The Experts below are selected from a list of 13119 Experts worldwide ranked by ideXlab platform
Paul E Verweij - One of the best experts on this subject based on the ideXlab platform.
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Bifidobacterial lipoglycan as a new cause for false-positive Platelia aspergillus enzyme-linked immunosorbent assay reactivity
Journal of Clinical Microbiology, 2005Co-Authors: Monique A.s.h. Mennink-kersten, Dorien Ruegebrink, Rocus R. Klont, Huub J.m. Op Den Camp, Adilia Warris, Françoise Gavini, Paul E VerweijAbstract:We previously hypothesized that a lipoglycan of Bifidobacterium bifidum subsp. pennsylvanicum cross-reacts with the Platelia Aspergillus (PA) enzyme-linked immunosorbent assay (ELISA) based on the presence of galactofuranosyl epitopes in the cell wall (M. A. S. H. Mennink-Kersten, R. R. Klont, A. Warris, H. J. M. Op den Camp, and P. E. Verweij, Lancet 363:325-327, 2004). We tested this hypothesis by testing bacterial suspensions of different Bifidobacterial species and other gram-positive and -negative bacteria with the PA ELISA, which is used to detect circulating galactomannan for the serodiagnosis of invasive aspergillosis. Furthermore, neonatal fecal samples were enumerated for Bifidobacteria by fluorescence in situ hybridization (FISH) and tested for PA ELISA reactivity. All Bifidobacteria, except B. infantis and B. adolescentis, showed reactivity 6- to 600-fold higher compared to the controls (i.e., Micrococcus luteus and Propionibacterium freudenreichii, which contain a cell wall lipomannan). Eggerthella lenta showed a 25-fold-higher reactivity. ELISA reactivity was clearly shown to be associated with bacterial lipoglycans containing a beta-1,5-galactofuranosyl chain. All neonatal feces showed PA ELISA reactivity and associated numbers of Bifidobacteria. Since high concentrations of Bifidobacteria are present in the human gut, these bacteria or excreted lipoglycan may cause false serum PA ELISA reactivity in selected patient groups, especially neonates.
Willem M De Vos - One of the best experts on this subject based on the ideXlab platform.
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mixed species genomic microarray analysis of fecal samples reveals differential transcriptional responses of Bifidobacteria in breast and formula fed infants
Applied and Environmental Microbiology, 2009Co-Authors: Eline S Klaassens, Rolf Boesten, Monique Haarman, Jan Knol, Frank H J Schuren, Elaine E Vaughan, Willem M De VosAbstract:Although their exact function remains enigmatic, Bifidobacteria are among the first colonizers of the newborn infant gut and further develop into abundant communities, notably in response to diet. Therefore, the transcriptional responses of Bifidobacteria in rapidly processed fecal samples from young infants that were fed either breast milk or a formula containing a mixture of galacto- and fructo-oligosaccharides were studied. The presence and diversity of the Bifidobacterial fecal communities were determined using PCR-denaturing gradient gel electrophoresis and quantitative real-time PCR for specific species. Changes in the total number of Bifidobacteria as well as in species diversity were observed, indicating the metabolic activities of the Bifidobacteria within the infant gut. In addition, total RNAs isolated from infant feces were labeled and hybridized to a bifidobacterium-specific microarray comprising approximately 6,000 clones of the major Bifidobacterial species of the human gut. Approximately 270 clones that showed the most prominent hybridization with the samples were sequenced. Fewer than 10% of the hybridizing clones contained rRNA genes, whereas the vast majority of the inserts showed matches with protein-encoding genes predicted to originate from Bifidobacteria. Although a wide range of functional groups was covered by the obtained sequences, the largest fraction (14%) of the transcribed genes assigned to a functional category were predicted to be involved in carbohydrate metabolism, while some were also implicated in exopolysaccharide production or folate production. A total of three of the above-described protein-encoding genes were selected for quantitative PCR and sequence analyses, which confirmed the expression of the corresponding genes and the expected nucleotide sequences. In conclusion, the results of this study show the feasibility of obtaining insight into the transcriptional responses of intestinal Bifidobacteria by analyzing fecal RNA and highlight the in vivo expression of Bifidobacterial genes implicated in host-related functions.
