The first Cyclospora cayetanensis lineage A genome from an isolate from Mexico

BACKGROUND

Cyclospora cayetanensis is a protozoan parasite that causes intestinal illness in humans worldwide. Despite its global distribution, most genomic data for C. cayetanensis has been obtained from isolates collected in the United States, leaving genetic variability among globally distributed isolates underexplored.

RESULTS

In the present study, the genome of an isolate of C. cayetanensis obtained from a child with diarrhea living in Mexico was sequenced and assembled. Evaluation of the assembly using a lineage typing system recently developed by the Centers for Disease Control and Prevention revealed that this isolate is lineage A.

CONCLUSIONS

Given that the only other whole genome assembly available from Mexico was classified as lineage B, the data presented here represent an important step in expanding our knowledge of the diversity of C. cayetanensis isolates from Mexico at the genomic level.

Division of Blastocystis ST10 into three new subtypes: ST42-ST44

The Blastocystis subtype ST10 has been recognized to contain a great deal of diversity at the sequence level, potentially indicating the presence of multiple new STs within the clade. However, the data needed to validate these new STs were not available. To help resolve this diversity, full-length small subunit (SSU) rRNA gene reference sequences were generated using Oxford Nanopore MinION long-read sequencing from 21 samples representing multiple domestic and wild hosts and geographic regions and covering the sequence diversity previously described using fragments of the SSU rRNA gene. Phylogenetic and pairwise distance analyses were used to compare full-length sequences of the SSU rRNA gene generated in this study with all other valid STs of Blastocystis. We present data supporting the division of ST10/ST23 cluster into five subtypes, ST10, ST23, and three new subtypes with the proposed ST designations of ST42, ST43, and ST44. As the host range of Blastocystis continues to expand with new subtypes and new hosts being frequently identified, the reference sequences provided in this study will assist in accurate sequence classification and help to clarify the epidemiology of this common intestinal microeukaryote.

Molecular characterization of Blastocystis and Entamoeba of muskoxen and sheep in Greenland

Molecular characterisation of endobionts that are shared among human and non-human hosts can help shed light on the epidemiology and inform studies that aim to unravel the role of these organisms in health and disease. Two of the most common of shared endobionts include the single-celled intestinal protists Blastocystis and Entamoeba. Here, we present the first known data on genetic diversity and host specificity of these two genera in Greenland. Faecal DNA samples from 243 muskoxen and 44 sheep were submitted to metabarcoding of nuclear small subunit ribosomal DNA. Entamoeba- and Blastocystis-specific sequences were clustered, and consensus sequences were subjected to taxonomic query. Using MinION-based sequencing, near-complete nuclear small subunit ribosomal DNA sequences were obtained from four faecal samples. Of the 243 muskox samples, 180 (74%) and 19 (8%) were positive for Blastocystis and Entamoeba, respectively. Forty (91%) and six (14%) of the 44 sheep samples were positive for Blastocystis and Entamoeba, respectively. Blastocystis subtypes (ST) 10, 14, 21, 24-26, and a novel subtype (ST40) were identified. Colonisation by more than one subtype was common. ST40 was common in muskoxen but limited to Northeast Greenland. Entamoeba bovis and the E. bovis-associated ribosomal lineages (RL) 1 and 8 were found, and three conditional lineages (CL) 3, 4, and 10 were confirmed; CL10 was promoted to RL12. Several novel lineages were identified, all of which were linked to the E. bovis complex. In conclusion, Blastocystis was far more common than Entamoeba and found in approximately three of every four animals; both can be considered common colonisers of large herbivorous mammals in Greenland. Multiple subtypes/lineages of both genera were commonly observed, some of which were novel, but most of which are seen in many other parts of the world.

A longitudinal study of Blastocystis in dairy calves from birth through 24 months demonstrates dynamic shifts in infection rates and subtype prevalence and diversity by age

Blastocystis is a common microeukaryotic intestinal parasite in humans and other animal hosts globally. However, no large-scale longitudinal study has ever been conducted for Blastocystis. To understand patterns of infection prevalence and subtype diversity and their relationship with host age, we have conducted the most comprehensive longitudinal study of Blastocystis infection ever performed. Dairy calves from a herd located in Maryland, USA, were followed from birth through 24 months of age, and 990 individual fecal samples from 30 calves were collected over the study period, representing three age groups (pre-weaned, post-weaned, and heifer). All samples were screened for Blastocystis via PCR, and subtype determination was performed using next-generation amplicon sequencing. Associations between age group and infection status were assessed using logistic regression analyses. Blastocystis infection prevalence increased with time, significant associations were observed between age groups and infection risk, and a cumulative prevalence of 100% was observed among the study population during the 24-month period. Thirteen previously reported subtypes (ST1-6, ST10, ST14, ST21, ST23-26) and one potentially novel subtype were observed. Diversity within ST10 supports the need for division of the subtype into new subtype designations. Associations between subtype and age group were explored, and relationships between subtypes and infection chronicity are described. While subtype diversity increased with age in the study population, distinct patterns of individual subtype prevalence and chronicity were observed, supporting the importance of subtype discrimination in studies of host infection and disease. The data from this study represent a significant advance in our understanding of Blastocystis infection dynamics within a single host population over time and can be used to inform future studies of Blastocystis epidemiology in both humans and other animal hosts.

