BioProject

Leptospirosis is a globally significant zoonotic disease caused by Leptospira spp. More...

Leptospirosis is a globally significant zoonotic disease caused by Leptospira spp. Iron is essential for growth of most bacterial species. Since availability of iron is low in the host, pathogens have evolved complex iron acquisition mechanisms to survive and establish infection. Virulence genes in some bacteria have been shown to be iron-regulated. In many bacteria, expression of iron-uptake and storage proteins is regulated by Fur. L. interrogans encodes four predicted Fur homologs; we have constructed a mutant in one of these, la1857. We conducted microarray analysis to identify differentially expressed genes in L. interrogans serovar Manilae grown under low iron compared with normal iron conditions found in EMJH medium. We also compared the transcriptional profile of the la1857 mutant versus wild-type Manilae under normal and low iron conditions. Overall design: Analysis used RNA derived from L. interrogans serovar Manilae grown under low iron (EMJH medium + 40 µM 2,2-dipyridyl) and normal iron as experimental and control samples, respectively. We have a serovar Manilae mutant in la1857, one of four predicted fur homologs. The mutant was also grown under low iron and normal iron conditions and compared with wild-type Manilae grown under low and normal iron conditions respectively. Three independent RNA samples (biological replicates) from parent and mutant strains grown with or without 2,2-dipyridyl were compared in a loop design resulting in 12 arrays. The orientation of Cy3 to Cy5 labeling was the same for replicates 1 and 3, while replicate 2 was a dye swap. Direct comparisons were made between arrays of experimental and control samples using raw data pulled from two different channels for data analysis. Data from wild-type Manilae grown under low iron versus normal iron and mutant versus wild-type under normal iron conditions is reported in the manuscript. Less...