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result(s) for
"Andersen, Lee O’Brien"
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Changes in the vaginal microbiota following antibiotic treatment for Mycoplasma genitalium, Chlamydia trachomatis and bacterial vaginosis
by
Jensen, Jørgen Skov
,
Johannesen, Thor Bech
,
Baig, Sharmin
in
Antibiotics
,
Azithromycin
,
Bacterial vaginosis
2020
The human vagina harbor a rich microbiota. The optimal state is dominated by lactobacilli that help to maintain health and prevent various diseases. However, the microbiota may rapidly change to a polymicrobial state that has been linked to a number of diseases. In the present study, the temporal changes of the vaginal microbiota in patients treated for sexually transmitted diseases or bacterial vaginosis (BV) and in untreated controls were studied for 26 days. The patients included 52 women treated with azithromycin, tetracyclines or moxifloxacin for present or suspected infection with Chlamydia trachomatis or Mycoplasma genitalium. Women with concurrent BV were also treated with metronidazole. The controls were 10 healthy women of matching age. The microbiota was analyzed by 16S rRNA gene deep sequencing, specific qPCRs and microscopy. There was generally good correlation between Nugent score and community state type (CST) and qPCR confirmed the sequencing results. By sequencing, more than 600 different taxa were found, but only 33 constituted more than 1 % of the sequences. In both patients and controls the microbiota could be divided into three different community state types, CST-I, CST-III and CST-IV. Without metronidazole, the microbiota remained relatively stable regarding CST although changes were seen during menstrual periods. Administration of metronidazole changed the microbiota from CST-IV to CST-III in approximately 50% of the treated patients. In contrast, the CST was generally unaffected by azithromycin or tetracyclines. In 30% of the BV patients, Gardnerella vaginalis was not eradicated by metronidazole. The majority of women colonized with Ureaplasma parvum remained positive after azithromycin while U. urealyticum was eradicated.
Journal Article
Impact of Blastocystis carriage and colonization intensity on gut microbiota composition in a non-westernized rural population from Colombia
2025
The role of Blastocystis, a common intestinal parasitic protist of humans and other animals, in human health and disease remains elusive. Recent studies suggest a connection between Blastocystis colonization, healthier lifestyles, and high-diversity gut microbiota. Nevertheless, studies concerning the relationship between Blastocystis colonization, its intensity, and gut microbiota composition -involving both bacterial and eukaryotic communities- remain limited.
This study examines the impact of Blastocystis carriage and colonization intensity on gut microbiota composition in a rural community in Colombia. A total of 88 human samples were collected from the rural population of Las Guacas village, located in the Cauca department in southwest Colombia. We utilized 16S and 18S rDNA sequencing to analyze both bacterial and eukaryotic microbiota, comparing Blastocystis-positive and -negative individuals, as well as groups with varying Blastocystis colonization intensity (low, medium, high), to identify distinct microbiota profiles and differentially abundant taxa linked to each condition.
The analysis revealed significant differences between Blastocystis-positive and -negative individuals. In terms of bacterial composition and structure, Blastocystis-positive individuals exhibited distinct microbiota profiles, as shown by beta diversity analysis. Taxa associated with colonization included Bacteroides, Prevotella, Oscillibacter, Faecalibacterium, and Alistipes. Higher Blastocystis colonization intensity was associated with an increased abundance of taxa such as Alistipes and Lachnospira, while lower intensities correlated with beneficial bacteria such as Akkermansia. Regarding eukaryotic composition, beta diversity analysis revealed distinct profiles associated with Blastocystis colonization. Differentially abundant taxa, including Entamoeba coli, were more prevalent in Blastocystis-positive individuals, while Blastocystis-negative individuals exhibited a higher abundance of opportunistic fungi, such as Candida albicans. Machine learning models, including random forest classifiers, supported these findings, identifying Faecalibacterium and Bacteroides as predictors of Blastocystis colonization.
These findings suggest that Blastocystis may modulate gut microbiota, contributing to microbial balance providing new insights into the ecological implications of Blastocystis in rural populations.
