Applying Gene Chip For Detect Staphylococcus Aureus In Foods

The time of traditional methods of detecting Staphylococcus aureus in foods are too long and do not get the results in short time. The potential of DNA microarray technology in high-throughput detection of bacteria is widely acknowledged but has not been fully realized yet. For the rapid detection of Staphylococcus aureus, a gene chip based on detection and identification system was development by using high-throughput of DNA macroarray to detect Staphylococcus aureus in foods.Extraction of chromosome DNA from Staphylococcus aureus, then amplification of Staphylococcus aureus's 16SrRNA by bacteria universal primers. The oligonucleotides probes complementary to species-specific 16SrRNA regions of targeted Staphylococcus aureus was designed. For decreasing ratio of false positive and negative, the bacteria univerial probe and Staphylococcus specific probe were designed especially. The undetection Staphylococcus aureus was ampified and labeled, and then PCR products were applied to the oligonucleotides microarray. Analyse and conclude oligonucleotides profiles, then we will attain a set of specific detection style. Then detect Staphylococcus aureus separating from foods by using designed gene chip. At last, the sensitivity of detection Staphylococcus aureus by using this gene chip was done.To detect Staphylococcus aureus by using designed gene chip, the result is good. At the same time, Shigella and Streptococcus suis in pigs were used for validating designed gene chip, the practice results were identical with theory results. Then detect Staphylococcus aureus separating from foods by using designed gene chip, the practice results were identical with theory results.The feasibility of gene chip detection Staphylococcus aureus was checked according to its gene chip with high specificity Staphylococcus aureus probes. The hybridization and washing conditions were optimized, the hybridization time was shortened. A new method was confirmed for the judgement of positive or negative based on the relative signal intensity. The detection of Staphylococcus aureus were deduced to the oligonucleotides profiles, just as the so-called specific probes. The result suggests that it is possible to realise the high-throughput detection of Staphylococcus aureus by the gene chip. The judgement method of singal guaranteed the stability of the detection result.The sensitivity of detection Staphylococcus aureus by using this gene chip was not good, the detection limit in a 30ul system for the gene chip detection system were 6.8xl0:>cfu. But the poor sensitivity for it do not represent the poor sensitivity of the chip system because it lies on both extraction of chromosome DNA and amplification efficiency.The gene chip detection Staphylococcus aureus has a good specificity, stability, and reliability. Most samples of Staphylococcus aureus could be detect correctly in short time. Owing to specificity and stability in detection of Staphylococcus aureus, the gene chip could be available in quick detection Staphylococcus aureus fields for the detection and identification of Staphylococcus aureus, and has a high practicability.