Exploring Blastocystis genetic diversity in rural schoolchildren from Colombia using next-generation amplicon sequencing reveals significant associations between contact with animals and infection risk

Blastocystis is a common intestinal protist with a global distribution in humans and many other animals. Yet, the status of Blastocystis as a pathogen, the risk factors associated with its transmission, and its zoonotic potential remain ill-defined. Here, we explored subtype (ST) diversity and potential risk factors for Blastocystis infection in 98 children from Apulo, Colombia. Samples were screened for Blastocystis via PCR, and ST identification was performed through next-generation amplicon sequencing (NGS). Associations between the presence of Blastocystis and individual STs and sociodemographic variables were assessed via logistic regression analyses. Seventy-one samples (72.4%) were Blastocystis-positive, and NGS revealed the presence of five STs (ST1-ST5). ST1, ST2, and ST3 were common and observed in nearly equal proportions (~ 40%), while samples with ST4 (1.4%) and ST5 (5.6%) were comparatively rare. The presence of mixed STs in the same sample was also common (28.2%). Comparisons among children within the same household identified that shared ST profiles were common, but diversity within family units was also observed. Logistic regression analyses returned significant associations between the presence of Blastocystis, individual subtypes, or mixed subtypes for several variables. Intriguingly, the presence of animals was one of the most common significant associations. Taken together, these data represent an important step forward in understanding both the potential routes and risk factors that may influence Blastocystis transmission and will be useful in shaping future studies which seek to clarify the relationships between STs, pathogenicity, and zoonotic transmission.

A hybrid sequencing and assembly strategy for generating culture free Giardia genomes

Giardia duodenalis is a pathogenic intestinal protozoan parasite of humans and many other animals. Giardia duodenalis is found throughout the world, and infection is known to have adverse health consequences for human and other mammalian hosts. Yet, many aspects of the biology of this ubiquitous parasite remain unresolved. Whole genome sequencing and comparative genomics can provide insight into the biology of G. duodenalis by helping to reveal traits that are shared by all G. duodenalis assemblages or unique to an individual assemblage or strain. However, these types of analyses are currently hindered by the lack of available G. duodenalis genomes, due, in part, to the difficulty in obtaining the genetic material needed to perform whole genome sequencing. In this study, a novel approach using a multistep cleaning procedure coupled with a hybrid sequencing and assembly strategy was assessed for use in producing high quality G. duodenalis genomes directly from cysts obtained from feces of two naturally infected hosts, a cat and dog infected with assemblage A and D, respectively. Cysts were cleaned and concentrated using cesium chloride gradient centrifugation followed by immunomagnetic separation. Whole genome sequencing was performed using both Illumina MiSeq and Oxford Nanopore MinION platforms. A hybrid assembly strategy was found to produce higher quality genomes than assemblies from either platform alone. The hybrid G. duodenalis genomes obtained from fecal isolates (cysts) in this study compare favorably for quality and completeness against reference genomes of G. duodenalis from cultured isolates. The whole genome assembly for assemblage D is the most contiguous genome available for this assemblage and is an important reference genome for future comparative studies. The data presented here support a hybrid sequencing and assembly strategy as a suitable method to produce whole genome sequences from DNA obtained from G. duodenalis cysts which can be used to produce novel reference genomes necessary to perform comparative genomics studies of this parasite.

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Assemblage A and D genomes were generated directly from cysts isolated from feces.

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Genomes were sequenced using Illumina and Oxford Nanopore sequencing platforms.

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A hybrid sequencing/assembly strategy was used to generate G. duodenalis genomes.

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A hybrid strategy yields reference quality genomes from fecal isolates.

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These methods have generated the most contiguous Assemblage D genome to date.

The Effects of Consuming White Button Mushroom Agaricus bisporus on the Brain and Liver Metabolome Using a Targeted Metabolomic Analysis

A targeted metabolomic analysis was performed on tissues derived from pigs fed diets supplemented with white button mushrooms (WBM) to determine the effect on the liver and brain metabolome. Thirty-one pigs were fed a grower diet alone or supplemented with either three or six servings of freeze-dried WBM for six weeks. Tissue metabolomes were analyzed using targeted liquid chromatography-mass spectrometry (LC-MS) combined with chemical similarity enrichment analysis (ChemRICH) and correlated to WBM-induced changes in fecal microbiome composition. Results indicated that WBM can differentially modulate metabolites in liver, brain cortex and hippocampus of healthy pigs. Within the glycero-phospholipids, there was an increase in alkyl-acyl-phosphatidyl-cholines (PC-O 40:3) in the hippocampus of pigs fed six servings of WBM. A broader change in glycerophospholipids and sphingolipids was detected in the liver with a reduction in several lipid species in pigs fed both WBM diets but with an increase in amino acids known as precursors of neurotransmitters in the cortex of pigs fed six servings of WBM. Metabolomic changes were positively correlated with increased abundance of Cryomorphaceae, Lachnospiraceae, Flammeovirgaceae and Ruminococcaceae in the microbiome suggesting that WBM can also positively impact tissue metabolite composition.

