Effect of Dietary Components on Larval Life History Characteristics in the Medfly (Ceratitis capitata: Diptera,Tephritidae)

Background

The ability to respond to heterogenous nutritional resources is an important factor in the adaptive radiation of insects such as the highly polyphagous Medfly. Here we examined the breadth of the Medfly’s capacity to respond to different developmental conditions, by experimentally altering diet components as a proxy for host quality and novelty.

Methodology/Principal Findings

We tested responses of larval life history to diets containing protein and carbohydrate components found in and outside the natural host range of this species. A 40% reduction in the quantity of protein caused a significant increase in egg to adult mortality by 26.5%±6% in comparison to the standard baseline diet. Proteins and carbohydrates had differential effects on larval versus pupal development and survival. Addition of a novel protein source, casein (i.e. milk protein), to the diet increased larval mortality by 19.4%±3% and also lengthened the duration of larval development by 1.93±0.5 days in comparison to the standard diet. Alteration of dietary carbohydrate, by replacing the baseline starch with simple sugars, increased mortality specifically within the pupal stage (by 28.2%±8% and 26.2%±9% for glucose and maltose diets, respectively). Development in the presence of the novel carbohydrate lactose (milk sugar) was successful, though on this diet there was a decrease of 29.8±1.6 µg in mean pupal weight in comparison to pupae reared on the baseline diet.

Conclusions

The results confirm that laboratory reared Medfly retain the ability to survive development through a wide range of fluctuations in the nutritional environment. We highlight new facets of the responses of different stages of holometabolous life histories to key dietary components. The results are relevant to colonisation scenarios and key to the biology of this highly invasive species.     

Metagenomic analysis of the Rhinopithecus bieti fecal microbiome reveals a broad diversity of bacterial and glycoside hydrolase profiles related to lignocellulose degradation

Background

The animal gastrointestinal tract contains a complex community of microbes, whose composition ultimately reflects the co-evolution of microorganisms with their animal host and the diet adopted by the host. Although the importance of gut microbiota of humans has been well demonstrated, there is a paucity of research regarding non-human primates (NHPs), especially herbivorous NHPs.

Results

In this study, an analysis of 97,942 pyrosequencing reads generated from Rhinopithecus bieti fecal DNA extracts was performed to help better understanding of the microbial diversity and functional capacity of the R. bieti gut microbiome. The taxonomic analysis of the metagenomic reads indicated that R. bieti fecal microbiomes were dominated by Firmicutes, Bacteroidetes, Proteobacteria and Actinobacteria phyla. The comparative analysis of taxonomic classification revealed that the metagenome of R. bieti was characterized by an overrepresentation of bacteria of phylum Fibrobacteres and Spirochaetes as compared with other animals. Primary functional categories were associated mainly with protein, carbohydrates, amino acids, DNA and RNA metabolism, cofactors, cell wall and capsule and membrane transport. Comparing glycoside hydrolase profiles of R. bieti with those of other animal revealed that the R. bieti microbiome was most closely related to cow rumen.

Conclusions

Metagenomic and functional analysis demonstrated that R. bieti possesses a broad diversity of bacteria and numerous glycoside hydrolases responsible for lignocellulosic biomass degradation which might reflect the adaptations associated with a diet rich in fibrous matter. These results would contribute to the limited body of NHPs metagenome studies and provide a unique genetic resource of plant cell wall degrading microbial enzymes. However, future studies on the metagenome sequencing of R. bieti regarding the effects of age, genetics, diet and environment on the composition and activity of the metagenomes are required.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1378-7) contains supplementary material, which is available to authorized users.     

Characterization of the fecal microbiome from non-human wild primates reveals species specific microbial communities

Background

Host-associated microbes comprise an integral part of animal digestive systems and these interactions have a long evolutionary history. It has been hypothesized that the gastrointestinal microbiome of humans and other non-human primates may have played significant roles in host evolution by facilitating a range of dietary adaptations. We have undertaken a comparative sequencing survey of the gastrointestinal microbiomes of several non-human primate species, with the goal of better understanding how these microbiomes relate to the evolution of non-human primate diversity. Here we present a comparative analysis of gastrointestinal microbial communities from three different species of Old World wild monkeys.