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Bifidobacterial diversity in human feces detected by genus specific pcr and denaturing gradient gel electrophoresis
Applied and Environmental Microbiology, 2001Co-Authors: Reetta Satokari, Elaine E Vaughan, A D L Akkermans, Maria Saarela, Willem M De VosAbstract:We describe the development and validation of a method for the qualitative analysis of complex Bifidobacterial communities based on PCR and denaturing gradient gel electrophoresis (DGGE). Bifidobacterium genus-specific primers were used to amplify an approximately 520-bp fragment from the 16S ribosomal DNA (rDNA), and the fragments were separated in a sequence-specific manner in DGGE. PCR products of the same length from different Bifidobacterial species showed good separation upon DGGE. DGGE of fecal 16S rDNA amplicons from five adult individuals showed host-specific populations of Bifidobacteria that were stable over a period of 4 weeks. Sequencing of fecal amplicons resulted in Bifidobacterium-like sequences, confirming that the profiles indeed represent the Bifidobacterial population of feces. Bifidobacterium adolescentis was found to be the most common species in feces of the human adult subjects in this study. The methodological approach revealed intragenomic 16S rDNA heterogeneity in the type strain of B. adolescentis, E-981074. The strain was found to harbor five copies of 16S rDNA, two of which were sequenced. The two 16S rDNA sequences of B. adolescentis E-981074T exhibited microheterogeneity differing in eight positions over almost the total length of the gene.
Francesca Turroni - One of the best experts on this subject based on the ideXlab platform.
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bifidobacterium bifidum and the infant gut microbiota an intriguing case of microbe host co evolution
Environmental Microbiology, 2019Co-Authors: Sabrina Duranti, Francesca Turroni, Gabriele Andrea Lugli, Christian Milani, Kieran James, Leonardo Mancabelli, Giulia Alessandri, Marta Mangifesta, Walter Mancino, Maria Cristina OssiprandiAbstract:Bifidobacterium bifidum is reported to be among the first colonizers of the newborn's gastrointestinal tract due to its ability to metabolize human milk oligosaccharides (HMOs). In order to investigate biological features that allow this Bifidobacterial species to colonize a newborn, Bifidobacterial internally transcribed spacer profiling of stool samples of 50 mother-infant dyads, as well as corresponding breastmilk samples, was performed. Hierarchical clustering based on Bifidobacterial population profiles found in infant faecal samples revealed the presence of four Bifidobacterial clusters or the so-called bifidotypes. Bifidobacterium bifidum was shown to be a key member among bifidotypes, in which its presence correlate with several different Bifidobacterial species retrieved in infant faecal samples. For this reason, we investigated cross-feeding behaviour facilitated by B. bifidum on a bioreactor model using human milk as growth substrate. Transcriptional profiles of this strain were evaluated when grown on nine specific glycans typically constituting HMOs. Remarkably, these analyses suggest extensive co-evolution with the host and other Bifidobacterial species in terms of resource provision and sharing, respectively, activities that appear to support a Bifidobacteria-dominant microbiome.
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Evidence for cholesterol-lowering activity by Bifidobacterium bifidum PRL2010 through gut microbiota modulation
Applied Microbiology and Biotechnology, 2015Co-Authors: Ilaria Zanotti, Alice Viappiani, Francesca Turroni, Christian Milani, Leonardo Mancabelli, Antonio Piemontese, Gilda Prevedini, Borja Sanchez, Abelardo Margolles, Lisa ElviriAbstract:Bifidobacteria are members of the human gut microbiota, which are known to influence the metabolic abilities of their host. Here, we investigated the capabilities of Bifidobacteria to reduce cholesterol levels in synthetic growth media, clearly demonstrating assimilation of this molecule by particular Bifidobacterial strains, including Bifidobacterium bifidum PRL2010 (LMG S-28692). The transcriptomic analysis of PRL2010 cells cultivated in the presence of cholesterol revealed a significantly increased transcription level of genes encoding putative transporters and reductases, indicative of specific mechanisms for cholesterol assimilation as well as cholesterol conversion to coprostanol. Cholesterol lowering activity of B. bifidum PRL2010 cells was further evaluated by means of an in vivo murine model, showing that the fecal microbiota of mice is modified toward those bacteria involved in the metabolism of cholesterol.
