No abstract

The effects of culture conditions (aerobic or anaerobic) and glucose in the medium on the production of spirosomes in Escherichia coli B were studied by SDS-PAGE and electron microscopy. The M, of the spirosome of E. coli B was estimated to be 97000. Electron microscopy revealed that the amount of spirosomes derived from anaerobic cultures was about eightfold larger than that from aerobic cultures. In SDS-PAGE, the bands of spirosome protein derived from anaerobic cultures were more intense than those derived from aerobic cultures, either in peptone water or in Davis-Mingioli's minimal medium. With increased glucose concentration under aerobic conditions, the intensity of the band of spirosome protein was similar to that observed under anaerobic conditions in basal media. These results suggest that spirosome production by E. coli B is related to its anaerobic glycolysis activity.

A mixture of extracellular carrageenases was isolated from the cell-free medium of a culture of marine Cytophaga sp. 1k-C783 grown on ZoBell 2216 E broth with 0.1% commercial carrageenan. A single active peak of K-carrageenase was separated and purified from the mixture by ammonium sulfate precipitation, ionexchange chromatography, and Sephadex G-200 gel filtration chromatography.

Serological examination of bovine and human sera for antibodies against Coxiella burnetii was carried out by the immunofluorescence technique.Twenty to 30% of the cows examined were antibody-positive.Sera from two veterinarians also had antibody against C. burnetii. These results suggest an increase in the number of infected cows with C. burnetii in Japan since 1954, and also imply the possibility of the prevalence of acute Q fever in the human population, which had been underestimated and undiagnosed for the last three decades.

A survey of Angiostrongylus cantonensis was carried out to investigate the mode of transmission from molluse to rat in a fixed study area of Yoron Island from 1979 to 1982. Rattus rattus was found to be infected with a small number of worms in spite of heavy infection with third-stage larvae in Achatina fulica and an abundance of this snail in the area. Natural infection and/or susceptibility with A. cantonensis were confirmed in three small snail species. Bradybaena circulus, Fruticicola despecta and Luchuena reticulata. Young A. fulica was found to be infected with fewer third-stage larvae than mature A. fulica. It was concluded that molluscs which were infected with a small number of third-stage larvae of A. cantonensis play an important role in maintaining the life cycle of A. cantonensis. The percentage of rat stomachs containing molluse tissue was relatively low, and the incidence and infection was low in rats. Infection with A. cantonensis did not occur very often in R. rattus in nature.