Wide Genetic Diversity of Blastocystis in White-Tailed Deer (Odocoileus virginianus) from Maryland, USA

Blastocystis is a gastrointestinal protist frequently reported in humans and animals worldwide. Wildlife populations, including deer, may serve as reservoirs of parasitic diseases for both humans and domestic animals, either through direct contact or through contamination of food or water resources. However, no studies of the occurrence and subtype distribution of Blastocystis in wildlife populations have been conducted in the United States. PCR and next generation amplicon sequencing were used to determine the occurrence and subtypes of Blastocystis in white-tailed deer (Odocoileus virginianus). Blastocystis was common, with 88.8% (71/80) of samples found to be positive. Twelve subtypes were identified, ten previously reported (ST1, ST3, ST4, ST10, ST14, ST21, and ST23–ST26) and two novel subtypes (ST30 and ST31). To confirm the validity of ST30 and ST31, MinION sequencing was used to obtain full-length SSU rRNA gene sequences, and phylogenetic and pairwise distance analyses were performed. ST10, ST14, and ST24 were the most commonly observed subtypes. Potentially zoonotic subtypes ST1, ST3, or ST4 were present in 8.5% of Blastocystis-positives. Mixed subtype infections were common (90.1% of Blastocystis-positives). This study is the first to subtype Blastocystis in white-tailed deer. White-tailed deer were found to be commonly infected/colonized with a wide diversity of subtypes, including two novel subtypes, zoonotic subtypes, and subtypes frequently reported in domestic animals. More studies in wildlife are needed to better understand their role in the transmission of Blastocystis.

Next-generation sequencing reveals wide genetic diversity of Blastocystis subtypes in chickens including potentially zoonotic subtypes

Blastocystis sp. is an intestinal protist parasite commonly found in the feces of humans and animals worldwide. Blastocystis exhibits extensive genetic diversity and has been identified in humans and a variety of animals including other mammals and birds. Blastocystis subtypes do not exhibit strict host specificity which raises the possibility of zoonotic transmission through either direct contact or fecal contamination of food or water. However, reports detailing the subtypes and prevalence of Blastocystis in avian species are limited. Therefore, this study investigated the presence of Blastocystis in chickens by molecular characterization of the small subunit rRNA (SSU rRNA) gene. Fecal samples from 130 chickens were collected from local markets in Uberlândia and Belo Horizonte in the state of Minas Gerais, Brazil. To detect and identify subtypes of Blastocystis, a next-generation amplicon sequencing protocol was used. Forty-four of the 130 (33.8%) chickens examined were positive for Blastocystis. Blastocystis subtypes ST6 (23/130; 17.7%), ST7 (43/130; 33.1%), ST10 (1/130; 0.8%), ST14 (5/130; 3.8%), ST25 (1/130; 0.8%), and a novel subtype (ST29) (2/130; 1.5%) were observed. A nanopore sequencing strategy was used to obtain the near full-length SSU rRNA gene nucleotide sequence and validate novel subtype ST29. Mixed infections containing multiple subtypes were common and identified in 63.6% of Blastocystis-positive chickens. All positive samples contained one or both potentially zoonotic subtypes ST6 and ST7. The prevalence of Blastocystis in chickens was high, and molecular characterization mostly identified subtypes previously found in humans. Thus, chickens may be a source of human infection and environmental contamination.

Use of Oxford Nanopore MinION to generate full-length sequences of the Blastocystis small subunit (SSU) rRNA gene

Background

Blastocystis sp. is one of the most common enteric parasites of humans and animals worldwide. It is well recognized that this ubiquitous protist displays a remarkable degree of genetic diversity in the SSU rRNA gene, which is currently the main gene used for defining Blastocystis subtypes. Yet, full-length reference sequences of this gene are available for only 16 subtypes of Blastocystis in part because of the technical difficulties associated with obtaining these sequences from complex samples.

Methods

We have developed a method using Oxford Nanopore MinION long-read sequencing and universal eukaryotic primers to produce full-length (> 1800 bp) SSU rRNA gene sequences for Blastocystis. Seven Blastocystis specimens representing five subtypes (ST1, ST4, ST10, ST11, and ST14) obtained both from cultures and feces were used for validation.

Results

We demonstrate that this method can be used to produce highly accurate full-length sequences from both cultured and fecal DNA isolates. Full-length sequences were successfully obtained from all five subtypes including ST11 for which no full-length reference sequence currently exists and for an isolate that contained mixed ST10/ST14.

Conclusions

The suitability of the use of MinION long-read sequencing technology to successfully generate full-length Blastocystis SSU rRNA gene sequences was demonstrated. The ability to produce full-length SSU rRNA gene sequences is key in understanding the role of genetic diversity in important aspects of Blastocystis biology such as transmission, host specificity, and pathogenicity.

Assessment of next generation amplicon sequencing of the beta-giardin gene for the detection of Giardia duodenalis assemblages and mixed infections

Giardia duodenalis is an enteric protozoan parasite commonly found in humans and many other animals around the world. The parasite is grouped into genetically related strains called assemblages which display differing degrees of host specificity. Although mixed assemblage infections have been documented the full extent of the occurrence and importance of mixed infections remains to be characterized as current sequencing technologies lack the sensitivity to readily detect mixed infections. Here we have developed a next generation amplicon sequencing (NGS) protocol and analysis pipeline for detecting Giardia assemblages using the beta-giardin gene. NGS was validated using 37 isolates that included Giardia muris and six assemblages (A-F) of Giardia duodenalis obtained from seven different hosts. NGS was compared to traditional PCR and direct Sanger sequencing for its ability to detect Giardia species, assemblages, and mixed assemblage infections. We demonstrate that NGS works as well as PCR and Sanger sequencing for assemblage detection as the same assemblage was observed in all samples by both methods. NGS has the further benefit of detecting mixed assemblage infections, low abundance assemblages, and intra-assemblage variation in samples which would have been missed using direct Sanger sequencing alone. NGS represents a powerful new tool for exploring Giardia infections not only in infected hosts but also in environmental specimens which may aide in understanding Giardia epidemiology.

