Peter Rådström

Quantitative interaction effects of carbon dioxide, sodium chloride, and sodium nitrite on neurotoxin gene expression in nonproteolytic Clostridium botulinum type B. (2004)

Lövenklev, Maria, Artin, Ingrid, Hagberg, Oskar, Borch, Elisabeth, Holst, Elisabet, Rådström, Peter

The effects of carbon dioxide, sodium chloride, and sodium nitrite on type B botulinum neurotoxin (BoNT/B) gene (cntB) expression in nonproteolytic Clostridium botulinum were investigated in a...

Relative neurotoxin gene expression in clostridium botulinum type B, determined using quantitative reverse transcription-PCR. (2004)

Lövenklev, Maria, Holst, Elisabet, Borch, Elisabeth, Rådström, Peter

A quantitative reverse transcription-PCR (qRT-PCR) method was developed to monitor the relative expression of the type B botulinum neurotoxin (BoNT/B) gene (cntB) in Clostridium botulinum. The levels...

Diagnostic PCR: validation and sample preparation are two sides of the same coin (2004)

Hoorfar, Jeffrey, Wolffs, Petra, Rådström, Peter

Increased use of powerful PCR technology for the routine detection of pathogens has focused attention on the need for international validation and preparation of official non-commercial guidelines....

Pre-PCR processing strategies (2004)

Rådström, Peter, Lövenklev, Maria, Wolffs, Petra, Löfström, Charlotta, Knutsson, Rickard

A review describes the sample prepn. for biochem. methods, enrichment methods, immunol. methods, and phys. methods. The pretreatment of a complex biol. sample is crucial, and for successful PCR the...

Physiological function of the maltose operon regulator, MalR, in Lactococcus lactis (2002)

Andersson, Ulrika, Rådström, Peter

Abstract Background Maltose metabolism is initiated by an ATP-dependent permease system in Lactococcus lactis . The subsequent degradation of intracellular maltose is performed by the concerted...

Evaluation of selective enrichment PCR procedures for Yersinia enterocolitica. (2002)

Knutsson, Rickard, Blixt, Ylva, Grage, Halfdan, Borch, Elisabeth, Rådström, Peter

Four enrichment PCR protocols for detecting unlysed cells of pathogenic Yersinia enterocolitica were studied. First, the probability of detecting Y. enterocolitica cells of known concentrations by a...

Enhanced Exopolysaccharide Production by Metabolic Engineering of Streptococcus thermophilus. (2002)

Levander, Fredrik, Svensson, Malin, Rådström, Peter

It is possible that the low levels of production of exopolysaccharides (EPSs) by lactic acid bacteria could be improved by altering the levels of enzymes in the central metabolism that influence the...

Modeling of 5' nuclease real-time responses for optimization of a high-throughput enrichment PCR procedure for Salmonella enterica. (2002)

Knutsson, Rickard, Löfström, Charlotta, Grage, Halfdan, Hoorfar, Jeffrey, Rådström, Peter

The performance of a 5' nuclease real-time PCR assay was studied to optimize an automated method of detection of preenriched Salmonella enterica cells in buffered peptone water (BPW). The...

Beta-glucose 1-phosphate-interconverting enzymes in maltose- and trehalose-fermenting lactic acid bacteria. (2002)

Andersson, Ulrika, Rådström, Peter

Maltose and trehalose catabolic pathways are linked through their common enzyme, beta-phosphoglucomutase, and metabolite, beta-glucose 1-phosphate, in Lactococcus lactis. Maltose is degraded by the...

Small-scale analysis of exopolysaccharides from Streptococcus thermophilus grown in a semi-defined medium (2001)

Levander, Fredrik, Svensson, Malin, Rådström, Peter

Abstract Background Exopolysaccharides (EPSs) produced by lactic acid bacteria are important for the texture of fermented foods and have received a great deal of interest recently. However, the low...

Use of aqueous two-phase systems in sample preparation for polymerase chain reaction-based detection of microorganisms (1996)

Lantz, Pär-Gunnar, Tjerneld, Folke, Hahn-Hägerdal, Bärbel, Rådström, Peter

An aqueous two-phase system, consisting of poly(ethylene glycol) (PEG) and dextran, was employed to separate polymerase chain reaction (PCR)-inhibitory substances from bacterial cells. The PCR...

Effects of Amplification Facilitators on Diagnostic PCR in the Presence of Blood, Feces, and Meat

Rådström, Peter

The full potential of diagnostic PCR is limited, in part, by the presence of inhibitors in complex biological samples that reduce the amplification efficiency. Therefore, different pre-PCR treatments...

