Effect of vancomycin on Bacillus subtilis

Genetic Evidence for an Alternative Citrate-Dependent Biofilm Formation Pathway in Staphylococcus aureus That Is Dependent on Fibronectin Binding Proteins and the GraRS Two-Component Regulatory System

“…Furthermore, the addition of additional divalent cations to the medium (including Mn and Mg) still resulted in citrate-mediated stimulation of biofilm formation (62). However, both vancomycin and bacitracin require divalent cations to be effective, and the antimicrobial capacity of bacitracin is reported to be inhibited by citrate, suggesting that citrate inhibits these antibiotics through the sequestration of cations (1,7,8,58). Furthermore, since emerging glycopeptide resistance in S. aureus is an important concern for human health (2), we chose to test glycopeptide resistance determinants as potential regulators of citrate-stimulated biofilm formation.…”

Antibiotics

“…L-Alanine showed a slight reversal of inhibition at a later period (12-14 hr} but these results are rather atypical since the test organism employed required large amounts of antibiotic (MIC = 144.7 (.Lg/ml) for inhibition. However, in a later study BEST and DuRHAM (1964) reported that the inhibition of growth and mucopeptide synthesis in a strain of B. subtilis by vancomycin at a level of 1. 3 (.Lg/mg cell dry weight could be reduced by the addition of 4 [.Lmolesfml of magnesium, especially when that ion was added simultaneously with the antibiotic.…”

Effects of Binding and Bactericidal Action of Vancomycin on Bacillus licheniformis Cell Wall Organization as Probed by 15 N Nuclear Magnetic Resonance Spectroscopy

“…The inhibition of peptidoglycan biosynthesis by vancomycin in cell-free systems is restricted to its complexing with lipidsoluble intermediates in the membrane fraction (12,13,18). However, in the whole cell, part of the bactericidal effect of vancomycin may also be associated with the strong binding of vancomycin to the cell wall (2,3,13). The binding of highly charged vancomycin molecules (2,3) to the amphoteric polyelectrolyte gel-like cell wall (22) is likely to result in changes in the threedimensional arrangements of the cell wall polymers and in the contacts between the cell wall and protoplast membrane, which could affect the relative rates of cell wall autolysis and the insertion of new cell wall material.…”

“…However, in the whole cell, part of the bactericidal effect of vancomycin may also be associated with the strong binding of vancomycin to the cell wall (2,3,13). The binding of highly charged vancomycin molecules (2,3) to the amphoteric polyelectrolyte gel-like cell wall (22) is likely to result in changes in the threedimensional arrangements of the cell wall polymers and in the contacts between the cell wall and protoplast membrane, which could affect the relative rates of cell wall autolysis and the insertion of new cell wall material. The activity of the major cell wall autolysin, N-acetylmuramoyl-L-alanine amidase (in Bacillus licheniformis and B. subtilis), has been shown to be related to the recognition of cell wall teichoic and teichuronic acids and to more subtle structural features of the cell wall (11,15,16,20,29 (7,21).…”

“…Cell walls were obtained from the supernatant by centrifugation at 20,000 x g for 15 min at 40C and washed five times in water, until a cell wall suspension devoid of whole cells was obtained. The absence of whole cells was assured by phase-contrast microscopy (2,29), and the pH was adjusted to pH 7 by addition of concentrated HCl, when needed. Intact cells and cell walls were packed into 10-mm NMR tubes (Wilmar, no.…”