Methodology/Principal Findings

We analyzed fecal samples from three different wild non-human primate species (black-and-white colobus [Colubus guereza], red colobus [Piliocolobus tephrosceles], and red-tailed guenon [Cercopithecus ascanius]). Three samples from each species were subjected to small subunit rRNA tag pyrosequencing. Firmicutes comprised the vast majority of the phyla in each sample. Other phyla represented were Bacterioidetes, Proteobacteria, Spirochaetes, Actinobacteria, Verrucomicrobia, Lentisphaerae, Tenericutes, Planctomycetes, Fibrobacateres, and TM7. Bray-Curtis similarity analysis of these microbiomes indicated that microbial community composition within the same primate species are more similar to each other than to those of different primate species. Comparison of fecal microbiota from non-human primates with microbiota of human stool samples obtained in previous studies revealed that the gut microbiota of these primates are distinct and reflect host phylogeny.

Conclusion/Significance

Our analysis provides evidence that the fecal microbiomes of wild primates co-vary with their hosts, and that this is manifested in higher intraspecies similarity among wild primate species, perhaps reflecting species specificity of the microbiome in addition to dietary influences. These results contribute to the limited body of primate microbiome studies and provide a framework for comparative microbiome analysis between human and non-human primates as well as a comparative evolutionary understanding of the human microbiome.     

Fecal Protease Activity Is Associated with Compositional Alterations in the Intestinal Microbiota

Objective

Intestinal proteases carry out a variety of functions in the gastrointestinal (GI) tract. Studies have reported that elevated enteric proteases in patients with GI disease can alter intestinal physiology, however the origin (human vs. microbial) of elevated proteases in patients with GI disease is unclear.

Aim

The aim of this study was to investigate the association between protease activity and the microbiota in human fecal samples.

Design

In order to capture a wide range of fecal protease (FP) activity stool samples were collected from 30 IBS patients and 24 healthy controls. The intestinal microbiota was characterized using 454 high throughput pyro-sequencing of the 16S rRNA gene. The composition and diversity of microbial communities were determined and compared using the Quantitative Insights Into Microbial Ecology (QIIME) pipeline. FP activity levels were determined using an ELISA-based method. FP activity was ranked and top and bottom quartiles (n=13 per quartile) were identified as having high and low FP activity, respectively.

Results

The overall diversity of the intestinal microbiota displayed significant clustering separation (p = 0.001) between samples with high vs. low FP activity. The Lactobacillales, Lachnospiraceae, and Streptococcaceae groups were positively associated with FP activity across the entire study population, whilst the Ruminococcaceae family and an unclassified Coriobacteriales family were negatively associated with FP activity.

Conclusions

These data demonstrate significant associations between specific intestinal bacterial groups and fecal protease activity and provide a basis for further causative studies investigating the role of enteric microbes and GI diseases.     

Liver Ischemic Preconditioning (IPC) Improves Intestinal Microbiota Following Liver Transplantation in Rats through 16s rDNA-Based Analysis of Microbial Structure Shift

Background

Ischemia-reperfusion (I/R) injury is associated with intestinal microbial dysbiosis. The “gut-liver axis” closely links gut function and liver function in health and disease. Ischemic preconditioning (IPC) has been proven to reduce I/R injury in the surgery. This study aims to explore the effect of IPC on intestinal microbiota and to analyze characteristics of microbial structure shift following liver transplantation (LT).

Methods

The LT animal models of liver and gut IPC were established. Hepatic graft function was assessed by histology and serum ALT/AST. Intestinal barrier function was evaluated by mucosal ultrastructure, serum endotoxin, bacterial translocation, fecal sIgA content and serum TNF-α. Intestinal bacterial populations were determined by quantitative PCR. Microbial composition was characterized by DGGE and specific bacterial species were determined by sequence analysis.

Principal Findings

Liver IPC improved hepatic graft function expressed as ameliorated graft structure and reduced ALT/AST levels. After administration of liver IPC, intestinal mucosal ultrastructure improved, serum endotoxin and bacterial translocation mildly decreased, fecal sIgA content increased, and serum TNF-α decreased. Moreover, liver IPC promoted microbial restorations mainly through restoring Bifidobacterium spp., Clostridium clusters XI and Clostridium cluster XIVab on bacterial genus level. DGGE profiles indicated that liver IPC increased microbial diversity and species richness, and cluster analysis demonstrated that microbial structures were similar and clustered together between the NC group and Liver-IPC group. Furthermore, the phylogenetic tree of band sequences showed key bacteria corresponding to 10 key band classes of microbial structure shift induced by liver IPC, most of which were assigned to Bacteroidetes phylum.