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investigation of the evolutionary development of the genus bifidobacterium by comparative genomics
Applied and Environmental Microbiology, 2014Co-Authors: Gabriele Andrea Lugli, Sabrina Duranti, Alice Viappiani, Francesca Turroni, Christian Milani, Leonardo Mancabelli, Marta Mangifesta, Chiara Ferrario, Bernard Taminiau, Veronique DelcenserieAbstract:The Bifidobacterium genus currently encompasses 48 recognized taxa, which have been isolated from different ecosystems. However, the current phylogeny of Bifidobacteria is hampered by the relative paucity of genotypic data. Here, we reassessed the taxonomy of this bacterial genus using genome-based approaches, which demonstrated that the previous taxonomic view of Bifidobacteria contained several inconsistencies. In particular, high levels of genetic relatedness were shown to exist between particular Bifidobacterium taxa which would not justify their status as separate species. The results presented are here based on average nucleotide identity analysis involving the genome sequences for each type strain of the 48 Bifidobacterial taxa, as well as phylogenetic comparative analysis of the predicted core genome of the Bifidobacterium genus. The results of this study demonstrate that the availability of complete genome sequences allows the reconstruction of a more robust Bifidobacterial phylogeny than that obtained from a single gene-based sequence comparison, thus discouraging the assignment of a new or separate Bifidobacterial taxon without such a genome-based validation.
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kefir fermented milk and kefiran promote growth of bifidobacterium bifidum prl2010 and modulate its gene expression
International Journal of Food Microbiology, 2014Co-Authors: Fausta Serafini, Sabrina Duranti, Douwe Van Sinderen, Francesca Turroni, Francesca Bottacini, Gabriele Andrea Lugli, Christian Milani, Patricia Ruasmadiedo, Nicole Zamboni, Abelardo MargollesAbstract:Bifidobacteria constitute one of the dominant groups of microorganisms colonizing the human gut of infants. Their ability to utilize various host-derived glycans as well as dietary carbohydrates has received considerable scientific attention. However, very little is known about the role of fermented foods, such as kefir, or their constituent glycans, such as kefiran, as substrates for Bifidobacterial growth and for the modulation of the expression of Bifidobacterial host-effector molecules. Here, we show that Bifidobacterium bifidum PRL2010 exhibits high growth performance among the Bifidobacterial strains tested when cultivated on kefir and/or kefiran polymer. Furthermore, a 16S rRNA metagenomic approach revealed that the microbiota of kefir is modified upon the addition of PRL2010 cells to the kefir matrix. Finally, our results show that kefir and kefiran are able to influence the transcriptome of B. bifidum PRL2010 causing increased transcription of genes involved in the metabolism of dietary glycans as well as genes that act as host–microbe effector molecules such as pili. Altogether, these data support the use of kefir as a valuable means for the delivery of effective microbial cells in probiotic therapy.
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Genetic analysis and morphological identification of pilus-like structures in members of the genus Bifidobacterium
2011Co-Authors: E. Foroni, Alice Viappiani, Francesca Turroni, Francesca Bottacini, F. Serafini, D. Amidani, O’connell M. Motherway, Z. Zhang, C. RivettiAbstract:Background: Cell surface pili in Gram positive bacteria have been reported to orchestrate the colonization of host tissues, evasion of immunity and the development of biofilms. So far, little if any information is available on the presence of pilus-like structures in human gut commensals like Bifidobacteria. Results and discussion: In this report, Atomic Force Microscopy (AFM) of various Bifidobacterial strains belonging to Bifidobacterium bifidum, Bifidobacterium longum subsp. longum, Bifidobacterium dentium, Bifidobacterium adolescentis and Bifidobacterium animalis subsp. lactis revealed the existence of appendages resembling pilus-like structures. Interestingly, these microorganisms harbour two to six predicted pilus gene clusters in their genome, with each organized in an operon encompassing the major pilin subunit-encoding gene (designated fimA or fimP) together with one or two minor pilin subunit-encoding genes (designated as fimB and/or fimQ), and a gene encoding a sortase enzyme (strA). Quantitative Real Time (qRT)-PCR analysis and RT-PCR experiments revealed a polycistronic mRNA, encompassing the fimA/P and fimB/Q genes, which are differentially expressed upon cultivation of Bifidobacteria on various glycans
Monique A.s.h. Mennink-kersten - One of the best experts on this subject based on the ideXlab platform.
