The pathogenicity of 42 strains of Bacteroides of human origin 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-fra-gilis 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.
CasciatoD. A.,
RosenblattJ. E.,
BluestoneR.,
GoldbergL. S.,
FinegoldS. M.1979; Susceptibility of isolates of Bacteroides to the bactericidal activity of normal human serum. J. infect. Dis 140:109
CatoE. P.,
JohnsonJ. L.1976; Reinstatement of species rank for Bacteroides fragilis, Bovatus, B. distasonis, B. thetaiotaomicron and B. vulgatus: designation of neotype strains for Bacteroides fragilis (Veillon and Zuber) Castellani and Chalmers and Bacteroides thetaiotaomicron (Distaso) Castellani and Chalmers. Int. J. syst. Bad 26:230
DuerdenB. I.,
HolbrookW. P.,
ColleeJ. G.,
WattB.1976; The characterization of clinically important gram-negative anaerobic bacilli by conventional bacteriological tests. J.appl.Bact 40:163
FinegoldS. M.,
AtteberyH. R.,
SutterV. L.1974; Effect of diet on human fecal flora: comparison of Japanese and American diets. Am. J. clin. Nutr 27:1456
HoldemanL. V.,
CatoE. P.,
MooreW. E. C.1977; Anaerobe laboratory manual. , 4. Virginia Polytechnic Institute and State University; Blacksburg, Virginia:
InghamH. R.,
SissonP. R.,
SelkonJ. B.1980; Current concepts of the pathogenetic mechanisms of non-sporing anaerobes: chemotherapeutic implications. J. antimicrob. Chemother 6:173
KellyM. J.1978; The quantitative and histological demonstration of pathogenic synergy between Escherichia coli and Bacteroides fragilis in guinea-pig wounds. J. med. Microbiol 11:513
MilesA. A.,
MilesE. M.,
BurkeJ.1957; The value and duration of defence reactions of the skin to the primary lodgement of bacteria. Br. J. exp. Path 38:79
MilesA. A.,
PillowJ., KhimjiP. L.1976; The action of iron on local klebsiella infection of the skin of the guinea-pig and its relation to the decisive period in primary infective lesions. Br. J. exp. Path 57:217
OnderdonkA.B.,
KasperD. L.,
CisnerosR. L.,
BartlettJ. G.1977; The capsular polysaccharide of Bacteroides fragilis as a virulence factor: comparison of the pathogenic potential of encapsulated and unencapsulated strains. J. infect. Dis 136:82
WeinsteinW. M.,
OnderdonkA. B.,
BartlettJ. G.,
GorbachS. L.1974; Experimental intra-abdominal abscesses in rats: development of an experimental model. Infect. Immun 10:1250