Using DNA microarrays to study host-microbe interactions

Complete genomic sequences of microbial pathogens and hosts offer sophistic ated new strategies for studying host-pathogen interactions. DNA microarray s exploit primary sequence data to measure transcript levels and detect seq uence polymorphisms, for every gene, simultaneously. The design and constru ction of a DNA microarray for any given microbial genome are straightforwar d. By monitoring microbial gene expression, one can predict the functions o f uncharacterized genes, probe the physiologic adaptations made under vario us environmental conditions, identify virulence-associated genes, and test the effects of drugs. Similarly, by using host gene microarrays, one can ex plore host response at the level of gene expression and provide a molecular description of the events that follow infection. Host profiling might also identify gene expression signatures unique for each pathogen, thus providi ng a novel tool for diagnosis, prognosis, and clinical management of infect ious disease.