Journal Article
Tart Cherry Concentrate Does Not Alter the Gut Microbiome, Glycaemic Control or Systemic Inflammation in a Middle-Aged Population
2019
Limited evidence suggests that the consumption of polyphenols may improve glycaemic control and insulin sensitivity. The gut microbiome produces phenolic metabolites and increases their bioavailability. A handful of studies have suggested that polyphenol consumption alters gut microbiome composition. There are no data available investigating such effects in polyphenol-rich Montmorency cherry (MC) supplementation. A total of 28 participants (aged 40–60 years) were randomized to receive daily MC or glucose and energy-matched placebo supplementation for 4 wk. Faecal and blood samples were obtained at baseline and at 4 wk. There was no clear effect of supplementation on glucose handling (Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) and Gutt indices), although the Matsuda index decreased significantly in the MC group post-supplementation, reflecting an increase in serum insulin concentration. Contrastingly, placebo, but not MC supplementation induced a 6% increase in the Oral Glucose Insulin Sensitivity (OGIS) estimate of glucose clearance. Serum IL-6 and C reactive protein were unaltered by either supplement. The faecal bacterial microbiome was sequenced; species richness and diversity were unchanged by MC or placebo and no significant correlation existed between changes in Bacteroides and Faecalibacterium abundance and any index of insulin sensitivity. Therefore, 4 weeks of MC supplementation did not alter the gut microbiome, glycaemic control or systemic concentrations of IL-6 and CRP in a middle-aged population.
Journal Article
High throughput resistance profiling of Plasmodium falciparum infections based on custom dual indexing and Illumina next generation sequencing-technology
2017
Genetic polymorphisms in
P. falciparum
can be used to indicate the parasite’s susceptibility to antimalarial drugs as well as its geographical origin. Both of these factors are key to monitoring development and spread of antimalarial drug resistance. In this study, we combine multiplex PCR, custom designed dual indexing and Miseq sequencing for high throughput SNP-profiling of 457 malaria infections from Guinea-Bissau, at the cost of 10 USD per sample. By amplifying and sequencing 15 genetic fragments, we cover 20 resistance-conferring SNPs occurring in
pfcrt
,
pfmdr1
,
pfdhfr
,
pfdhps
, as well as the entire length of
pfK13
, and the mitochondrial barcode for parasite origin. SNPs of interest were sequenced with an average depth of 2,043 reads, and bases were called for the various SNP-positions with a p-value below 0.05, for 89.8–100% of samples. The SNP data indicates that artemisinin resistance-conferring SNPs in
pfK13
are absent from the studied area of Guinea-Bissau, while the
pfmdr1
86 N allele is found at a high prevalence. The mitochondrial barcodes are unanimous and accommodate a West African origin of the parasites. With this method, very reliable high throughput surveillance of antimalarial drug resistance becomes more affordable than ever before.
Journal Article
Stool Microbiota Diversity Analysis of Blastocystis-Positive and Blastocystis-Negative Individuals
by
Berg, Rebecca P. K. D.
,
van der Giezen, Mark
,
Bowtell, Joanna L.
in
Bacteria
,
Bacteroides
,
Bioinformatics
2022
Blastocystis is a unicellular eukaryote found in the gastrointestinal tract of both human and other animal hosts. The clinical significance of colonic Blastocystis colonization remains obscure. In this study, we used metabarcoding and bioinformatics analyses to identify differences in stool microbiota diversity between Blastocystis-positive and Blastocystis-negative individuals (n = 1285). Alpha diversity was significantly higher in Blastocystis carriers. At phylum level, Firmicutes and Bacteroidetes were enriched in carriers, while Proteobacteria were enriched in non-carriers. The genera Prevotella, Faecalibacterium, Flavonifracter, Clostridium, Succinivibrio, and Oscillibacter were enriched in carriers, whereas Escherichia, Bacteroides, Klebsiella, and Pseudomonas were enriched in non-carriers. No difference in beta diversity was observed. Individuals with Blastocystis-positive stools appear to have gut microbiomes associated with eubiosis unlike those with Blastocystis-negative stools, whose gut microbiomes are similar to those associated with dysbiosis. The role of Blastocystis as an indicator organism and potential modulator of the gut microbiota warrants further scrutiny.
