Janina Krywienczyk’s research while affiliated with Swiss Federal Institute of Technology in Lausanne and other places

The serological relationship between three varieties of Bacillus popilliae was investigated by double diffusion and immunoelectrophoresis, using antigens prepared from homogenized vegetative cells in the logarithmic growth phase. The results showed the existence of a close serological relationship among the three varieties in agreement with a recently proposed taxonomic scheme for the milky disease bacteria (Wyss, 1971).

The identity of a cell line derived from hemocytes ofMalacosoma disstria was investigated serologically by using complement fixation, double diffusion, immunoelectrophoresis in agarose, and acrylamide gel electrophoresis. TheM. disstria cell line antiserum gave a specific cross-reaction with its homologous antigen and withM. disstria larval antigen, although cross-reactions with cell lines fromAedes aegypti, Bombyx mori, andChoristoneura fumiferana and with larval antigens ofB. mori andC. fumiferana were also produced. Antisera againstA. aegypti andB. mori cell lines showed very similar cross-reaction with both the cell line antigens. Also, these two antisera gave a strong reaction withB. mori larval antigen, but no reaction withA. aegypti larval antigen. These tests confirm the identity of ourM. disstria cell line. Also, they indicate: (a) that theA. aegypti andB. mori cell lines tested are similar, and (b) that they are closely related toB. mori, but not at all related toA. aegypti.

Subcellular fractions from Malacosoma disstria larvae, both healthy and infected with cytoplasmic polyhedrosis virus, were examined by double diffusion in agarose, immunoelectrophoresis, acrylamide gel electrophoresis, and combined methods. An antigen of viral origin was detected in the soluble fraction from the infected larvae. The mitochondrial fraction contained virions. Microsomal fractions showed nonspecific reactions.

Two European milky disease isolates, Bacillus fribourgensis and Bacillus popilliae melolontha, were compared serologically with Bacillus popilliae. A close relationship exists between all three pathogens. Double diffusion experiments and a complement fixation test suggest that the European milky disease pathogens are identical whereas B. popilliae shows distinct differences. Two antigens of the European isolates are not shared by B. popilliae, which has one specific antigen that is not present in B. fribourgensis or B. popilliae melolontha.

Ribosomes from guinea pig liver, Cavia cobaya; frog liver, Rana pipiens; midgut of the silkworm, Bombyx mori; an earthworm, Lumbricus terrestris; a bacterium, Escherichia coli; a fungus of the genus Lactarius; and also the synthetic polyribonucleotides poly A and poly U were serologically compared with the cytoplasmic polyhedrosis viruses from Bombyx mori, the tent caterpillar Malacosoma disstria, and the tussock moth Orgyia leucostigma. The method of double diffusion on cellulose acetate membranes was used. Extensive cross-reactivity was observed, and it is attributed to the ribose phosphate backbone of RNA as a common antigen.

Subcellular microsomal subfractions such as whole ribosomes, rough membranes, and smooth membranes, from healthy silkworm larvae and from those infected with cytoplasmic polyhedrosis, were prepared. Ribosomal preparations from healthy and diseased insects could not be serologically distinguished by the method of double diffusion on cellulose acetate membranes. Antisera against cytoplasmic polyhedrosis viruses appeared to share at least one antigen with the ribosomes from healthy and larvae of diseased silkworm and guinea-pig liver.

The toxic parasporal protein of Bacillus thuringiensis strain 562-5A, solubilized both in gut juice and under alkaline conditions, has been studied by serological methods and compared with similar preparations from B. thuringiensis var. thuringiensis. It was found that strain 562-5A differs in at least one antigen from B. thuringiensis var. thuringiensis but shares at least four antigens with it. Crystals dissolved in Bombyx mori larval gut juice and subjected to electrophoretic separation gave fractions that were serologically similar but of different toxicity.