomes of Malawian twin pairs discordant for kwashiorkor.

Kwashiorkor, an enigmatic form of severe acute malnutrition, is the consequence of inadequate nutrient intake plus additional environmental insults. To investigate the role of the gut microbiome, we studied 317 Malawian twin pairs during the first 3 years of life. During this time, half of the twin pairs remained well nourished, whereas 43% became discordant, and 7% manifested concordance for acute malnutrition. Both children in twin pairs discordant for kwashiorkor were treated with a peanut-based, ready-to-use therapeutic food (RUTF). Time-series metagenomic studies revealed that RUTF produced a transient maturation of metabolic functions in kwashiorkor gut microbiomes that regressed when administration of RUTF was stopped. Previously frozen fecal communities from several discordant pairs were each transplanted into gnotobiotic mice. The combination of Malawian diet and kwashiorkor microbiome produced marked weight loss in recipient mice, accompanied by perturbations in amino acid, carbohydrate, and intermediary metabolism that were only transiently ameliorated with RUTF. These findings implicate the gut microbiome as a causal factor in kwashiorkor.

[Pantoea agglomerans: a new pathogen at the neonatal intensive care unit?]. / Pantoea agglomerans: ¿un nuevo patógeno en la unidad de cuidados intensivos neonatales?

Late-onset sepsis is very frequent among preterm infants and cases due to Gram negative pathogens have elevated morbidity and mortality. Pantoea agglomerans is a Gram negative organism which has been rarely reported causing disease in humans. We present a case of P. agglomerans late-onset fulminant sepsis in a preterm newborn at a neonatal intensive care unit. Up to date none P. agglomerans sepsis has been reported among this population in our country.

Pantoea agglomerans: ¿un nuevo patógeno en la unidad de cuidados intensivos neonatales?: a new pathogen at the neonatal intensive care unit? / Pantoea agglomerans

La sepsis tardía es especialmente frecuente en los recién nacidos pretérmino, y los bacilos gramnegativos son responsables de los casos más graves con una elevada mortalidad asociada. Pantoea agglomerans es un bacilo gramnegativo que pocas veces se ha descrito como patógeno en el ser humano, menos aún en el recién nacido. Se presenta el caso clínico de un recién nacido pretérmino que sufrió una sepsis fulminante por Pantoea agglomerans en una unidad de cuidados intensivos neonatales. Hasta la fecha no se ha descrito ningún caso de sepsis por P. agglomerans en esta población en España.(AU)

Late-onset sepsis is very frequent among preterm infants and cases due to Gram negative pathogens have elevated morbidity and mortality. Pantoea agglomerans is a Gram negative organism which has been rarely reported causing disease in humans. We present a case of P. agglomerans late-onset fulminant sepsis in a preterm newborn at a neonatal intensive care unit. Up to date none P. agglomerans sepsis has been reported among this population in our country.(AU)

Pantoea agglomerans: ¿un nuevo patógeno en la unidad de cuidados intensivos neonatales?: a new pathogen at the neonatal intensive care unit? / Pantoea agglomerans

La sepsis tardía es especialmente frecuente en los recién nacidos pretérmino, y los bacilos gramnegativos son responsables de los casos más graves con una elevada mortalidad asociada. Pantoea agglomerans es un bacilo gramnegativo que pocas veces se ha descrito como patógeno en el ser humano, menos aún en el recién nacido. Se presenta el caso clínico de un recién nacido pretérmino que sufrió una sepsis fulminante por Pantoea agglomerans en una unidad de cuidados intensivos neonatales. Hasta la fecha no se ha descrito ningún caso de sepsis por P. agglomerans en esta población en España.

Late-onset sepsis is very frequent among preterm infants and cases due to Gram negative pathogens have elevated morbidity and mortality. Pantoea agglomerans is a Gram negative organism which has been rarely reported causing disease in humans. We present a case of P. agglomerans late-onset fulminant sepsis in a preterm newborn at a neonatal intensive care unit. Up to date none P. agglomerans sepsis has been reported among this population in our country.

Contribution of host genotype to the composition of health-associated supragingival and subgingival microbiomes.

AIM: Periodontitis and caries are two of the most prevalent diseases to affect humans, however; the individual susceptibility to these diseases varies significantly in the population. The aim of this investigation, therefore, was to examine the influence of host genotype on the composition of health-associated supragingival and subgingival microbiomes. MATERIALS AND METHODS: Subgingival and supragingival plaque was collected from orally and systemically healthy adult monozygotic and dizygotic twin pairs. Zygosity was determined by multiplexed PCR amplification of 13 short tandem repeats. Terminal restriction fragment length polymorphism was used for bacterial community profiling. The number of species shared by the twin pairs as well as the similarity of the microbial communities between the twins was computed and compared using two-sample t-test RESULTS: There was no difference in the number of species shared by the twin pairs as well as the similarity of the microbial communities between the twin dyads. Age was not a modifier of genetic influence on these microbial parameters. There was no difference between monozygotic and dizygotic twin pairs in the correlation between supragingival and subgingival community similarity. CONCLUSION: The contributory role of host genotype, if any, is not apparent on an established, health-associated oral microbial community.

Placental intravascular organisms: a case report.

Ascending amniotic fluid bacterial infection is a cause of perinatal morbidity and mortality. A diagnosis of amniotic cavity infection can be inferred by documenting maternal (acute chorioamnionitis) and/or fetal (chorionic plate vasculitis; umbilical vasculitis/funisitis) inflammatory response. A definitive diagnosis of intrauterine/neonatal sepsis as a cause of stillbirth requires positive blood cultures obtained at postmortem examination. However, if postmortem examination is not performed, acute chorioamnionitis with/without fetal inflammatory response cannot be classified as a cause of demise. We present a case of intrauterine demise associated with acute chorioamnionitis, villitis, and intervillositis of the placenta. Although postmortem examination was denied, a conclusive diagnosis of intrauterine sepsis could be rendered by demonstration of gram-positive cocci within fetal vessels of umbilical cord, chorionic plate, and stem villi. This report highlights the importance of identification of placental intravascular organisms as unequivocal evidence of fetal sepsis, especially in cases where cultures cannot be obtained.

Horizontal transmission of mutans streptococci in children.

It has not been established whether transmission of mutans streptococci occurs between unrelated children older than 4 years of age. The aim of the study was to investigate the possible transmission of mutans streptococci genotypes from child to child in kindergarten. We studied 96 children (ages 5-6 yrs) in three San Francisco Bay Area public schools. Mutans streptococci colonies from each child were isolated from selective culture on Mitis Salivarius Sucrose Bacitracin agar. We used arbitrary primed polymerase chain reactions to determine the mutans streptococci genotypes. Two children (not siblings) in each of the three schools (6%) shared an identical amplitype of S. mutans, unique to each pair. The 19 S. sobrinus amplitypes were found in 12 children, and all were unique to each child. The presence of matching genotypes of S. mutans demonstrates horizontal transmission of this species between unrelated children aged 5-6 years.

Late-onset sepsis in a preterm twin may harbinger life-threatening sepsis for the asymptomatic co-twin.

We report extremely preterm twins who developed late-onset Escherichia coli sepsis in the second postnatal week within a short time of each other. The asymptomatic twin was not treated initially, and within 2 days developed life-threatening septicemia and meningitis, followed by other serious morbidity. Occurrence of late-onset sepsis in a twin should prompt concurrent investigation and consideration of presumptive treatment of the apparently asymptomatic co-twin.