Staphylococcus epidermidis: metabolic adaptation and biofilm formation in response to different oxygen concentrations

Abstract

Staphylococcus epidermidis has become a major health hazard. It is necessary to study its metabolism and hopefully uncover therapeutic targets. Cultivating S. epidermidis at increasing oxygen concentration [O2] enhanced growth, while inhibiting biofilm formation. Respiratory oxidoreductases were differentially expressed, probably to prevent reactive oxygen species formation. Under aerobiosis, S. epidermidis expressed high oxidoreductase activities, including glycerol-3-phosphate dehydrogenase, pyruvate dehydrogenase, ethanol dehydrogenase and succinate dehydrogenase, as well as cytochromes bo and aa3; while little tendency to form biofilms was observed. Under microaerobiosis, pyruvate dehydrogenase and ethanol dehydrogenase decreased while glycerol-3-phosphate dehydrogenase and succinate dehydrogenase nearly disappeared; cytochrome bo was present; anaerobic nitrate reductase activity was observed; biofilm formation increased slightly. Under anaerobiosis, biofilms grew; low ethanol dehydrogenase, pyruvate dehydrogenase and cytochrome bo were still present; nitrate dehydrogenase was the main terminal electron acceptor. KCN inhibited the aerobic respiratory chain and increased biofilm formation. In contrast, methylamine inhibited both nitrate reductase and biofilm formation. The correlation between the expression and/or activity or redox enzymes and biofilm-formation activities suggests that these are possible therapeutic targets to erradicate S. epidermidis.

Metabolism, ATP production and biofilm generation by Staphylococcus epidermidis in either respiratory or fermentative conditions

“…1). As expected from previous respiratory chain protein expression results (Uribe-Alvarez et al 2016), the ability of cells to consume oxygen was proportional to [O 2 ] in the growth medium. In aerobic conditions and in the presence of lactate the rate of oxygen consumption was 70 natgO (mg prot.…”

“…Biofilm generation was measured in sterile Costar 96-well polystyrene plates as previously reported (Calà et al 2015;Uribe-Alvarez et al 2016). Briefly, in each well, 0.4% crystal violet in 33% glacial acetic acid was mixed with the indicated, inhibitors sodium cyanide (NaCN) (100 µM), butane-1,4-bisphosphate (B1,4BP) (1 mM) or, carbonyl cyanide m-chlorophenyl hydrazone (CCCP) (0.1, 0.5, or 1 µM, as indicated).…”

“…Inside the body, this bacterium has to face attack from the immune system, high [O 2 ] (Fang et al 2016) and antibiotics (Leid 2009), most likely triggering a stress response. Within the organism, S. epidermidis may find areas with low [O 2 ], similar to its natural habitat; it is likely that the bacterium will make an effort to remain in the hypoxic area, adhering to the surface and organizing into biofilms (Lewis 2007;Uribe-Alvarez et al 2016). In regard to hypoxic environments within the host, these are often found at or near artificial devices such as catheters or prosthetic valves, where biofilms may force removal of implanted devices (Fey and Olson 2010;Büttner et al 2015).…”

Dissemination and loss of a biofilm‐related genomic island in marine Pseudoalteromonas mediated by integrative and conjugative elements

“…This evidence included the following findings: (i) the deletion of GI prfC greatly impaired the ability of 11900 to form robust pellicle-type or attached biofilms; (ii) the displacement of GI prfC by the ICE also resulted in the reduced ability of 11900 to form robust pellicle-type or attached biofilms and (iii) the expression of oxidoreductase genes and the thioesterase gene in 11900 was significantly induced during pellicle formation. It has been reported that oxidoreductase genes affect biofilm formation of Staphylococcus epidermidis and Streptomyces gandocaensis via the respiratory chain or compound synthesis (Park et al, 2016;Uribe-Alvarez et al, 2016). The role and regulation of the oxidoreductase genes and the thioesterase gene in GI prfC during biofilm formation of 11900 require further investigation.…”

Wolbachia pipientis grows in Saccharomyces cerevisiae evoking early death of the host and deregulation of mitochondrial metabolism

“…Gels were run for about an hour at 15 mA/gel in a Bio‐rad electrophoresis chamber. In‐gel NADH‐NBT oxido‐reductase (100 μg protein), succinate‐NBT oxido‐reductase (150 μg protein), cytochrome c oxidase (100 μg protein), and in‐gel ATPase (100 μg protein) activities were done as reported previously (Uribe‐Alvarez et al., ). 20 μg protein of solubilized Bovine Heart Mitochondria (BHM) were loaded in each gel as controls.…”