| 1. |
- Arndt, D. S., et al.
(författare)
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STATE OF THE CLIMATE IN 2017
- 2018
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Ingår i: Bulletin of The American Meteorological Society - (BAMS). - : American Meteorological Society. - 0003-0007 .- 1520-0477. ; 99:8, s. S1-S310
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Forskningsöversikt (refereegranskat)
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| 2. |
- Butler, Éile, et al.
(författare)
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A pilot study investigating lactic acid bacterial symbionts from the honeybee in inhibiting human chronic wound pathogens
- 2016
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Ingår i: International Wound Journal. - Oxford : Blackwell Publishing. - 1742-4801 .- 1742-481X. ; 13:5, s. 729-37
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Tidskriftsartikel (refereegranskat)abstract
- Treatment and management of chronic wounds is a large burden on the health sector and causes substantial suffering for the patients. We believe that 13 lactic acid bacteria (LAB) symbionts isolated from the honey crop of the honeybee are important players in the antimicrobial action of honey, by producing antimicrobial substances and can be used in combination with heather honey as an effective treatment in wound management. A total of 22 patients with chronic ulcers were included; culture-dependent and molecular-based (MALDI-MS and 16S rRNA gene sequencing) techniques were used to identify bacteria from chronic wounds. These clinical isolates were used for in vitro antimicrobial testing with standardised viable LAB and sterilised heather honey mixture. Twenty of the patients' wounds were polymicrobial and 42 different species were isolated. Patient isolates that were tested in vitro were inhibited by the LAB and honey combination with inhibitory zones comparable with different antibiotics. LAB and heather honey in combination presents a new topical option in chronic wound management because of the healing properties of honey, antimicrobial metabolite production from the LAB and their bactericidal effect on common chronic wound pathogens. This new treatment may be a stepping stone towards an alternative solution to antibiotics.
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| 3. |
- Butler, Éile, et al.
(författare)
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Proteins of novel lactic acid bacteria from Apis mellifera mellifera: an insight into the production of known extra-cellular proteins during microbial stress
- 2013
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Ingår i: BMC Microbiology. - : Springer Science and Business Media LLC. - 1471-2180. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Background: Lactic acid bacteria (LAB) has been considered a beneficial bacterial group, found as part of the microbiota of diverse hosts, including humans and various animals. However, the mechanisms of how hosts and LAB interact are still poorly understood. Previous work demonstrates that 13 species of Lactobacillus and Bifidobacterium from the honey crop in bees function symbiotically with the honeybee. They protect each other, their hosts, and the surrounding environment against severe bee pathogens, bacteria, and yeasts. Therefore, we hypothesized that these LAB under stress, i.e. in their natural niche in the honey crop, are likely to produce bioactive substances with antimicrobial activity. Results: The genomic analysis of the LAB demonstrated varying genome sizes ranging from 1.5 to 2.2 mega-base pairs (Mbps) which points out a clear difference within the protein gene content, as well as specialized functions in the honeybee microbiota and their adaptation to their host. We demonstrate a clear variation between the secreted proteins of the symbiotic LAB when subjected to microbial stressors. We have identified that 10 of the 13 LAB produced extra-cellular proteins of known or unknown function in which some are arranged in interesting putative operons that may be involved in antimicrobial action, host interaction, or biofilm formation. The most common known extra-cellular proteins secreted were enzymes, DNA chaperones, S-layer proteins, bacteriocins, and lysozymes. A new bacteriocin may have been identified in one of the LAB symbionts while many proteins with unknown functions were produced which must be investigated further. Conclusions: The 13 LAB symbionts likely play different roles in their natural environment defending their niche and their host and participating in the honeybee's food production. These roles are partly played through producing extracellular proteins on exposure to microbial stressors widely found in natural occurring flowers. Many of these secreted proteins may have a putative antimicrobial function. In the future, understanding these processes in this complicated environment may lead to novel applications of honey crop LAB proteins.
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| 4. |
- Dyrhage, Karl, et al.
(författare)
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Genome Evolution of a Symbiont Population for Pathogen Defence in Honeybees
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Ingår i: Genome Biology and Evolution. - 1759-6653.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The honeybee gut microbiome is thought to be important for bee health, but the role of the individual members is poorly understood. Here, we present closed genomes and associated mobilomes of 102 Apilactobacillus kunkeei isolates obtained from the honey crop (foregut) of honeybees sampled from beehives in Helsingborg in the south of Sweden and from the islands Gotland and Åland in the Baltic Sea. Each beehive contained a unique composition of isolates and repeated sampling of similar isolates from two beehives in Helsingborg suggests that the bacterial community is stably maintained across bee generations during the summer months. The sampled bacterial population contained an open pan- genome structure with a high genomic density of transposons. A subset of strains affiliated with phylogroup A inhibited growth of the bee pathogen Melisococcus plutonius, all of which contained a 19.5 kb plasmid for the synthesis of the antimicrobial compound kunkecin A, while a subset of phylogroups B and C strains contained a 32.9 kb plasmid for the synthesis of a putative polyketide antibiotic. This study suggests that the mobile gene pool of A. kunkeei plays a key role in pathogen defence in honeybees, providing new insights into the evolutionary dynamics of defensive symbiont populations.
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| 5. |
- Dyrhage, Karl, et al.