Conclusion

Liver IPC cannot only improve hepatic graft function and intestinal barrier function, but also promote restorations of intestinal microbiota following LT, which may further benefit hepatic graft by positive feedback of the “gut-liver axis”.     

Characterization of the Vaginal Microbiota among Sexual Risk Behavior Groups of Women with Bacterial Vaginosis

Background

The pathogenesis of bacterial vaginosis (BV) remains elusive. BV may be more common among women who have sex with women (WSW). The objective of this study was to use 454 pyrosequencing to investigate the vaginal microbiome of WSW, women who have sex with women and men (WSWM), and women who have sex with men (WSM) with BV to determine if there are differences in organism composition between groups that may inform new hypotheses regarding the pathogenesis of BV.

Methods

Vaginal swab specimens from eligible women with BV at the Mississippi State Department of Health STD Clinic were used. After DNA extraction, 454 pyrosequencing of PCR-amplified 16S rRNA gene sequences was performed. Sequence data was classified using the Ribosomal Database Program classifer. Complete linkage clustering analysis was performed to compare bacterial community composition among samples. Differences in operational taxonomic units with an abundance of ≥2% between risk behavior groups were determined. Alpha and beta diversity were measured using Shannon’s Index implemented in QIIME and Unifrac analysis, respectively.

Results

33 WSW, 35 WSWM, and 44 WSM were included. The vaginal bacterial communities of all women clustered into four taxonomic groups with the dominant taxonomic group in each being Lactobacillus, Lachnospiraceae, Prevotella, and Sneathia. Regarding differences in organism composition between risk behavior groups, the abundance of Atopobium (relative ratio (RR)=0.24; 95%CI 0.11-0.54) and Parvimonas (RR=0.33; 95%CI 0.11-0.93) were significantly lower in WSW than WSM, the abundance of Prevotella was significantly higher in WSW than WSWM (RR=1.77; 95%CI 1.10-2.86), and the abundance of Atopobium (RR=0.41; 95%CI 0.18-0.88) was significantly lower in WSWM than WSM. Overall, WSM had the highest diversity of bacterial taxa.

Conclusion

The microbiology of BV among women in different risk behavior groups is heterogeneous. WSM in this study had the highest diversity of bacterial taxa. Additional studies are needed to better understand these differences.     

Effects of Syzygium aromaticum-Derived Triterpenes on Postprandial Blood Glucose in Streptozotocin-Induced Diabetic Rats Following Carbohydrate Challenge

Purpose

Recent reports suggest that the hypoglycaemic effects of the triterpenes involve inhibition of glucose transport in the small intestine. Therefore, the effects of Syzygium spp-derived triterpenes oleanolic acid (OA) and maslinic acid (MA) were evaluated on carbohydrate hydrolyzing enzymes in STZ-induced diabetic rats and consequences on postprandial hyperglycaemia after carbohydrate loading.

Methods

We determined using Western blot analysis the expressions of α-amylase and α-glucosidase and glucose transporters SGLT1 and GLUT2 in the small intestine intestines isolated from diabetic rats treated with OA/MA for 5 weeks. In vitro assays were used to assess the inhibitory activities of OA and MA against α-amylase, α-glucosidase and sucrase.

Results

OA and MA ameliorated postprandial hyperglycemia in carbohydrate loaded diabetic rats as indicated by the significantly small glucose area under the curve (AUC) in treated diabetic animals compared with that in untreated diabetic rats. Western blotting showed that OA and MA treatment not only down-regulated the increase of SGLT1 and GLUT2 expressions in the small intestine of STZ-induced diabetic rats, but also inhibited small intestine α-amylase, sucrase and α-glucosidase activity. IC₅₀ values of OA against α-amylase (3.60 ± 0.18 mmol/L), α-glucosidase (12.40 ± 0.11 mmol/L) and sucrase (11.50 ± 0.13 mmol/L) did not significantly differ from those of OA and acarbose.

Conclusions

The results of suggest that OA and MA may be used as potential supplements for treating postprandial hyperglycemia.

Novelty of the Work

The present observations indicate that besides improving glucose homeostasis in diabetes, OA and MA suppress postprandial hyperglycaemia mediated in part via inhibition of carbohydrate hydrolysis and reduction of glucose transporters in the gastrointestinal tract. Inhibition of α-glucosidase and α-amylase can significantly decrease the postprandial hyperglycaemia after a mixed carbohydrate diet and therefore can be an important strategy in the management of postprandial blood glucose levels in NIDDM patients.     

