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Biomedical subjects

A Roy

Publications and source records attributed to A Roy.

At least 541 records · Page 30Linked to original sources
PubMed1970

Increased fragility of Escherichia coli after infection with bacteriophage M13.

Male strains of Escherichia coli infected with filamentous phage M13 released the progeny phage particles from intact cells. At the same time, the cells continued to grow and multiply at a slightly lower rate than the uninfected cells. Concomitant with the phage release, lipopolysaccharide from the cell wall of the infected cells was also released. The buoyant density of E. coli HfrC in diaginol, 1.25 g/cc, did not change as a result of infection. Detergents like sodium dodecyl sulfate and Sarkosyl specifically lysed the infected cells. The infected cells showed enhanced fragility as indicated by inactivation by various stresses, namely heat, osmotic shock, and freezing and thawing. It is concluded that the infection with M13 causes certain alterations in the surface structure of E. coli, thus making the cells more fragile.

Coliphages↗
PubMed1969

Correlations between virulence and other characters of Clostridium perfringens type A.

The correlation analysis which has already proved its value in ecology has not yet been applied to the determination of virulence indicators. Its application to a group of Clostridium perfringens type A strains has brought out some characters that may be considered as virulence indicators. This study suggests that the toxicity of the culture supernatant fluids for mice is significantly correlated with the virulence for mice and guinea pigs. A significant correlation was found between the virulence of the fluid cultures for mice or guinea pigs and the coagulation of milk, production of gas (in deep agar), hydrogen sulfide production, and fermentation of glucose, sucrose, maltose, and levulose.

Animals↗