Abstract: Detection of the antimicrobial resistance in common veterinary pathogen by using oligonucleotide array was studied. A pair of primers was designed to amplify fragments of gyrA gene from E. coli, S. aureus and M. gallisepticum, and simultaneously label fluorescence with cy5-dCTP. A series of oligonucleotide probes with which to detect the resistance to fluoroquinolones in the above three bacterial apecies were designed, then dotted and immobilized onto the oligonucleotide array by APS-PDC method. The labelled PCR products were hybridized with the oligonucleotide array, and the signals were scanned and analyzed with a ImaGene 3.0 software. The results showed that the hybridized oligonucleotide array presented detectable signals, and were consistent with the facts. This study demonstrated that the array could distinguish single base mutation between wild types and mutant types of E. coli，S. aureus，M. gallisepticum, and was able to identify differences in the wild strains and mutant strains occurring at positions 83 and 87 of the GyrA subunit. The preliminary results demonstrated that oligonucleotide array provided an accurate, sensitive and feasible tool for the detection of resistance in veterinary bacteria. The present study may provide a basis for further research and development of gene chip in monitoring resistance to antimicrobial agents.

Key words: Oligonucleotide array, Resistance, Detection