P614 Slime production in blood isolates of Staphylococcus aureus under various growth conditions

2007 ◽  
Vol 29 ◽  
pp. S143
Author(s):  
O. Aslan ◽  
B. Aksu ◽  
F. Babacan
Keyword(s):  
Staphylococcus Aureus ◽  
Growth Conditions ◽  
Slime Production

scholarly journals Anaerobic Conditions Induce Expression of Polysaccharide Intercellular Adhesin in Staphylococcus aureus and Staphylococcus epidermidis

2001 ◽  
Vol 69 (6) ◽  
pp. 4079-4085 ◽  
Author(s):  
Sarah E. Cramton ◽  
Martina Ulrich ◽  
Friedrich Götz ◽  
Gerd Döring
Keyword(s):  
Staphylococcus Aureus ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Extracellular Polysaccharide ◽  
Growth Conditions ◽  
Anaerobic Conditions ◽  
Anaerobic Environment ◽  
Specific Mrna

ABSTRACT Products of the intercellular adhesion (ica) operon in Staphylococcus aureus and Staphylococcus epidermidis synthesize a linear β-1,6-linked glucosaminylglycan. This extracellular polysaccharide mediates bacterial cell-cell adhesion and is required for biofilm formation, which is thought to increase the virulence of both pathogens in association with prosthetic biomedical implants. The environmental signal(s) that triggers ica gene product and polysaccharide expression is unknown. Here we demonstrate that anaerobic in vitro growth conditions lead to increased polysaccharide expression in both S. aureus and S. epidermidis, although the regulation is less stringent inS. epidermidis. Anaerobiosis also dramatically stimulates ica-specific mRNA expression inica- and polysaccharide-positive strains of both S. aureus and S. epidermidis.These data suggest a mechanism whereby ica gene expression and polysaccharide production may act as a virulence factor in an anaerobic environment in vivo.

scholarly journals Within-Host Adaptation of Staphylococcus aureus in a Bovine Mastitis Infection Is Associated with Increased Cytotoxicity

2021 ◽  
Vol 22 (16) ◽  
pp. 8840
Author(s):  
Katharina Mayer ◽  
Martin Kucklick ◽  
Helene Marbach ◽  
Monika Ehling-Schulz ◽  
Susanne Engelmann ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Bovine Mastitis ◽  
Adaptive Strategy ◽  
Subclinical Mastitis ◽  
Growth Conditions ◽  
Typical Feature ◽  
Host Adaptation ◽  
Bovine Mammary Epithelial Cells ◽  
Strain Pair

Within-host adaptation is a typical feature of chronic, persistent Staphylococcus aureus infections. Research projects addressing adaptive changes due to bacterial in-host evolution increase our understanding of the pathogen’s strategies to survive and persist for a long time in various hosts such as human and bovine. In this study, we investigated the adaptive processes of S. aureus during chronic, persistent bovine mastitis using a previously isolated isogenic strain pair from a dairy cow with chronic, subclinical mastitis, in which the last variant (host-adapted, Sigma factor SigB-deficient) quickly replaced the initial, dominant variant. The strain pair was cultivated under specific in vitro infection-relevant growth-limiting conditions (iron-depleted RPMI under oxygen limitation). We used a combinatory approach of surfaceomics, molecular spectroscopic fingerprinting and in vitro phenotypic assays. Cellular cytotoxicity assays using red blood cells and bovine mammary epithelial cells (MAC-T) revealed changes towards a more cytotoxic phenotype in the host-adapted isolate with an increased alpha-hemolysin (α-toxin) secretion, suggesting an improved capacity to penetrate and disseminate the udder tissue. Our results foster the hypothesis that within-host evolved SigB-deficiency favours extracellular persistence in S. aureus infections. Here, we provide new insights into one possible adaptive strategy employed by S. aureus during chronic, bovine mastitis, and we emphasise the need to analyse genotype–phenotype associations under different infection-relevant growth conditions.