(författare)
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Genome Evolution of a Symbiont Population for Pathogen Defense in Honeybees
- 2022
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Ingår i: Genome Biology and Evolution. - : Oxford University Press (OUP). - 1759-6653. ; 14:11
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Tidskriftsartikel (refereegranskat)abstract
- The honeybee gut microbiome is thought to be important for bee health, but the role of the individual members is poorly understood. Here, we present closed genomes and associated mobilomes of 102 Apilactobacillus kunkeei isolates obtained from the honey crop (foregut) of honeybees sampled from beehives in Helsingborg in the south of Sweden and from the islands Gotland and angstrom land in the Baltic Sea. Each beehive contained a unique composition of isolates and repeated sampling of similar isolates from two beehives in Helsingborg suggests that the bacterial community is stably maintained across bee generations during the summer months. The sampled bacterial population contained an open pan-genome structure with a high genomic density of transposons. A subset of strains affiliated with phylogroup A inhibited growth of the bee pathogen Melissococcus plutonius, all of which contained a 19.5 kb plasmid for the synthesis of the antimicrobial compound kunkecin A, while a subset of phylogroups B and C strains contained a 32.9 kb plasmid for the synthesis of a putative polyketide antibiotic. This study suggests that the mobile gene pool of A. kunkeei plays a key role in pathogen defense in honeybees, providing new insights into the evolutionary dynamics of defensive symbiont populations.
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| 6. |
- Ellegaard, Kirsten M., et al.
(författare)
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Extensive intra-phylotype diversity in lactobacilli and bifidobacteria from the honeybee gut
- 2015
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Ingår i: BMC Genomics. - : Springer Science and Business Media LLC. - 1471-2164. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- Background: In the honeybee Apis mellifera, the bacterial gut community is consistently colonized by eight distinct phylotypes of bacteria. Managed bee colonies are of considerable economic interest and it is therefore important to elucidate the diversity and role of this microbiota in the honeybee. In this study, we have sequenced the genomes of eleven strains of lactobacilli and bifidobacteria isolated from the honey crop of the honeybee Apis mellifera. Results: Single gene phylogenies confirmed that the isolated strains represent the diversity of lactobacilli and bifidobacteria in the gut, as previously identified by 16S rRNA gene sequencing. Core genome phylogenies of the lactobacilli and bifidobacteria further indicated extensive divergence between strains classified as the same phylotype. Phylotype-specific protein families included unique surface proteins. Within phylotypes, we found a remarkably high level of gene content diversity. Carbohydrate metabolism and transport functions contributed up to 45% of the accessory genes, with some genomes having a higher content of genes encoding phosphotransferase systems for the uptake of carbohydrates than any previously sequenced genome. These genes were often located in highly variable genomic segments that also contained genes for enzymes involved in the degradation and modification of sugar residues. Strain-specific gene clusters for the biosynthesis of exopolysaccharides were identified in two phylotypes. The dynamics of these segments contrasted with low recombination frequencies and conserved gene order structures for the core genes. Hits for CRISPR spacers were almost exclusively found within phylotypes, suggesting that the phylotypes are associated with distinct phage populations. Conclusions: The honeybee gut microbiota has been described as consisting of a modest number of phylotypes; however, the genomes sequenced in the current study demonstrated a very high level of gene content diversity within all three described phylotypes of lactobacilli and bifidobacteria, particularly in terms of metabolic functions and surface structures, where many features were strain-specific. Together, these results indicate niche differentiation within phylotypes, suggesting that the honeybee gut microbiota is more complex than previously thought.
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| 7. |
- Forsgren, Eva, et al.
(författare)
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Novel lactic acid bacteria inhibiting Paenibacillus larvae in honey bee larvae
- 2010
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Ingår i: Apidologie. - : Springer Science and Business Media LLC. - 0044-8435 .- 1297-9678. ; 41:1, s. 99-108
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Tidskriftsartikel (refereegranskat)abstract
- We evaluated the antagonistic effects of newly identified lactic acid bacteria (LAB) in the genera Lactobacillus and Bifidobacterium, originating from the honey stomach, on the honey bee pathogen, Paenibacillus larvae. We used inhibition assays on agar plates and honey bee larval bioassays to investigate the effects of honey bee LAB on P. larvae growth in vitro and on AFB infection in vivo. The individual LAB phylotypes showed different inhibition properties against P. larvae growth on agar plates, whereas a combination of all eleven LAB phylotypes resulted in a total inhibition (no visible growth) of P. larvae. Adding the LAB mixture to the larval food significantly reduced the number of AFB infected larvae in exposure bioassays. The results demonstrate that honey bee specific LAB possess beneficial properties for honey bee health. Possible benefits to honey bee health by enhancing growth of LAB or by applying LAB to honey bee colonies should be further investigated.
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| 8. |
- Forsum, Urban, 1946-, et al.
(författare)
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Bacterial vaginosis--a microbiological and immunological enigma.
- 2005
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Ingår i: APMIS : acta pathologica, microbiologica, et immunologica Scandinavica. - : Wiley. - 0903-4641 .- 1600-0463. ; 113:2, s. 81-90
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Tidskriftsartikel (refereegranskat)abstract
- The development of bacterial vaginosis (BV) among women of childbearing age and the resulting quantitative and qualitative shift from normally occurring lactobacilli in the vagina to a mixture of mainly anaerobic bacteria is a microbiological and immunological enigma that so far has precluded the formulation of a unifying generally accepted theory on the aetiology and clinical course of BV. This critical review highlights some of the more important aspects of BV research that could help in formulating new basic ideas respecting the biology of BV, not least the importance of the interleukin mediators of local inflammatory responses and the bacterial shift from the normally occurring lactobacilli species: L. crispatus, L. gasseri, L. jensenii, and L. iners to a mixed flora dominated by anaerobic bacteria.
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| 9. |
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| 10. |
- Hernández Vásquez, Magda, et al.
