Cell wall turnover was examined in parent and mutant strains of Staphylococcus aureus. Peptidoglycan and teichoic acid were observed to undergo turnover in the wild-type strain during exponential growth; however, the rate of turnover did not decrease when the growth rate slowed, as the culture entered stationary phase. Isolated native cell walls and crude soluble autolytic enzyme were prepared ...

The biochemical phenotype of rodA mutants was not affected by the simultaneous presence in double mutants of the lyt gene which makes them 90 to 95% deficient in autolysin action. The only morphological effect of this deficiency on the expression of the rod gene was that both the rod and the coccal forms of the mutant failed to separate and grew as long chains of cells. Inhibition of protein sy...

An autolysin obtained from culture fluid of Staphylococcus aureus strain 8507 was purified 3,000-fold. One milligram of this preparation (S-5DL) will solubilize 12 mg of cell wall in 1 hr. The major activity is N-acetylmuramyl-l-alanine amidase. Recovery of lytic activity in the purified preparation was repeatably only 20% of the starting level. This suggests that other cell wall lytic enzymes ...

Mutants of Streptococcus pneumoniae that contain active autolysin and yet cannot be induced to lyse during treatment with penicillin (Lyt+Tol+ mutants) have been described. We have now shown that these mutants are temperature dependent (32 degrees C); at 37 degrees C these bacteria underwent penicillin-induced lysis. In addition, mutants at the lysis-permissive temperature showed the so-called ...

Dodecylglycerol has a minimum inhibitory concentration of 4 micrograms/ml compared to 9 micrograms/ml for monolaurin (dodecanoylglycerol) with Streptococcus faecium ATCC 9790 as the test organism. The greater potency of dodecylglycerol can be correlated to its greater retention by the cell. Gram-positive bacteria were more susceptible than Gram-negative bacteria to dodecylglycerol. The antibact...

We have analyzed genetically three clinical isolates (3180, 3870, and 1244) of Streptococcus pneumoniae with high-level ciprofloxacin resistance. Isolates 3180 and 3870 were atypical because of their insolubility in deoxycholate. However, they hybridized specifically with pneumococcal autolysin and pneumolysin gene probes and have typical pneumococcal atpC and atpA gene sequences. Analysis of t...

Choline-containing pneumococcal cell wals are sensitive to autolysin, whereas ethanolamine-containing walls are not. Bacteria were labeled with radioactive peptidoglycan precursors while growing either in choline- or in ethanolaminecontaining media. Subsequently, the labeled cells were allowed to grow for four to five generations in nonradioactive medium supplemented with the alternative amino ...

Host- and phage-coded cell wall hydrolases have been used to fight Streptococcus pneumoniae growing as planktonic cells in vitro as well as in animal models. Until now, however, the usefulness of these enzymes in biofilm-grown pneumococci has gone untested. The antipneumococcal activity of different cell wall hydrolases produced by S. pneumoniae and a number of its phages was examined in an in ...

Streptococcus pneumoniae is both an aggressive pathogen and a normal part of the human respiratory microbiome. Clinicians and microbiologists have struggled to develop tests that can identify pneumococcal respiratory infection and accurately distinguish colonization from invasive disease. Molecular methods hold the promise of an improved ability to rapidly detect microorganisms in respiratory s...