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Developed a next generation sequencing (NGS) protocol to detect Giardia

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Comparison of NGS to Sanger sequencing for sensitivity and accuracy

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NGS improved detection of mixed assemblages and detects low abundance assemblages

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NGS allowed detection of intra-assemblage variabilities

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Mixed assemblages may be far more common than previously thought

Blastocystis subtype distribution in domestic and captive wild bird species from Brazil using next generation amplicon sequencing

Blastocystis is a food and water borne intestinal parasite commonly identified in humans and many other animals worldwide. Of the nine potentially zoonotic subtypes of Blastocystis, seven have been reported in bird species. However molecular studies of Blastocystis subtype diversity in birds are limited. In this study, fecal samples from 109 domestic and captive wild birds from Minas Gerais, Brazil were tested for the presence of Blastocystis subtypes using PCR and next generation amplicon sequencing of a fragment of the small subunit ribosomal RNA (SSU rRNA) gene. Birds from 11 orders and 38 species from both local markets and bird conservation facilities were sampled. Blastocystis was present in 14.7% of samples, and eight subtypes, six previously reported (ST5, ST6, ST7, ST10, ST14, ST24) and two novel subtypes (named ST27 and ST28), were identified. The most commonly identified subtypes were ST7 and ST6 identified in 10 (62.5%) and 6 (37.5%) of 16 Blastocystis positive samples. At least one of the three zoonotic subtypes identified (ST5, ST6, and ST7) was found in 81.3% of Blastocystis positive samples. Infection with multiple Blastocystis subtypes was common and identified in 62.5% of positive samples. This study is the first to use next generation amplicon sequencing to characterize Blastocystis subtype diversity in birds. The findings presented here confirm that birds may serve as reservoirs of zoonotic subtypes of Blastocystis and that the role of birds in transmission of Blastocystis to humans requires further study.

Use of next-generation amplicon sequencing to study Blastocystis genetic diversity in a rural human population from Mexico

BACKGROUND

The intestinal parasite Blastocystis is found in humans and animals around the world. It is spread through the consumption of contaminated food and water and has been associated with a variety of intestinal symptoms. Blastocystis is one of the most common intestinal parasites in humans, yet its prevalence and distribution in humans in North America is not well characterized.

METHODS

Next-generation amplicon sequencing of a region of the Blastocystis SSU rRNA gene was applied to DNA extracted from fecal specimens obtained from 182 inhabitants of a rural population in Mexico to characterize Blastocystis prevalence, subtype distribution, and intra-host subtype diversity in humans.

RESULTS

Of the 182 samples tested in this study, 68.1% (124) contained one or more Blastocystis subtypes. Subtype 3 was the most common subtype observed and was found in 81.5% of the positive samples. Subtype 1, 16.9% of the positive samples, and subtype 2, 17.7% of the positive samples, were also found in this population. Mixed infections were observed in 13.7% of the positive samples. In this population, the odds of having Blastocystis increased in adulthood (> 15 years; OR: 1.72, P < 0.0001), and the odds of having subtype 1 increased in the presence of farm animals (OR: 1.51, P = 0.03). The odds of having subtype 1, subtype 2, or a mixed infection decreased in the presence of cement flooring (OR: - 1.61, P = 0.005; OR: - 1.14, P = 0.03; OR: - 1.48, P = 0.02) possibly indicating socioeconomic factors are involved in the risk of acquiring one of these subtypes.

CONCLUSIONS

These data contribute to our understanding of the epidemiology of Blastocystis infection in humans and can be used to shape future studies which aim to better characterize the transmission pathways and health outcomes of Blastocystis infections.

Dietary patterns influence epicardial adipose tissue fatty acid composition and inflammatory gene expression in the Ossabaw pig

Epicardial adipose tissue (EAT) inflammation is implicated in the development and progression of coronary atherosclerosis. Dietary saturated and polyunsaturated fatty acids (SFAs and PUFA) can influence adipose tissue inflammation. We investigated the influence of dietary patterns, with emphasis on dietary fat type, and statin therapy, on EAT fatty acid (FA) composition and inflammatory gene expression. Thirty-two Ossabaw pigs were fed isocaloric amounts of a Heart Healthy (high in unsaturated fat) or Western (high in saturated fat) diets +/- atorvastatin for 6 months. EAT FA composition reflected dietary fat composition. There was no significant effect of atorvastatin on EAT FA composition. Total and long-chain SFAs were positively associated with inflammatory signaling (TLR2) and a gene involved in lipid mediator biosynthesis (PTGS2) (P<.0003). Medium-chain SFAs capric and lauric acids were negatively associated with IL-6 (all P<.0003). N-6 and n-3 PUFAs were positively associated with anti-inflammatory signaling genes (PPARG, FFAR4 and ADIPOQ) and long-chain n-3 PUFAs were positively associated with a gene involved in lipid mediator biosynthesis (ALOX5) (all P<.0003). These data indicate that dietary patterns, differing in fat type, influence EAT FA composition. Associations between EAT SFAs, PUFAs, and expression of genes related to inflammation provide a link between dietary quality and EAT inflammation.

