Crohn's disease (CD) is an inflammatory bowel disease of complex etiology, although dysbiosis of the gut microbiota has been implicated in chronic immune-mediated inflammation associated with CD. ...Here we combined shotgun metagenomic and metaproteomic approaches to identify potential functional signatures of CD in stool samples from six twin pairs that were either healthy, or that had CD in the ileum (ICD) or colon (CCD). Integration of these omics approaches revealed several genes, proteins, and pathways that primarily differentiated ICD from healthy subjects, including depletion of many proteins in ICD. In addition, the ICD phenotype was associated with alterations in bacterial carbohydrate metabolism, bacterial-host interactions, as well as human host-secreted enzymes. This eco-systems biology approach underscores the link between the gut microbiota and functional alterations in the pathophysiology of Crohn's disease and aids in identification of novel diagnostic targets and disease specific biomarkers.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Clustered regularly interspaced short palindromic repeats (CRISPRs) are a family of DNA direct repeats found in many prokaryotic genomes. Repeats of 21-37 bp typically show weak dyad symmetry and are ...separated by regularly sized, nonrepetitive spacer sequences. Four CRISPR-associated (Cas) protein families, designated Cas1 to Cas4, are strictly associated with CRISPR elements and always occur near a repeat cluster. Some spacers originate from mobile genetic elements and are thought to confer "immunity" against the elements that harbor these sequences. In the present study, we have systematically investigated uncharacterized proteins encoded in the vicinity of these CRISPRs and found many additional protein families that are strictly associated with CRISPR loci across multiple prokaryotic species. Multiple sequence alignments and hidden Markov models have been built for 45 Cas protein families. These models identify family members with high sensitivity and selectivity and classify key regulators of development, DevR and DevS, in Myxococcus xanthus as Cas proteins. These identifications show that CRISPR/cas gene regions can be quite large, with up to 20 different, tandem-arranged cas genes next to a repeat cluster or filling the region between two repeat clusters. Distinctive subsets of the collection of Cas proteins recur in phylogenetically distant species and correlate with characteristic repeat periodicity. The analyses presented here support initial proposals of mobility of these units, along with the likelihood that loci of different subtypes interact with one another as well as with host cell defensive, replicative, and regulatory systems. It is evident from this analysis that CRISPR/cas loci are larger, more complex, and more heterogeneous than previously appreciated.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The etiology of vulvar lichen sclerosus (LS) remains unclear; however, alterations in cutaneous and gut microbiota may be contributing to the pathogenesis of this inflammatory condition. To explore ...this hypothesis, we conducted a pilot case-control study, obtaining dermal swab and stool samples from prepubertal girls with vulvar LS (n = 5), girls with nonspecific vulvovaginitis (n = 5), and healthy controls (n = 3). Samples (n = 56) were subjected to total DNA extractions. Resulting DNA was purified, subjected to PCR (targeting the V3V4 region of the 16S rRNA gene), sequenced, and analyzed using QIIME, MetagenomeSeq, and DESeq2 software packages. Our findings showed that there were significant differences in the cutaneous and gut microbiotas of girls with LS compared to controls. On the skin, girls with LS had a statistically significantly higher relative abundance of Porphyromonas spp., Parvimonas spp., Peptoniphilus spp., Prevotella spp., Dialister spp., and Peptostreptococcus spp., but a lower relative abundance of Cornyebacterium compared to the control group. In the gut samples, girls with LS had a significantly higher relative abundance of Dialister spp., Clostridiales spp., Paraprevotella spp., Escherichia coli, Bifidobacterium adolescentis, and Akkermansia muciniphila, and a lower relative abundance of Roseburia faecis and Ruminococcus bromii compared to controls. These results suggest a potential association between cutaneous and gut dysbiosis and pediatric vulvar LS. Future studies involving larger samples sizes are warranted to further evaluate this association.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Obesity has been linked to the human gut microbiota; however, the contribution of gut bacterial species to the obese phenotype remains controversial because of conflicting results from studies in ...different populations. To explore the possible dysbiosis of gut microbiota in obesity and its metabolic complications, we studied men and women over a range of body mass indices from the Old Order Amish sect, a culturally homogeneous Caucasian population of Central European ancestry. We characterized the gut microbiota in 310 subjects by deep pyrosequencing of bar-coded PCR amplicons from the V1-V3 region of the 16S rRNA gene. Three communities of interacting bacteria were identified in the gut microbiota, analogous to previously identified gut enterotypes. Neither BMI nor any metabolic syndrome trait was associated with a particular gut community. Network analysis identified twenty-two bacterial species and four OTUs that were either positively or inversely correlated with metabolic syndrome traits, suggesting that certain members of the gut microbiota may play a role in these metabolic derangements.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The function of the appendix is largely unknown, but its microbiota likely contributes to function. Alterations in microbiota may contribute to appendicitis, but conventional culture studies have not ...yielded conclusive information. We conducted a pilot, culture-independent 16S rRNA-based microbiota study of paired appendix and rectal samples.