Effects of Administration of Live or Inactivated Virulent Rhodococccus equi and Age on the Fecal Microbiome of Neonatal Foals

Background

Rhodococcus equi is an important pathogen of foals. Enteral administration of live, virulent R. equi during early life has been documented to protect against subsequent intrabronchial challenge with R. equi, indicating that enteral mucosal immunization may be protective. Evidence exists that mucosal immune responses develop against both live and inactivated micro-organisms. The extent to which live or inactivated R. equi might alter the intestinal microbiome of foals is unknown. This is an important question because the intestinal microbiome of neonates of other species is known to change over time and to influence host development. To our knowledge, changes in the intestinal microbiome of foals during early life have not been reported. Thus, the purpose of this study was to determine whether age (during the first month of life) or administration of either live virulent R. equi (at a dose reported to protect foals against subsequent intrabronchial challenge, viz., 1×10¹⁰ colony forming units [CFU]) or inactivated virulent R. equi (at higher doses, viz., 2×10¹⁰ and 1×10¹¹ [CFU]) altered the fecal microbiome of foals.

Methodology/Principal Findings

Fecal swab samples from 42 healthy foals after vaccination with low-dose inactivated R. equi (n = 9), high-dose inactivated R. equi (n = 10), live R. equi (n = 6), control with cholera toxin B (CTB, n = 9), and control without CTB (n = 8) were evaluated by 454-pyrosequencing of the 16S rRNA gene and by qPCR. No impact of treatment was observed among vaccinated foals; however, marked and significant differences in microbial communities and diversity were observed between foals at 30 days of age relative to 2 days of age.

Conclusions

The results suggest age-related changes in the fecal microbial population of healthy foals do occur, however, mucosal vaccination does not result in major changes of the fecal microbiome in foals.     

Supragingival Microbial Profiles of Permanent and Deciduous Teeth in Children with Mixed Dentition

Objectives

The present study was designed to investigate the microbial profiles of teeth in different locations in mixed-dentition-stage children, and to compare the microbiomes of permanent and deciduous teeth in the same healthy oral cavity.

Methods

Supragingival plaque samples of teeth in various locations—the first permanent molars, deciduous molars, deciduous canines and incisors and permanent incisors—were collected from 20 healthy mixed-dentition-stage children with 10–12 permanent teeth erupted. Plaque DNA was extracted, and the V3–V4 hypervariable region of the bacterial 16S rRNA gene was amplified and subjected to sequencing.

Results

On average, 18,051 high-quality sequences per sample were generated. Permanent tooth sites tended to host more diverse bacterial communities than those of deciduous tooth sites. A total of 12 phyla, 21 classes, 38 orders, 66 families, 74 genera were detected ultimately. Five predominant phyla (Proteobacteria, Firmicutes, Bacteroidetes, Fusobacteria and Actinobacteria) were highly variable among sites. Of 26 genera with a mean relative abundance of >0.1%, 16 showed significant differences in relative abundance among the groups. More than 20% of the total operational taxonomical units were detected only in permanent or deciduous teeth. The variation in the microbial community composition was due mainly to permanent teeth being enriched in Actinomyces and deciduous teeth in Treponema. The core microbiome of supragingival plaque in mixed dentition comprised 19 genera with complex correlationships.

Conclusion

Our results suggest differences in microbial diversity and composition between permanent and deciduous teeth sites in mixed dentition. Moreover, the core microbiome of these sites was determined. These findings enhance our understanding of the development of the native oral microbiota with age.     

Influence of the Carbohydrate Moieties on the Immunoreactivity and Digestibility of the Egg Allergen Ovomucoid

Background

Ovomucoid (OM) has two carbohydrate chains on each of the first and second domains and one in the third. The contribution of the covalently bound carbohydrate chains to the overall OM allergenicity is controversial. Another aspect directly related with the immunological properties of OM that has not been studied in depth is the importance of the carbohydrate chains on its digestibility.

Objective

The aim of the study was to assess the involvement of the carbohydrate moieties of OM in its digestibility and allergenic properties.

Methods

IgE-binding and basophil activation by glycosylated and enzymatically deglycosylated OM (dOM) were compared using blood from egg-allergic patients. The peptides obtained after digestion using a physiologically relevant model were identified by RP-HPLC-MS/MS and the IgE-binding of the resulting fragments was evaluated by DOT-Blot.