Journal Article
Stability and resilience of the intestinal microbiota in children in daycare – a 12 month cohort study
by
Krogfelt, Karen Angeliki
,
O’Brien Andersen, Lee
,
Petersen, Andreas Munk
in
Abundance
,
Age Factors
,
Analysis
2018
Background
We performed a 12-month cohort study of the stability and resilience of the intestinal microbiota of healthy children in daycare in Denmark in relation to diarrheal events and exposure to known risk factors for gastrointestinal health such as travelling and antibiotic use. In addition, we analyzed how gut microbiota recover from such exposures.
Results
We monitored 32 children in daycare aged 1–6 years. Fecal samples were submitted every second month during a one-year observational period. Information regarding exposures and diarrheal episodes was obtained through questionnaires. Bacterial communities were identified using 16S rRNA gene sequencing. The core microbiota (mean abundance > 95%) dominated the intestinal microbiota, and none of the tested exposures (diarrheal events, travel, antibiotic use) were associated with decreases in the relative abundance of the core microbiota. Samples exhibited lower intra-individual variation than inter-individual variation. Half of all the variation between samples was explained by which child a sample originated from. Age explained 7.6–9.6% of the variation, while traveling, diarrheal events, and antibiotic use explained minor parts of the beta diversity. We found an age-dependent increase of alpha diversity in children aged 1–3 years, and while diarrheal events caused a decrease in alpha diversity, a recovery time of 40–45 days was observed.
Among children having had a diarrheal event, we observed a 10x higher relative abundance of
Prevotella
. After travelling, a higher abundance of two
Bacteroides
species and 40% less
Lachnospiraceae
were seen. Antibiotic use did not correlate with changes in the abundance of any bacteria.
Conclusion
We present data showing that Danish children in daycare have stable intestinal microbiota, resilient to the exposures investigated. An early age-dependent increase in the diversity was demonstrated. Diarrheal episodes decreased alpha diversity with an estimated recovery time of 40–45 days.
Journal Article
Substantial Intestinal Microbiota Differences Between Patients With Ulcerative Colitis From Ghana and Denmark
by
Krogfelt, Karen Angeliki
,
Petersen, Andreas Munk
,
Nielsen, Henrik Vedel
in
Abundance
,
African diet
,
Antibiotics
2022
Ulcerative colitis (UC) is a relapsing nontransmural inflammatory disease that is restricted to the colon and is characterized by flare-ups of bloody diarrhea. In this study, we aimed to investigate intestinal bacterial diversity in healthy controls and patients with UC with and without active disease, from Ghana and Denmark.
The study included 18 UC patients (9 with active and 9 with inactive disease) and 18 healthy controls from Ghana. In addition 16 UC patients from Denmark (8 UC with active and 8 UC with inactive disease) and 19 healthy controls from Denmark. Microbiota diversity analysis relied on sequencing of ribosomal small subunit genes. Purified genomic DNA was submitted to PCR using a primer set targeting prokaryotes and eukaryotes. The purified DNA was sequenced on the Illumina MiSeq system in a 2 × 250 bp set up (Illumina, San Diego, CA, USA). Blinded analysis of the taxonomy table was performed using BioNumerics-7.5 (Applied Maths NV, Sint-Martens-Latem, Belgium).
When analyzing the taxonomy data for prokaryotes, cluster and principal component analysis shows Danish healthy controls clustered together, but separate from healthy controls from Ghana, which also clustered together. The Shannon diversity index (SDI) for prokaryotes shows significant differences between Danish healthy controls and patients in comparison with the corresponding groups from Ghana (
= 0.0056). Significant increased abundance of
was detected in healthy controls from Ghana in comparison with healthy controls from Denmark. The SDI of the prokaryotes ranges between 0 and 3.1 in the Ghana study groups, while in the Danish study groups it ranges between 1.4 and 3.2, the difference is however not significant (
= 0.138). Our data show a significant increased abundance of eukaryotes species in the healthy control group from Ghana and Denmark in comparison with patient groups from Ghana and Denmark.
