Variation in the expression of cell envelope proteins of coagulase-negative staphylococci cultured under iron-restricted conditions in human peritoneal dialysate

Wilcox, Mark H.; Williams, Paul; Smith, David George Emslie; Modun, Belinda; Finch, Roger; Denyer, Stephen Paul

doi:10.1099/00221287-137-11-2561

Cited by 29 publications

(40 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…B. subtilis also has three Fur homologues, involved in the regulation of iron (Fur) (4), peroxide stress response (PerR) (4), and zinc uptake (Zur) (10). It is possible that, in addition to Fur, staphylococci have another ferric-iron repressor, SirR (15), which is a homologue of the ferric-iron repressor DtxR (32).Our previous studies identified a number of iron-regulated S. aureus and S. epidermidis proteins, which are expressed in vivo both during human infection (30,35) and in an experimental animal model (23,25). To date, only two of these proteins have been characterized.…”

mentioning

confidence: 99%

Molecular Cloning and Analysis of a Putative Siderophore ABC Transporter from Staphylococcus aureus

2000

View full text Add to dashboard Cite

From a mass-excised Staphylococcus aureus ZapII expression library, we cloned an operon encoding a novel ABC transporter with significant homology to bacterial siderophore transporter systems. The operon encodes four genes designated sstA, -B, -C, and -D encoding two putative cytoplasmic membrane proteins (sstA and sstB), an ATPase (sstC), and a membrane-bound 38-kDa lipoprotein (sstD). The sst operon is preceded by two putative Fur boxes, which indicated that expression of the sst operon was likely to be iron dependent. SstD was overexpressed in Escherichia coli, purified by Triton X-114 phase partitioning, and used to generate monospecific antisera in rats. Immunoblotting studies located SstD in the membrane fraction of S. aureus and showed that expression of the lipoprotein was reduced under iron-rich growth conditions. Triton X-114 partitioning studies on isolated membranes provided additional biochemical evidence that SstD in S. aureus is a lipoprotein. Immunoreactive polypeptides of approximately 38 kDa were detected in a wide range of staphylococcal species, but no antigenic homolog was detected in Bacillus subtilis. Expression of SstD in vivo was confirmed by immunoblotting studies with S. aureus recovered from a rat intraperitoneal chamber implant model. To further define the contribution of SstD in promoting growth of S. aureus in vitro and in vivo, we used antisense RNA technology to modulate expression of SstD. Expression of antisense sstD RNA in S. aureus resulted in a decrease in SstD expression under both iron-rich and iron-restricted growth conditions. However, this reduction in SstD levels did not affect the growth of S. aureus in vitro in an iron-limited growth medium or when grown in an intraperitoneal rat chamber implant model in vivo.Acquisition of nutrients, such as iron, for growth in the host environment is essential for bacterial pathogens to establish an infection. An effective mechanism for scavenging iron involves the production and secretion of low-molecular-weight ferriciron chelators, siderophores, which scavenge iron from the host and transport it into the cell via specific ABC transporters (27). In comparison to the wealth of information available concerning gram-negative siderophore transport (11, 26), very little is known about ferric-siderophore uptake in staphylococci. It has been demonstrated that Staphylococcus aureus produces at least three siderophores, staphyloferrins A (22) and B (8, 12) and aureochelin (7), and it also utilizes a range of exogenous siderophores, such as the enterobacterial siderophore enterobactin (21). However, to date there are no published reports on staphylococcal genes coding for siderophore biosynthesis and very little is known about siderophore uptake. Three iron-regulated staphylococcal ABC transporters have been identified, but these have only been partially characterized, and in each case the transported solute has not been identified. In S. aureus, the sirABC operon has homology to gram-negative siderophore transporters, in particular, the c...

show abstract

mentioning

confidence: 99%

Molecular Cloning and Analysis of a Putative Siderophore ABC Transporter from Staphylococcus aureus

2000

View full text Add to dashboard Cite

show abstract

“…The expression of ironrepressible OMPs by coagulase-negative staphylococci grown in vitro in pooled human peritoneal dialysate closely resembled that observed in bacteria recovered from peritoneal chamber implants in an animal model [20][21][22]. Also, parent and mutant staphylococcal strains, which were found to differ markedly in their abilities to accumulate on surfaces when examined in vitro in conventional complex growth media, were indistinguishable in repeat experiments using pooled human serum.…”

Section: Discussionmentioning

confidence: 54%

“…The whole cell protein profiles of PIF grown bacteria indicated grossly reduced expression of proteins compared with broth cultured cells. Such protein repression has been noted after bacterial culture in other human body fluids and is believed to reflect nutrient limitation [20,21,24]. Several novel proteins were expressed in bacteria cultured in PIF; for example, protein bands of 24 kDa and 36 kDa were seen in the OMP profiles ofA.…”