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Bifidobacterial lipoglycan as a new cause for false-positive Platelia aspergillus enzyme-linked immunosorbent assay reactivity
Journal of Clinical Microbiology, 2005Co-Authors: Monique A.s.h. Mennink-kersten, Dorien Ruegebrink, Rocus R. Klont, Huub J.m. Op Den Camp, Adilia Warris, Françoise Gavini, Paul E VerweijAbstract:We previously hypothesized that a lipoglycan of Bifidobacterium bifidum subsp. pennsylvanicum cross-reacts with the Platelia Aspergillus (PA) enzyme-linked immunosorbent assay (ELISA) based on the presence of galactofuranosyl epitopes in the cell wall (M. A. S. H. Mennink-Kersten, R. R. Klont, A. Warris, H. J. M. Op den Camp, and P. E. Verweij, Lancet 363:325-327, 2004). We tested this hypothesis by testing bacterial suspensions of different Bifidobacterial species and other gram-positive and -negative bacteria with the PA ELISA, which is used to detect circulating galactomannan for the serodiagnosis of invasive aspergillosis. Furthermore, neonatal fecal samples were enumerated for Bifidobacteria by fluorescence in situ hybridization (FISH) and tested for PA ELISA reactivity. All Bifidobacteria, except B. infantis and B. adolescentis, showed reactivity 6- to 600-fold higher compared to the controls (i.e., Micrococcus luteus and Propionibacterium freudenreichii, which contain a cell wall lipomannan). Eggerthella lenta showed a 25-fold-higher reactivity. ELISA reactivity was clearly shown to be associated with bacterial lipoglycans containing a beta-1,5-galactofuranosyl chain. All neonatal feces showed PA ELISA reactivity and associated numbers of Bifidobacteria. Since high concentrations of Bifidobacteria are present in the human gut, these bacteria or excreted lipoglycan may cause false serum PA ELISA reactivity in selected patient groups, especially neonates.
Motomitsu Kitaoka - One of the best experts on this subject based on the ideXlab platform.
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α n acetylgalactosaminidase from infant associated Bifidobacteria belonging to novel glycoside hydrolase family 129 is implicated in alternative mucin degradation pathway
Journal of Biological Chemistry, 2012Co-Authors: Masashi Kiyohara, Takane Katayama, Motomitsu Kitaoka, Shin Kurihara, Takashi Nakatomi, Shinya Fushinobu, Hideyuki Suzuki, Tomonari Tanaka, Shinichiro Shoda, Kenji YamamotoAbstract:Bifidobacteria inhabit the lower intestine of mammals including humans where the mucin gel layer forms a space for commensal bacteria. We previously identified that infant-associated Bifidobacteria possess an extracellular membrane-bound endo-α-N-acetylgalactosaminidase (EngBF) that may be involved in degradation and assimilation of mucin-type oligosaccharides. However, EngBF is highly specific for core-1-type O-glycan (Galβ1–3GalNAcα1-Ser/Thr), also called T antigen, which is mainly attached onto gastroduodenal mucins. By contrast, core-3-type O-glycans (GlcNAcβ1–3GalNAcα1-Ser/Thr) are predominantly found on the mucins in the intestines. Here, we identified a novel α-N-acetylgalactosaminidase (NagBb) from Bifidobacterium bifidum JCM 1254 that hydrolyzes the Tn antigen (GalNAcα1-Ser/Thr). Sialyl and galactosyl core-3 (Galβ1–3/4GlcNAcβ1–3(Neu5Acα2–6)GalNAcα1-Ser/Thr), a major tetrasaccharide structure on MUC2 mucin primarily secreted from goblet cells in human sigmoid colon, can be serially hydrolyzed into Tn antigen by previously identified Bifidobacterial extracellular glycosidases such as α-sialidase (SiaBb2), lacto-N-biosidase (LnbB), β-galactosidase (BbgIII), and β-N-acetylhexosaminidases (BbhI and BbhII). Because NagBb is an intracellular enzyme without an N-terminal secretion signal sequence, it is likely involved in intracellular degradation and assimilation of Tn antigen-containing polypeptides, which might be incorporated through unknown transporters. Thus, Bifidobacteria possess two distinct pathways for assimilation of O-glycans on gastroduodenal and intestinal mucins. NagBb homologs are conserved in infant-associated Bifidobacteria, suggesting a significant role for their adaptation within the infant gut, and they were found to form a new glycoside hydrolase family 129.