Results

No structural changes were observed after deglycosylation of OM. 80% of the patients showed lower IgE binding to dOM as compared with OM and, in some patients, IgE reactivity could not be inhibited by pre-incubation with dOM. A subtle reduction in the percentage of activated basophils was observed when incubated with dOM as compared to OM. Following simulated digestion, dOM was more extensively degraded than OM, particularly during the gastric phase and both, OM and dOM, yielded, after the duodenal phase, immunoreactive fragments that were totally or partially coincident with previously described epitopes.

Conclusion

& Clinical Relevance: this work demonstrated an enhanced IgE reactivity towards carbohydrate containing OM in some egg-allergic patients that could be attributed to cross-sensitization or sensitization to the glycosylated components. The carbohydrate chains contributed to an increased resistance to proteolysis, and thus, to its allergenic potency. Evaluation of the products of digestion of OM and dOM revealed the presence of high-frequency IgE-binding epitopes that could remain linked by disulphide bonds.     

Small RNAs from plants,bacteria and fungi within the order Hypocreales are ubiquitous in human plasma

Background

The human microbiome plays a significant role in maintaining normal physiology. Changes in its composition have been associated with bowel disease, metabolic disorders and atherosclerosis. Sequences of microbial origin have been observed within small RNA sequencing data obtained from blood samples. The aim of this study was to characterise the microbiome from which these sequences are derived.

Results

Abundant non-human small RNA sequences were identified in plasma and plasma exosomal samples. Assembly of these short sequences into longer contigs was the pivotal novel step in ascertaining their origin by BLAST searches. Most reads mapped to rRNA sequences. The taxonomic profiles of the microbes detected were very consistent between individuals but distinct from microbiomes reported at other sites. The majority of bacterial reads were from the phylum Proteobacteria, whilst for 5 of 6 individuals over 90% of the more abundant fungal reads were from the phylum Ascomycota; of these over 90% were from the order Hypocreales. Many contigs were from plants, presumably of dietary origin. In addition, extremely abundant small RNAs derived from human Y RNAs were detected.

Conclusions

A characteristic profile of a subset of the human microbiome can be obtained by sequencing small RNAs present in the blood. The source and functions of these molecules remain to be determined, but the specific profiles are likely to reflect health status. The potential to provide biomarkers of diet and for the diagnosis and prognosis of human disease is immense.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-15-933) contains supplementary material, which is available to authorized users.     

Dietary Patterns and Clinical Outcomes in Hemodialysis Patients in Japan: A Cohort Study

Background & Objectives

Little is known about actual dietary patterns and their associations with clinical outcomes in hemodialysis patients. We identified dietary patterns in hemodialysis patients in Japan and examined associations between dietary patterns and clinical outcomes.

Design, setting, participants, measurements

We used data from 3,080 general-population participants in the Hisayama study (year 2007), and data from 1,355 hemodialysis patients in the Japan Dialysis Outcomes and Practice Patterns Study (JDOPPS: years 2005–2007). Food intake was measured using a brief self-administered diet-history questionnaire (BDHQ). To identify food groups with the Hisayama population data, we used principal components analysis with Promax rotation. We adjusted the resulting food groups for total daily energy intake, and then we used those adjusted food-group scores to identify dietary patterns in the JDOPPS patients by cluster analysis (Ward’s method). We then used Cox regression to examine the association between dietary patterns and a composite of adverse clinical outcomes: hospitalization due to cardiovascular disease or death due to any cause.

Results

We identified three food groups: meat, fish, and vegetables. Using those groups we then identified three dietary patterns: well-balanced, unbalanced, and other. After adjusting for potential confounders, we found an association between an unbalanced diet and important clinical events (hazard ratio 1.90, 95% C.I. 1.19–3.04).

Conclusions

Hemodialysis patients whose diet was unbalanced were more likely to have adverse clinical outcomes. Thus hemodialysis patients might benefit not only from portion control, but also from a diet that is well-balanced diet with regard to the food groups identified here as meat, fish, and vegetables.     

