scholarly journals Staphylococcus epidermidismetabolic adaptation and biofilm formation in response to varying oxygen

2019 ◽  
Author(s):  
Ulrik H. Pedroza-Dávila ◽  
Cristina Uribe-Alvarez ◽  
Lilia Morales-García ◽  
Emilio Espinoza-Simón ◽  
Adriana Muhlia-Almazán ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Respiratory Activity ◽  
Health Hazard ◽  
High Oxygen ◽  
Host Cells ◽  
Metabolic Inhibitors ◽  
Low Oxygen ◽  
High Hydrogen ◽  
Oxygen Concentrations

ABSTRACTStaphylococcus epidermidisis a Gram-positive saprophytic bacterium found in the microaerobic/anaerobic layers of the skin. It becomes a health hazard when introduced across the skin by punctures or wounds.S. epidermidisforms biofilms in low O2environments. As oxygen concentrations ([O2]) decreased, the metabolism ofS. epidermidiswas modified ranging from fully aerobic to anaerobic. Respiratory activity increased at high [O2], while anaerobically grown cells exhibited the highest rate of fermentation. High aerobic metabolism coincided with high hydrogen peroxide-mediated damage. Remarkably, the rate of growth decreased at low [O2] even though the concentration of ATP was high. Under these conditions bacteria associated into biofilms. Then, in the presence of metabolic inhibitors, biofilm formation decreased. It is suggested that when [O2] is lowS. epidermidisaccumulates ATP in order to synthesize the proteins and polysaccharides needed to attach to surfaces and form biofilms.ImportanceBacteria and humans coexist, establishing all kinds of relationships that may change from saprophytic to infectious as environmental conditions vary. S. epidermidis is saprophytic when living in the skin. Inside the organism it evokes a pathologic reaction and is thus rejected by the organism. Additionally it is forced to adapt to high oxygen concentrations, becoming vulnerable to reactive oxygen species, which may come from leukocyte attack. Avoiding both, high oxygen and leukocytes is a must for bacteria. Escaping from oxygen involves a clever response: whenever it finds a low oxygen environment it attaches to surfaces, associating into biofilms. Biofilms protectS. epidermidisagainst host cells. Understanding these responses is a must in order to develop treatments and prevent infection success.

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

2020 ◽  
Author(s):  
Ulrik Pedroza-Davila ◽  
Cristina Uribe-Alvarez ◽  
Lilia Morales-Garcia ◽  
Emilio Espinosa-Simon ◽  
Ofelia Méndez-Romero ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Health Hazard ◽  
Metabolic Inhibitors ◽  
High Concentration ◽  
Atp Production ◽  
Aerobic Activity ◽  
Hypoxic Conditions ◽  
Effect Of Oxygen

Abstract Staphylococcus epidermidis is a Gram-positive saprophytic bacterium found in the microaerobic/anaerobic layers of the skin that becomes a health hazard when it is carried across the skin through punctures or wounds. Pathogenicity is enhanced by the ability of S. epidermidis to associate into biofilms, where it avoids attacks by the organism and antibiotics . To test the effect of oxygen on metabolism and biofilm generation, cells were cultured at different oxygen concentrations ([O2 ]). As [O2 ] decreased, S. epidermidis metabolism went from respiratory to fermentative. Remarkably, the rate of growth decreased at low [O 2 ] while a high concentration of ATP ([ATP]) was kept. Under hypoxic conditions bacteria associated into biofilms. Aerobic activity sensitized the cell to hydrogen peroxide-mediated damage. In the presence of metabolic inhibitors, biofilm formation decreased. It is suggested that at low [O2 ] S. epidermidis limits its growth and develops the ability to form biofilms.

scholarly journals Metabolic Signatures of Cryptosporidium parvum-Infected HCT-8 Cells and Impact of Selected Metabolic Inhibitors on C. parvum Infection under Physioxia and Hyperoxia

Biology ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 60
Author(s):  
Juan Vélez ◽  
Zahady Velasquez ◽  
Liliana M. R. Silva ◽  
Ulrich Gärtner ◽  
Klaus Failing ◽  
...  
Keyword(s):  
Host Cell ◽  
Cryptosporidium Parvum ◽  
Cell Metabolism ◽  
Lactate Production ◽  
Glucose Consumption ◽  
Host Cells ◽  
Metabolic Inhibitors ◽  
Low Oxygen ◽  
Metabolic Signatures

