Detection of Bacillus cereus by PCR-based technique and Gold nanoparticles

Amini, E. (2015) Detection of Bacillus cereus by PCR-based technique and Gold nanoparticles. Masters thesis, University of Zabol.

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Bacillus cereus is a gram-positive and anaerobic spore. This bacteria produces enterotoxin that causes diarrhea and vomiting. Due to its resistance to temperature changes, conventional methods of strilization and cooking are not enough to control it. So, rapid and precise detection of the bacteria is requierd in the food quality control centers. In this study, to identify the Bacillus cereus, nheB and hblD genes were used to design the primers. PCR results showed amplification of expected fragments of 842 and 396 bp corresponded to nheB and hblD genes, respectively. The sensitivity and specificity of the primers in Bacillus cereus and 10 negative controls were evaluated. According to the results, sensitivity for hblD and nheB genes were 0.01 and 0.5 ng/μl respectively, and specificity were 100% for both genes. Then nheB gene sequencing was performed and result was deposited to NCBI gene bank. After designing probes for binding to the target molecule and the gold nanoparticle, experiments were carried out on optimization the detection using gold nanoparticles. The results revealed specificity of 100% and sensitivy of 12 x 105 CFU/mL. Comparison of PCR and gold nanoparticles probes with biochemical methods to detect Bacillus cereus showed greater sensitivity and speed of these methods to biochemical methods. In addition hybridization of probes and DNA molecules at wavelengths between 400 and 700 nm was investigated, changing in color from red to blue related to the binding of probes for target DNA were observed.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Bacillus cereus, hblD gene, nheB gene, PCR, Gold nanoparticles
Subjects: Q Science > QH Natural history > QH301 Biology
Depositing User: admin admin1 admin2
Date Deposited: 24 Apr 2016 03:59
Last Modified: 24 Apr 2016 03:59

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