(författare)
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Transcription factor FOXP2 is a flow-induced regulator of collecting lymphatic vessels
- 2021
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Ingår i: EMBO Journal. - : EMBO Press. - 0261-4189 .- 1460-2075. ; 40:12
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Tidskriftsartikel (refereegranskat)abstract
- The lymphatic system is composed of a hierarchical network of fluid absorbing lymphatic capillaries and transporting collecting vessels. Despite distinct functions and morphologies, molecular mechanisms that regulate the identity of the different vessel types are poorly understood. Through transcriptional analysis of murine dermal lymphatic endothelial cells (LECs), we identified Foxp2, a member of the FOXP family of transcription factors implicated in speech development, as a collecting vessel signature gene. FOXP2 expression was induced after initiation of lymph flow in vivo and upon shear stress on primary LECs in vitro. Loss of FOXC2, the major flow-responsive transcriptional regulator of lymphatic valve formation, abolished FOXP2 induction in vitro and in vivo. Genetic deletion of Foxp2 in mice using the endothelial-specific Tie2-Cre or the tamoxifen-inducible LEC-specific Prox1-CreERT2 line resulted in enlarged collecting vessels and defective valves characterized by loss of NFATc1 activity. Our results identify FOXP2 as a new flow-induced transcriptional regulator of collecting lymphatic vessel morphogenesis and highlight the existence of unique transcription factor codes in the establishment of vessel-type-specific endothelial cell identities.
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| 11. |
- Lamei, Sepideh, et al.
(författare)
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Improvement of identification methods for honeybee specific Lactic Acid Bacteria; Future approaches
- 2017
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 12:3
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Tidskriftsartikel (refereegranskat)abstract
- Honeybees face many parasites and pathogens and consequently rely on a diverse set of individual and group-level defenses to prevent disease. The crop microbiota of Apis mellifera, composed of 13 Lactic Acid Bacterial (LAB) species within the genera Lactobacillus and Bifidobacterium, form a beneficial symbiotic relationship with each other and the honeybee to protect their niche and their host. Possibly playing a vital role in honeybee health, it is important that these honeybee specific Lactic Acid Bacterial (hbs-LAB) symbionts can be correctly identified, isolated and cultured, to further investigate their health promoting properties. We have previously reported successful identification to the strain level by culturedependent methods and we recently sequenced and annotated the genomes of the 13 hbs- LAB. However, the hitherto applied techniques are unfortunately very time consuming, expensive and not ideal when analyzing a vast quantity of samples. In addition, other researchers have constantly failed to identify the 13 hbs-LAB from honeybee samples by using inadequate media and/or molecular techniques based on 16S rRNA gene sequencing with insufficient discriminatory power. The aim of this study was to develop better and more suitable methods for the identification and cultivation of hbs-LAB. We compared currently used bacterial cultivation media and could for the first time demonstrate a significant variation in the hbs-LAB basic requirements for optimal growth. We also present a new bacterial identification approach based on amplicon sequencing of a region of the 16S rRNA gene using the Illumina platform and an error correction software that can be used to successfully differentiate and rapidly identify the 13 hbs-LAB to the strain level.
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| 12. |
- Lamei, Sepideh, et al.
(författare)
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The secretome of honey bee-specific lactic acid bacteria inhibits Paenibacillus larvae growth
- 2019
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Ingår i: Journal of Apicultural Research. - : Informa UK Limited. - 0021-8839 .- 2078-6913. ; 58:3, s. 405-412
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Tidskriftsartikel (refereegranskat)abstract
- American Foulbrood (AFB) is a particularly pernicious bacterial disease of honey bees due to the extreme persistence of endospores of the causative agent Paenibacillus larvae. These spores are resistant to harsh environmental conditions, unaffected by antimicrobial agents and can remain viable for decades. The germination of the endospore in the larval midgut is the crucial first step leading to infection, followed by vegetative growth, tissue invasion and disease, culminating in spore formation when the host´s nutrients have been exhausted. Therefore, inhibiting spore germination or impeding early vegetative growth would be a highly effective strategy for limiting the impact of AFB. We previously showed that honey bee-specific lactic acid bacteria (hbs–LAB) had a major inhibitory effect on P. larvae both in culture and in larval bioassays. The present study documents the progress towards characterization of compounds, processes and interactions between P. larvae and the hbs–LAB responsible for this inhibitory effect. Firstly, we used an agar diffusion assay and larval infection bioassay to show that most, if not all, of the inhibitory effect was associated with the extracellular fraction (secretome). Secondly, we employed a turbidimetric growth assay to demonstrate that the hbs–LAB secretome strongly inhibited P. larvae vegetative growth, however, probably not by reducing spore germination. The inhibition was similarly effective against both major P. larvae genotypes (ERIC-I and II) in all experiments. The implications of our results for characterization of the secretome and for the management and treatment of AFB and P. larvae are further discussed.
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| 13. |
- Langefeld, Carl D., et al.
(författare)
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Transancestral mapping and genetic load in systemic lupus erythematosus
- 2017
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Ingår i: Nature Communications. - : NATURE PUBLISHING GROUP. - 2041-1723. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Systemic lupus erythematosus (SLE) is an autoimmune disease with marked gender and ethnic disparities. We report a large transancestral association study of SLE using Immunochip genotype data from 27,574 individuals of European (EA), African (AA) and Hispanic Amerindian (HA) ancestry. We identify 58 distinct non-HLA regions in EA, 9 in AA and 16 in HA (similar to 50% of these regions have multiple independent associations); these include 24 novel SLE regions (P < 5 x 10(-8)), refined association signals in established regions, extended associations to additional ancestries, and a disentangled complex HLA multigenic effect. The risk allele count (genetic load) exhibits an accelerating pattern of SLE risk, leading us to posit a cumulative hit hypothesis for autoimmune disease. Comparing results across the three ancestries identifies both ancestry-dependent and ancestry-independent contributions to SLE risk. Our results are consistent with the unique and complex histories of the populations sampled, and collectively help clarify the genetic architecture and ethnic disparities in SLE.
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| 14. |
- Mårtensson, Anders, et al.
