Cytochemical Interpretation of the Mechanism of Penicillin Action 1

Pratt, Robertson; Dufrénoy, Jean

doi:10.1128/mmbr.12.1.79-103.1948

Cited by 13 publications

(6 citation statements)

References 75 publications

(88 reference statements)

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“…correlating our work with other published pertinent observations bearing on the mechanism of penicillin action is now in press (Pratt and Dufrenoy, 1948).…”

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confidence: 70%

Cytochemical Mechanisms of Penicillin Action

Dufrénoy

Pratt

1948

J Bacteriol

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The present work is a continuation of our studies of the changes induced by penicillin and certain other diffusible substances in susceptible test organisms. Proper application of suitable staining techniques to assay plates clearly demonstrates inhibition zones around "penicylinders" containing bacteriostatic concentrations of penicillin within 2 to 3 hours after the antibiotic has begun to diffuse through a test plate, although no measurable zones are evident on untreated plates until several hours later. Among the reagents that have been useful for revealing zones of inhibited bacterial activity are appropriate redox indicators, notable among which is triphenyl-tetrazolium chloride," and certain dyes that have been recommended for the detection of nucleic acid. A summary

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“…correlating our work with other published pertinent observations bearing on the mechanism of penicillin action is now in press (Pratt and Dufrenoy, 1948).…”

supporting

confidence: 70%

Cytochemical Mechanisms of Penicillin Action

Dufrénoy

Pratt

1948

J Bacteriol

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“…From a study of large body induction in Bacillus mycoides and Escherichia coli by the use of magnesium sulfate, Knaysi (1949) also believes that the enlargement of the cells is due chiefly to actual growth. Mercuric chloride (Fildes, 1940) and penicillin (Pratt and Dufrenoy, 1948) are both known to react with sulfhydryl groups, and the large bodies produced by them very likely result from a disturbance of the normal metabolic activities of the bacteria. Whether bacteria transforming into large bodies in the absence of these agents undergo similar metabolic changes is completely unknown.…”

Section: Discussionmentioning

confidence: 99%

The Formation and Development of Large Bodies in Proteus Vulgaris Ox-19 I

Stempen

Hutchinson

1951

J Bacteriol

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“…With low concentrations of ampicillin, both clumping of elongated gram-negative filaments and destruction of antibiotic by penicillinase can occur. The penicillin-enhancing effect of nutrients released during penicillin-induced lysis (Pratt and Dufrenoy, 1948) was minimized by using cultures diluted with three parts of fresh broth. Change in bacterial sensitivity may occur during the course of an experiment.…”

Section: Discussionmentioning

confidence: 99%

KINETICS OF THE ACTION OF AMPICILLIN ONESCHERICHIA COLI

Seligman

Hewitt

1963

J Bacteriol

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Seligman, Stephen J. (University of California, Los Angeles) and William L. Hewitt . Kinetics of the action of ampicillin on Escherichia coli . J. Bacteriol. 85: 1160–1164. 1963.—The curve of the number of viable Escherichia coli after exposure to ampicillin can be divided into three phases: a lag phase, a rapid bactericidal phase, and a slow bactericidal phase. Some of the variables affecting the magnitude of the first two of these phases were investigated. Progressive lowering of drug concentration resulted in prolongation of the lag phase and decrease in slope and extent of the rapid bactericidal phase. The production of elongated gram-negative forms and the emergence of a mutant with increased penicillinase activity complicated interpretation of the lower dose curves. With sufficient drug concentration, the length of the lag phase and the slope of the rapid bactericidal curve were independent of the size of inoculum up to 10 8 organisms. Varying pH revealed that maximal activity, as measured by the shortest lag phase and steepest slope of the rapid bactericidal phase, was present at slightly acid pH levels. Increasing pH resulted principally in prolongation of lag phase. With greater acidity, decrease in slope of the rapid bactericidal phase was more prominent. Cultures studied under conditions of lessened metabolic activity exhibited prolonged lag phase and decreased slope and extent of rapid bactericidal phase.

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Cytochemical Interpretation of the Mechanism of Penicillin Action 1

Cited by 13 publications

References 75 publications

Cytochemical Mechanisms of Penicillin Action

Cytochemical Mechanisms of Penicillin Action

The Formation and Development of Large Bodies in Proteus Vulgaris Ox-19 I

KINETICS OF THE ACTION OF AMPICILLIN ONESCHERICHIA COLI

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