Iron-regulated small RNA expression as Neisseria gonorrhoeae FA 1090 transitions into stationary phase growth.

Background: For most pathogens, iron (Fe) homeostasis is crucial for maintenance within the host and the ability to cause disease. The primary transcriptional regulator that controls intracellular Fe levels is the Fur (ferric uptake regulator) protein, which exerts its action on transcription by binding to a promoter-proximal sequence termed the Fur box. Fur-regulated transcriptional responses are often fine-tuned at the post-transcriptional level through the action of small regulatory RNAs (sRNAs).

Whole-Genome Sequences of the Archetypal K1 Escherichia coli Neonatal Isolate RS218 and Contemporary Neonatal Bacteremia Clinical Isolates SCB11, SCB12, and SCB15.

Neonatal bacteremia Escherichia coli strains commonly belong to the K1 capsular type. Their ability to cause invasive neonatal disease appears to be determined by other virulence factors that have yet to be identified. We report here the genome sequences of four E.

Control of RNA stability by NrrF, an iron-regulated small RNA in Neisseria gonorrhoeae.

Regulation of gene expression by small noncoding RNAs (sRNAs) plays a critical role in bacterial response to physiological stresses. NrrF, a trans-acting sRNA in Neisseria meningitidis and Neisseria gonorrhoeae, has been shown in the meningococcus to control indirectly, in response to iron (Fe) availability, the transcription of genes encoding subunits of succinate dehydrogenase, a Fe-requiring enzyme. Given that in other organisms, sRNAs target multiple mRNAs to control gene expression, we used a global approach to examine the role of NrrF in controlling gonococcal transcription.

Protocol for gene expression profiling using DNA microarrays in Neisseria gonorrhoeae.

Gene expression profiling using DNA microarrays has become commonplace in current molecular biology practices, and has dramatically enhanced our understanding of the biology of Neisseria spp., and the interaction of these organisms with the host. With the choice of microarray platforms offered for gene expression profiling and commercially available arrays, investigators must ask several central questions to make decisions based on their research focus.

Transcriptional and functional analysis of the Neisseria gonorrhoeae Fur regulon.

To ensure survival in the host, bacteria have evolved strategies to acquire the essential element iron. In Neisseria gonorrhoeae, the ferric uptake regulator Fur regulates metabolism through transcriptional control of iron-responsive genes by binding conserved Fur box (FB) sequences in promoters during iron-replete growth. Our previous studies showed that Fur also controls the transcription of secondary regulators that may, in turn, control pathways important to pathogenesis, indicating an indirect role for Fur in controlling these downstream genes.

Levels of L-selectin (CD62L) on human leukocytes in disseminated cryptococcosis with and without associated HIV-1 infection.

Patients with disseminated cryptococcosis typically have measurable levels of cryptococcal polysaccharide in serum samples but minimal leukocyte infiltration into infected tissues. In vitro data have shown that cryptococcal polysaccharide induces L-selectin (CD62L) shedding from leukocytes. To assess shedding in vivo, we compared leukocyte L-selectin levels in human immunodeficiency virus (HIV) type 1-negative and -positive subjects with and without circulating cryptococcal polysaccharide.