Purification and Characterization of PCR-Inhibitory Components in Blood Cells

Al-Soud, Waleed Abu, Rådström, Peter

In a recent study, immunoglobulin G in human plasma was identified as a major inhibitor of diagnostic PCR (W. Abu Al-Soud, L. J. Jönsson, and P. Rådström. J. Clin. Microbiol. 38:345–350, 2000)....

Identification and Characterization of Immunoglobulin G in Blood as a Major Inhibitor of Diagnostic PCR

Al-Soud, Waleed Abu, Jönsson, Leif J., Rådström, Peter

A major inhibitor of diagnostic PCR in human plasma was identified and the mechanism of inhibition was characterized. Human blood was divided by centrifugation into buffy coat, plasma, platelets, and...

Requirement for Phosphoglucomutase in Exopolysaccharide Biosynthesis in Glucose- and Lactose-Utilizing Streptococcus thermophilus

Levander, Fredrik, Rådström, Peter

To study the influence of phosphoglucomutase (PGM) activity on exopolysaccharide (EPS) synthesis in glucose- and lactose-growing Streptococcus thermophilus, a knockout PGM mutant and a strain with...

Physiological Role of β-Phosphoglucomutase in Lactococcus lactis

Levander, Fredrik, Andersson, Ulrika, Rådström, Peter

A β-phosphoglucomutase (β-PGM) mutant of Lactococcus lactis subsp. lactis ATCC 19435 was constructed using a minimal integration vector and double-crossover recombination. The mutant and the...

Development of a Combined Selection and Enrichment PCR Procedure for Clostridium botulinum Types B, E, and F and Its Use To Determine Prevalence in Fecal Samples from Slaughtered Pigs

Dahlenborg, Maria, Borch, Elisabeth, Rådström, Peter

A specific and sensitive combined selection and enrichment PCR procedure was developed for the detection of Clostridium botulinum types B, E, and F in fecal samples from slaughtered pigs. Two...

Capacity of Nine Thermostable DNA Polymerases To Mediate DNA Amplification in the Presence of PCR-Inhibiting Samples

Rådström, Peter

The PCR is an extremely powerful method for detecting microorganisms. However, its full potential as a rapid detection method is limited by the inhibition of the thermostable DNA polymerase from...

Modeling of 5′ Nuclease Real-Time Responses for Optimization of a High-Throughput Enrichment PCR Procedure for Salmonella enterica

Knutsson, Rickard, Löfström, Charlotta, Grage, Halfdan, Hoorfar, Jeffrey, Rådström, Peter

The performance of a 5′ nuclease real-time PCR assay was studied to optimize an automated method of detection of preenriched Salmonella enterica cells in buffered peptone water (BPW). The...

Enhanced Exopolysaccharide Production by Metabolic Engineering of Streptococcus thermophilus

Levander, Fredrik, Svensson, Malin, Rådström, Peter

It is possible that the low levels of production of exopolysaccharides (EPSs) by lactic acid bacteria could be improved by altering the levels of enzymes in the central metabolism that influence the...

Rapid and Specific Detection of Salmonella spp. in Animal Feed Samples by PCR after Culture Enrichment

Löfström, Charlotta, Knutsson, Rickard, Axelsson, Charlotta Engdahl, Rådström, Peter

A PCR procedure has been developed for routine analysis of viable Salmonella spp. in feed samples. The objective was to develop a simple PCR-compatible enrichment procedure to enable DNA...

Impact of DNA Polymerases and Their Buffer Systems on Quantitative Real-Time PCR

Wolffs, Petra, Grage, Halfdan, Hagberg, Oskar, Rådström, Peter

An investigation of the influence of five DNA polymerase-buffer systems on real-time PCR showed that the choice of both DNA polymerase and the buffer system affected the amplification efficiency as...

Rapid Quantification of Yersinia enterocolitica in Pork Samples by a Novel Sample Preparation Method, Flotation, Prior to Real-Time PCR

Wolffs, Petra, Knutsson, Rickard, Norling, Börje, Rådström, Peter

The development of real-time PCR thermal cycles in the late 1990s has opened up the possibility of accurate quantification of microorganisms in clinical, environmental, and food samples. However, a...

Relative Neurotoxin Gene Expression in Clostridium botulinum Type B, Determined Using Quantitative Reverse Transcription-PCR

Lövenklev, Maria, Holst, Elisabet, Borch, Elisabeth, Rådström, Peter

A quantitative reverse transcription-PCR (qRT-PCR) method was developed to monitor the relative expression of the type B botulinum neurotoxin (BoNT/B) gene (cntB) in Clostridium botulinum. The levels...

Quantitative Interaction Effects of Carbon Dioxide, Sodium Chloride, and Sodium Nitrite on Neurotoxin Gene Expression in Nonproteolytic Clostridium botulinum Type B

Lövenklev, Maria, Artin, Ingrid, Hagberg, Oskar, Borch, Elisabeth, Holst, Elisabet, Rådström, Peter

The effects of carbon dioxide, sodium chloride, and sodium nitrite on type B botulinum neurotoxin (BoNT/B) gene (cntB) expression in nonproteolytic Clostridium botulinum were investigated in a...

