Title: Development of a Universal DNA Microarray for Detecting Exogenous Antimicrobial Resistance Genes in Diverse Bacteria Authors
Submitted to: Annual Conference of Antimicrobial Resistance
Publication Type: Abstract Only
Publication Acceptance Date: May 28, 2006
Publication Date: June 28, 2006
Citation: Frye, J.G., Cray, P.J., Jackson, C.R., Englen, M.D. 2006. Development of a universal dna microarray for detecting exogenous antimicrobial resistance genes in diverse bacteria. Annual Conference of Antimicrobial Resistance. S8:43. Technical Abstract: Background: The horizontal transfer of exogenous antimicrobial resistance genes between bacteria is one of the factors leading to the spread of antimicrobial resistance. To study the epidemiology of this spread, it is necessary to identify the genes responsible for resistance. Currently, each gene must be screened individually in order to identify the gene responsible for the observed resistance expressed by a bacterium. The inability to rapidly identify these genes limits research progress. Methods: A DNA microarray was constructed to simultaneously detect all sequenced antimicrobial resistance genes. Antimicrobial resistance gene sequences were downloaded from the National Center for Biotechnology Information database; 70mer oligonucleotide probes were designed to detect them, they were then synthesized and arrayed onto glass slides. Total DNA from control and test strains were labeled with fluorescent dye and hybridization, scanning and analysis were done following standard methods. Results: The microarray successfully detected resistance genes in a variety of diverse bacteria, including Salmonella, E. coli, Camplyobacter and Enterococcus. Hybridization results were validated by positive controls and confirmed by PCR and Southern blotting. The microarray reliably tested for hundreds of genes per assay and detected dozens of genes in resistant isolates. Conclusions: The microarray can be used to rapidly screen for almost all exogenous resistant genes in one assay. This technique will facilitate monitoring the spread of antimicrobial resistance and improve our understanding of the epidemiology of the genes causing resistance.