document

Real-time PCR detection of Campylobacter spp.: A comparison toclassic culturing and enrichment

de Boer, P. (author), Rahaoui, H. (author), Leer, R.J. (author), Montijn, R.C. (author), van der Vossen, J.M.B.M. (author)

The major disadvantage of the current gold standard for detection of the food pathogen Campylobacter, i.e. culturing, is the lengthy procedure. In this study we assessed the use of real-time PCR for detection of Campylobacter. To this end, 926 poultry samples, taken from transport containers and broiler caeca in The Netherlands in 2007, were...

article 2015

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Intragastric immunization with recombinant Lactobacillus casei expressing flagellar antigen confers antibody-independent protective immunity against Salmonella enterica serovar Enteritidis

Kajikawa, A. (author), Satoh, E. (author), Leer, R.J. (author), Yamamoto, S. (author), Igimi, S. (author), TNO Kwaliteit van Leven (author)

A recombinant Lactobacillus casei expressing a flagellar antigen from Salmonella enterica serovar Enteritidis was constructed and evaluated as a mucosal vaccine. Intragastric immunization of the recombinant strain conferred protective immunity against Salmonella infection in mice. This immunization did not result in antigen-specific antibody in...

article 2007

document

Unravelling the multiple effects of lactic acid stress on Lactobacillus plantarum by transcription profiling

Pieterse, B. (author), Leer, R.J. (author), Schuren, F.H.J. (author), van der Werf, M.J. (author), TNO Kwaliteit van Leven (author)

The organic acid lactate is the predominant fermentation product of Lactobacillus plantarum. The undissociated form of this organic acid is a strong growth inhibitor for the organism. Different theories have been postulated to explain the inhibitory effects of lactic acid: (i) toxicity arising from the dissipation of the membrane potential, (ii)...

article 2005

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Functional analysis of three plasmids from Lactobacillus plantarum

TNO Kwaliteit van Leven (author), van Kranenburg, R. (author), Golic, N. (author), Bongers, R. (author), Leer, R.J. (author), de Vos, W.M. (author), Siezen, R.J. (author), Kleerebezem, M. (author)

Lactobacillus plantarum WCFS1 harbors three plasmids, pWCFS101, pWCFS102, and pWCFS103, with sizes of 1,917, 2,365, and 36,069 bp, respectively. The two smaller plasmids are of unknown function and contain replication genes that are likely to function via the rolling-circle replication mechanism. The host range of the p WCFS101 replicon includes...

article 2005

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Molecular characterization of a novel glucosyltransferase from Lactobacillus reuteri strain 121 synthesizing a unique , highly branched glucan with alpha-(1-4) and alpha-(1-6) glucosidic bonds

Kralj, S. (author), van Geel-Schutten, G.H. (author), Rahaoui, H. (author), Leer, R.J. (author), Faber, E.J. (author), van der Maarel, M.J.E.C. (author), Dijkhuizen, L. (author), TNO Voeding (author)

article 2002

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Lactobacilli as vehicles for targeting antigens to mucosal tissues by surface exposition of foreign antigens

Pouwels, P.H. (author), Vriesema, A. (author), Martinez, B. (author), Tielen, F.J. (author), Seegers, J.F.M.L. (author), Leer, R.J. (author), Jore, J. (author), Smit, E. (author), TNO Voeding (author)

bookPart 2001

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Strain-dependent induction of cytokine profiles in the gut by orally administered Lactobacillus strains

Maassen, C.B.M. (author), van Holten-Neelen, C. (author), Balk, F. (author), den Bak-Glashouwer, M.-J.H. (author), Leer, R.J. (author), Laman, J.D. (author), Boersma, W.J.A. (author), Claassen, E. (author)

Different Lactobacillus strains are frequently used in consumer food products. In addition, recombinant lactobacilli which contain novel expression vectors can now be used in immunotherapeutic applications such as oral vaccination strategies and in T cell tolerance induction approaches for autoimmune disease. Both for food and clinical...

article 2000

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Engineering the microflora to vaccinate the mucosa: Serum immunoglobulin G responses and activated draining cervical lymph nodes following mucosal application of tetanus toxin fragment C-expressing lactobacilli

Shaw, D.M. (author), Gaerthé, B. (author), Leer, R.J. (author), van der Stap, J.G.M.M. (author), Smittenaar, C. (author), Heijne den Bak-Glashouwer, M.-J. (author), Thole, J.E.R. (author), Tielen, F.J. (author), Pouwels, P.H. (author), Havenith, C.E.G. (author)

article 2000

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Instruments for oral disease-intervention strategies: Recombinant Lactobacillus casei expressing tetanus toxin fragment C for vaccination or myelin proteins for oral tolerance induction in multiple sclerosis

Maassen, C.B.M. (author), Laman, J.D. (author), Heijne den Bak-Glashouwer, M.J. (author), Tielen, F.J. (author), van Holten-Neelen, J.C.P.A. (author), Hoogteijling, L. (author), Antonissen, C. (author), Leer, R.J. (author), Pouwels, P.H. (author), Boersma, W.J.A. (author), Shaw, D.M. (author)

Lactobacillus strains possess properties that make them attractive candidates as vehicles for oral administration of therapeutics. In this report we describe the construction and analysis of recombinant Lactobacillus casei applicable in oral vaccination against an infectious disease (tetanus) and in oral tolerance induction for intervention in...

article 1999

document

Cloning, sequence analysis, and characterization of the genes involved in isoprimeverose metabolism in Lactobacillus pentosus

Chaillou, S. (author), Lokman, B.C. (author), Leer, R.J. (author), Posthuma, C. (author), Postma, P.W. (author), Pouwels, P.H. (author)