Growth conditions required for bacteriocin production by strains of Staphylococcus aureus

2004 ◽  
Vol 20 (9) ◽  
pp. 941-947 ◽  
Author(s):  
Jana�na dos Santos Nascimento ◽  
Jana�na Abrantes ◽  
Marcia Giambiagi-deMarval ◽  
Maria do Carmo de Freire Bastos
Keyword(s):  
Staphylococcus Aureus ◽  
Growth Conditions ◽  
Bacteriocin Production

scholarly journals Proteomic and Membrane Lipid Correlates of Re-duced Host Defense Peptide Susceptibility in a snoD Mutant of Staphylococcus aureus

Antibiotics ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 169
Author(s):  
Christian Kohler ◽  
Richard Proctor ◽  
Arnold Bayer ◽  
Michael Yeaman ◽  
Michael Lalk ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Compositional Data ◽  
Insertion Site ◽  
Growth Conditions ◽  
Membrane Lipid ◽  
Anaerobic Growth ◽  
Short Chain ◽  
Aureus Strain ◽  
Branched Chain ◽  
The Impact

We previously described a transposon mutant in Staphylococcus aureus strain SH1000 that exhibited reduced susceptibility to cationic thrombin-induced platelet microbicidal proteins (tPMPs). The transposon insertion site was mapped to the gene snoD, the staphylococcal nuo orthologue. Hence, further studies have been performed to understand how this mutation impacts susceptibility to tPMP, by comparing proteomics profiling and membrane lipid analyses of the parent vs. mutant strains. Surprisingly, the mutant showed differential regulation of only a single protein when cultivated aerobically (FadB), and only a small number of proteins under anaerobic growth conditions (AdhE, DapE, Ddh, Ald1, IlvA1, AgrA, Rot, SA2366, and SA2367). Corresponding to FadB impact on lipid remodeling, membrane fatty acid analyses showed that the snoD mutant contained more short chain anteiso-, but fewer short chain iso-branched chain fatty acids under both aerobic and anaerobic conditions vs. the parental strain. Based upon these proteomic and membrane compositional data, a hypothetical “network” model was developed to explain the impact of the snoD mutation upon tPMP susceptibility.

Validation of Predictive Mathematical Models Describing Growth of Staphylococcus aureus

1996 ◽  
Vol 59 (1) ◽  
pp. 11-15 ◽  
Author(s):  
ISABEL WALLS ◽  
VIRGINIA N. SCOTT ◽  
DANE T. BERNARD
Keyword(s):  
Staphylococcus Aureus ◽  
Mathematical Models ◽  
Growth Kinetics ◽  
Growth Rates ◽  
Close Agreement ◽  
Growth Conditions ◽  
Lag Phase ◽  
Growth Data ◽  
Gompertz Equation ◽  
Ph Range

An investigation was performed on the growth of Staphylococcus aureus in a commercially available, sterile, homogeneous food at 12°C with 1.2 and 5.9% NaCl; at 25°C with 10.4% NaCl; and at 20 and 35°C with 1.2, 5.3, 12.5, and 15.8% NaCl; over a pH range of 5.5 to 7.5. Growth data were fitted to the Gompertz equation and the resulting growth kinetics were compared with predictions from the Pathogen Modeling Program (PMP) and Food MicroModel (FMM). For the PMP, predicted lag-phase durations varied from 0.5 to 130 h longer than the observed values. In general, close agreement with growth rates was obtained but there was a 10-fold difference in one case. For FMM, predicted lag-phase durations ranged from 27 h shorter to 47 h longer than the observed values. Again, close agreement with growth rates was obtained, but in one case a fivefold difference was observed. In general, for the sterile foods used under the growth conditions tested, the models underestimated the growth of S. aureus. This implies that while the models can be used as a guide to indicate growth rates in foods they should not be relied upon as the sole determinant of the product's safety.

scholarly journals The Posttranslocational Chaperone Lipoprotein PrsA Is Involved in both Glycopeptide and Oxacillin Resistance in Staphylococcus aureus

2012 ◽  
Vol 56 (7) ◽  
pp. 3629-3640 ◽  
Author(s):  
Ambre Jousselin ◽  
Adriana Renzoni ◽  
Diego O. Andrey ◽  
Antoinette Monod ◽  
Daniel P. Lew ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Wall Stress ◽  
Growth Conditions ◽  
Transcriptional Analysis ◽  
Pharmacological Intervention ◽  
Content Type ◽  
Cell Wall Stress ◽  
Oxacillin Resistance ◽  
Mrsa Strains

