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Identification of pathogenic microbial cells and spores by electrochemical detection on a biochip.

Gabig-Ciminska M, Andresen H, Albers J, Hintsche R, Enfors SO - Microb. Cell Fact. (2004)

Bottom Line: Despite the recent development of different detection methods, new effective control measures and better diagnostic tools are required for quick and reliable detection of pathogenic micro-organisms.The method was also successful when applied directly to unpurified spore and cell extract samples.The assay for the haemolytic enterotoxin genes resulted in reproducible signals from B. cereus and B. thuringiensis while haemolysin-negative B. subtilis strain did not yield any signal.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biotechnology, Royal Institute of Technology KTH, S-10691 Stockholm, Sweden. gabig@biotech.univ.gda.pl

ABSTRACT
BACKGROUND: Bacillus cereus constitutes a significant cause of acute food poisoning in humans. Despite the recent development of different detection methods, new effective control measures and better diagnostic tools are required for quick and reliable detection of pathogenic micro-organisms. Thus, the objective of this study was to determine a simple method for rapid identification of enterotoxic Bacillus strains. Here, a special attention is given to an electrochemical biosensor since it meets the requirements of minimal size, lower costs and decreased power consumption. RESULTS: A bead-based sandwich hybridization system was employed in conjugation with electric chips for detection of vegetative cells and spores of Bacillus strains based on their toxin-encoding genes. The system consists of a silicon chip based potentiometric cell, and utilizes paramagnetic beads as solid carriers of the DNA probes. The specific signals from 20 amol of bacterial cell or spore DNA were achieved in less than 4 h. The method was also successful when applied directly to unpurified spore and cell extract samples. The assay for the haemolytic enterotoxin genes resulted in reproducible signals from B. cereus and B. thuringiensis while haemolysin-negative B. subtilis strain did not yield any signal. CONCLUSIONS: The sensitivity, convenience and specificity of the system have shown its potential. In this respect an electrochemical detection on a chip enabling a fast characterization and monitoring of pathogens in food is of interest. This system can offer a contribution in the rapid identification of bacteria based on the presence of specific genes without preceding nucleic acid amplification.

No MeSH data available.


Related in: MedlinePlus

Outline of the bead-based sandwich hybridization on the electric chip. The two alternative positions of the detection probes are indicated.
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Figure 1: Outline of the bead-based sandwich hybridization on the electric chip. The two alternative positions of the detection probes are indicated.

Mentions: Electrochemical measurements for detection of DNA of selected genes were performed with the electric silicon chip according to the protocol described in Methods. DNA target was hybridized to the magnetic beads with immobilized amino-linked capture probes as well as with gene specific detection probes labeled with biotin (Table 1, Figure 1).


Identification of pathogenic microbial cells and spores by electrochemical detection on a biochip.

Gabig-Ciminska M, Andresen H, Albers J, Hintsche R, Enfors SO - Microb. Cell Fact. (2004)

Outline of the bead-based sandwich hybridization on the electric chip. The two alternative positions of the detection probes are indicated.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC411050&req=5

Figure 1: Outline of the bead-based sandwich hybridization on the electric chip. The two alternative positions of the detection probes are indicated.
Mentions: Electrochemical measurements for detection of DNA of selected genes were performed with the electric silicon chip according to the protocol described in Methods. DNA target was hybridized to the magnetic beads with immobilized amino-linked capture probes as well as with gene specific detection probes labeled with biotin (Table 1, Figure 1).

Bottom Line: Despite the recent development of different detection methods, new effective control measures and better diagnostic tools are required for quick and reliable detection of pathogenic micro-organisms.The method was also successful when applied directly to unpurified spore and cell extract samples.The assay for the haemolytic enterotoxin genes resulted in reproducible signals from B. cereus and B. thuringiensis while haemolysin-negative B. subtilis strain did not yield any signal.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biotechnology, Royal Institute of Technology KTH, S-10691 Stockholm, Sweden. gabig@biotech.univ.gda.pl

ABSTRACT
BACKGROUND: Bacillus cereus constitutes a significant cause of acute food poisoning in humans. Despite the recent development of different detection methods, new effective control measures and better diagnostic tools are required for quick and reliable detection of pathogenic micro-organisms. Thus, the objective of this study was to determine a simple method for rapid identification of enterotoxic Bacillus strains. Here, a special attention is given to an electrochemical biosensor since it meets the requirements of minimal size, lower costs and decreased power consumption. RESULTS: A bead-based sandwich hybridization system was employed in conjugation with electric chips for detection of vegetative cells and spores of Bacillus strains based on their toxin-encoding genes. The system consists of a silicon chip based potentiometric cell, and utilizes paramagnetic beads as solid carriers of the DNA probes. The specific signals from 20 amol of bacterial cell or spore DNA were achieved in less than 4 h. The method was also successful when applied directly to unpurified spore and cell extract samples. The assay for the haemolytic enterotoxin genes resulted in reproducible signals from B. cereus and B. thuringiensis while haemolysin-negative B. subtilis strain did not yield any signal. CONCLUSIONS: The sensitivity, convenience and specificity of the system have shown its potential. In this respect an electrochemical detection on a chip enabling a fast characterization and monitoring of pathogens in food is of interest. This system can offer a contribution in the rapid identification of bacteria based on the presence of specific genes without preceding nucleic acid amplification.

No MeSH data available.


Related in: MedlinePlus