Publications by authors named "B Luef"

25 Publications

Commensal and Opportunistic Bacteria Present in the Microbiota in Atlantic Cod () Larvae Differentially Alter the Hosts' Innate Immune Responses.

Microorganisms 2021 Dec 24;10(1). Epub 2021 Dec 24.

Department of Biotechnology and Food Science, Norwegian University of Science and Technology, 7491 Trondheim, Norway.

The roles of host-associated bacteria have gained attention lately, and we now recognise that the microbiota is essential in processes such as digestion, development of the immune system and gut function. In this study, Atlantic cod larvae were reared under germ-free, gnotobiotic and conventional conditions. Water and fish microbiota were characterised by 16S rRNA gene analyses. The cod larvae's transcriptional responses to the different microbial conditions were analysed by a custom Agilent 44 k oligo microarray. Gut development was assessed by transmission electron microscopy (TEM). Water and fish microbiota differed significantly in the conventional treatment and were dominated by different fast-growing bacteria. Our study indicates that components of the innate immune system of cod larvae are downregulated by the presence of non-pathogenic bacteria, and thus may be turned on by default in the early larval stages. We see indications of decreased nutrient uptake in the absence of bacteria. The bacteria also influence the gut morphology, reflected in shorter microvilli with higher density in the conventional larvae than in the germ-free larvae. The fact that the microbiota alters innate immune responses and gut morphology demonstrates its important role in marine larval development.
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http://dx.doi.org/10.3390/microorganisms10010024DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8779962PMC
December 2021

Recent advances in cultivation-independent molecular-based techniques for the characterization of vaginal eubiosis and dysbiosis.

Fac Rev 2020 9;9:21. Epub 2020 Dec 9.

Department of Gynecology and Obstetrics, University of Southern Denmark, Institute of Clinical Research, Research Unit of Gynaecology and Obstetrics, Kløvervænget 10, 10th floor, 5000 Odense C, Denmark.

"The bacterial vaginosis syndrome" has significant adverse effects for women and babies, including preterm birth and increased risk of acquisition of sexually transmitted infections and HIV. Currently, the gold standard for diagnosis is Gram stain microscopy of vaginal secretions, which is not readily available, is somewhat subjective, and does not differentiate between the likely different subtypes of vaginal dysbioses that may have different etiologies, microbiology, responses to antibiotics, and phenotypic outcomes. With new information from molecular-based, cultivation-independent studies, there is increasing interest in the use of molecular techniques for the diagnosis of bacterial vaginosis. We reviewed the current evidence on and the rationale behind the use of molecular techniques for the diagnosis of bacterial vaginosis. We found a number of commercially available molecular diagnostic tests, a few of which have US Food and Drug Administration (FDA) and/or Conformité Européenne diagnostic (CE-IVD) approval, and we have compared their performance with respect to sensitivities and specificities. Molecular-based tests have the advantage of objectivity, quantification, detection of fastidious organisms, and validity for self-obtained vaginal swabs. The performance of the molecular tests against standard microscopy is impressive, but further education of users on interpretation is needed. Bacterial vaginosis is the major cause of vaginal dysbiosis and should be recognized for the threat it is to women's genital tract health. Quantitative assessment of microbial abundance, the diversity of other organisms present, specific primers for gene sequence regions, and clades and biovars of target microbes should be recognized and incorporated into future molecular diagnostic tests to better differentiate between vaginal eubiosis and dysbiosis.
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http://dx.doi.org/10.12703/r/9-21DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7886079PMC
December 2020

The influence of the vaginal microbiota on preterm birth: A systematic review and recommendations for a minimum dataset for future research.

Placenta 2019 04 8;79:30-39. Epub 2019 Apr 8.

Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine Perinatal Research, University of Texas Medical Branch at Galveston, Galveston, TX, USA. Electronic address:

Objective: This systematic review aims to identify, critically appraise and summarize the results of studies examining the relationship between the vaginal microbiota and preterm birth (PTB).

Methods: We searched the electronic databases Medline, EMBASE and the Cochrane Controlled Register of Trials for studies in any language reporting on vaginal microbiota and PTB published from 1990 to November 29th, 2017. We included any study that performed lower genital tract microbiota assessment in asymptomatic pregnant women and reported on spontaneous preterm birth, with either intact or ruptured membranes.

Results: The search strategy yielded 2171 unique citations, of which nine studies were eligible for inclusion in this review. In six studies an association was found between the composition of the vaginal microbiota and PTB, but findings differed between subgroups, ethnicities and degree of risk of PTB. In three studies no association was found. Two of these studies found a significant difference in richness and Shannon diversity between term and PTB.

Conclusions: We have demonstrated that there is a paucity of molecular based, culture-independent studies that analyse the relationship between the vaginal microbiota and PTB as an outcome. The heterogeneity precluded a meta-analysis. Studies provide contradictory evidence and the quality of the clinical information in the studies is poor. To improve quality of future studies we have provided a database of essential and desirable items of quality that are method and topic specific.
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http://dx.doi.org/10.1016/j.placenta.2019.03.011DOI Listing
April 2019

Re: Clindamycin to reduce preterm birth in a low resource setting: a randomised placebo-controlled clinical trial.

BJOG 2018 11;125(12):1632-1633

Division of Surgery, Northwick Park Institute of Medical Research Campus, University College London, London, UK.

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http://dx.doi.org/10.1111/1471-0528.15439DOI Listing
November 2018

Validation of hospital discharge diagnoses for hypertensive disorders of pregnancy.

Acta Obstet Gynecol Scand 2016 Nov;95(11):1288-1294

HCA Research, Hans Christian Andersen Children's Hospital, Odense University Hospital, Odense, Denmark.

Introduction: A correct diagnosis of preeclampsia and gestational hypertension is important for treatment and epidemiological studies. Changes in diagnostic criteria and underreporting in certain subsets of patients may hamper validity of the diagnoses.

Materials And Methods: We validated the discharge diagnoses of preeclampsia and gestational hypertension, which are reported to the Danish National Patient Registry, in a cohort of 2163 pregnant women by retrospective evaluation of electronic hospital data.

Results: A preeclampsia discharge diagnosis was found in 113 (5.2%) of the participants. After validation, significantly more patients fulfilled criteria for diagnosis of preeclampsia (n = 163, 7.5%, p = 0.002); more had severe preeclampsia, 14 (0.6%) vs. 70 (3.2%), p < 0.001 and gestational hypertension, 62 (2.9%) vs. 46 (2.1%), p = 0.12. The diagnostic sensitivity for preeclampsia by discharge diagnosis was 55.8%; severe preeclampsia 18.6%; gestational hypertension 39.1%. Corresponding positive predictive values were 80.5, 92.9 and 29.0%. Misclassification occurred in 4.3, 2.7 and 3.3%, respectively. Misclassification was more prevalent in obese compared to lean women (10% vs. 3.6%, p < 0.0001).

Conclusions: Discharge diagnoses substantially underestimated the prevalence of preeclampsia, especially severe preeclampsia. Misclassification was most common in obese preeclamptic women. These findings depict the limitations associated with the direct use of discharge diagnoses of hypertensive disorders in pregnancy for research purposes.
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http://dx.doi.org/10.1111/aogs.13006DOI Listing
November 2016
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