(författare)
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Clinical efficacy of a topical lactic acid bacterial microbiome in chronic rhinosinusitis: A randomized controlled trial
- 2017
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Ingår i: Laryngoscope Investigative Otolaryngology. - : Wiley. - 2378-8038. ; 2:6, s. 410-416
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Tidskriftsartikel (refereegranskat)abstract
- ObjectiveA locally disturbed commensal microbiome might be an etiological factor in chronic rhinosinusitis (CRS) in general and in CRS without nasal polyps (CRSsNP) in particular. Lactic acid bacteria (LAB) have been suggested to restore commensal microbiomes. A honeybee LAB microbiome consisting of various lactobacilli and bifidobacteria have been found potent against CRS pathogens in vitro. Recently, we examined effects of single nasal administrations of this microbiome in healthy subjects and found it inert. In this study, we examined effects of repeated such administrations in patients with CRSsNP.Study DesignThe study was of a randomized, double-blinded, crossover, and sham-controlled design.MethodsTwenty patients received 2 weeks' treatment administered using a nasal spray-device. The subjects were monitored with regard to symptoms (SNOT-22 questionnaire, i.e., the primary efficacy variable), changes to their microbiome, and inflammatory products (IL-6, IL-8, TNF-, IL-8,a, and MPO) in nasal lavage fluids.ResultsNeither symptom scores, microbiological explorations, nor levels of inflammatory products in nasal lavage fluids were affected by LAB (c.f. sham).ConclusionTwo weeks' nasal administration of a honeybee LAB microbiome to patients with CRSsNP is well tolerated but affects neither symptom severity nor the microbiological flora/local inflammatory activity.Level of Evidence1b
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| 15. |
- Mårtensson, Anders, et al.
(författare)
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Effects of a honeybee lactic acid bacterial microbiome on human nasal symptoms, commensals, and biomarkers
- 2016
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Ingår i: International Forum of Allergy & Rhinology. - : Wiley. - 2042-6984 .- 2042-6976. ; 6:9, s. 956-963
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Lactic acid bacteria (LAB) can restore commensal microbiomes and prevent infections. Arguably, nasal administrations of LAB may therefore be beneficial in chronic rhinosinusitis (CRS). Previous studies have examined effects of topical/nasal LAB in children with secretory otitis media, but little is as yet known about their effects on the human nasal airway. The aim of this pilot study was to examine effects on nasal symptoms and commensal bacteria in healthy subjects of nasal administration of a honeybee LAB microbiome; ie, a mixture of 9 Lactobacillus spp. and 4 Bifidobacterium spp. obtained from the honeybee Apis mellifera. Furthermore, we aimed to assess whether or not the honeybee LAB produced a local inflammatory response.METHODS: Twenty-two healthy subjects received a single administration of honeybee LAB in a sham-controlled, double-blinded, and crossover design. Using questionnaires, microbiological methods, and nasal lavages, they were assessed regarding symptoms, changes to commensal bacteria, and inflammatory products in nasal lavage fluids.RESULTS: The honeybee LAB did not produce any symptoms or other untoward effects. No changes were observed of commensal bacteria by the honeybee LAB, and no inflammatory response was detected (compared to sham); ie, unaffected nasal lavage fluid levels of monocyte chemoattractant protein-1 (MCP-1), interleukin-8 (IL-8), monokine induced by interferon-γ (MIG), interleukin-15 (IL-15), epidermal growth factor (EGF), eotaxin, interferon gamma-induced protein-10 (IP-10), and interleukin-1 receptor antagonist (IL-1RA).CONCLUSION: A single human nasal administration of a honeybee LAB microbiome is well tolerated. Specifically, it does not affect commensal bacteria and does not produce an inflammatory response.
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| 16. |
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| 17. |
- Olofsson, Tobias C., et al.
(författare)
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Bifidobacterium mellis sp. nov., isolated from the honey stomach of the honey bee Apis mellifera
- 2023
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Ingår i: International Journal of Systematic and Evolutionary Microbiology. - : Microbiology Society. - 1466-5026 .- 1466-5034. ; 73:3
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Tidskriftsartikel (refereegranskat)abstract
- A novel Bifidobacterium strain, Bin7NT, was isolated from the honey stomach of the honey bee Apis mellifera. Cells are Gram-positive, non-motile, non-sporulating, facultative anaerobic and fructose 6-phosphate phosphoketolase-positive. Their optimal growth is at 37 °C in anaerobiosis in MRS (De Man, Rogosa and Sharpe) added with cysteine. The honey bee microbiota was composed of several phylotypes of Bifidobacterium and Lactobacillus. Comparative analysis of 16S rRNA gene sequence similarity revealed that strain Bin7NT grouped with Bifidobacterium species originating from honey bees and was closely related to Bifidobacterium asteroides DSM 20089T (99.67 % similarity). However, the highest average nucleotide identity and digital DNA– DNA hybridization values of 94.88 and 60.6 %, respectively, were obtained with Bifidobacterium choladohabitans JCM 34586T. The DNA G+C content of the type strain is 60.8 mol%. The cell-wall peptidoglycan is of the A4β l-Orn–d-Asp type. The main cellular fatty acids of strain Bin7NT are C18: 1 ω9c, C16: 0, C18: 1 ω7c and C18: 0. Phenotypic characterization and genotyping based on the genome sequences clearly show that this strain is distinct from the type strains of the so far recognized Bifidobacterium species. Thus, Bifidobacterium mellis sp. nov. (Bin7NT=DSM 29108T=CCUG 66113T) is proposed as novel Bifidobacterium species.
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| 18. |
- Olofsson, Tobias C., et al.
(författare)
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Fighting Off Wound Pathogens in Horses with Honeybee Lactic Acid Bacteria.