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distribution of in vitro fermentation ability of lacto n biose i a major building block of human milk oligosaccharides in Bifidobacterial strains
Applied and Environmental Microbiology, 2010Co-Authors: Jinzhong Xiao, Toshitaka Odamaki, Keiji Iwatsuki, Sachiko Takahashi, Mamoru Nishimoto, Tomoko Yaeshima, Motomitsu KitaokaAbstract:This study investigated the potential utilization of lacto-N-biose I (LNB) by individual strains of Bifidobacteria. LNB is a building block for the human milk oligosaccharides, which have been suggested to be a factor for selective growth of Bifidobacteria. A total of 208 strains comprising 10 species and 4 subspecies were analyzed for the presence of the galacto-N-biose/lacto-N-biose I phosphorylase (GLNBP) gene (lnpA) and examined for growth when LNB was used as the sole carbohydrate source. While all strains of Bifidobacterium longum subsp. longum, B. longum subsp. infantis, B. breve, and B. bifidum were able to grow on LNB, none of the strains of B. adolescentis, B. catenulatum, B. dentium, B. angulatum, B. animalis subsp. lactis, and B. thermophilum showed any growth. In addition, some strains of B. pseudocatenulatum, B. animalis subsp. animalis, and B. pseudolongum exhibited the ability to utilize LNB. With the exception for B. pseudocatenulatum, the presence of lnpA coincided with LNB utilization in almost all strains. These results indicate that Bifidobacterial species, which are the predominant species found in infant intestines, are potential utilizers of LNB. These findings support the hypothesis that GLNBP plays a key role in the colonization of Bifidobacteria in the infant intestine.
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bifidobacterium bifidum lacto n biosidase a critical enzyme for the degradation of human milk oligosaccharides with a type 1 structure
Applied and Environmental Microbiology, 2008Co-Authors: Hisashi Ashida, Masashi Kiyohara, Jun Wada, Hidehiko Kumagai, Takane Katayama, Motomitsu Kitaoka, Takuro Ando, Masanori Yamaguchi, Kenji YamamotoAbstract:Breast-fed infants often have intestinal microbiota dominated by Bifidobacteria in contrast to formula-fed infants. We found that several Bifidobacterial strains produce a lacto-N-biosidase that liberates lacto-N-biose I (Galβ1,3GlcNAc; type 1 chain) from lacto-N-tetraose (Galβ1,3GlcNAcβ1,3Galβ1,4Glc), which is a major component of human milk oligosaccharides, and subsequently isolated the gene from Bifidobacterium bifidum JCM1254. The gene, designated lnbB, was predicted to encode a protein of 1,112 amino acid residues containing a signal peptide and a membrane anchor at the N and C termini, respectively, and to possess the domain of glycoside hydrolase family 20, carbohydrate binding module 32, and bacterial immunoglobulin-like domain 2, in that order, from the N terminus. The recombinant enzyme showed substrate preference for the unmodified β-linked lacto-N-biose I structure. Lacto-N-biosidase activity was found in several Bifidobacterial strains, but not in the other enteric bacteria, such as clostridia, bacteroides, and lactobacilli, under the tested conditions. These results, together with our recent finding of a novel metabolic pathway specific for lacto-N-biose I in Bifidobacterial cells, suggest that some of the Bifidobacterial strains are highly adapted for utilizing human milk oligosaccharides with a type 1 chain.