search SubbaRow directed at Lederle Laboratories for
antibiotics with wider range of cures than the then
available penicillin and streptomycin led to the
discovery of polymyxin, widely used even today in
cattle-feed, and Aureomycin, the first of
tetracycline antibiotics which all of us have had
some time or the other in our lives.
Tetracyclines have saved millions of lives over the
last 50 years.
Aureomycin was presented to medicine in 1948, the
year SubbaRow died. It was the first broad-spectrum
antibiotic, that is, one effective against both
gram-positive and gram-negative germs. It was
thus more powerful than either Fleming's penicillin
or Waksman's streptomycin.
When SubbaRow's centenary year began in 1994,
tetracyclines --especially Doxycycline -- helped
confine and then eradicate the plague epidemic that
broke out in Gujarat and Maharashtra. It was a debt
SubbaRow paid to his motherland almost half a century
after death which claimed him soon after the
unveiling of Aureomycin before a medical gathering at
the New York Academy of Sciences.
Along with pheno‑sulphazole on trial in the
Texas polio epidemic of 1948 was an antibiotic called
Aureomycin. It too did not make the grade in the
fight against the crippling disease but it was one of
the first drugs to be effective against viruses and
rickettsiae. Rickettsiae occupy a position between
viruses and bacteria.
The discovery and development of Aureomycin came from
a screening programme SubbaRow instituted in the
spring of 1944 simultaneously with the programme that
got him Hetrazan. It was an antibiotic SubbaRow had
acquired with the help of "amateurs", men with no
pre-conceived ideas who investigated the unknown with
a truly scientific spirit.
SubbaRow had by then completed his work on
fermentation and isolation of penicillin and wanted
to look for sources of new antibiotics. Since
filamentous moulds, Aspergilli and Penicillia, had
all been surveyed extensively, he wished to institute
a more thorough examination of Actinomycetes.
Actinomycetes are close to bacteria in appearance but
resemble fungi in their growth. His decision was
influenced by the recent announcement of streptomycin
obtained from an actinomycete and by the feeling that
bacteria had not received due attention as antibiotic
producers because penicillin had overshadowed
SubbaRow got his first amateur when he looked for a
plant physiologist for his antibiotic screening
programme. Remembering his pleasant meeting
with an old plant physiologist at the University of
Wisconsin, he asked Ed Backus on his mycology group
to write to his brother at Madison to meet the
professor and secure the services of one of his
students. Benjamin Minge Duggar, when
approached by the elder Backus, said his own services
were available for SubbaRow. A distinguished
authority on fungus diseases of plants, he had
retired some six months earlier with the reputation
as one who had made mushroom cultivation in the
United States independent of European spawn.
SubbaRow had reservations about "prima donnas" but
was touched by the fact that Duggar had to retire
because of the age rule. Duggar was not only active
but anxious to dedicate the evening of his life to
something of more significance to human welfare than
mushroom cultivation. He was willing to screen plant
extracts and mould broths. It was a job he had never
done before and he would not be handicapped by
experience and theories.
Duggar came over on April 1, 1944. He began to screen
soil and other samples received from everywhere. He
prefixed A to code numbers for actinomycetes that he
isolated and B for bacteria.
first break came with B-71, the 71st bacterial
isolate, found in a sample of Colorado soil. To let
Duggar concentrate on actinomycetes, SubbaRow handed
over the isolate identified as Bacillus
polymyxa to John Porter, a mycologist on his staff.
Porter and his associates were able to secure from
this the antibiotic polymyxin. Polymyxin was found by
physicians to be effective against undulant fever,
whooping cough and meningitis. But SubbaRow withdrew
it as it was somewhat harmful to kidneys.
in August 1945, Du-ggar noticed a beautiful growth on
agar in test tubes to which he had trans�ferred
actinomycetes isolated from some University of
Missouri soil samples. The conspicuous
grey‑brown spores at the top were followed by a
pink and a white zone ending in a moist golden area
at the bottom. On agar plates, the actinomycete
produced an antibiotic which arrested the growth of a
broad spectrum of deadly disease germs ‑-those
susceptible as well as those resistant to the then
known sulphas and antibiotics.
as the versatility of A‑377 (the 377th
actinomycete isolated), Duggar was disappointed it
was not active against the tubercle germ. An
anti‑TB drug more potent but safer than
streptomycin was one of the objectives set for him.