Metabolomics Analysis Identifies Intestinal Microbiota-Derived Biomarkers of Colonization Resistance in Clindamycin-Treated Mice

Background

The intestinal microbiota protect the host against enteric pathogens through a defense mechanism termed colonization resistance. Antibiotics excreted into the intestinal tract may disrupt colonization resistance and alter normal metabolic functions of the microbiota. We used a mouse model to test the hypothesis that alterations in levels of bacterial metabolites in fecal specimens could provide useful biomarkers indicating disrupted or intact colonization resistance after antibiotic treatment.

Methods

To assess in vivo colonization resistance, mice were challenged with oral vancomycin-resistant Enterococcus or Clostridium difficile spores at varying time points after treatment with the lincosamide antibiotic clindamycin. For concurrent groups of antibiotic-treated mice, stool samples were analyzed using quantitative real-time polymerase chain reaction to assess changes in the microbiota and using non-targeted metabolic profiling. To assess whether the findings were applicable to another antibiotic class that suppresses intestinal anaerobes, similar experiments were conducted with piperacillin/tazobactam.

Results

Colonization resistance began to recover within 5 days and was intact by 12 days after clindamycin treatment, coinciding with the recovery bacteria from the families Lachnospiraceae and Ruminococcaceae, both part of the phylum Firmicutes. Clindamycin treatment caused marked changes in metabolites present in fecal specimens. Of 484 compounds analyzed, 146 (30%) exhibited a significant increase or decrease in concentration during clindamycin treatment followed by recovery to baseline that coincided with restoration of in vivo colonization resistance. Identified as potential biomarkers of colonization resistance, these compounds included intermediates in carbohydrate or protein metabolism that increased (pentitols, gamma-glutamyl amino acids and inositol metabolites) or decreased (pentoses, dipeptides) with clindamycin treatment. Piperacillin/tazobactam treatment caused similar alterations in the intestinal microbiota and fecal metabolites.

Conclusions

Recovery of colonization resistance after antibiotic treatment coincided with restoration of several fecal bacterial metabolites. These metabolites could provide useful biomarkers indicating intact or disrupted colonization resistance during and after antibiotic treatment.     

Diets Rich in Saturated and Polyunsaturated Fatty Acids Induce Morphological Alterations in the Rat Ventral Prostate

Aim

To evaluate the influence of dietary lipid quality on the body mass, carbohydrate metabolism and morphology of the rat ventral prostate.

Materials and Methods

Wistar rats were divided into four groups: SC (standard chow), HF-S (high-fat diet rich in saturated fatty acids), HF-P (high-fat diet rich in polyunsaturated fatty acids) and HF-SP (high-fat diet rich in saturated and polyunsaturated fatty acids). We analyzed body mass, fat mass deposits, plasma blood, insulin resistance and the ventral prostate structure.

Results

Groups that received high-fat diets were heavier and presented larger fat deposits than SC group. The HF-S and HF-SP groups had higher glucose, insulin and total cholesterol serum levels and insulin resistance compared with the SC. The acinar area, epithelium height and area density of the lumen were higher in the HF-SP than in the other groups. The epithelium area density and epithelial cell proliferation were greater in the HF-P and HF-SP than in the SC group. All of the groups that received high-fat diets had greater area density of the stroma, area density of smooth muscle cells and stromal cell proliferation compared with the SC group.

Conclusion

Diets rich in saturated and/or polyunsaturated fatty acids induced overweight. Independently of insulin resistance, polyunsaturated fatty acids increased prostate stromal and epithelial cell proliferation. Saturated fatty acids influenced only stromal cellular proliferation. These structural and morphometric alterations may be considered risk factors for the development of adverse remodeling process in the rat ventral prostate.     

Integrating Bacterial and Viral Water Quality Assessment to Predict Swimming-Associated Illness at a Freshwater Beach: A Cohort Study

Background & Objective

Recreational waters impacted by fecal contamination have been linked to gastrointestinal illness in swimmer populations. To date, few epidemiologic studies examine the risk for swimming-related illnesses based upon simultaneous exposure to more than one microbial surrogate (e.g. culturable E. coli densities, genetic markers). We addressed this research gap by investigating the association between swimming-related illness frequency and water quality determined from multiple bacterial and viral genetic markers.

Methods

Viral and bacterial genetic marker densities were determined from beach water samples collected over 23 weekend days and were quantified using quantitative polymerase chain reaction (qPCR). These genetic marker data were paired with previously determined human exposure data gathered as part of a cohort study carried out among beach users at East Fork Lake in Ohio, USA in 2009. Using previously unavailable genetic marker data in logistic regression models, single- and multi-marker/multi-water quality indicator approaches for predicting swimming-related illness were evaluated for associations with swimming-associated gastrointestinal illness.