- 2016
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Ingår i: Current Microbiology. - : Springer Science and Business Media LLC. - 0343-8651 .- 1432-0991. ; 73:4, s. 463-73
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Tidskriftsartikel (refereegranskat)abstract
- In the global perspective of antibiotic resistance, it is urgent to find potent topical antibiotics for the use in human and animal infection. Healing of equine wounds, particularly in the limbs, is difficult due to hydrostatic factors and exposure to environmental contaminants, which can lead to heavy bio-burden/biofilm formation and sometimes to infection. Therefore, antibiotics are often prescribed. Recent studies have shown that honeybee-specific lactic acid bacteria (LAB), involved in honey production, and inhibit human wound pathogens. The aim of this pilot study was to investigate the effects on the healing of hard-to-heal equine wounds after treatment with these LAB symbionts viable in a heather honey formulation. For this, we included ten horses with wound duration of >1 year, investigated the wound microbiota, and treated wounds with the novel honeybee LAB formulation. We identified the microbiota using MALDI-TOF mass spectrometry and DNA sequencing. In addition, the antimicrobial properties of the honeybee LAB formulation were tested against all wound isolates in vitro. Our results indicate a diverse wound microbiota including fifty-three bacterial species that showed 90 % colonization by at least one species of Staphylococcus. Treatment with the formulation promoted wound healing in all cases already after the first application and the wounds were either completely healed (n = 3) in less than 20 days or healing was in progress. Furthermore, the honeybee LAB formulation inhibited all pathogens when tested in vitro. Consequently, this new treatment option presents as a powerful candidate for the topical treatment of hard-to-heal wounds in horses.
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| 19. |
- Olofsson, Tobias, et al.
(författare)
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Detection and Identification of a Novel Lactic Acid Bacterial Flora Within the Honey Stomach of the Honeybee Apis mellifera.
- 2008
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Ingår i: Current Microbiology. - : Springer Science and Business Media LLC. - 0343-8651 .- 1432-0991. ; 57:4, s. 356-363
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Tidskriftsartikel (refereegranskat)abstract
- This investigation concerned the question of whether honeybees collect bacteria that are beneficial for humans from the flowers that contribute to formation of their honey. Bacteria originating from the types of flowers involved, and found in different anatomic parts of the bees, in larvae, and in honey of different types, were sampled during a 2-year period. 16S rRNA sequencing of isolates and clones was employed. A novel bacterial flora composed of lactic acid bacteria (LAB) of the genera Lactobacillus and Bifidobacterium, which originated in the honey stomach of the honeybee, was discovered. It varied with the sources of nectar and the presence of other bacterial genera within the honeybee and ended up eventually in the honey. It appeared that honeybees and the novel LAB flora may have evolved in mutual dependence on one another. It was suggested that honey be considered a fermented food product because of the LAB involved in honey production. The findings are seen as having clear implications for future research in the area, as providing a better understanding the health of honeybees and of their production and storage of honey, and as having clear relevance for future honeybee and human probiotics.
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| 20. |
- Olofsson, Tobias, et al.
(författare)
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Honeybee-Specific Bifidobacteria and Lactobacilli
- 2017
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Ingår i: The Bifidobacteria and Related Organisms : Biology, Taxonomy, Applications - Biology, Taxonomy, Applications. - 9780128050606 ; , s. 235-241
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Bokkapitel (refereegranskat)abstract
- Honeybees are one of our most important insects, not only for their pollination services but also for their production of honey. Honey is the main food for honeybees, produced from collected nectars and transported to the hive. Humans have consumed this mysterious food and applied it since ancient times in traditional medicine around the world. In 2005 we discovered an unknown key to honeybees’ health and to honey production, which was the presence of previously unknown species of lactobacilli and bifidobacteria. These bacterial species are constant in all honeybees and present in large amounts in fresh honey originating in all continents. They work synergistically to defend their host against microbial incoming threats introduced by nectar foraging and end up in newly produced honey through detaching from the honey stomach. Our research has shown that these beneficial symbiotic bacteria possess antimicrobial characteristics and produce a myriad of bioactive metabolites that protect honeybees against pathogens and explain honeys’ therapeutically significant properties, known by humans since ancient times. Therefore, understanding of the mechanisms of action behind these characteristics through genomic and proteomic studies are crucial in order to find future alternative to antibiotics. In this chapter we discuss the importance of these microbiota in honeybee health and the traditional medicine that is honey with focus on future perspectives.
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| 21. |
- Olofsson, Tobias, et al.
(författare)
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Lactic acid bacterial symbionts in honeybees - an unknown key to honey's antimicrobial and therapeutic activities
- 2016
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Ingår i: International Wound Journal. - : Wiley. - 1742-4801 .- 1742-481X. ; 13:5, s. 668-79
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Tidskriftsartikel (refereegranskat)abstract
- Could honeybees' most valuable contribution to mankind besides pollination services be alternative tools against infections? Today, due to the emerging antibiotic-resistant pathogens, we are facing a new era of searching for alternative tools against infections. Natural products such as honey have been applied against human's infections for millennia without sufficient scientific evidence. A unique lactic acid bacterial (LAB) microbiota was discovered by us, which is in symbiosis with honeybees and present in large amounts in fresh honey across the world. This work investigates if the LAB symbionts are the source to the unknown factors contributing to honey's properties. Hence, we tested the LAB against severe wound pathogens such as methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa and vancomycin-resistant Enterococcus (VRE) among others. We demonstrate a strong antimicrobial activity from each symbiont and a synergistic effect, which counteracted all the tested pathogens. The mechanisms of action are partly shown by elucidating the production of active compounds such as proteins, fatty acids, anaesthetics, organic acids, volatiles and hydrogen peroxide. We show that the symbionts produce a myriad of active compounds that remain in variable amounts in mature honey. Further studies are now required to investigate if these symbionts have a potential in clinical applications as alternative tools against topical human and animal infections.
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| 22. |
- Olofsson, Tobias, et al.
(författare)
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Lactobacillus apinorum sp. nov., Lactobacillus mellifer sp. nov., Lactobacillus mellis sp. nov., Lactobacillus melliventris sp. nov., Lactobacillus kimbladii sp. nov., Lactobacillus helsingborgensis sp. nov., and Lactobacillus kullabergensis sp. nov., isolated from the honey stomach of the honeybee Apis mellifera.
