Genetically resistant C3H mice have been made phenotypically susceptible to mouse hepatitis virus (MHV) by cortisone (1), cytoxan (2), and eperythrozoon infection (3). There is extensive evidence that cultured macrophages from genetically resistant or susceptible strains of mice reflect the genetic resistance or susceptibility of the host. Yet the effects of cortisone, cytoxan, and epierythrozo...

Eperythrozoon coccoides is a common blood parasite of rodents and the etiological agent of a chronic infection present in many mouse colonies. After primary infection, mice develop a parasitemia and anemia followed by a chronic, latent infection. During the acute phase of infection, mice manifest a striking suppression of interferon production in response to induction with Newcastle disease vir...

Eperythrozoon coccoides was shown to inhibit the interferon response in mice only during the first 3 weeks after acute infection. By 6 weeks the production of interferon in response to Newcastle disease virus returned to a normal level. Antibody to E. coccoides could be demonstrated by three methods: (i) neutralization, (ii) indirect fluorescent antibody, and (iii) gel diffusion. The clearance ...

The 16S rRNA gene sequences of Mycoplasma cavipharyngis and Mycoplasma fastidiosum have been determined. Phylogenetic analysis showed that these species formed a new cluster within the so-called pneumoniae group of the mollicutes (class Mollicutes). This cluster will be referred to as the M. fastidiosum cluster. Interestingly, the M. fastidiosum cluster formed a sister lineage to the haemotroph...

Several workers have observed the incidental occurrence of a viral disease in various strains of transplantable leukemias in mice. Nelson (1-4) has fully described a filterable agent causing acute hepatitis in leukemic mice of the Princeton strain. Although he made repeated efforts to keep the leukemia in passage, it was regularly lost after a few transfers. Marked pathological changes were not...