Dietary Patterns Differentially Affect Microbiome Composition and Function in a Porcine Model of Obesity-related Metabolic Disorder (OR23-04-19)

Objectives

To determine the impact of two isocaloric diets containing (38% ,15% and 47% energy from fat, protein and carbohydrate, respectively): Western diet (WD) rich in saturated fat, refined carbohydrate, low in fiber and high in cholesterol, and a heart healthy diet (HHD) rich in unsaturated fat, unrefined carbohydrate, fruits/vegetables, high in fiber and low in cholesterol, on the composition and function of the gut microbiome

Methods

Thirty-Ossabaw pigs were fed WD or HHD diets with half within each group therapeutically treated with statin (atorvastatin [Lipitor]). The fecal microbiome was analyzed one and six months after dietary intervention by 16S rRNA sequencing and metagenomic function was empirically inferred

Results

Genus diversity was transiently affected with a reduced Shannon Diversity index one month after feeding the WD or HHD (FDR P < 0.05) with no change between groups at 6 months. Bacterial communities were clustered and separated by diet independent of gender and separated by treatment with statin in the HHD only. Verrucomicrobiaceae (Akkermansia) and Methanobacteriales (Methanobrevibacter) were increased in pigs as early as one month after feeding the HHD, as was Clostridiales and Bifidobacterium (associated with optimal intestinal health). There was an enrichment of Proteobacteria (Succinivibrionaceae, Desulfovibrionaceae) in pigs fed the WD. Additional members of the Firmicutes phylum were detected. Diet-dependent associations (all P < 0.05) were identified between Lachnospiraceae members and early host dyslipidemia, inflammation, and atheromatous lesions in the left anterior descending proximal (LAD) and LAD/Left circumflex (LCX) bifurcation six months post-intervention.

Conclusions

These data document for the first time a distinctive bacterial profile in Ossabaw pigs with a diet-induced dyslipidemia and early stage atherosclerosis. Taken together these results represent a new model to examine mechanistic pathways of dietary patterns and/or drug interactions and its effect on modulating microbiome in developing atherosclerosis.

Funding Sources

USDA project 8040-51530-056-00 and Inter Agency USDA Agreement 588-1950-9-001 between BHNRC and Jean Mayer USDA-HNRCA

A Western-Type Dietary Pattern Induces an Atherogenic Gene Expression Profile in the Coronary Arteries of the Ossabaw Pig

BACKGROUND

Current cardiovascular risk reduction guidance focuses on shifts in dietary patterns, rather than single foods or nutrients. Experimental studies are needed to identify the mechanisms by which food-based diets affect the development and progression of atherosclerosis.

OBJECTIVES

The aim of this study was to investigate the effect of 2 food-based dietary patterns and statin therapy on the transcriptome of the left anterior descending coronary artery of the Ossabaw pig.

METHODS

Pigs were randomly assigned to 1 of 4 groups and fed isocaloric diets for 6 mo; Heart Healthy-style diet (HHD) (high in unsaturated fat, unrefined grain, fruits/vegetables) or Western-style diet (WD) (high in saturated fat, cholesterol, refined grain), with or without atorvastatin. A 2-factor edge R analysis was used to determine differential gene expression in the left anterior descending coronary artery.

RESULTS

Relative to the HHD, the WD resulted in the differential expression of 143 genes, of which 139 genes were upregulated and 4 genes were downregulated (all log fold change ≥0.6, false discovery rate <0.10). The WD, compared with the HHD, resulted in the statistically significant upregulation of 8 atherosclerosis-associated pathways implicated in immune and inflammatory processes. There were no genes with significant differential expression attributable to statin therapy.

CONCLUSIONS

These data suggest that a WD induces alterations in the transcriptome of the coronary artery consistent with an inflammatory atherogenic phenotype in the Ossabaw pig with no significant modification by concurrent statin therapy.

Next generation amplicon sequencing improves detection of Blastocystis mixed subtype infections

Blastocystis is a highly prevalent enteric protist parasite of humans and animals. Transmission occurs via the fecal-oral route through ingestion of contaminated food or water. Genetic diversity studies have identified numerous subtypes (STs) within the genus Blastocystis based on polymorphism at the SSU rRNA gene. Although there is evidence of frequent mixed subtype infections, the extent of within-host subtype diversity remains largely unexplored. Accurate assessment of Blastocystis ST diversity is crucial to understand epidemiology and sources of Blastocystis transmission to humans. Here, we report the application of next generation sequencing (NGS) for detection and characterization of Blastocystis subtypes to investigate intra-host Blastocystis diversity. A total of 75 specimens obtained from cattle feces, previously identified as Blastocystis positive, were examined using next generation amplicon sequencing. A fragment of the SSU rRNA gene was amplified using Blastocystis-specific primers and resulting amplicons were used for NGS. Comparison of Sanger and NGS results suggest greater sensitivity using the NGS approach. Using Sanger sequencing, mixed infections were suspected in 18 specimens but only confirmed through cloning in three, while NGS identified 49 mixed infections (16 times more). In addition, NGS revealed greater diversity of subtypes with 14 detected compared to 11 by Sanger. Nine more infections with potentially zoonotic STs were detected by NGS than Sanger. Indeed, subtype 3, the most common subtype found in humans, was found in 37% (28) of specimens tested by NGS but in only four specimens using Sanger. Our findings indicate that mixed Blastocystis infections may be far more common than previously thought due to the limitations of current detection methods. This next generation amplicon sequencing strategy improves detection of mixed subtype infections and low abundance subtypes and represents a valuable resource for future Blastocystis studies to improve our understanding of its epidemiology.