- 2014
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Ingår i: International Journal of Systematic and Evolutionary Microbiology. - : Microbiology Society. - 1466-5026 .- 1466-5034. ; 64, s. 3109-3119
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Tidskriftsartikel (refereegranskat)abstract
- We discovered a symbiotic lactic acid bacterial (LAB) microbiota in the honey stomach of the honeybee Apis mellifera. The microbiota was composed of several phylotypes of Bifidobacterium and Lactobacillus. 16S ribosomal ribonucleic acid (rRNA) gene analyses and phenotypic and genetic characteristics revealed that the Lactobacillus phylotypes isolated represent seven novel species. One is grouped with Lactobacillus kunkeei and the others belong to the Lactobacillus buchneri and Lactobacillus delbrueckii subgroups of Lactobacillus. We propose the names Lactobacillus apinorum sp. nov., Lactobacillus mellifer sp. nov., Lactobacillus mellis sp. nov., Lactobacillus melliventris sp. nov., Lactobacillus kimbladii sp. nov., Lactobacillus helsingborgensis sp. nov., and Lactobacillus kullabergensis sp. nov., with the respective type strains being Fhon13NT ( = DSM 26257T = CCUG 63287T), Bin4NT ( = DSM 26254T = CCUG 63291T), Hon2NT ( = DSM 26255T = CCUG 63289T), Hma8NT ( = DSM 26256T = CCUG 63629T), Hma2NT ( = DSM 26263T = CCUG 63633T), Bma5NT ( = DSM 26265T = CCUG 63301T) and Biut2NT ( = DSM 26262T = CCUG 63631T).
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| 23. |
- Olofsson, Tobias, et al.
(författare)
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Phylogenetic comparison of bacteria isolated from the honey stomachs of honey bees Apis mellifera and bumble bees Bombus spp.
- 2009
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Ingår i: Journal of Apicultural Research. - 0021-8839. ; 48:4, s. 233-237
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Tidskriftsartikel (refereegranskat)abstract
- It has recently been discovered that the honey bee Apis mellifera has a large flora of symbiotic lactic acid bacteria in its honey stomach, belonging to the genera Lactobacillus and Bifidobacterium. It appears that the flora may protect the honey bees, their larvae and their food against harmful microorganisms. Since bumble bees (Bombus spp.) are related to honey bees and have a honey stomach where they store nectar during their flight we investigated whether their honey stomachs also contain symbiotic lactic acid bacteria. Bacterial isolates cultivated from both the surface and from the honey stomachs of bumble bees were identified using 16S rRNA gene analyzes. The results showed that bumble bees also possess lactic acid bacteria in their honey stomachs but in fewer phylotypes and only belonging to the genus Lactobacillus In contrast to honey bees, bumble bees do not produce honey or bee bread but feed their larvae directly with nectar and pollen, and their society does not survive the winter in temperate climates. It was therefore concluded that bumble bees have less need than honey bees of an extensive lactic acid bacterial flora.
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| 24. |
- Piccart, K, et al.
(författare)
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Short communication: Lactic acid bacteria from the honeybee inhibit the in vitro growth of mastitis pathogens.
- 2016
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Ingår i: Journal of Dairy Science. - : American Dairy Science Association. - 1525-3198 .- 0022-0302.
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Tidskriftsartikel (refereegranskat)abstract
- Despite the increasing knowledge of prevention and control strategies, bovine mastitis remains one of the most challenging diseases in the dairy industry. This study investigated the antimicrobial activity of 13 species of lactic acid bacteria (LAB), previously isolated from the honey crop of the honeybee, on several mastitis pathogens. The viable LAB were first reintroduced into a sterilized heather honey matrix. More than 20 different bovine mastitis isolates were tested against the mixture of the 13 LAB species in the honey medium using a dual-culture overlay assay. The mastitis isolates were identified through bacteriological culturing, followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Additionally, the mastitis isolates were subjected to antimicrobial susceptibility testing through disk diffusion. Growth of all tested mastitis pathogens, including the ones displaying antimicrobial resistance to one or more antimicrobial compounds, were inhibited to some extent by the honey and LAB combination. The antibacterial effect of these LAB opens up new perspectives on alternative treatment and prevention of bovine mastitis.
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| 25. |
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| 26. |
- Tamarit, Daniel, et al.
(författare)
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Functionally Structured Genomes in Lactobacillus kunkeei Colonizing the Honey Crop and Food Products of Honeybees and Stingless Bees
- 2015
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Ingår i: Genome Biology and Evolution. - : Oxford University Press (OUP). - 1759-6653. ; 7:6, s. 1455-1473
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Tidskriftsartikel (refereegranskat)abstract
- Lactobacillus kunkeei is the most abundant bacterial species in the honey crop and food products of honeybees. The 16 S rRNA-genes of strains isolated from different bee species are nearly identical in sequence and therefore inadequate as markers for studies of coevolutionary patterns. Here, we have compared the 1.5Mb genomes of ten L. kunkeei strains isolated from all recognized Apis species and another two strains from Meliponini species. Agene flux analysis, including previously sequenced Lactobacillus species as outgroups, indicated the influence of reductive evolution. The genome architecture is unique in that vertically inherited core genes are located near the terminus of replication, whereas genes for secreted proteins and putative host-adaptive traits are located near the origin of replication. We suggest that these features have resulted from a genome-wide loss of genes, with integrations of novel genes mostly occurring in regions flanking the origin of replication. The phylogenetic analyses showed that the bacterial topology was incongruent with the host topology, and that strains of the same microcluster have recombined frequently across the host species barriers, arguing against codiversification. Multiple genotypes were recovered in the individual hosts and transfers of mobile elements could be demonstrated for strains isolated from the same host species. Unlike other bacteria with small genomes, short generation times and multiple rRNA operons suggest that L. kunkeei evolves under selection for rapid growth in its natural growth habitat. The results provide an extended framework for reductive genome evolution and functional genome organization in bacteria.