ABSTRACTUnderstanding in detail the factors which permitStaphylococcus aureusto counteract cell wall-active antibiotics is a prerequisite to elaborating effective strategies to prolong the usefulness of these drugs and define new targets for pharmacological intervention. Methicillin-resistantS. aureus(MRSA) strains are major pathogens of hospital-acquired and community-acquired infections and are most often treated with glycopeptides (vancomycin and teicoplanin) because of their resistance to most penicillins and a limited arsenal of clinically proven alternatives. In this study, we examined PrsA, a lipid-anchored protein of the parvulin PPIase family (peptidyl-prolylcis/transisomerase) found ubiquitously in all Gram-positive species, in which it assists posttranslocational folding at the outer surface of the cytoplasmic membrane. We show by both genetic and biochemical assays thatprsAis directly regulated by the VraRS two-component sentinel system of cell wall stress. Disruption ofprsAis tolerated byS. aureus, and its loss results in no detectable overt macroscopic changes in cell wall architecture or growth rate under nonstressed growth conditions. Disruption ofprsAleads, however, to notable alterations in the sensitivity to glycopeptides and dramatically decreases the resistance of COL (MRSA) to oxacillin. Quantitative transcriptional analysis reveals thatprsAandvraRare coordinately upregulated in a panel of stable laboratory and clinical glycopeptide-intermediateS. aureus(GISA) strains compared to their susceptible parents. Collectively, our results point to a role forprsAas a facultative facilitator of protein secretion or extracellular folding and provide a framework for understanding whyprsAis a key element of the VraRS-mediated cell wall stress response.

scholarly journals Copper Stress Induces a Global Stress Response in Staphylococcus aureus and Represses sae and agr Expression and Biofilm Formation

2009 ◽  
Vol 76 (1) ◽  
pp. 150-160 ◽  
Author(s):  
Jonathan Baker ◽  
Sutthirat Sitthisak ◽  
Mrittika Sengupta ◽  
Miranda Johnson ◽  
R. K. Jayaswal ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Transcriptional Profiling ◽  
Resistance Mechanism ◽  
Growth Conditions ◽  
Copper Resistance ◽  
Transcriptional Analysis ◽  
Copper Stress ◽  
High Copper

ABSTRACT Copper is an important cofactor for many enzymes; however, high levels of copper are toxic. Therefore, bacteria must ensure there is sufficient copper for use as a cofactor but, more importantly, must limit free intracellular levels to prevent toxicity. In this study, we have used DNA microarray to identify Staphylococcus aureus copper-responsive genes. Transcriptional profiling of S. aureus SH1000 grown in excess copper identified a number of genes which fall into four groups, suggesting that S. aureus has four main mechanisms for adapting to high levels of environmental copper, as follows: (i) induction of direct copper homeostasis mechanisms; (ii) increased oxidative stress resistance; (iii) expression of the misfolded protein response; and (iv) repression of a number of transporters and global regulators such as Agr and Sae. Our experimental data confirm that resistance to oxidative stress and particularly to H2O2 scavenging is an important S. aureus copper resistance mechanism. Our previous studies have demonstrated that Eap and Emp proteins, which are positively regulated by Agr and Sae, are required for biofilm formation under low-iron growth conditions. Our transcriptional analysis has confirmed that sae, agr, and eap are repressed under high-copper conditions and that biofilm formation is indeed repressed under high-copper conditions. Therefore, our results may provide an explanation for how copper films can prevent biofilm formation on catheters.

scholarly journals Phase variation of slime production in Staphylococcus aureus: implications in colonization and virulence.

1993 ◽  
Vol 61 (11) ◽  
pp. 4857-4862 ◽  
Author(s):  
R Baselga ◽  
I Albizu ◽  
M De La Cruz ◽  
E Del Cacho ◽  
M Barberan ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Phase Variation ◽  
Slime Production
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