A Western-type dietary pattern and atorvastatin induce epicardial adipose tissue interferon signaling in the Ossabaw pig

Epicardial adipose tissue (EAT) inflammation is thought to potentiate the development of coronary artery disease (CAD). Overall diet quality and statin therapy are important modulators of inflammation and CAD progression. Our objective was to examine the effects and interaction of dietary patterns and statin therapy on EAT gene expression in the Ossabaw pig. Pigs were randomized to 1 of 4 groups; Heart Healthy diet (high in unsaturated fat, unrefined grain, fruits/vegetables [HHD]) or Western diet (high in saturated fat, cholesterol, refined grain [WD]), with or without atorvastatin. Diets were fed in isocaloric amounts for 6 months. A two-factor edge R analysis identified the differential expression of 21 genes. Relative to the HHD, the WD resulted in a significant 12-fold increase of radical s-adenosyl methionine domain containing 2 (RSAD2), a gene induced by interferon signaling. Atorvastatin led to the significant differential expression of 17 genes predominately involved in interferon signaling. Results were similar using the Porcine Translational Research Database. Pathway analysis confirmed the up-regulation of interferon signaling in response to the WD and atorvastatin independently. An expression signature of the largely interferon related differentially expressed genes had no predictive capability on a histological assessment of atherosclerosis in the underlying coronary artery. These results suggest that a WD and atorvastatin evoke an interferon mediated immune response in EAT of the Ossabaw pig, which is not associated with the presence of atherosclerosis.

The Effect of Dietary Mushroom Agaricus bisporus on Intestinal Microbiota Composition and Host Immunological Function

A study was designed to determine the potential prebiotic effect of dietary mushrooms on the host immune response, and intestinal microbiota composition and function. Thirty-one six-week-old pigs were fed a pig grower diet alone or supplemented with either three or six servings of freeze-dried white button (WB)-mushrooms for six weeks. Host immune response was evaluated in peripheral blood mononuclear cells (PBMC), and alveolar macrophages (AM) after stimulation with Salmonella typhymurium-Lipopolysaccharide (LPS). Isolated DNA from fecal and proximal colon contents were used for 16S rDNA taxonomic analysis and linear discriminant analysis effect size (LEfSe) to determine bacterial abundance and metabolic function. Pigs gained weight with no difference in body composition or intestinal permeability. Feeding mushrooms reduced LPS-induced IL-1β gene expression in AM (P < 0.05) with no change in LPS-stimulated PBMC or the intestinal mucosa transcriptome. LEfSe indicated increases in Lachnospiraceae, Ruminococcaceae within the order Clostridiales with a shift in bacterial carbohydrate metabolism and biosynthesis of secondary metabolites in the mushroom-fed pigs. These results suggested that feeding WB mushrooms significantly reduced the LPS-induced inflammatory response in AM and positively modulated the host microbiota metabolism by increasing the abundance of Clostridiales taxa that are associated with improved intestinal health.

The Effect of Feeding Cocoa Powder and Lactobacillus rhamnosus on the Composition and Function of Pig Intestinal Microbiome

BACKGROUND

Dietary habits have been linked with variability of gut microbiota composition and disease risk.

OBJECTIVE

The aim of this study was to evaluate the effect of feeding a cocoa powder with or without a probiotic on the composition and function of the fecal microbiome of pigs.

METHODS

Four groups of 8 pigs each were fed a standard growth diet supplemented with cocoa powder, Lactobacillus rhamnosus (LGG), cocoa powder + LGG, or an equal amount of fiber similar to that found in cocoa powder (control group). Fecal samples were collected prior to and 4 wk after initiation of the dietary intervention. Microbiota composition was determined after amplification of the first 2 variable regions of the 16S ribosomal DNA (rDNA). Predictions of metagenomic function were calculated using 16S rDNA sequence data through Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt).

RESULTS

After 4 wk of treatment, bacterial abundance analysis demonstrated a prebiotic effect of cocoa powder on endogenous Bifidobacteriaceae and Lactobacillaceae and increased abundance of saccharolytic butyrate-producing bacteria like Roseburia. An increased bacterial evenness, Shannon diversity index, and diverse metabolic profile were detected in microbiomes of pigs fed the cocoa powder + LGG (P < 0.05) but not in pigs in the other 3 groups.

CONCLUSION

The data generated from this work demonstrated that 4-wk dietary treatment with cocoa powder alone or in combination with LGG probiotic had an impact on the composition and function of the fecal microbiota of healthy pigs.

The Ossabaw Pig Is a Suitable Translational Model to Evaluate Dietary Patterns and Coronary Artery Disease Risk

Background

Animal models that mimic diet-induced human pathogenesis of chronic diseases are of increasing importance in preclinical studies. The Ossabaw pig is an established model for obesity-related metabolic disorders when fed extreme diets in caloric excess.

Objective

To increase the translational nature of this model, we evaluated the effect of diets resembling 2 human dietary patterns, the Western diet (WD) and the Heart Healthy Diet (HHD), without or with atorvastatin (-S or +S) therapy, on cardiometabolic risk factors and atherosclerosis development.

Methods

Ossabaw pigs (n = 32; 16 boars and 16 gilts, aged 5-8 wk) were randomized according to a 2 × 2 factorial design into 4 groups (WD-S, WD+S, HHD-S, and HHD+S) and were fed the respective diets for 6 mo. The WD (high in saturated fat, cholesterol, and refined grain) and the HHD (high in unsaturated fat, whole grain, and fruit and vegetables) were isocaloric [38% of energy (%E) from fat, 47%E from carbohydrate, and 15%E from protein]. Body composition was determined by using dual-energy X-ray absorptiometry, serum fatty acid (FA) profiles by gas chromatography, cardiometabolic risk profile by standard procedures, and degree of atherosclerosis by histopathology.

