Staphylococcus epidermidis is an opportunistic bacterium whose infections often involve the formation of a biofilm on implanted biomaterials. In S. epidermidis, the exopolysaccharide facilitating bacterial adherence in a biofilm is polysaccharide intercellular adhesin (PIA), whose synthesis requires the enzymes encoded within the intercellular adhesin operon (icaADBC). In vitro, the formation o...

The tricarboxylic acid (TCA) cycle, a crucial component of respiratory metabolism, is composed of a set of eight enzymes present in the mitochondrial matrix. However, most of the TCA cycle enzymes are encoded in the nucleus in higher eukaryotes. In addition, evidence has accumulated demonstrating that nuclear genes were acquired from the mitochondrial genome during the course of evolution. For ...

The cell cycle is a highly regulated process that enables the accurate transmission of chromosomes to daughter cells. Here we uncover a previously unknown link between the tricarboxylic acid (TCA) cycle and cell cycle progression in the Caenorhabditis elegans early embryo. We found that down-regulation of TCA cycle components, including citrate synthase, malate dehydrogenase, and aconitase, res...

UNLABELLED A recent controversial hypothesis suggested that the bactericidal action of antibiotics is due to the generation of endogenous reactive oxygen species (ROS), a process requiring the citric acid cycle (tricarboxylic acid [TCA] cycle). To test this hypothesis, we assessed the ability of oxacillin to induce ROS production and cell death in Staphylococcus epidermidis strain 1457 and an i...

Although the tricarboxylic acid (TCA) cycle is the prime means of carbon metabolism for energy generation in normal myocardium, the noninvasive quantification of TCA cycle flux in intact cardiac tissues is difficult. A novel approach for estimating citric acid cycle flux using 13C nuclear magnetic resonance (NMR) is presented and evaluated experimentally by comparison with measured myocardial o...

Staphylococcus epidermidis is a skin-resident bacterium and a major cause of biomaterial-associated infections. The transition from residing on the skin to residing on an implanted biomaterial is accompanied by regulatory changes that facilitate bacterial survival in the new environment. These regulatory changes are dependent upon the ability of bacteria to "sense" environmental changes. In S. ...

BACKGROUND Although myocardial oxidative tricarboxylic acid (TCA) cycle activity and contractile function are closely linked in normal cardiac muscle, their relation during postischemic reperfusion, when contractility often is reduced, is not well defined. METHODS AND RESULTS To test the hypothesis that oxidative TCA cycle flux is reduced in reperfused myocardium with persistent contractile d...

We examined the relationship between tricarboxylic acid (TCA) cycle intermediate (TCAI) pool size, TCA cycle flux (calculated from leg O2uptake), and pyruvate dehydrogenase activity (PDHa) in human skeletal muscle. Six males performed moderate leg extensor exercise for 10 min, followed immediately by intense exercise until exhaustion (3.8 ± 0.5 min). The sum of seven measured TCAI (ΣTCAI) incre...

Liver-specific phosphoenolpyruvate carboxykinase (PEPCK) null mice, when fasted, maintain normal whole body glucose kinetics but develop dramatic hepatic steatosis. To identify the abnormalities of hepatic energy generation that lead to steatosis during fasting, we studied metabolic fluxes in livers lacking hepatic cytosolic PEPCK by NMR using 2H and 13C tracers. After a 4-h fast, glucose produ...