A Heme-responsive Regulator Controls Synthesis of Staphyloferrin B in Staphylococcus aureus.

Staphylococcus aureus possesses a multitude of mechanisms by which it can obtain iron during growth under iron starvation conditions. It expresses an effective heme acquisition system (the iron-regulated surface determinant system), it produces two carboxylate-type siderophores staphyloferrin A and staphyloferrin B (SB), and it expresses transporters for many other siderophores that it does not synthesize. The ferric uptake regulator protein regulates expression of genes encoding all of these systems.

Effectiveness of Repeated Courses of Pulmonary Rehabilitation on Functional Exercise Capacity in Patients With COPD.

Purpose: To determine whether an as-needed repeated pulmonary rehabilitation (PR) intervention produces a clinically important improvement in exercise capacity.

Methods: The study included a retrospective analysis of characteristics and 6-minute walk distance (6MWD) of patients with chronic obstructive pulmonary disease (COPD) who completed PR at 2 centers. Data were abstracted from all patients with COPD completing 2 courses of rehabilitation and those of randomly sampled patients completing only 1 course of PR.

Identification of a positively charged platform in Staphylococcus aureus HtsA that is essential for ferric staphyloferrin A transport.

In response to iron starvation, Staphylococcus aureus secretes both staphyloferrin A and staphyloferrin B, which are high-affinity iron-chelating molecules. The structures of both HtsA and SirA, the ferric-staphyloferrin A [Fe(III)-SA] and ferric-staphyloferrin B [Fe(III)-SB] receptors, respectively, have recently been determined. The structure of HtsA identifies a novel form of ligand entrapment composed of many positively charged residues.

TCA cycle activity in Staphylococcus aureus is essential for iron-regulated synthesis of staphyloferrin A, but not staphyloferrin B: the benefit of a second citrate synthase.

Staphylococcus aureus elaborates two citrate-containing siderophores, staphyloferrin A (SA) and staphyloferrin B (SB), that enhance growth under iron-restriction, yet, paradoxically, expression of the TCA cycle citrate synthase, CitZ, is downregulated during iron starvation. Iron starvation does, however, result in expression of SbnG, recently identified as a novel citrate synthase that is encoded from within the iron-regulated SB biosynthetic locus, suggesting an important role for SbnG in staphyloferrin production. We demonstrate that during growth of S.

Comprehensive pulmonary rehabilitation results in clinically meaningful improvements in anxiety and depression in patients with chronic obstructive pulmonary disease.

Purpose: Pulmonary rehabilitation (PR) improves anxiety and depression in patients with chronic obstructive pulmonary disease. However, little is known regarding its ability to produce clinically meaningful improvements in these outcomes.

Methods: We retrospectively analyzed 366 patients who participated in our 8-week outpatient PR program.