background and objectives: isolation of xanthomonas campestris from soil has a wide range of applications from monitoring of phytopathogenic populations in soil to screening of improved xanthan-producing strains. identification of xanthomonas campestris and its pathovars requires pathogenicity tests in addition to phenotypic and molecular characterization. materials and methods: thirty phenotyp...

Stochastic switching is an example of phenotypic bet hedging, where offspring can express a phenotype different from that of their parents. Phenotypic switching is well documented in viruses, yeast, and bacteria and has been extensively studied when the selection pressures vary through time. However, there has been little work on the evolution of phenotypic switching under both spatially and te...

This study reports the rates of phenotypic switching in strains of Candida albicans isolated from superficial and invasive infections. Of 19 invasive strains, 68% showed switching activity, often at very high rates, compared with only 28% of 40 strains isolated from superficial sites (P = 0.004).

A study of cell surface phenotypes of PBL of myasthenia gravis (MG) patients showed that their T cells had a significantly higher percentage of 4B4+ T cells (the helper/inducer subset) than ageand sex-matched controls. The PBL of MG patients proliferated significantly higher than those of normal subjects (NS) in response to the purified a chain of the acetylcholine receptor (AChR). Anti-AChR an...

Although the CD5 (T1) antigen was initially described as a pan-T cell membrane glycoprotein, we report that 14 of 40 normal individuals were found to have 5% or greater of their blood mononuclear cells characterized as CD3 (T3)+ but CDSby dual immunofluorescence flow cytometry. These cells expressed normal quantities of surface CD3 and CD2 but low levels of CD7, were CD8' and CD4-, and CD16-. I...