Metabolically Improved Exopolysaccharide Production by Streptococcus thermophilus and Its Influence on the Rheological Properties of Fermented Milk

Svensson, Malin, Waak, Elisabet, Svensson, Ulla, Rådström, Peter

Altered levels of enzymes in the central carbon metabolism in Streptococcus thermophilus increased the exopolysaccharide (EPS) production 3.3 times over that of the parent strain. The influence of...

Quantification of Campylobacter spp. in Chicken Rinse Samples by Using Flotation prior to Real-Time PCR

Wolffs, Petra, Norling, Börje, Hoorfar, Jeffrey, Griffiths, Mansel, Rådström, Peter

Real-time PCR is fast, sensitive, specific, and can deliver quantitative data; however, two disadvantages are that this technology is sensitive to inhibition by food and that it does not distinguish...

Molecular and Biochemical Analysis of the Galactose Phenotype of Dairy Streptococcus thermophilus Strains Reveals Four Different Fermentation Profiles

De Vin, Filip, Rådström, Peter, Herman, Lieve, De Vuyst, Luc

Lactose-limited fermentations of 49 dairy Streptococcus thermophilus strains revealed four distinct fermentation profiles with respect to galactose consumption after lactose depletion. All the...

Effects of Amplification Facilitators on Diagnostic PCR in the Presence of Blood, Feces, and Meat

Rådström, Peter

The full potential of diagnostic PCR is limited, in part, by the presence of inhibitors in complex biological samples that reduce the amplification efficiency. Therefore, different pre-PCR treatments...

Purification and Characterization of PCR-Inhibitory Components in Blood Cells

Al-Soud, Waleed Abu, Rådström, Peter

In a recent study, immunoglobulin G in human plasma was identified as a major inhibitor of diagnostic PCR (W. Abu Al-Soud, L. J. Jönsson, and P. Rådström. J. Clin. Microbiol. 38:345–350, 2000)....

Identification and Characterization of Immunoglobulin G in Blood as a Major Inhibitor of Diagnostic PCR

Al-Soud, Waleed Abu, Jönsson, Leif J., Rådström, Peter

A major inhibitor of diagnostic PCR in human plasma was identified and the mechanism of inhibition was characterized. Human blood was divided by centrifugation into buffy coat, plasma, platelets, and...

Requirement for Phosphoglucomutase in Exopolysaccharide Biosynthesis in Glucose- and Lactose-Utilizing Streptococcus thermophilus

Levander, Fredrik, Rådström, Peter

To study the influence of phosphoglucomutase (PGM) activity on exopolysaccharide (EPS) synthesis in glucose- and lactose-growing Streptococcus thermophilus, a knockout PGM mutant and a strain with...

Physiological Role of β-Phosphoglucomutase in Lactococcus lactis

Levander, Fredrik, Andersson, Ulrika, Rådström, Peter

A β-phosphoglucomutase (β-PGM) mutant of Lactococcus lactis subsp. lactis ATCC 19435 was constructed using a minimal integration vector and double-crossover recombination. The mutant and the...

Development of a Combined Selection and Enrichment PCR Procedure for Clostridium botulinum Types B, E, and F and Its Use To Determine Prevalence in Fecal Samples from Slaughtered Pigs

Dahlenborg, Maria, Borch, Elisabeth, Rådström, Peter

A specific and sensitive combined selection and enrichment PCR procedure was developed for the detection of Clostridium botulinum types B, E, and F in fecal samples from slaughtered pigs. Two...

Capacity of Nine Thermostable DNA Polymerases To Mediate DNA Amplification in the Presence of PCR-Inhibiting Samples

Rådström, Peter

The PCR is an extremely powerful method for detecting microorganisms. However, its full potential as a rapid detection method is limited by the inhibition of the thermostable DNA polymerase from...

Modeling of 5′ Nuclease Real-Time Responses for Optimization of a High-Throughput Enrichment PCR Procedure for Salmonella enterica

Knutsson, Rickard, Löfström, Charlotta, Grage, Halfdan, Hoorfar, Jeffrey, Rådström, Peter

The performance of a 5′ nuclease real-time PCR assay was studied to optimize an automated method of detection of preenriched Salmonella enterica cells in buffered peptone water (BPW). The...

Enhanced Exopolysaccharide Production by Metabolic Engineering of Streptococcus thermophilus

Levander, Fredrik, Svensson, Malin, Rådström, Peter

It is possible that the low levels of production of exopolysaccharides (EPSs) by lactic acid bacteria could be improved by altering the levels of enzymes in the central metabolism that influence the...