Two genes, xylP and xylQ, from the xylose regulon of Lactobacillus pentosus were cloned and sequenced. Together with the repressor gene of the regulon, xylR, the xylPQ genes form an operon which is inducible by xylose and which is transcribed from a promoter located 145 bp upstream of xylP. A putative xylR binding site (xylO) and a cre-like...

article 1998

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Lactic acid bacteria as antigen delivery vehicles for oral immunization purposes

Pouwels, P.H. (author), Leer, R.J. (author), Shaw, M. (author), Heijne Den Bak-Glashouwer, M.J. (author), Tielen, F.D. (author), Smit, E. (author), Martinez, B. (author), Jore, J. (author), Conway, P.L. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)

In vaccination programmes in which large numbers of subjects are involved, the oral route of administration is more convenient as compared to the more frequently used parenteral route. This is particularly relevant when vaccines are to be applied in less industrialized countries. Lactic acid bacteria in general and strains of Lactobacillus in...

article 1998

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The Lactobacillus acidophilus S-layer protein gene expression site comprises two consensus promoter sequences, one of which directs transcription of stable mRNA

Boot, H.J. (author), Kolen, C.P.A.M. (author), Andreadaki, F.J. (author), Leer, R.J. (author), Pouwels, P.H. (author), Prins Maurits Laboratorium TNO (author)

S-proteins are proteins which form a regular structure (S-layer) on the outside of the cell walls of many bacteria. Two S-protein-encoding genes are located in opposite directions on a 6.0-kb segment of the chromosome of Lactobacillus acidophilus ATCC 4356 bacteria. Inversion of this chromosomal segment occurs through recombination between two...

article 1996

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A convenient and reproducible method to genetically transform bacteria of the genus Bifidobacterium

Argnani, A. (author), Leer, R.J. (author), van Luijk, N. (author), Pouwels, P.H. (author), TNO Voeding (author)

A protocol was developed for the introduction of foreign plasmid DNA into various Bifidobacterium strains. The method, which is applicable to all Bifidobacterium species tested so far, is based on electroporation of bacteria made competent by preincubation in electroporation buffer for several hours at 4°C. Transformation of Bifidobacterium...

article 1996

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The potential of Lactobacillus as a carrier for oral immunization: Development and preliminary characterization of vector systems for targeted delivery of antigens

Centraal Instituut voor Voedingsonderzoek TNO TNO Preventie en Gezondheid (author), Pouwels, P.H. (author), Leer, R.J. (author), Boersma, W.J.A. (author)

Oral administration of lactobacilli evokes mucosal and systemic immune responses against epitopes associated with these organisms (Gerritse et al., 1990, 1991). The adjuvant function of different Lactobacillus species was investigated under the conditions of intraperitoneal (i.p.) injection or oral administration. After i.p. injection of...

article 1996

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Expression of Bacillus subtilis levanase gene in Lactobacillus plantarum and Lactobacillus casei

Wanker, E. (author), Leer, R.J. (author), Pouwels, P.H. (author), Schwab, H. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)

Two Lactobacillus-Escherichia coli shuttle vectors, harbouring the levanase gene from Bacillus subtilis under the control of its own promoter (pLPEW1) or behind the E. coli tac promoter (pE-SIEW2), were constructed. Lactobacillus plantarum showed the same growth characteristics on selective plates and in liquid media containing inulin, after...

article 1995

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Genetic analysis of acidocin B: A novel bacteriocin produced by Lactobacillus acidophilus

Leer, R.J. (author), van der Vossen, J.M.B.M. (author), van Giezen, M. (author), van Noort, J.M. (author), Pouwels, P.H. (author), Centraal Instituut voor Voedingsonderzoek TNO (author)

The genes encoding the production of acidocin B, a bacteriocin produced by Lactobacillus acidophilus strain M46 which is active against Listeria monocytogenes, Clostridium sporogenes, Brochothrix thermosphacta, Lactobacillus fermentum and Lactobacillus delbrueckii subsp. bulgaricus, but inactive against most other Lactobacillus species, were...

article 1995

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The potential of lactobacillus as a carrier for oral immunization: Development and preliminary characterization of vector systems for targeted delivery of antigens

Pouwels, P.H. (author), Leer, R.J. (author), Zegers, N.D. (author), Claassen, E. (author), Boersma, W.J.A. (author), TNO Preventie en Gezondheid (author)

conference paper 1995

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Heterologous gene expression in Lactobacillus

Posno, M. (author), Kottenhagen, M. (author), Lokman, B.C. (author), Jore, J. (author), Leer, R.J. (author), Pouwels, P.H. (author), Medisch Biologisch Laboratorium TNO Centraal Instituut voor Voedingsonderzoek TNO (author)

conference paper 1994

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Structural and functional analysis of plasmid vectors for Lactobacillus

Leer, R.J. (author), van Luijk, N. (author), Posno, M. (author), Pouwels, P.H. (author), Medisch Biologisch Laboratorium TNO Centraal Instituut voor Voedingsonderzoek TNO (author)

conference paper 1994

document

Development of safe oral vaccines based on Lactobacillus as a vector with adjuvanticity

Boersma, W.J.A. (author), Zegers, N.D. (author), van der Bogaerdt, A. (author), Leer, R.J. (author), Bergmans, A. (author), Pouwels, P.H. (author), Posno, M. (author), Claassen, E. (author), Centraal Instituut voor Voedingsonderzoek TNO TNO Voeding (author)

Single dose live oral vaccines are most urgently needed to meet the prerequisites as phrased in the `Children's Vaccine Initiative'. The use of a Generally Regarded as Safe (GRAS) micro-organism as Lactobacillus as oral vaccine carrier has the advantage a.o. that these bacteria have probiotic, health beneficial properties and can be used as ...

article 1994