Results

Serum FA profiles reflected the predominant dietary FA. Pigs fed the WD had 1- to 4-fold higher concentrations of LDL cholesterol, non-HDL cholesterol, HDL cholesterol, high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor α (TNF-α), alkaline phosphatase (ALP), and alanine aminotransferase (ALT) compared with HHD-fed pigs (all P-diet < 0.05). Statin therapy significantly lowered concentrations of LDL cholesterol (-39%), non-HDL cholesterol (-38%), and triglycerides (-6%) (P-statin < 0.02). A greater degree of atheromatous changes (macrophage infiltration, foam cells, fatty streaks) and lesion incidence was documented in the coronary arteries (P-diet < 0.05), as well as 2- to 3-fold higher lipid deposition in the aortic arch or thoracic aorta of WD- compared with HHD-fed pigs (P-diet < 0.001).

Conclusions

Ossabaw pigs manifested a dyslipidemic and inflammatory profile accompanied by early-stage atherosclerosis when fed a WD compared with an HHD, which was moderately reduced by atorvastatin therapy. This phenotype presents a translational model to examine mechanistic pathways of whole food-based dietary patterns on atherosclerosis development.

Flavanol-Enriched Cocoa Powder Alters the Intestinal Microbiota, Tissue and Fluid Metabolite Profiles, and Intestinal Gene Expression in Pigs

BACKGROUND

Consumption of cocoa-derived polyphenols has been associated with several health benefits; however, their effects on the intestinal microbiome and related features of host intestinal health are not adequately understood.

OBJECTIVE

The objective of this study was to determine the effects of eating flavanol-enriched cocoa powder on the composition of the gut microbiota, tissue metabolite profiles, and intestinal immune status.

METHODS

Male pigs (5 mo old, 28 kg mean body weight) were supplemented with 0, 2.5, 10, or 20 g flavanol-enriched cocoa powder/d for 27 d. Metabolites in serum, urine, the proximal colon contents, liver, and adipose tissue; bacterial abundance in the intestinal contents and feces; and intestinal tissue gene expression of inflammatory markers and Toll-like receptors (TLRs) were then determined.

RESULTS

O-methyl-epicatechin-glucuronide conjugates dose-dependently increased (P< 0.01) in the urine (35- to 204-fold), serum (6- to 186-fold), and adipose tissue (34- to 1144-fold) of pigs fed cocoa powder. The concentration of 3-hydroxyphenylpropionic acid isomers in urine decreased as the dose of cocoa powder fed to pigs increased (75-85%,P< 0.05). Compared with the unsupplemented pigs, the abundance ofLactobacillusspecies was greater in the feces (7-fold,P= 0.005) and that ofBifidobacteriumspecies was greater in the proximal colon contents (9-fold,P= 0.01) in pigs fed only 20 or 10 g cocoa powder/d, respectively. Moreover, consumption of cocoa powder reducedTLR9gene expression in ileal Peyer's patches (67-80%,P< 0.05) and mesenteric lymph nodes (43-71%,P< 0.05) of pigs fed 2.5-20 g cocoa powder/d compared with pigs not supplemented with cocoa powder.

CONCLUSION

This study demonstrates that consumption of cocoa powder by pigs can contribute to gut health by enhancing the abundance ofLactobacillusandBifidobacteriumspecies and modulating markers of localized intestinal immunity.

Transcriptomic Profile of Whole Blood Cells from Elderly Subjects Fed Probiotic Bacteria Lactobacillus rhamnosus GG ATCC 53103 (LGG) in a Phase I Open Label Study

We examined gene expression of whole blood cells (WBC) from 11 healthy elderly volunteers participating on a Phase I open label study before and after oral treatment with Lactobacillus rhamnosus GG-ATCC 53103 (LGG)) using RNA-sequencing (RNA-Seq). Elderly patients (65–80 yrs) completed a clinical assessment for health status and had blood drawn for cellular RNA extraction at study admission (Baseline), after 28 days of daily LGG treatment (Day 28) and at the end of the study (Day 56) after LGG treatment had been suspended for 28 days. Treatment compliance was verified by measuring LGG-DNA copy levels detected in host fecal samples. Normalized gene expression levels in WBC RNA were analyzed using a paired design built within three analysis platforms (edgeR, DESeq2 and TSPM) commonly used for gene count data analysis. From the 25,990 transcripts detected, 95 differentially expressed genes (DEGs) were detected in common by all analysis platforms with a nominal significant difference in gene expression at Day 28 following LGG treatment (FDR<0.1; 77 decreased and 18 increased). With a more stringent significance threshold (FDR<0.05), only two genes (FCER2 and LY86), were down-regulated more than 1.5 fold and met the criteria for differential expression across two analysis platforms. The remaining 93 genes were only detected at this threshold level with DESeq2 platform. Data analysis for biological interpretation of DEGs with an absolute fold change of 1.5 revealed down-regulation of overlapping genes involved with Cellular movement, Cell to cell signaling interactions, Immune cell trafficking and Inflammatory response. These data provide evidence for LGG-induced transcriptional modulation in healthy elderly volunteers because pre-treatment transcription levels were restored at 28 days after LGG treatment was stopped. To gain insight into the signaling pathways affected in response to LGG treatment, DEG were mapped using biological pathways and genomic data mining packages to indicate significant biological relevance.