Overall, healthy controls and patients with UC from Denmark have increased diversity of prokaryotes. Healthy controls from Denmark and Ghana have increased abundance of eukaryotes in comparison with UC patient groups from Denmark and Ghana.
Journal Article
Parasitic Intestinal Protists of Zoonotic Relevance Detected in Pigs by Metabarcoding and Real-Time PCR
by
Tams, Katrine Wegener
,
Berg, Rebecca P. K. D.
,
Marving, Ellinor
in
Animal diseases
,
Animal health
,
Balantioides coli
2021
Several parasite species are shared between humans and pigs. We explored the application of next-generation sequencing-based metabarcoding supplemented with real-time PCR to fecal DNAs from 259 samples from 116 pigs in Denmark to detect and differentiate single-celled intestinal parasites of zoonotic relevance. Enterocytozoon bieneusi, Balantioides coli, and Giardia duodenalis were observed in 34/37 (92%), 148/259 (57%), and 86/259 (33%) samples, respectively. Entamoeba polecki ST1, E. polecki ST3, and Entamoeba hartmanni were detected in 104/259 (40%), 161/259 (62%), and 8/259 (3%) samples, respectively. Metabarcoding and real-time PCR detected Cryptosporidium in 90/259 (35%) and 239/259 (92%) of the samples, respectively, with Cryptosporidium suis and Cryptosporidium scrofarum observed in nearly equal proportions. Blastocystis subtypes 1, 3, 5, and 15 were found in 72 (28%), 6 (2%), 176 (68%), and 36 (14%) of 259 samples, respectively. Iodamoeba was identified in 1/259 samples (<1%), while none of 37 tested samples was positive for Dientamoeba fragilis. Our results illustrate how metabarcoding exemplifies a ‘one-fits-many’ approach to detecting intestinal single-celled parasites in feces supplemented with real-time PCR for selected parasites. Using metabarcoding with pathogen-specific assays may help detect emerging and previously underdetected pathogens and further elucidate the role of micro-eukaryotic parasites in human and animal health and disease.
Journal Article
Babesia spp. and other pathogens in ticks recovered from domestic dogs in Denmark
by
Krogfelt, Karen Angeliki
,
Jensen, Jørgen Skov
,
Al Marai, Dua
in
Animals
,
Animals, Domestic - microbiology
,
Animals, Domestic - parasitology
2015
Background
Newly recognized endemic foci for human babesiosis include Europe, where
Ixodes ricinus
, a vector for several species of
Babesia
, is the most commonly identified tick. Vector-based surveillance provides an early warning system for the emergence of human babesiosis, which is likely to be under-reported at emerging sites. In the present study, we set out to screen
I. ricinus
collected from Danish domestic dogs for
Babesia
, in order to identify whether humans in Denmark are exposed to the parasite.
Findings
A total of 661 ticks (
Ixodes
spp.) were collected from 345 Danish domestic dogs during April-September 2011 and pooled, one sample per dog. DNA was extracted from each sample and examined by PCR and sequencing for
Rickettsia
spp.,
Borrelia burgdorferi
sensu lato,
Bartonella
spp.,
Francisella tularensis
, Candidatus
Neoehrlichia mikurensis
, and
Babesia
spp. In total, 34% of the samples were positive for tick-borne microorganisms potentially pathogenic to humans:
Rickettsia
spp. were detected in 16% of the pools, with 79% being
R. helvetica. Borrelia burgdorferi
sensu lato was found in 15%, with the main species identified as
Borrelia afzelii
(39%). Likewise, 8% of the samples were positive for
Babesia
spp. (
Babesia microti
, 82%;
Babesia venatorum
(‘EU1’), 18%). Lastly, 1% of the samples tested positive for Candidatus
Neoehrlichia mikurensis
, and 0.6% for
Bartonella
spp. No ticks were found to be infected with
Francisella tularensis
.
Conclusions
Our data are in support of endemic occurrence of potentially zoonotic
Babesia
in Denmark and confirms
I. ricinus
as a vector of multiple pathogens of public health concern.
Journal Article