Peptidoglycan types of bacterial cell walls and their taxonomic implications.

Enzymatic Methods for the Determination of Small Quantities of Isomeric Chondroitin Sulfates

Purification and Properties of Bacterial Chondroitinases and Chondrosulfatases

4Crawford, L. V., R. Dulbecco, M. Fried, L. Montagnier, and M. G. P. Stoker, these PNoCEEDINGS, 52, 148 (1964). Bourgaux, P., D. Bourgaux-Ramoisy, and M. G. P. Stoker, Virology, 25, 364 (1965). 6Black, P. H., and W. P. Rowe, these PROCEEDINGS, 50, 606 (1963). 7Diderholm, H., B. Stenkvist, J. Ponten, and T. Wesslen, Exptl. Cell Res., 37, 452 (1965). 8 Black, P. H., and W. P. Rowe, J. Nati. Cancer Inst., 32, 253 (1964). 9 Hopps, H. E., B. C. Bernheim, A. Nisalak, J. H. Tjio, and J. E. Smadel, J. Immunol., 91, 416 (1963). 10Black, P. H., E. M. Crawford, and L. V. Crawford, Virology, 24, 381 (1964). 11 Weil, R., Virology, 14 (1961). 12 Black, P. H., and W. P. Rowe, Virology, in press. 13 A clone of fibroblasts (C13), derived from the BHK-21 line,' was obtained from Professor M. Stoker, Giasgow, Scotland, and was used at the 80th-lOOth generations since cloning. 14 Pope, J. H., and W. P. Rowe, J. Exptl. Med., 120, 121 (1964). 16 Black, P. H., W. P. Rowe, H. C. Turner, and R. J. Huebner, these PROCEEDINGS, 50, 1148 (1963). 16 Defendi, V., J. Lehman, and P. Kraemer, Virology, 19, 592 (1963). 17 Black, P. H., and W. P. Rowe, Proc. Soc. Exptl. Biol. Med., 114, 721 (1963). 18 Gotlieb-Stematsky, T., and R. Shilo, Virology, 22, 314 (1964). 19 Dulbecco, R., personal communication. 20 Le Bouvier, G., personal communication. 21 Crawford, L. V., and P. H. Black, Virology, 24, 388 (1964). 22 Mayor, H. D., R. M. Jamison, and L. E. Jordan, Virology, 19, 359 (1963). 23Stoker, M., and P. Abel, in Cold Spring Harbor Symposia on Quantitative Biology, vol. 17, (1962), p. 375. 24 Black, P. H., unpublished data. 25 Vinograd, J., R. Bruner, R. Kent, and J. Weigle, these PROCEEDINGS, 49, 902 (1963).

https://www.pnas.org/content/pnas/54/4/1133.full.pdf

Mechanism of action of penicillins: a proposal based on their structural similarity to acyl-D-alanyl-D-alanine.

Staphylococcus aureus and Staphylococcus epidermidis are major human pathogens of increasing importance due to the dissemination of antibiotic-resistant strains. Evidence suggests that the ability to form matrix-encased biofilms contributes to the pathogenesis of S. aureus and S. epidermidis. In this study, we investigated the functions of two staphylococcal biofilm matrix polymers: poly-N-acetylglucosamine surface polysaccharide (PNAG) and extracellular DNA (ecDNA). We measured the ability of a PNAG-degrading enzyme (dispersin B) and DNase I to inhibit biofilm formation, detach preformed biofilms, and sensitize biofilms to killing by the cationic detergent cetylpyridinium chloride (CPC) in a 96-well microtiter plate assay. When added to growth medium, both dispersin B and DNase I inhibited biofilm formation by both S. aureus and S. epidermidis. Dispersin B detached preformed S. epidermidis biofilms but not S. aureus biofilms, whereas DNase I detached S. aureus biofilms but not S. epidermidis biofilms. Similarly, dispersin B sensitized S. epidermidis biofilms to CPC killing, whereas DNase I sensitized S. aureus biofilms to CPC killing. We concluded that PNAG and ecDNA play fundamentally different structural roles in S. aureus and S. epidermidis biofilms.

Differential roles of poly-N-acetylglucosamine surface polysaccharide and extracellular DNA in Staphylococcus aureus and Staphylococcus epidermidis biofilms.

Richard E. Thompson

Papers

Composition of the cell wall of Staphylococcus aureus: its relation to the mechanism of action of penicillin.