5. ANTIBIOSIS AND ANTIBIOTICS
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beings, the problems involved are always essentially of a biochemical
nature.
C. THE COMPARATIVE POINT OF VIEW
If antibiotics, in principle, are a fit subject for a comparative biochemical study, one should, however, recognize that a number of difficulties are to be expected, some of them being the result of the fragmentary character of our present knowledge but others being of a more
fundamental nature.
The biochemical problems to be considered fall under two main
headings: those pertaining to the action of antibiotics upon sensitive
cells and those concerned with their biosynthesis.
1. Action of Antibiotics
The main point of interest is the comparative study of the biochemical mechanisms which, in each particular case, are responsible for the
antibiotic effects observed. The study should be undertaken with a view
to explain: first, modes of action in relation to the chemical nature of the
antibiotic; second, effects observed in different organisms in relation to
their cell structure and biochemical activities, the problems of specificity,
or natural resistance, being here included.
Intimately connected with the main question, are the problems pertaining to the biochemical basis responsible for the acquisition of resistance. The many known examples of cross resistance should be stressed
since they occur, not only between chemically related antibiotics, but
also between substances that are structurally quite different, pointing
probably, when such is the case, to a similarity in mode of action.
For such a study, the meaning of antibiotic could well be broadened
to include synthetic antimicrobial agents, at least insofar as what is
known about them is likely to throw additional light on the problems
raised by the naturally occurring antibiotics.
The effects of antibiotics upon sensitive cells are many and diverse.
They may vary not only with the nature of the antibiotic and that of
the organism submitted to its action, but also, for a given system, with
concentration and experimental conditions. A wealth of information is
thus available, but unfortunately, it is extremely difficult to coordinate.
Our knowledge of the modes of action of antibiotics, to say nothing of
their mechanisms of action, is at present very sketchy. In fact, only a
minor fraction of all the known antibiotics has been subjected to that
type of investigation, and in a very few cases only has it been possible
to recognize a primary biochemical lesion (IS, 19).
259
beings, the problems involved are always essentially of a biochemical
nature.
C. THE COMPARATIVE POINT OF VIEW
If antibiotics, in principle, are a fit subject for a comparative biochemical study, one should, however, recognize that a number of difficulties are to be expected, some of them being the result of the fragmentary character of our present knowledge but others being of a more
fundamental nature.
The biochemical problems to be considered fall under two main
headings: those pertaining to the action of antibiotics upon sensitive
cells and those concerned with their biosynthesis.
1. Action of Antibiotics
The main point of interest is the comparative study of the biochemical mechanisms which, in each particular case, are responsible for the
antibiotic effects observed. The study should be undertaken with a view
to explain: first, modes of action in relation to the chemical nature of the
antibiotic; second, effects observed in different organisms in relation to
their cell structure and biochemical activities, the problems of specificity,
or natural resistance, being here included.
Intimately connected with the main question, are the problems pertaining to the biochemical basis responsible for the acquisition of resistance. The many known examples of cross resistance should be stressed
since they occur, not only between chemically related antibiotics, but
also between substances that are structurally quite different, pointing
probably, when such is the case, to a similarity in mode of action.
For such a study, the meaning of antibiotic could well be broadened
to include synthetic antimicrobial agents, at least insofar as what is
known about them is likely to throw additional light on the problems
raised by the naturally occurring antibiotics.
The effects of antibiotics upon sensitive cells are many and diverse.
They may vary not only with the nature of the antibiotic and that of
the organism submitted to its action, but also, for a given system, with
concentration and experimental conditions. A wealth of information is
thus available, but unfortunately, it is extremely difficult to coordinate.
Our knowledge of the modes of action of antibiotics, to say nothing of
their mechanisms of action, is at present very sketchy. In fact, only a
minor fraction of all the known antibiotics has been subjected to that
type of investigation, and in a very few cases only has it been possible
to recognize a primary biochemical lesion (IS, 19).