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Biomedical subjects

S Masuda

Publications and source records attributed to S Masuda.

At least 415 records · Page 23Linked to original sources
PubMed1975

Simple and effective method for selecting protein A-dificient mutants by consedimentation with sensitized sheep erythrocytes.

An effective slection method for protein A-deficient mutants was devised by means of cosedimentation with sensitized sheep erythrocytes and anti-protein A serum agar plates. Hitherto, two types of mutants have been successfully isolated by this method. One was deficient in both cell-bound protein A and soluble protein A. The other seems to release extracellularly soluble protein A but does not possess cell-bound protein A. Spontaneous mutants of the former type were contained in the culture of Staphylococcus aureus 248betaH in a concentration of approximately 10-minus-5, which is ten times as much as the latter. Repeated cosedimentation procedure greatly increased the efficiency of isolation of the mutants. As a result, a majority of the bacterial cells remaining in the final supernatant after three cosedimentation procedures were of the two mutant types. Details of the method as well as some preliminary results are described.

Animals↗
PubMed1971

Effects of intrarenal inoculation of Staphylococcus aureus on mice.

The extreme susceptibility of the mouse kidney to infection with Staphylococcus aureus was confirmed by direct intrarenal (i.r.) inoculation with this organism. By applying Poisson's distribution formula to the results from infection of mice with small inocula (as few as one coccus or less per kidney), it was estimated that even three organisms could multiply in situ to produce abscess lesions, if the organisms were inoculated directly into the kidneys. This susceptibility of the mouse kidney for staphylococcal infection was not uniformly manifested with every strain, but correlated well with the virulence found through intravenous infection of the strains tested. The i.r. inoculation method by which infection of mice was easily established, using a small inoculum of S. aureus, similar to the amount suspected to occur in natural infections of man, is applicable for the analysis of the mechanisms of staphylococcal infections and any resulting immunity in man. The present paper describes the details and some experimental results obtained by our method.

Animals↗