Cryptosporidium parvum is an apicomplexan zoonotic parasite recognized as the second leading-cause of diarrhoea-induced mortality in children. In contrast to other apicomplexans, C.parvum has minimalistic metabolic capacities which are almost exclusively based on glycolysis. Consequently, C. parvum is highly dependent on its host cell metabolism. In vivo (within the intestine) infected epithelial host cells are typically exposed to low oxygen pressure (1–11% O2, termed physioxia). Here, we comparatively analyzed the metabolic signatures of C. parvum-infected HCT-8 cells cultured under both, hyperoxia (21% O2), representing the standard oxygen condition used in most experimental settings, and physioxia (5% O2), to be closer to the in vivo situation. The most pronounced effect of C. parvum infection on host cell metabolism was, on one side, an increase in glucose and glutamine uptake, and on the other side, an increase in lactate release. When cultured in a glutamine-deficient medium, C. parvum infection led to a massive increase in glucose consumption and lactate production. Together, these results point to the important role of both glycolysis and glutaminolysis during C. parvum intracellular replication. Referring to obtained metabolic signatures, we targeted glycolysis as well as glutaminolysis in C. parvum-infected host cells by using the inhibitors lonidamine [inhibitor of hexokinase, mitochondrial carrier protein (MCP) and monocarboxylate transporters (MCT) 1, 2, 4], galloflavin (lactate dehydrogenase inhibitor), syrosingopine (MCT1- and MCT4 inhibitor) and compound 968 (glutaminase inhibitor) under hyperoxic and physioxic conditions. In line with metabolic signatures, all inhibitors significantly reduced parasite replication under both oxygen conditions, thereby proving both energy-related metabolic pathways, glycolysis and glutaminolysis, but also lactate export mechanisms via MCTs as pivotal for C. parvum under in vivo physioxic conditions of mammals.

scholarly journals Accumulation-Associated Protein Enhances Staphylococcus epidermidis Biofilm Formation under Dynamic Conditions and Is Required for Infection in a Rat Catheter Model

2014 ◽  
Vol 83 (1) ◽  
pp. 214-226 ◽  
Author(s):  
Carolyn R. Schaeffer ◽  
Keith M. Woods ◽  
G. Matt Longo ◽  
Megan R. Kiedrowski ◽  
Alexandra E. Paharik ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Host Cells ◽  
Content Type ◽  
Microtiter Plates ◽  
Allelic Replacement ◽  
Abiotic Surfaces ◽  
Cell Accumulation ◽  
Accumulation Associated Protein

Biofilm formation is the primary virulence factor ofStaphylococcus epidermidis.S. epidermidisbiofilms preferentially form on abiotic surfaces and may contain multiple matrix components, including proteins such as accumulation-associated protein (Aap). Following proteolytic cleavage of the A domain, which has been shown to enhance binding to host cells, B domain homotypic interactions support cell accumulation and biofilm formation. To further define the contribution of Aap to biofilm formation and infection, we constructed anaapallelic replacement mutant and anicaADBC aapdouble mutant. When subjected to fluid shear, strains deficient in Aap production produced significantly less biofilm than Aap-positive strains. To examine thein vivorelevance of our findings, we modified our previously described rat jugular catheter model and validated the importance of immunosuppression and the presence of a foreign body to the establishment of infection. The use of our allelic replacement mutants in the model revealed a significant decrease in bacterial recovery from the catheter and the blood in the absence of Aap, regardless of the production of polysaccharide intercellular adhesin (PIA), a well-characterized, robust matrix molecule. Complementation of theaapmutant with full-length Aap (containing the A domain), but not the B domain alone, increased initial attachment to microtiter plates, as did intransexpression of the A domain in adhesion-deficientStaphylococcus carnosus. These results demonstrate Aap contributes toS. epidermidisinfection, which may in part be due to A domain-mediated attachment to abiotic surfaces.

