The Journal of Medical Microbiology, Vol 14, Issue 1 131-140, Copyright © 1981 by Society for General Microbiology
The pathogenicity of Bacteroides fragilis and related species estimated by intracutaneous infection in the guinea-pig
J. P. Maskell
The pathogenicity of 42 strains of Bacteroides of human origins was
estimated by intracutaneous injection of bacterial suspensions into
guinea-pig skin. Comparisons of living and heat-killed suspensions revealed
that B. fragilis strains maintained themselves and possibly multiplied in
the skin, whereas the lesions induced by non-fragilis strains appeared to
be due mainly to toxicity. Measurement of skin pathogenicity in terms of
the number of viable organisms in the inoculum that produced a lesion 10 mm
in diameter showed that B. fragilis was, on average, 17 times as pathogenic
as non-fragilis strains. Skin tests of pathogens may be of value in the
analysis of virulence factors of Bacteroides and possibly of other
anaerobic organisms.
