Previously, Pollack et al., Bjorn et al. and Sanai et al. reported that an incidence of the exotoxin producing
P. aeruginosa was 87, 89 and 87 % among clinical isolates, respectively.
In the present study, the exotoxin production of clinical and environmental isolates of
P. aeruginosa was tested by an intradermal inoculation of their culture filtrates into any guinea pig and correlation between the exotoxin producibility of isolates and their isolating sources or serotypes was investigated.
Exotoxin production was observed to be 79% among clinical isolates from patients with underlying diseases, while it was 22% positive from the environmental isolates of
P. aeruginosa. Difference was significant at P<0.05. Actually, number of the exotoxin positive strains from different clinical source tested were 8 out of 12 isolates from urine, 12 out of 15 isolates from sputum, 9 out of 10 isolates from pus and 3 out of 5 isolates from others (bile, ear discharge and tonsil), suggesting not significant dependency upon the isolating sources.
So far as the present results were concerned, as difinite relation of the exotoxin producibility to any serotype of the isolates was not observable, that is, there were 7 exotoxin positive strain out of 9 A type isolates (78%), 12 out of 13 B type isolates (92%), 1 out of 1 D type isolates, 2 out of 6 E type isolates (50%), 1 out of 2 F type isolates (50%), 6 out of 8 G type isolates (75%) and 3 out of 3 I type isolates (100%).
However, a higher frequency of the exotoxin producing strains among both B and I serotypes of isolates was remained for further investigation.
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