We collected appendix and rectal swabs from 21 children undergoing appendectomy, six with normal appendices and fifteen with appendicitis (nine perforated). After DNA extraction, we amplified and sequenced 16S rRNA genes and analyzed sequences using CLoVR. We identified organisms differing in relative abundance using ANOVA (p<0.05) by location (appendix vs. rectum), disease (appendicitis vs. normal), and disease severity (perforated vs. non-perforated).
We identified 290 taxa in the study's samples. Three taxa were significantly increased in normal appendices vs. normal rectal samples: Fusibacter (p = 0.009), Selenomonas (p = 0.026), and Peptostreptococcus (p = 0.049). Five taxa were increased in abundance in normal vs. diseased appendices: Paenibacillaceae (p = 0.005), Acidobacteriaceae GP4 (p = 0.019), Pseudonocardinae (p = 0.019), Bergeyella (p = 0.019) and Rhizobium (p = 0.045). Twelve taxa were increased in the appendices of appendicitis patients vs. normal appendix: Peptostreptococcus (p = 0.0003), Bilophila (p = 0.0004), Bulleidia (p = 0.012), Fusobacterium (p = 0.018), Parvimonas (p = 0.003), Mogibacterium (p = 0.012), Aminobacterium (p = 0.019), Proteus (p = 0.028), Actinomycineae (p = 0.028), Anaerovorax (p = 0.041), Anaerofilum (p = 0.045), Porphyromonas (p = 0.010). Five taxa were increased in appendices in patients with perforated vs. nonperforated appendicitis: Bulleidia (p = 0.004), Fusibacter (p = 0.005), Prevotella (p = 0.021), Porphyromonas (p = 0.030), Dialister (p = 0.035). Three taxa were increased in rectum samples of patients with appendicitis compared to the normal patients: Bulleidia (p = 0.034), Dialister (p = 0.003), and Porphyromonas (p = 0.026).
Specific taxa are more abundant in normal appendices compared to the rectum, suggesting that a distinctive appendix microbiota exists. Taxa with altered abundance in diseased and severely diseased (perforated) samples may contribute to appendicitis pathogenesis, and may provide microbial signatures in the rectum useful for guiding both treatment and diagnosis of appendicitis.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The composition of the oral microbiota from 10 individuals with healthy oral tissues was determined using culture-independent techniques. From each individual, 26 specimens, each from different oral ...sites at a single point in time, were collected and pooled. An 11th pool was constructed using portions of the subgingival specimens from all 10 individuals. The 16S ribosomal RNA gene was amplified using broad-range bacterial primers, and clone libraries from the individual and subgingival pools were constructed. From a total of 11,368 high-quality, nonchimeric, near full-length sequences, 247 species-level phylotypes (using a 99% sequence identity threshold) and 9 bacterial phyla were identified. At least 15 bacterial genera were conserved among all 10 individuals, with significant interindividual differences at the species and strain level. Comparisons of these oral bacterial sequences with near full-length sequences found previously in the large intestines and feces of other healthy individuals suggest that the mouth and intestinal tract harbor distinct sets of bacteria. Co-occurrence analysis showed significant segregation of taxa when community membership was examined at the level of genus, but not at the level of species, suggesting that ecologically significant, competitive interactions are more apparent at a broader taxonomic level than species. This study is one of the more comprehensive, high-resolution analyses of bacterial diversity within the healthy human mouth to date, and highlights the value of tools from macroecology for enhancing our understanding of bacterial ecology in human health.