Section: Discussionmentioning

confidence: 90%

“…2a, lanes F and G). OMPs have been described in both Gram-positive and Gram-negative bacteria which are produced in response to specific nutrient limitations, such as iron for example [20,21,24]. Also, it was apparent that ileostomy fluid-derived proteins, of approximate molecular weights 12 kDa and 33 kDa, bound to the bacteria during incubation.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Toxin production, adherence and protein expression by clinicalAeromonasspp. isolates in broth and human pooled ileostomy fluid

et al. 1994

Self Cite

View full text Add to dashboard Cite

SUMMARYThe physiological behaviour of clinical Aeromonas spp. isolates was compared following culture in a conventional broth and human pooled ileostomy fluid (PIF). Protein expression was markedly affected by the growth medium, with an overall reduction in whole cell proteins in bacteria grown in ileostomy fluid. In addition, novel outer membrane proteins were produced in PIF but not in broth. The majority of A. hydrophila and A. sobria isolates produced toxin in both broth and PIF, whereas no cytotoxin positive A. caviae were found. Toxin titres were at least two doubling dilutions higher in 40% and 21 % of A. hydrophila and A. sobria isolates, respectively, following culture in brain heart infusion broth compared with PIF. Bacterial adherence to Vero and A-549 cells was significantly more common in A. hydrophila (53 %) and A. sobria (64%) than in A. caviae (15%) (P < 001). We observed increased adherence by 6 aeromonas strains previously classified as adherence-positive, but not by 6 non-adherers, in PIF compared with brain heart infusion broth. The influence of growth medium on the expression of potential virulence determinants by Aeromonas spp. provides a rationale for the use of human ileostomy fluid in future in vitro studies, in order to simulate the nutrient conditions found in vivo.

show abstract

“…Most bacteria respond to the environmental cue of restricted iron availability by derepressing siderophone-mediated iron transport systems (11). Previously, other researchers (4,5,12,13) have shown that growth of staphylococci in HPD resulted in the induction of two immunodominant, iron-regulated cytoplasmic membrane proteins. These iron-regulated proteins were thought to be putative siderophore receptors and also expressed by S. epidermidis grown in vitro in iron-restricted nutrient broth, and in vivo in a chamber implanted intraperitoneally in rats.…”

Section: Discussionmentioning

confidence: 99%

Growth and Siderophore Production of Staphylococci in Human Peritoneal Dialysate

et al. 2003

View full text Add to dashboard Cite

Although activity of iron uptake system (IUS) was thought to play an important role in staphylococcal growth in human peritoneal dialysate (HPD) solution, siderophore production, one of the well-known IUS, was not yet detected directly in HPD solution. Therefore, we tried to detect siderophore production directly in HPD solution by using a newly developed chrome azurol S (CAS) agar diffusion assay and to investigate the effect of IUS activity on bacterial growth in HPD solution. According to the susceptibility test for streptonigrin and the productivity of siderophore in the iron-deficient (ID) medium, Staphylococcus aureus ATCC 6538 strain and Staphylococcus epidermidis clinical isolate had higher IUS activity and grew better than S. aureus ATCC 25923 strain in the ID medium. These bacteria did not grow and produce siderophore in the unused chronic ambulatory peritoneal dialysis solution. However, these bacteria grew and produced siderophore in the HPD solution. Moreover, S. aureus ATCC 25923 strain with lower activity of IUS grew poorly and produced smaller amount of siderophore in HPD compared to S. aureus ATCC 6538 strain and S. epidermidis clinical isolate with higher activity of IUS like in the ID medium. To the best of our knowledge, this is the first report that siderophore production is directly detected in the HPD by CAS agar diffusion assay. These results indicated that activity of IUS plays an important role in bacterial growth in the HPD solution and pathogenesis of continuous ambulatory peritoneal dialysis peritonitis.

show abstract

Variation in the expression of cell envelope proteins of coagulase-negative staphylococci cultured under iron-restricted conditions in human peritoneal dialysate

Cited by 29 publications

References 33 publications

Molecular Cloning and Analysis of a Putative Siderophore ABC Transporter from Staphylococcus aureus

Molecular Cloning and Analysis of a Putative Siderophore ABC Transporter from Staphylococcus aureus

Toxin production, adherence and protein expression by clinicalAeromonasspp. isolates in broth and human pooled ileostomy fluid

Growth and Siderophore Production of Staphylococci in Human Peritoneal Dialysate

Contact Info

Product

Resources

About