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

2015 ◽  
Vol 74 (1) ◽  
pp. ftv111 ◽  
Author(s):  
Cristina Uribe-Alvarez ◽  
Natalia Chiquete-Félix ◽  
Martha Contreras-Zentella ◽  
Sergio Guerrero-Castillo ◽  
Antonio Peña ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Metabolic Adaptation ◽  
Oxygen Concentrations

scholarly journals Shifts in microbial transcription patterns prior to onset of Necrotizing enterocolitis may indicate low oxygen levels in the gut

2018 ◽  
Author(s):  
Yonatan Sher ◽  
Matthew R. Olm ◽  
Tali Raveh-Sadka ◽  
Christopher Brown ◽  
Ruth Sher ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Necrotizing Enterocolitis ◽  
Premature Infants ◽  
Oxygen Affinity ◽  
High Oxygen ◽  
Host Cells ◽  
Multiple Time ◽  
List Type ◽  
Low Oxygen ◽  
High Oxygen Affinity

SummaryPremature infants are at risk for developing necrotizing enterocolitis (NEC), an inflammatory disease that can progress to necrosis of gut tissue. Previous attempts have failed to identify any consistent predictor of NEC. We hypothesized that prior to the appearance of NEC symptoms, the gut microbiome shifts in its transcriptional profile. To test this hypothesis we integrated genome-resolved metagenomic and metatranscriptomic data from multiple time-points in the first month of life of four preterm infants, two of whom later developed NEC. Gut microbiomes of NEC infants showed increased transcription of high oxygen affinity cytochrome oxidases and lower transcription of genes to detoxify nitric oxide, an antimicrobial compound released by host cells. These results, and high transcription of H2 production genes, suggest low O2 conditions prior to NEC onset, and are consistent with hypoxic conditions in diseased gut tissue. The findings motivate further testing of transcript data as a predictor of NEC.HighlightsTranscription of high oxygen affinity microbial cytochrome oxidase may predict necrotizing enterocolitis (NEC) development.Lower transcription of microbial genes to detoxify nitric oxide (NO) may also predict NEC development.Higher transcription of H2 production genes by Escherichia sp. was found in the gut of premature infants that develop NEC.

scholarly journals Peri-Implant Tissue Is an Important Niche for Staphylococcus epidermidis in Experimental Biomaterial-Associated Infection in Mice

2006 ◽  
Vol 75 (3) ◽  
pp. 1129-1136 ◽  
Author(s):  
Corine A. N. Broekhuizen ◽  
Leonie de Boer ◽  
Kim Schipper ◽  
Christopher D. Jones ◽  
Shan Quadir ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Modern Medicine ◽  
Host Cells ◽  
Mouse Strains ◽  
Cell Layers ◽  
Tissue Interface ◽  
Higher Doses ◽  
Culture Positive ◽  
Culture Negative

ABSTRACT Biomaterial-associated infections (BAI), which are predominantly caused by Staphylococcus epidermidis, are a significant problem in modern medicine. Biofilm formation is considered the pivotal element in the pathogenesis, but in previous mouse studies we retrieved S. epidermidis from peri-implant tissue. To assess the kinetics and generality of tissue colonization, we investigated BAI using two S. epidermidis strains, two biomaterials, and two mouse strains. With small inocula all implants were culture negative, whereas surrounding tissues were positive. When higher doses were used, tissues were culture positive more often than implants, with higher numbers of CFU. This was true for the different biomaterials tested, for both S. epidermidis strains, at different times, and for both mouse strains. S. epidermidis colocalized with host cells at a distance that was >10 cell layers from the biomaterial-tissue interface. We concluded that in mouse experimental BAI S. epidermidis peri-implant tissue colonization is more important than biofilm formation.

Photolysis of Aqueous Solutions of 9,10-Anthraquinone-2-sulfonate. Part I. Dependence of Product Yields on Reaction Conditions

1972 ◽  
Vol 50 (3) ◽  
pp. 381-387 ◽  
Author(s):  
A. D. Broadbent ◽  
R. P. Newton
Keyword(s):  
Aqueous Solutions ◽  
High Oxygen ◽  
Low Oxygen ◽  
Reaction Conditions ◽  
Fenton's Reagent ◽  
Product Yields ◽  
Preferential Formation ◽  
Naoh Solution ◽  
Derivatives Of ◽  
Oxygen Concentrations

The products of the photolysis of neutral aqueous solutions of 9,10-anthraquinone-2-sulfonate or of the action of Fenton's reagent on this quinone have been identified as 1- and 2-hydroxy- and dihydroxy-9,10-anthraquinone sulfonates. High quinone and low oxygen concentrations favor production of monohydroxy-anthraquinone sulfonates, while low quinone and high oxygen concentrations result in preferential formation of dihydroxylated derivatives of the quinone. Photolysis in aqueous NaOH solution gives essentially only 2-hydroxy-9,10-anthraquinone sulfonates.

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