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| 27. |
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| 28. |
- Vasquez, Alejandra, et al.
(författare)
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DNA-based classification and sequence heterogeneities in the 16S rRNA genes of Lactobacillus casei/paracasei and related species
- 2005
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Ingår i: Systematic and Applied Microbiology. - : Elsevier BV. - 0723-2020 .- 1618-0984. ; 28:5, s. 430-441
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Tidskriftsartikel (refereegranskat)abstract
- The sequence differences within the 16S rRNA genes of Lactobacillus casei/paracasei and related species, Lactobacillus zeae and Lactobacillus rhamnosus, were investigated. Thirty-seven strains of mostly human or cheese origin were grouped by restriction endonuclease analysis (REA) of the total chromosomal DNA and by temporal temperature gradient gel electrophoresis (TTGE) of PCR-amplified 16S rRNA gene fragments. REA verified that all strains were genomically unique and singled out three major clusters, one L. rhamnosus-cluster and two clusters containing L. paracasei strains. The groups obtained by TTGE corresponded with one exception to the REA-clusters. In the TTGE clustering all L. paracasei strains formed one general group with one TTGE-band in common, and this group was sub-divided into five subgroups due to the presence of more than one TTGE-band in four of the subgroups. The occurrence of multiple TTGE-bands was investigated by amplifying and cloning of the 16S rRNA genes from the strains showing this phenomenon, thereby 12 clones from each strain were sequenced, demonstrating polymorphisms in almost all the cases. Subjecting the clones displaying sequence variations to TTGE as well as sequencing of 16S rDNA revealed by ribotyping of the strains, verified the presence of polymorphisms within the 16S rRNA genes. The migration characteristic of amplified DNA from a single clone corresponded to a specific band in the TTGE-pattern of the strain from which the clone originated. Southern blot hybridisation with a 16S rDNA probe demonstrated the presence of at least five 16S rRNA genes in L. casei/paracasei. A higher degree of variable positions than previously reported was observed in the 16S rRNA gene fragments of the members in the complex. Sequence comparison between the 16S rRNA gene copies of L. casei (CCUG 21451(T)) and L. zeae (CCUG 35515(T)) demonstrated that the two species shared almost the same sequence in some copies while the others were more different. Our results provide one explanation for the difficulties in reaching clear-cut taxa within the L. casei/paracasei complex.
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| 29. |
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| 30. |
- Vasquez, Alejandra, et al.
(författare)
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Symbionts as major modulators of insect health: lactic Acid bacteria and honeybees.
- 2012
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:3
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Tidskriftsartikel (refereegranskat)abstract
- Lactic acid bacteria (LAB) are well recognized beneficial host-associated members of the microbiota of humans and animals. Yet LAB-associations of invertebrates have been poorly characterized and their functions remain obscure. Here we show that honeybees possess an abundant, diverse and ancient LAB microbiota in their honey crop with beneficial effects for bee health, defending them against microbial threats. Our studies of LAB in all extant honeybee species plus related apid bees reveal one of the largest collections of novel species from the genera Lactobacillus and Bifidobacterium ever discovered within a single insect and suggest a long (>80 mya) history of association. Bee associated microbiotas highlight Lactobacillus kunkeei as the dominant LAB member. Those showing potent antimicrobial properties are acquired by callow honey bee workers from nestmates and maintained within the crop in biofilms, though beekeeping management practices can negatively impact this microbiota. Prophylactic practices that enhance LAB, or supplementary feeding of LAB, may serve in integrated approaches to sustainable pollinator service provision. We anticipate this microbiota will become central to studies on honeybee health, including colony collapse disorder, and act as an exemplar case of insect-microbe symbiosis.
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| 31. |
- Vasquez, Alejandra
(författare)
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Systematics of Lactobacillus spp. of probiotic potential
- 2004
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Lactobacillus is a heterogeneous bacterial genus comprising at present 91 species. The high species number often makes classification and identification difficult, especially as the taxonomy to a high degree has been based on phenotypical traits. Members of the genus are of commercial importance, involved in a range of industrial products and applied as probiotics, “live microorganisms which when administered in adequate amounts confer a health benefit on the host”. The development of phylogenetic analysis of the 16S rRNA gene sequence in the 1980s resulted in many changes within the taxonomy of the genus, and showed a discrepancy between the former phenotypic identification and the present molecular-based phylogeny. Therefore, the phylogeny of the genus based on 16S rRNA gene sequence analysis was evaluated in Paper V, concerning the increasing number of species since Schleifer and Ludwig performed such a study in 1995. However, closely related organisms of probiotic interest within Lactobacillus are still under taxonomic discussion. Due to that fact, the present investigation evaluated molecular-based identification methods for differentiation of members of Lactobacillus acidophilus and Lactobacillus casei/paracasei complexes, respectively. At present, these two assemblies contain strains of probiotic applications, e.g. Lactobacillus rhamnosus GG, Lactobacillus casei Shirota, “Lactobacillus paracasei defensis”, Lactobacillus gasseri SBT2055SR, and Lactobacillus acidophilus ADH. As the identity of the conceivable exogenous strain is one of the most important features in finding new probiotics, the identification of members within the complexes is indispensable. In the present study PCR-based methods, REA, RFLP, 16S rRNA gene sequencing and TTGE were used for the differentiation and identification of species and strains within the two complexes of L. acidophilus and L. casei/paracasei. In Paper I and II, the identification possibilities and the classification of the L. casei/paracasei complex were studied. The different members of the group could be differentiated with TTGE. The results indicated that one underlying reason for the difficulties in reaching clear-cut taxa within the complex might be the presence of polymorphisms within the 16S rRNA genes. In addition, a higher degree of variable positions than previously reported was observed in the 16S rRNA gene fragments of the members in the complex. Sequence comparison between the 16S rRNA gene copies of L. casei (CCUG 21451T) and L. zeae (CCUG 35515T) demonstrated that the two species shared almost the same sequences. In Paper III, the composition of the vaginal lactobacilli flora and the L. acidophilus complex were identified with genotypic-based methods. It was shown that the dominating Lactobacillus species in the healthy vagina of Swedish women were Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus iners and Lactobacillus jensenii. For the first time L. iners was shown as a dominating species in the vaginal ecosystem. With the vaginal lactobacilli flora in mind, we selected strains of human origin for an administration study. Vaginal probiotics are a rather new area of investigation. Consequently, not much is known about the mechanisms, conditions or characteristics needed for vaginal probiotics. In Paper IV, five exogenous strains were re-isolated from vaginal and faecal samples after oral administration. Surprisingly, the most commonly recovered exogenous species was Lactobacillus plantarum 52A, suggesting that this strain possesses the qualities required for establishment in the gastrointestinal tract but also in the vaginal environment. Transmission electron microscopy studies indicated different surface composition of 52A compared to other L. plantarum strains. In conclusion, the present doctoral thesis has investigated the Lactobacillus genus by molecular-based technologies, and selected strains within the genus had been proved to be able to survive and establish in the human gastrointestinal tract and vagina. This could be used as a platform for future investigations of probiotics in general and vaginal ones in particular.
