The Peptide Subunit Nα-(L-Alanyl-D-isoglutaminyl)-L-lysyl -D-alanine in Cell Wall Peptidoglycans of Staphylococcus aureus Strain Copenhagen, Micrococcus roseus R 27, and Sreptococcus pyogenes Group A, Type 14

Biochemistry ◽  
1966 ◽  
Vol 5 (12) ◽  
pp. 3748-3764 ◽  
Author(s):  
Emilio Munoz ◽  
Jean-Marie Ghuysen ◽  
Melina Leyh-Bouille ◽  
Jean-Francois Petit ◽  
Hans Heymann ◽  
...  
1963 ◽  
Vol 117 (6) ◽  
pp. 925-935 ◽  
Author(s):  
William G. Juergens ◽  
Arnold R. Sanderson ◽  
Jack L. Strominger

Antisera, prepared against formalin-killed cells of Staphylococcus aureus, strain Copenhagen, agglutinated the cell walls of this strain. The agglutination was inhibited by the teichoic acid from the cell wall of this strain, by any degradation product of this teichoic acid which contained the α-acetylglucosaminyl-ribitol unit, by α-phenyl-acetylglucosaminide, and by N-acetylglucosamine, but not by a large number of other haptens related to the cell wall. In quantitative experiments, however, only 40 to 50 per cent of antibody adsorption to cell wall could be inhibited by teichoic acid or by N-acetylglucosamine. The α-acetylglucosaminyl-ribitol unit in the teichoic acid is, therefore, an important immunological determinant in the cell wall of this strain, although other immunological specificities may also exist. The cell walls were also agglutinated by heterologous antisera prepared against streptococcal Group A carbohydrate or against horse serum azophenyl-ß-acetylglucosaminide. The heterologous agglutination, however, was specific for the ß-acetylglucosaminyl-ribitol units in the teichoic acid.


2016 ◽  
Vol 60 (6) ◽  
pp. 3455-3461 ◽  
Author(s):  
Xiaoyu Liu ◽  
Shijie Zhang ◽  
Baolin Sun

Increasing cases of infections caused by methicillin-resistantStaphylococcus aureus(MRSA) strains in healthy individuals have raised concerns worldwide. MRSA strains are resistant to almost the entire family of β-lactam antibiotics due to the acquisition of an extra penicillin-binding protein, PBP2a. Studies have shown thatspoVGis involved in oxacillin resistance, while the regulatory mechanism remains elusive. In this study, we have found that SpoVG plays a positive role in oxacillin resistance through promoting cell wall synthesis and inhibiting cell wall degradation in MRSA strain N315. Deletion ofspoVGin strain N315 led to a significant decrease in oxacillin resistance and a dramatic increase in Triton X-100-induced autolytic activity simultaneously. Real-time quantitative reverse transcription-PCR revealed that the expression of 8 genes related to cell wall metabolism or oxacillin resistance was altered in thespoVGmutant. Electrophoretic mobility shift assay indicated that SpoVG can directly bind to the putative promoter regions oflytN(murein hydrolase),femA, andlytSR(the two-component system). These findings suggest a molecular mechanism in which SpoVG modulates oxacillin resistance by regulating cell wall metabolism in MRSA.


Biochemistry ◽  
1965 ◽  
Vol 4 (10) ◽  
pp. 2245-2254 ◽  
Author(s):  
J. M. Ghuysen ◽  
D. J. Tipper ◽  
Claire H. Birge ◽  
J. L. Strominger

Biochemistry ◽  
1965 ◽  
Vol 4 (3) ◽  
pp. 474-485 ◽  
Author(s):  
Jean-Marie Ghuysen ◽  
Donald J. Tipper ◽  
Jack L. Strominger

2004 ◽  
Vol 72 (12) ◽  
pp. 7155-7163 ◽  
Author(s):  
Matthias Grundmeier ◽  
Muzaffar Hussain ◽  
Petra Becker ◽  
Christine Heilmann ◽  
Georg Peters ◽  
...  

