Speaker Abstract: S-14
Microarray-Based Methods for Microbial Gene Expression Profiling and Strain Identification
Scott A. Jackson, Ph.D., Center for Food Safety and Applied Nutrition/FDA
DNA microarrays have proven to be useful tools for rapid, whole-genome investigations. To this end, we have used microarrays to investigate both gene expression profiles and genomic variability among enteric pathogens. For example, we are interrogating the gene expression profiles of strains of Salmonella enterica that are defective in methyl-directed mismatch repair (MMR) and thus exhibit a mutator phenotype. MMR-defective strains of enteric pathogens are prevalent in nature and have likely played a major role in shaping the genome and ultimately in the evolution of enteric pathogens. To help us understand the mutator phenotypes of S. enterica both in vitro and during the course of infection, we are using DNA microarrays that contain ~98% of the genes found in three serovars of this human pathogen.
We are also using the power of microarrays to interrogate the genomic diversity of strains of E.coli O157:H7 and S. enterica, interrogating the unique sequence signatures that have accrued in these enteric pathogens during their evolution. We have developed a modified resequencing chip that will rapidly provide detailed genomic information, from many strains in parallel, including the presence of SNPs, insertions, and deletions. Cladistic analyses of these data will allow us to group strains based on DNA changes, which can ultimately provide a framework for strain identification without the need for total genomic sequencing.
2004 FDA Science Forum | FDA Chapter, Sigma Xi | CFSAN | FDA
Last updated on 2004-MAY-28 by frf