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| 32. |
- Vasquez, Alejandra, et al.
(författare)
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The lactic acid bacteria involved in the production of bee pollen and bee bread
- 2009
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Ingår i: Journal of Apicultural Research. - 0021-8839. ; 48:3, s. 189-195
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Tidskriftsartikel (refereegranskat)abstract
- Recently a large flora of lactic acid bacteria (LAB) was identified in the honey stomach of the honey bee Apis mellifera. In this study, the presence of this flora in bee pollen and bee bread was investigated. Pollen was collected from the legs of honey bees, and both two week old and two month old bee bread were also obtained for the study. Bacterial isolates cultivated from these bee products were identified using 16S rRNA gene analyzes. The majority of the honey stomach LAB flora was recovered in a viable state from both the pollen and the two week old bee bread, but not from the two month old bee bread. It is demonstrated for the first time that bee bread is probably fermented by the honey stomach LAB flora that has been added to the pollen via regurgitated nectar from the honey stomach. This discovery helps to explain how honey bees standardize the production of bee bread and how it is stored. The presence of the honey stomach LAB and its antimicrobial substances in bee bread also suggests a possible role in the defence against honey bee diseases since the bee bread is consumed by both the larvae and the adult bees.
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| 33. |
- Vasquez, Alejandra, et al.
(författare)
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Vaginal Lactobacillus flora of healthy Swedish women
- 2002
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Ingår i: Journal of clinical microbiology. - 0095-1137 .- 1098-660X. ; 40:8, s. 2746-2749
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Tidskriftsartikel (refereegranskat)abstract
- Species of the Lactobacillus acidophilus complex are generally considered to constitute most of the vaginal Lactobacillus flora, but the flora varies between studies. However, this may be due to difficulties in identifying the closely related species within the L. acidophilus complex by using traditional methods and to variations in the vaginal status of the participants. Two hundred two isolates from the vaginal fluids of 23 Swedish women without bacterial vaginosis, as defined by the criteria of Nugent et al. (R. P. Nugent, M. A. Krohn, and S. L. Hillier, J. Clin. Microbiol. 29:297-301, 1991), were typed by randomly amplified polymorphic DNA (RAPD) analysis and identified to the species level by temporal temperature gradient gel electrophoresis, multiplex PCR, and 16S ribosomal DNA sequencing. The vaginal flora of most participants was dominated by a single RAPD type, but five of them harbored two RAPD types representing two different species or strains. The most frequently occurring species were Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus iners, and Lactobacillus jensenii. L. iners has not previously been reported as one of the predominant Lactobacillus species in the vagina.
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| 34. |
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| 35. |
- Wang, Yibing, et al.
(författare)
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An individualized strategy to estimate the effect of deformable registration uncertainty on accumulated dose in the upper abdomen
- 2018
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Ingår i: Physics in Medicine and Biology. - : IOP PUBLISHING LTD. - 0031-9155 .- 1361-6560. ; 63:12
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Tidskriftsartikel (refereegranskat)abstract
- In the abdomen, it is challenging to assess the accuracy of deformable image registration (DIR) for individual patients, due to the lack of clear anatomical landmarks, which can hamper clinical applications that require high accuracy DIR, such as adaptive radiotherapy. In this study, we propose and evaluate a methodology for estimating the impact of uncertainties in DIR on calculated accumulated dose in the upper abdomen, in order to aid decision making in adaptive treatment approaches. Sixteen liver metastasis patients treated with SBRT were evaluated. Each patient had one planning and three daily treatment CT-scans. Each daily CT scan was deformably registered 132 times to the planning CT-scan, using a wide range of parameter settings for the registration algorithm. A subset of realistic registrations was then objectively selected based on distances between mapped and target contours. The underlying 3D transformations of these registrations were used to assess the corresponding uncertainties in voxel positions, and delivered dose, with a focus on accumulated maximum doses in the hollow OARs, i.e. esophagus, stomach, and duodenum. The number of realistic registrations varied from 5 to 109, depending on the patient, emphasizing the need for individualized registration parameters. Considering for all patients the realistic registrations, the 99th percentile of the voxel position uncertainties was 5.6 +/- 3.3 mm. This translated into a variation (difference between 1st and 99th percentile) in accumulated Dmax in hollow OARs of up to 3.3 Gy. For one patient a violation of the accumulated stomach dose outside the uncertainty band was detected. The observed variation in accumulated doses in the OARs related to registration uncertainty, emphasizes the need to investigate the impact of this uncertainty for any DIR algorithm prior to clinical use for dose accumulation. The proposed method for assessing on an individual patient basis the impact of uncertainties in DIR on accumulated dose is in principle applicable for all DIR algorithms allowing variation in registration parameters.
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