1. When a relatively avirulent strain of hemolytic streptococcus was injected into the skin of rabbits a considerable amount of skin sensitivity to streptococcus filtrate developed, and there was scant demonstrable immunity. 2. When the same strain of streptococcus was made highly virulent by repeated passages through rabbits, little sensitization and considerable immunity was produced. 3. Rabb...

It was found in a previous investigation that various virulent strains of Pasteurella pestis showed a reduction in virulence in aerated broth at 37 C whenever several generations of growth occurred either from small inocula (104 cells/ml) or after repeated passage using larger inocula (Fukui, et al., 1957b). This attenuation seemed to be caused by growth conditions favoring the selection of avi...

We modified the haemagglutinin-neuraminidase (HN) glycoprotein of the virulent Newcastle disease virus (NDV) strain Banjarmasin/010/10 (Ban/010) by adding C-terminal extensions similar to those found in certain avirulent NDV strains. Extension of the 571 aa wt Ban/010 HN protein to 577 and 616 aa by removal of one or two translational stop codons moderately reduced HN function and viral pathoge...

The production of reactive oxygen species (ROS), via consumption of oxygen in a so-called oxidative burst, is one of the earliest cellular responses following successful pathogen recognition. Apoplastic generation of superoxide (O2 ), or its dismutation product hydrogen peroxide (H2O2), has been documented following recognition of a variety of pathogens (Doke, 1983; Auh and Murphy, 1995; Grant ...

The production of reactive oxygen species (ROS), via consumption of oxygen in a so-called oxidative burst, is one of the earliest cellular responses following successful pathogen recognition. Apoplastic generation of superoxide (O2 ), or its dismutation product hydrogen peroxide (H2O2), has been documented following recognition of a variety of pathogens (Doke, 1983; Auh and Murphy, 1995; Grant ...

XBAT35 belongs to a subfamily of Arabidopsis (Arabidopsis thaliana) RING-type E3s that are similar in domain architecture to the rice (Oryza sativa) XA21 Binding Protein3, a defense protein. The XBAT35 transcript undergoes alternative splicing to produce two protein isoforms, XBAT35.1 and XBAT35.2. Here, we demonstrate that XBAT35.2 localizes predominantly to the Golgi and is involved in cell d...

US policy regarding health care worker-to-patient transmission of bloodborne pathogens, issued in 1991, is flawed. We review current evidence of such nosocomial infections and conclude that a standardized national policy is needed, which includes improved surveillance and follow-up of blood exposures to patients and targeted practice restrictions for infected practitioners performing exposure-p...

The multiple banded antigen (MBA) is a predicted virulence factor of Ureaplasma species. Antigenic variation of the MBA is a potential mechanism by which ureaplasmas avoid immune recognition and cause chronic infections of the upper genital tract of pregnant women. We tested whether the MBA is involved in the pathogenesis of intra-amniotic infection and chorioamnionitis by injecting virulent or...

To elucidate the relationship between the virulence of intracellular bacterium and its ability to induce 3'/8 T cells in the host during infection, we examined the differences in appearance of 3'/8 T cells in mice infected with Salmonella choleraesuis virulent strain RF-1 carrying a virulence plasmid of 50 kb, and with avirulent strain 31N-1 cured of the 50-kb plasmid. The number of 3'/8 T cell...

Highly virulent avian influenza viruses can arise from avirulent strains maintained in poultry, but evidence to support their generation from viruses in wild birds is lacking. The most likely mechanism for the acquisition of virulence by benign avian viruses is the introduction of mutations by error-prone RNA polymerase, followed by the selection of virulent viruses. To investigate whether this...