Rapid and Specific Detection of Salmonella spp. in Animal Feed Samples by PCR after Culture Enrichment

Löfström, Charlotta, Knutsson, Rickard, Axelsson, Charlotta Engdahl, Rådström, Peter

A PCR procedure has been developed for routine analysis of viable Salmonella spp. in feed samples. The objective was to develop a simple PCR-compatible enrichment procedure to enable DNA...

Impact of DNA Polymerases and Their Buffer Systems on Quantitative Real-Time PCR

Wolffs, Petra, Grage, Halfdan, Hagberg, Oskar, Rådström, Peter

An investigation of the influence of five DNA polymerase-buffer systems on real-time PCR showed that the choice of both DNA polymerase and the buffer system affected the amplification efficiency as...

Rapid Quantification of Yersinia enterocolitica in Pork Samples by a Novel Sample Preparation Method, Flotation, Prior to Real-Time PCR

Wolffs, Petra, Knutsson, Rickard, Norling, Börje, Rådström, Peter

The development of real-time PCR thermal cycles in the late 1990s has opened up the possibility of accurate quantification of microorganisms in clinical, environmental, and food samples. However, a...

Relative Neurotoxin Gene Expression in Clostridium botulinum Type B, Determined Using Quantitative Reverse Transcription-PCR

Lövenklev, Maria, Holst, Elisabet, Borch, Elisabeth, Rådström, Peter

A quantitative reverse transcription-PCR (qRT-PCR) method was developed to monitor the relative expression of the type B botulinum neurotoxin (BoNT/B) gene (cntB) in Clostridium botulinum. The levels...

Quantitative Interaction Effects of Carbon Dioxide, Sodium Chloride, and Sodium Nitrite on Neurotoxin Gene Expression in Nonproteolytic Clostridium botulinum Type B

Lövenklev, Maria, Artin, Ingrid, Hagberg, Oskar, Borch, Elisabeth, Holst, Elisabet, Rådström, Peter

The effects of carbon dioxide, sodium chloride, and sodium nitrite on type B botulinum neurotoxin (BoNT/B) gene (cntB) expression in nonproteolytic Clostridium botulinum were investigated in a...

Molecular and Biochemical Analysis of the Galactose Phenotype of Dairy Streptococcus thermophilus Strains Reveals Four Different Fermentation Profiles

De Vin, Filip, Rådström, Peter, Herman, Lieve, De Vuyst, Luc

Lactose-limited fermentations of 49 dairy Streptococcus thermophilus strains revealed four distinct fermentation profiles with respect to galactose consumption after lactose depletion. All the...

Metabolically Improved Exopolysaccharide Production by Streptococcus thermophilus and Its Influence on the Rheological Properties of Fermented Milk

Svensson, Malin, Waak, Elisabet, Svensson, Ulla, Rådström, Peter

Altered levels of enzymes in the central carbon metabolism in Streptococcus thermophilus increased the exopolysaccharide (EPS) production 3.3 times over that of the parent strain. The influence of...

Quantification of Campylobacter spp. in Chicken Rinse Samples by Using Flotation prior to Real-Time PCR

Wolffs, Petra, Norling, Börje, Hoorfar, Jeffrey, Griffiths, Mansel, Rådström, Peter

Real-time PCR is fast, sensitive, specific, and can deliver quantitative data; however, two disadvantages are that this technology is sensitive to inhibition by food and that it does not distinguish...

First Case of Type E Wound Botulism Diagnosed Using Real-Time PCR▿

Artin, Ingrid, Björkman, Per, Cronqvist, Jonas, Rådström, Peter, Holst, Elisabet

Wound botulism is a growing problem among injecting drug users. The condition is often difficult to diagnose, with laboratory confirmation in only 50% of the cases. Here we present a real-time...

Phosphoketolase Pathway Dominates in Lactobacillus reuteri ATCC 55730 Containing Dual Pathways for Glycolysis▿

Årsköld, Emma, Lohmeier-Vogel, Elke, Cao, Rong, Roos, Stefan, Rådström, Peter

Metabolic flux analysis indicated that the heterofermentative Lactobacillus reuteri strain ATCC 55730 uses both the Embden-Meyerhof pathway (EMP) and phosphoketolase pathway (PKP) when glucose or...

Effects of Carbon Dioxide on Neurotoxin Gene Expression in Nonproteolytic Clostridium botulinum Type E▿

Artin, Ingrid, Carter, Andrew T., Holst, Elisabet, Lövenklev, Maria, Mason, David R., Peck, Michael W., ...

Carbon dioxide is an antimicrobial gas commonly used in modified atmosphere packaging. In the present study, the effects of carbon dioxide on the growth of and neurotoxin production by nonproteolytic...