KIM5 intracellular expression profiling

Microarrays were used to determine the transcriptional profile of Y. pestis that is growing inside macrophages. J774A.1 macrophage-like cells were infected with Y. pestis KIM5 and incubated in the presence of gentamicin in tissue culture media. RNA was isolated from intracellular bacteria at various time points post infection. Control bacteria were grown for 4 hours in tissue culture medium under the same conditions without macrophages or gentamicin. The transcriptional profiles of intracellular Y. pestis at different time points were compared to those of control Y. pestis using the 70-mer oligonucleotide microarrays obtained from Pathogen Functional Genomics Resource Center/J. Craig Venter Institute (Y. pestis microarray version 2). RNA from samples of Yersinia pestis KIM5 at 3 time points in were compared to 12 Yersinia pestis in DMEM for 4 hours.