Staphylococcal Spheroplasts and L-Colonies. III. Induction by Lysostaphin

Watanakunakorn, Chatrchai; Goldberg, Leonard M.; Carleton, Judith; Hamburger, Morton

doi:10.1093/infdis/119.1.67

Cited by 18 publications

(12 citation statements)

References 14 publications

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“…The results of the present study confirm the previous report that WDS could be induced by lysostaphin in medium containing 5%, NaCl (8). Only a portion of the exposed staphylococci became WDS.…”

Section: Discussionsupporting

confidence: 92%

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Light and Scanning-Beam Electron Microscopy of Wall-Defective Staphylococcus aureus Induced by Lysostaphin

et al. 1971

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The serial morphological changes of Staphylococcus aureus after exposure to lysostaphin (one unit per ml) in hypertonic culture medium containing 5% NaCl were studied over an 8-hr period at 37 C. S. aureus stained gram-negative almost instantaneously upon contact with lysostaphin. Many cells were lysed, but wall-defective staphylococci with corrugated surface were detected as early as 5 min by use of scanning-beam electron microscopy. Wall-defective staphylococci enlarged progressively with increasing periods of incubation. The absorbance of the lysostaphin-treated culture decreased significantly by 2 min, remained stationary for 2 hr, and then progressively increased. The number of vegetative colony-forming units decreased progressively with increasing periods of incubation) whereas the number of

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Section: Discussionsupporting

confidence: 92%

“…The present investigation was designed to study the serial morphological changes of S. aureus after exposure to lysostaphin (4, 5) which damages cell walls within 2 min (6) and is capable of inducing WDS in hypertonic medium (8). Observations were made over an 8-hr period by using Gram stain, phase microscopy, and the SEM.…”

mentioning

confidence: 99%

Light and Scanning-Beam Electron Microscopy of Wall-Defective Staphylococcus aureus Induced by Lysostaphin

et al. 1971

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“…This optimum concentration was also shown when a different lot of horse serum was used. These results are in sharp contrast to those reported by other investigators (2,8,9). The generally used concentration in cultures of L-phase variants has been 5-10%.…”

Section: Discussioncontrasting

confidence: 76%

“…L-Phase variant induction in Staphylococcus aureus has been reported by many workers since the initial success of Diens and Sharp (2). The essential and common procedure for inducing the variants in various bacterial species is removal of the cell wall by a digesting enzyme (9) or inhibition of cell wall synthesis by penicillins (2) and the addition of an osmotic stabilizer and 5-10% serum to the culture medium. The generally used stabilizer is sucrose or sodium chloride.…”

mentioning

confidence: 99%

Induction of L‐Phase Variant from Protoplast of Staphylococcus aureus

Makino

1983

Microbiology and Immunology

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Protoplasts of Staphylococcus aureus 209P and Cowan I were induced by treatment with lysostaphin. These protoplasts were sensitive to detergent, a low concentration of sodium chloride and low temperature.Almost all protoplast cells spread on CLYS agar medium (casein hydrolysate, yeast extract, Na-lactate, and NaCI) formed typical L-form colonies. Horse serum (0.25%) and M g2 + (lOa msr) are essential factors for formation of the L-form colonies of 209P. In the case of Cowan I, M g2 + was not required.The active factor(s) in horse serum was heat-resistant and protein in nature.L-Phase variant induction in Staphylococcus aureus has been reported by many workers since the initial success of Diens and Sharp (2). The essential and common procedure for inducing the variants in various bacterial species is removal of the cell wall by a digesting enzyme (9) or inhibition of cell wall synthesis by penicillins (2) and the addition of an osmotic stabilizer and 5-10% serum to the culture medium. The generally used stabilizer is sucrose or sodium chloride. These are necessary to protect the fragile cells from cell bursting due to increased osmotic pressure. The addition of serum is also indispensable, but its function in the growth of L-phase variants still remains obscure.The induction of protoplast fusion by polyethylene glycol, which was first demonstrated in plant protoplasts by Kao and Michayluk (5), was extended to various microbial protoplasts (3, 7) including Staphylococcus aureus (4, 6). The cell fusion method will provide an excellent opportunity for studying genetic recombination and chromosomal mapping in Staphylococcus aureus, concerning which there has been little work done. Before investigation of protoplast fusing, however, it is necessary to determine the conditions that will allow highly efficient induction of protoplasts and L-phase variants.In this communication, a preliminary experiment on cell conversion to L-phase variants with high efficiency in Staphylococcus aureus is described. Some characteristics of the serum factor are also mentioned.

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“…The literature ascribes this morphology to a bacterium whose cell wall has been completely removed and thus the membrane tension causes the spherical shape. 12 Figure 1D displays the ‘sphero-rod’ phenotype 9,13 , which is a hybrid between the elongated and spheroplast morphologies. In Pseudomonas aeruginosa this phenotype is attributed to the affinity of β-lactam therapeutics to bind two different penicillin-binding proteins.…”

Section: Resultsmentioning

confidence: 99%

Mechanism of action-based classification of antibiotics using high-content bacterial image analysis

et al. 2013

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Image-based screening has become a mature field over the past decade, largely due to the detailed information that can be obtained about compound mode of action by considering the phenotypic effects of test compounds on cellular morphology. However, very few examples exist of extensions of this approach to bacterial targets. We now report the first high-throughput, high-content platform for the prediction of antibiotic modes of action using image-based screening. This approach employs a unique feature segmentation and extraction protocol to quantify key size and shape metrics of bacterial cells over a range of compound concentrations, and matches the trajectories of these metrics to those of training set compounds of known molecular target to predict the test compound's mode of action. This approach has been used to successfully predict the modes of action of a panel of known antibiotics, and has been extended to the evaluation of natural products libraries for the de novo prediction of compound function directly from primary screening data.

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Staphylococcal Spheroplasts and L-Colonies. III. Induction by Lysostaphin

Cited by 18 publications

References 14 publications

Light and Scanning-Beam Electron Microscopy of Wall-Defective Staphylococcus aureus Induced by Lysostaphin

Light and Scanning-Beam Electron Microscopy of Wall-Defective Staphylococcus aureus Induced by Lysostaphin

Induction of L‐Phase Variant from Protoplast of Staphylococcus aureus

Mechanism of action-based classification of antibiotics using high-content bacterial image analysis

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