Results

Data pertaining to genetic marker exposure and 8- or 9-day health outcomes were available for a total of 600 healthy susceptible swimmers, and with this population we observed a significant positive association between human adenovirus (HAdV) exposure and diarrhea (odds ratio  = 1.6; 95% confidence interval: 1.1–2.3) as well as gastrointestinal illness (OR  = 1.5; 95% CI: 1.0–2.2) upon adjusting for culturable E. coli densities in multivariable models. No significant associations between bacterial genetic markers and swimming-associated illness were observed.

Conclusions

This study provides evidence that a combined measure of recreational water quality that simultaneously considers both bacterial and viral densities, particularly HAdV, may improve prediction of disease risk than a measure of a single agent in a beach environment likely influenced by nonpoint source human fecal contamination.     

Peptides Corresponding to the Predicted Heptad Repeat 2 Domain of the Feline Coronavirus Spike Protein Are Potent Inhibitors of Viral Infection

Background

Feline infectious peritonitis (FIP) is a lethal immune-mediated disease caused by feline coronavirus (FCoV). Currently, no therapy with proven efficacy is available. In searching for agents that may prove clinically effective against FCoV infection, five analogous overlapping peptides were designed and synthesized based on the putative heptad repeat 2 (HR2) sequence of the spike protein of FCoV, and the antiviral efficacy was evaluated.

Methods

Plaque reduction assay and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) cytotoxicity assay were performed in this study. Peptides were selected using a plaque reduction assay to inhibit Feline coronavirus infection.

Results

The results demonstrated that peptide (FP5) at concentrations below 20 μM inhibited viral replication by up to 97%. The peptide (FP5) exhibiting the most effective antiviral effect was further combined with a known anti-viral agent, human interferon-α (IFN-α), and a significant synergistic antiviral effect was observed.

Conclusion

Our data suggest that the synthetic peptide FP5 could serve as a valuable addition to the current FIP prevention methods.     

Helicobacter pylori Eradication Causes Perturbation of the Human Gut Microbiome in Young Adults

Background

Accumulating evidence shows that Helicobacter pylori protects against some metabolic and immunological diseases in which the development of these diseases coincide with temporal or permanent dysbiosis. The aim of this study was to assess the effect of H. pylori eradication on the human gut microbiome.

Methods

As part of the currently on-going ESSAY (Eradication Study in Stable Adults/Youths) study, we collected stool samples from 17 H. pylori-positive young adult (18–30 years-old) volunteers. The same cohort was followed up 6, 12 and 18 months-post H. pylori eradication. The impact of H. pylori on the human gut microbiome pre- and post-eradication was investigated using high throughput 16S rRNA gene (V3-V4 region) sequencing using the Illumina Miseq followed by data analysis using Qiime pipeline.

Results

We compared the composition and diversity of bacterial communities in the fecal microbiome of the H. pylori-positive volunteers, before and after H. pylori eradication therapy. The 16S rRNA gene was sequenced at an average of 150,000–170,000 reads/sample. The microbial diversity were similar pre- and post-H. pylori eradication with no significant differences in richness and evenness of bacterial species. Despite that the general profile of the gut microbiome was similar pre- and post-eradication, some changes in the bacterial communities at the phylum and genus levels were notable, particularly the decrease in relative abundance of Bacterioidetes and corresponding increase in Firmicutes after H. pylori eradication. The significant increase of short-chain fatty acids (SCFA)-producing bacteria genera could also be associated with increased risk of metabolic disorders.

Conclusions

Our preliminary stool metagenomics study shows that eradication of H. pylori caused perturbation of the gut microbiome and may indirectly affect the health of human. Clinicians should be aware of the effect of broad spectrum antibiotics used in H. pylori eradication regimen and be cautious in the clinical management of H. pylori infection, particularly in immunocompromised patients.     

Dietary Factors Impact on the Association between CTSS Variants and Obesity Related Traits

Background/Aims

Cathepsin S, a protein coded by the CTSS gene, is implicated in adipose tissue biology–this protein enhances adipose tissue development. Our hypothesis is that common variants in CTSS play a role in body weight regulation and in the development of obesity and that these effects are influenced by dietary factors–increased by high protein, glycemic index and energy diets.