Lyme disease is the most common tick-borne human illness in North America. In order to understand the molecular pathogenesis, natural diversity, population structure and epizootic spread of the North ...American Lyme agent, Borrelia burgdorferi sensu stricto, a much better understanding of the natural diversity of its genome will be required. Towards this end we present a comparative analysis of the nucleotide sequences of the numerous plasmids of B. burgdorferi isolates B31, N40, JD1 and 297. These strains were chosen because they include the three most commonly studied laboratory strains, and because they represent different major genetic lineages and so are informative regarding the genetic diversity and evolution of this organism. A unique feature of Borrelia genomes is that they carry a large number of linear and circular plasmids, and this work shows that strains N40, JD1, 297 and B31 carry related but non-identical sets of 16, 20, 19 and 21 plasmids, respectively, that comprise 33-40% of their genomes. We deduce that there are at least 28 plasmid compatibility types among the four strains. The B. burgdorferi ∼900 Kbp linear chromosomes are evolutionarily exceptionally stable, except for a short ≤20 Kbp plasmid-like section at the right end. A few of the plasmids, including the linear lp54 and circular cp26, are also very stable. We show here that the other plasmids, especially the linear ones, are considerably more variable. Nearly all of the linear plasmids have undergone one or more substantial inter-plasmid rearrangements since their last common ancestor. In spite of these rearrangements and differences in plasmid contents, the overall gene complement of the different isolates has remained relatively constant.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Young adults are increasingly using non-cigarette products, such as hookahs, since they are perceived as healthier alternatives to cigarette smoking. However, hookah users are exposed to not only ...carcinogenic compounds but also microorganisms that may play an active role in the development of both infectious and chronic diseases among users. Nevertheless, existing hookah research in this area has focused only on microorganisms that may be transferred to users through the smoking apparatus and not on bacterial communities associated with hookah tobacco. To address this knowledge gap, we conducted time-series experiments on commercially available hookah brands (Al Fakher (flavors: two apple, mint, and watermelon) and Fumari (flavors: white gummy bear, ambrosia, and mint chocolate chill)) stored under three different temperature and relative humidity conditions over 14 days. To characterize bacterial communities, the total DNA was extracted on days 0, 5, 9, and 14, PCR-amplified for the V3V4 region of the bacterial 16S rRNA gene, sequenced on the Illumina HiSeq platform, and analyzed using R. Diversity (alpha and beta) analyses revealed that the microbiotas of Fumari and Al Fakher products differed significantly and that flavor had a significant effect on the hookah microbiota. Overall,
Pseudomonas
,
Bacillus
,
Sphingomonas
, and
Methylobacterium
were the predominant bacterial taxa across all products
.
Additionally, we observed compositional differences between hookah brands across the 14-day incubation
.
These data suggest that the bacterial communities of hookah tobacco are diverse and differ across brands and flavors, which may have critical implications regarding exposures to specific bacteria among hookah users.
Key points
•
Commercial hookah products harbor diverse bacterial communities
.
•
Brands and flavors impact the diversity of these communities
.
•
Research on their viability and transmission to users’ respiratory tracts is needed
.
Graphical abstract
Short bowel syndrome (SBS) presents an increasing problem in pediatrics. SBS often results from surgical resection of necrotic bowel following necrotizing enterocolitis or treatment of anatomic ...gastrointestinal defects. SBS is associated with significant morbidity and mortality, and creates substantial burdens for patients, families, and the health system. Recent reports have demonstrated that the fecal microbiome of children with SBS is significantly different from healthy control and severe intestinal microbial imbalances is associated with poor growth. We hypothesized that children with SBS and adverse clinical features such as PN dependent, shorter bowel length and lack of ileocecal valve would demonstrate more gut dysbiosis compare with the SBS non-PN dependent. An improved understanding of SBS pathogenesis would enhance management and potentially suggest new interventions. We studied microbial communities of SBS and control non-SBS patients from the jejunum, obtained endoscopically or by ostomy aspiration, and stool. We enrolled SBS patients who did and did not require parenteral nutrition (PN), as a surrogate marker for the seriousness of their disease. We studied the microbiota using high-throughput DNA sequencing of 16S rRNA genes and statistical analyses. We found that microbial diversity was significantly greater in jejunal aspirate than in stool samples in SBS patients, unlike non-SBS patients; that SBS patients receiving enteral feeds had greater diversity, and that SBS patients on PN and enteral feeds had lower differences in diversity in jejunal vs. stool samples. We found a trend toward increased diversity in patients with an intact ileocecal valve, and found that certain taxa were more abundant in the certain sample types, and in SBS patients vs. non-SBS patients. SBS patients have lower microbial diversity, especially patients with more severe disease, patients requiring PN, and those lacking an ileocecal valve. SBS patients, particularly those with more complex characteristics, exhibit differences in their intestinal microbiota. Particular individual taxa were over- and under-represented in patients with more unfavorable disease. While diminished diversity and alterations in microbiota composition are likely consequences of SBS, future efforts aimed at increasing microbial diversity and interventions targeting specific microbiota characteristics might constitute a testable approach to ameliorate some clinical SBS clinical consequences.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The mosquito’s innate immune system controls both Plasmodium and bacterial infections. We investigated the competitiveness of mosquitoes genetically modified to alter expression of their own ...anti-Plasmodium immune genes in a mixed-cage population with wild-type mosquitoes. We observed that genetically modified mosquitoes with increased immune activity in the midgut tissue did not have an observed fitness disadvantage and showed reduced microbial loads in both the midgut and reproductive organs. These changes result in a mating preference of genetically modified males for wild-type females, whereas wild-type males prefer genetically modified females. These changes foster the spread of the genetic modification in a mosquito cage population.
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