Biomaterial Database

Demonstration of bacteroides capsules by light microscopy and ultrastructural cytochemistry. 1983

H Strohm, and C M Payne, and K J Ryan

Forty-six anaerobic gram-negative bacilli, including 26 members of the Bacteroides fragilis group (BFG), were examined for capsules by the India ink technic. Thirty-five were encapsulated, including all the BFG strains. As a follow-up, seven of these isolates and two previously studied reference strains (B. fragilis ATCC 23745 and Bacteroides vulgatus ATCC 8482) were examined for capsules by ultrastructural cytochemistry. Using the periodic acid thiocarbohydrazide silver proteinate (PATCSP) method of Thiéry, all the BFG examined were encapsulated. In addition to the reference strains, this included one strain of B. fragilis and four of Bacteroides thetaiotaomicron. One non-BFG strain showed no capsular material. Differences between these results and those reported previously with the ruthenium red technic may reflect species differences in the chemical composition of Bacteroides capsules.

UI	MeSH Term	Description	Entries
D007281	Ink	Pigmented or colored fluid used for writing, staining, painting, drawing, printing, or copying images.	Inks
D011135	Polysaccharides, Bacterial	Polysaccharides found in bacteria and in capsules thereof.	Bacterial Polysaccharides
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D006651	Histocytochemistry	Study of intracellular distribution of chemicals, reaction sites, enzymes, etc., by means of staining reactions, radioactive isotope uptake, selective metal distribution in electron microscopy, or other methods.	Cytochemistry
D001441	Bacteroides fragilis	Gram-negative bacteria occurring in the lower intestinal tracts of man and other animals. It is the most common species of anaerobic bacteria isolated from human soft tissue infections.