Methods

Four tag SNPs (rs7511673, rs11576175, rs10888390 and rs1136774) were selected to capture all common variation in the CTSS region. Association between these four SNPs and several adiposity measurements (BMI, waist circumference, waist for given BMI and being a weight gainer–experiencing the greatest degree of unexplained annual weight gain during follow-up or not) given, where applicable, both as baseline values and gain during the study period (6–8 years) were tested in 11,091 European individuals (linear or logistic regression models). We also examined the interaction between the CTSS variants and dietary factors–energy density, protein content (in grams or in % of total energy intake) and glycemic index–on these four adiposity phenotypes.

Results

We found several associations between CTSS polymorphisms and anthropometric traits including baseline BMI (rs11576175 (SNP N°2), p = 0.02, β = −0.2446), and waist change over time (rs7511673 (SNP N°1), p = 0.01, β = −0.0433 and rs10888390 (SNP N°3), p = 0.04, β = −0.0342). In interaction with the percentage of proteins contained in the diet, rs11576175 (SNP N°2) was also associated with the risk of being a weight gainer (p_interaction = 0.01, OR = 1.0526)–the risk of being a weight gainer increased with the percentage of proteins contained in the diet.

Conclusion

CTSS variants seem to be nominally associated to obesity related traits and this association may be modified by dietary protein intake.     

Characterization of the rumen microbiome of Indian Kankrej cattle (Bos indicus) adapted to different forage diet

Present study described rumen microbiome of Indian cattle (Kankrej breed) to better understand the microbial diversity and largely unknown functional capacity of the rumen microbiome under different dietary treatments. Kankrej cattle were gradually adapted to a high-forage diet (four animals with dry forage and four with green forage) containing 50 % (K1), 75 % (K2) to 100 % (K3) forage, and remaining concentrate diet, each for 6 weeks followed by analysis of rumen fiber adherent and fiber-free metagenomic community by shotgun sequencing using ion torrent PGM platform and EBI-metagenomics annotation pipeline. Taxonomic analysis indicated that rumen microbiome was dominated by Bacteroidetes followed by Firmicutes, Fibrobacter, Proteobacteria, and Tenericutes. Functional analysis based on gene ontology classified all reads in total 157 categories based on their functional role in biological, molecular, and cellular component with abundance of genes associated with hydrolase activity, membrane, transport, transferase, and different metabolism (such as carbohydrate and protein). Statistical analysis using STAMP revealed significant differences (P?相似文献   

A Prospective Cohort Study Examining the Associations of Dietary Calcium Intake with All-Cause and Cardiovascular Mortality in Older Chinese Community-Dwelling People

Background

Most epidemiological studies of calcium intake and mortality risk have been conducted in populations with moderate to high calcium intake, and limited studies have focused on populations with low habitual calcium intake (i.e., mean dietary calcium intake <700 mg/d).

Objective

This study investigated the association between dietary calcium intake and death from all causes and cardiovascular disease in Chinese population with low habitual calcium intake.

Design

Data from 3,139 Chinese men and women in a population-based prospective cohort study, aged >=65 years and free of heart diseases or stroke at baseline, were analyzed. Primary outcome measures, identified from the death registry, were death from all causes and cardiovascular disease. Dietary calcium intake assessed using a validated food frequency questionnaire was categorized into sex-specific quartiles. Data on use of supplemental calcium (yes or no) including individual calcium supplements and other calcium containing supplement were collected. Cox regression models adjusted for demographic and lifestyle variables were used to estimate hazard ratios (HRs) and 95% confidence intervals (CI).

Results

During a median of 9.1 years of follow-up, 529 all-cause deaths (344 men, 185 women) and 114 (74 men, 40 women) deaths from cardiovascular disease were identified. An inverse trend between dietary calcium intake and mortality was observed. Compared with the lowest quartile (<458 mg/d for men, <417 mg/d for women), the highest quartile of dietary calcium intake (>762 mg/d for men, >688 mg/d for women) had a significantly reduced risk of all-cause mortality (multivariate HR=0.63, 95% CI=0.49-0.81, P _trend<0.001) but an insignificant decreased risk of cardiovascular mortality (multivariate HR=0.70, 95% CI=0.41-1.21, P _trend=0.228). Similar inverse association was observed when the analyses were stratified on calcium supplemental use.

Conclusions

Higher intake of dietary calcium was associated with reduced risk of all-cause mortality and possibly cardiovascular mortality in Chinese older people with low habitual calcium intake.