Ultrastructure of the endotoxin produced by gram-negative bacteria associated with organic dusts.
Dutkiewicz J; Tucker J; Burrell R; Olenchock SA; Schwegler-Berry D; Keller GE III; Ochalska B; Kaczmarski F; Skorska C
Syst Appl Microbiol 1992 Aug; 15(3):474-485
The isolates of two out of four examined bacterial species associated with organic dusts (Erwinia herbicola and Enterobacter sp.) showed an ability to shed the membrane vesicles while growing on a solid medium. The formation of such vesicles was not observed in strains of other two species (Acinetobacter calcoaceticus and Alcaligenes faecalis) that revealed a lower degree of the outer membrane development. The preparations of crude lipopolysaccharide isolated with two methods from strains of all four species were found to be composed of vesicular particles resembling those shed from the outer membrane of E. herbicola and Enterobacter sp. The similar structures were found in natural environment, using wood as a model substrate. It has been shown by electron microscopy and specific immunolabelling that wood dust from American basswood contained numerous gram-negative bacteria of the species Erwinia herbicola that were shedding large amounts of the endotoxin-containing membrane vesicles, measuring about 30 nm. Bacteria were not found in the samples of wood dust from other kinds of timber. These results were in full accord with those received by the examination of the wood dust samples by culture and by Limulus test for the presence of endotoxin. The presented results suggest that the significant portion of an environmental "dust-borne" endotoxin occurs in the form of microvesicles, what may respresent an increased risk for the people exposed to various organic dusts.
Cotton-dust; Dust-particles; Dusts; Wood-dusts; Organic-dusts; Bacterial-dusts; Bacteria; Lung; Microorganisms; Endotoxins;
Author Keywords: Gram-negative Bacteria; Endotoxin; Ultrastructure; Microvesicles; Erwinia-Herbicola; Wood Dust
Professor Dr. Jacek Dutkiewicz, Institute of Agricultural Medicine, Szkolna 16, PL-201 24 Lublin, Poland
Systematic and Applied Microbiology