ABSTRACT Staphylococcus aureus fibronectin-binding proteins (FnBPs) play a critical role in S. aureus pathogenesis. FnBPs mediate adhesion to fibronectin and invasion of mammalian cells, including epithelial, endothelial, and fibroblastic cells, by fibronectin bridging to the host cell fibronectin receptor integrin (α5)β1. Strain Newman is a laboratory strain frequently used for genetic, functional, and in vivo studies. However, despite pronounced production of FnBPs, strain Newman is only weakly adherent to immobilized Fn and weakly invasive. We examined whether these effects are due to a structural difference of FnBPs. Here, we show that both fnbA Newman and fnbB Newman contain a centrally located point mutation resulting in a stop codon. This leads to a truncation of both FnBPs at the end of the C domain at identical positions. Most likely, the stop codon occurred first in fnbB Newman and was subsequently transferred to fnbA Newman by replacement of the entire region encompassing the C, D, and W domains with the respective sequence of fnbB Newman. Using heterologous expression in Staphylococcus carnosus, we found that truncated FnBPs were completely secreted into the culture medium and not anchored to the cell wall, since they lack the sortase motif (LPETG). Consequently, this led to a loss of FnBP-dependent functions, such as strong adhesion to immobilized fibronectin, binding of fibrinogen, and host cell invasion. This mutation may explain some of the earlier reported conflicting data with strain Newman. Thus, care should be taken when drawing negative conclusions about the role of FnBPs as a virulence factor in a given model.


2014 ◽  
Vol 58 (9) ◽  
pp. 5024-5035 ◽  
Author(s):  
Michie Saito ◽  
Yuki Katayama ◽  
Tomomi Hishinuma ◽  
Akira Iwamoto ◽  
Yoshifumi Aiba ◽  
...  

ABSTRACTHeterogeneous vancomycin-intermediateStaphylococcus aureus(hVISA) clinical strain Mu3 spontaneously generates VISA strains at an extremely high frequency (≥1 × 10−6). The generated VISA strains usually grow more slowly than does the parent hVISA strain, but they form colonies on vancomycin-containing agar plates before 48 h of incubation. However, we noticed a curious group of VISA strains, designated “slow VISA” (sVISA), whose colonies appear only after 72 h of incubation. They have extremely prolonged doubling times but have vancomycin MICs of 8 to ∼24 mg/liter when determined after 72 to ∼144 h of incubation. We established strain Mu3-6R-P (6R-P), which has a vancomycin MIC of 16 mg/liter (at 72 h), as a representative sVISA strain. Its cell wall was thickened and autolytic activity was decreased compared to the respective qualities of the parent hVISA strain Mu3. Whole-genome sequencing of 6R-P revealed only one mutation, encoded byrpoB(R512P), which replaced the 512th arginine of the RNA polymerase β-subunit with proline. Its VISA phenotype was unstable, and the strain frequently reverted to hVISA with concomitant losses of pinpoint colony morphology and cell wall thickness and reduced autolytic activity. Sequencing of therpoBgenes of the phenotypic revertant strains revealed mutations affecting the 512th codon, where the proline of 6R-P was replaced with leucine, serine, or histidine. Slow VISA generated in the tissues of an infected patient serves as a temporary shelter for hVISA to survive vancomycin therapy. The sVISA strain spontaneously returns to hVISA when the threat of vancomycin is lifted. TherpoB(R512P) mutation may be regarded as a regulatory mutation that switches the reversible phenotype of sVISA on and off.


2018 ◽  
Vol 67 (4) ◽  
pp. 237
Author(s):  
A. TZORA ◽  
C. VOIDAROU ◽  
A. KARAMOUTSIOS ◽  
J. SKOUFOS

Objective of the present study was to study the outcome of inoculation of Staphylococcus aureus into the teat duct of female goats, which simulates mammary natural infections. In total, 22 lactating goats were used in the study; 8 animals were challenged with a S. aureus strain at a depth of 2 mm into one teat duct (group A), 8 animals were challenged with the same strain at 6 mm into one teat duct (group B) and 6 animals were challenged directly into one gland cistern (group C). Challenge dose was always 1300 cfu. Animals were examined clinically before and after challenge; milk samples were collected for bacteriological and cytological examination, and milk yield measurements were also performed. Goats in group A or B developed a significantly milder response than animals in group C. It is concluded that the evidence indicates a protective role of the normal teat of the udder of goats and that the results also underline the significance of maintaining healthy teats for prevention of mastitis in dairy herds.


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