1
INTRODUCTION OF
Antibiotics,
in
today’s most up-to-date therapeutic armamentarium, occupy strategically the
most coveted and key position during the span of past half-century across the
globe. This conglomeration of drugs affords an effective management and
critical control of a host of deadly human related pathogenic microorganisms
which previously caused pathetic prolonged human sufferings orultimately
leading to death irrespective of the physical condition, age factor or economic
status of an individual.
The
word ‘antibiotic’ has been coined from the term antibiosis that
evidently means ‘against life’ (anti—against and bios—life).
Over
the years various versions of ‘definitions’ for an antibiotic have been
postulated which are enumerated as under.
The
most widely accepted definition of an antibiotic accepted by the
scientific jargons is—‘a chemical substance produced by a microorganism,
that has the capacity, in low concentration, to inhibit or kill, selectively,
other microorganisms.’ This definition lays particular emphasis on the
terminology ‘selectivity’ or ‘selective toxicity’ that explicitly
suggests that the substance either checks the growth of pathogens or
exerts a bactericidal action on the microbes without displaying a likewise
action on the host organism i.e.., the human beings.
The
above definition clearly excludes the compounds having the pure synthetic
genesis (origin).
However,
in a rather broader perspective these ‘synthetic substances’ are virtually
treated at par with the natural compounds along with their corresponding
derivatives under the terminology ‘antimicrobials’ which may be further
categorized into antifungals and antibacterials based on the
particular type of microbe undergoing inhibition. Hence, in order to
circumvent the practical aspects, both the terminologies viz., ‘antibiotic’
and ‘antimicrobial’ may be employed interchangeably irrespective of
the particular source of the compound.
Even
in the ancient and primitive era, dating back to 2500 years, the anti-infective
characteristic features of fungi and moulds usually observed in
various food products like: mouldy bread, yoghurt, and soybean curds, and other
similar materials to wounds and boils to curb their infection. This sort of age-old
treatment one may regard as a folk-medicine style of antibiotic therapy.
It is,
however, pertinent to mention here that the real impetus and legitimate
recognition of the antibiotics in the so called ‘modern drugs’ was virtually
accomplished by the famous french scientist Louis Pasteur. The epoch making
introduction of pyocyanase interestingly extracted from Pseudomonas
aeruginosa as a prominent therapeutic agent under the ‘antibiotics’ is
indeed one of the greatest achievements in the history of medicine. This event
was immediately followed by another historic invention of Alexander Fleming for
the drug penicillin; and the subsequent antimicrobial activity of Penicillium
notatum discovered by Chain Florey and his co-workers.
In
fact, the most effective and wonderful class of life saving antibiotics
comprise of a plethora of active substances that are found to be effective on
either Gram +ve or Gram –ve micro-organisms; besides the ones that are
invariably known as the broad-spectrum antibiotics.
In
general, the antibiotics are produced on a large scale by three known
methods, namely:
(a)
fermentation process; (b) semi-synthetic process; (c) synthetic
process. Recently, with the advent of a tremendous quantum jump and
diversification in the specific field of ‘biotechnology’, the first two
processes stated above have not only gained an enormous increase in the rate of
production but also improved their yield and purity. Nevertheless, the fermentation
process is further categorized into two types: (a) surface
method; (b) submerged method. It is worthwhile to mention here that the second
method has a much greater efficiency limit and hence used commercially. Over
the years, a vast number of altogether newer, purer, and high-yielding microbial
strains have been developed, tried and tested for evaluating their antibiotic
yielding strength besides the efficiency in their extraction.
0 Comment:
Post a Comment