Trial Registration: ClinicalTrials.gov NCT01274598

A Single Meal Containing Raw, Crushed Garlic Influences Expression of Immunity- and Cancer-Related Genes in Whole Blood of Humans

BACKGROUND

Preclinical and epidemiologic studies suggest that garlic intake is inversely associated with the progression of cancer and cardiovascular disease.

OBJECTIVE

We designed a study to probe the mechanisms of garlic action in humans.

METHODS

We conducted a randomized crossover feeding trial in which 17 volunteers consumed a garlic-containing meal (100 g white bread, 15 g butter, and 5 g raw, crushed garlic) or a garlic-free control meal (100 g white bread and 15 g butter) after 10 d of consuming a controlled, garlic-free diet. Blood was collected before and 3 h after test meal consumption for gene expression analysis in whole blood. Illumina BeadArray was used to screen for genes of interest, followed by real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) on selected genes. To augment human study findings, Mono Mac 6 cells were treated with a purified garlic extract (0.5 μL/mL), and mRNA was measured by qRT-PCR at 0, 3, 6, and 24 h.

RESULTS

The following 7 genes were found to be upregulated by garlic intake: aryl hydrocarbon receptor (AHR), aryl hydrocarbon receptor nuclear translocator (ARNT), hypoxia-inducible factor 1α (HIF1A), proto-oncogene c-Jun (JUN), nuclear factor of activated T cells (NFAT) activating protein with immunoreceptor tyrosine-based activation motif 1 (NFAM1), oncostatin M (OSM), and V-rel avian reticuloendotheliosis viral oncogene homolog (REL). Fold-increases in mRNA transcripts ranged from 1.6 (HIF1A) to 3.0 (NFAM1) (P < 0.05). The mRNA levels of 5 of the 7 genes that were upregulated in the human trial were also upregulated in cell culture at 3 and 6 h: AHR, HIF1A, JUN, OSM, and REL. Fold-increases in mRNA transcripts in cell culture ranged from 1.7 (HIF1A) to 12.1 (JUN) (P < 0.01). OSM protein was measured by ELISA and was significantly higher than the control at 3, 6, and 24 h (24 h: 19.5 ± 1.4 and 74.8 ± 1.4 pg/mL for control and garlic, respectively). OSM is a pleiotropic cytokine that inhibits several tumor cell lines in culture.

CONCLUSION

These data indicate that the bioactivity of garlic is multifaceted and includes activation of genes related to immunity, apoptosis, and xenobiotic metabolism in humans and Mono Mac 6 cells. This trial is registered at clinicaltrials.gov as NCT01293591.

Safety of Bifidobacterium animalis subsp. lactis (B. lactis) strain BB-12-supplemented yogurt in healthy adults on antibiotics: a phase I safety study

Probiotics are live microorganisms that, when administered in sufficient doses, provide health benefits on the host. The United States Food and Drug Administration (FDA) requires phase I safety studies for probiotics when the intended use of the product is as a drug. The purpose of the study was to determine the safety of Bifidobacterium animalis subsp lactis (B. lactis) strain BB-12 (BB-12)-supplemented yogurt when consumed by a generally healthy group of adults who were prescribed a 10-day course of antibiotics for a respiratory infection. Secondary aims were to assess the ability of BB-12 to affect the expression of whole blood immune markers associated with cell activation and inflammatory response. A phase I, double-blinded, randomized controlled study was conducted in compliance with FDA guidelines for an Investigational New Drug (IND). Forty participants were randomly assigned to consume 4 ounces of either BB-12 -supplemented yogurt or non-supplemented control yogurt daily for 10 d. The primary outcome was to assess safety and tolerability, assessed by the number of reported adverse events. A total of 165 non-serious adverse events were reported, with no differences between the control and BB-12 groups. When compared to the control group, B lactis fecal levels were modestly higher in the BB-12-supplemented group. In a small subset of patients, changes in whole blood expression of genes associated with regulation and activation of immune cells were detected in the BB-12-supplemented group. BB-12-supplemented yogurt is safe and well tolerated when consumed by healthy adults concurrently taking antibiotics. This study will form the basis for future randomized clinical trials investigating the potential immunomodulatory effects of BB-12-supplemented yogurt in a variety of disease states.

A high fat, high cholesterol diet leads to changes in metabolite patterns in pigs--a metabolomic study

Non-targeted metabolite profiling can identify biological markers of dietary exposure that lead to a better understanding of interactions between diet and health. In this study, pigs were used as an animal model to discover changes in metabolic profiles between regular basal and high fat/high cholesterol diets. Extracts of plasma, fecal and urine samples from pigs fed high fat or basal regular diets for 11 weeks were analysed using ultra-high performance liquid chromatography with high-resolution mass spectrometry (UHPLC-HRMS) and chemometric analysis. Cloud plots from XCMS online were used for class separation of the most discriminatory metabolites. The major metabolites contributing to the discrimination were identified as bile acids (BAs), lipid metabolites, fatty acids, amino acids and phosphatidic acid (PAs), phosphatidylglycerol (PGs), glycerophospholipids (PI), phosphatidylcholines (PCs) and tripeptides. These results suggest the developed approach can be used to identify biomarkers associated with specific feeding diets and possible metabolic disorders related to diet.