Study on universal microarray system for detection of common clinical infectious bacteria

  Objective   For the rapid and efficient detection of biological agents and clinical infectious bacteria, a based detection system which employed 16SrDNA sequence as its detection target was etablished.

  Methods   Oligonucleotide probes of 16 strains of bacteria were designed by using some bioinformatics softwares and methods and tested by using this microarray system.

  Results   A microarray based detection system was successfully developed.The results showed that most of the bacteria can be determined at the species level.The detection limit for oligonucleotide microarray system was 200 CFU for Pseudomonas aerugi nosa and 235 CFU for Staphylococcus aureus.Aliquots of bacterial suspension were spiked into horse blood, and subject to analyse with microarray system, the sensitivity was greatly decreased to 2 000 CFU of Pseudomonas aeruginosa and 23 500 CFU of Staphylococcus aureus.But with the serial dilution of L egionella pneumoniae chromosomal DNA, a 10 times sensitivity than that of PCR-electrophoresis was observed.As for the bland test for pooled samples, two strains of bacteria in a single sample could be deteced by this method at the same time.

  Conclusion   The oligonucleotide microarray could determine most of the test strains at species level.The overall time for sample process, hybridization and data acquisition lasted about 4.5 hours.