Isolation From Normal Mice of a Pneumotropic Virus Which Forms Elementary Bodies

Abstract

In the course of attempts to isolate viruses by direct inoculation of albino Swiss mice with throat washings from clinical cases of influenza, non-influenzal pneumonias were frequently encountered in the passage mice. The pneumonias observed were of two types. One type was indistinguishable in the gross from that produced by influenza virus and the etiological agent of this type was found to be a filterable virus which was subsequently identified, on the basis of serological reactions, with that described by Horsfall and Hahn (1). Dochez, Mills, and Mulliken (2) and Gordon, Freeman, and Clampit (3) have described similar pneumonia-producing viruses isolated from apparently normal mice. The second type of pneumonia encountered was likewise found to be due to a filterable virus, but the microscopic demonstration of elementary bodies, the characteristic appearance of the early lesions, the greater virulence, and the serological reactions definitely distinguish this virus from the former. A brief description of it has been published (4). It will be dealt with in detail here. Isolation of VirusAlbino Swiss mice from 4 to 5 weeks old were used throughout the course of this study. The first strain (a) of this virus was isolated in March 1939, a second strain (b) was isolated in April, and a third (c) in May of the same year. These three strains were derived from mice in the course of serial passages of throat washings from three different cases of clinical influenza. The passages were initiated by the intranasal inoculation of three or four mice with 0.05 co. each of untreated throat washings from the respective patients. Although neither the mice nor the lungs showed gross signs of infection within 5 to 6 days after inoculation of the throat washings, the pooled lungs from each strain were ground with alundum and sufficient broth to give approximately 10 per cent

Chlamydial Respiratory Infection during Allergen Sensitization Drives Neutrophilic Allergic Airways Disease

“…These studies employed the natural mouse pathogen C. muridarum, which was originally isolated from a mouse with respiratory infection (33,34). The time course, as well as the immunological and histopathological progression, of C. muridarum infection of mice closely resembles that observed with Chlamydophila pneumoniae infection in humans (8, 9).…”

Closing in on Chlamydia and its intracellular bag of tricks

“…However, relatively little can yet be gleaned from genome comparisons on differential pathogenic properties of chlamydiae. Five of the six fully sequenced genomes are from chlamydiae infecting humans, with the remaining one being from the mouse biovar of C. trachomatis (MoPn), which was initially isolated from lungs of serially passaged mice inoculated with throat washings from clinical cases of human influenza (Nigg & Eaton, 1944). Moreover, only limited consideration of the evolutionary path of Chlamydia has been possible to date as the genome sample size is still too small (C. trachomatis and C. pneumoniae).…”

Studies on Pneumonia Virus of Mice (Pvm)

“…This virus was recognized first in 1938 in New York during the course of studies with Swiss mice. It has been encountered since in similar mice in California (3) and Minnesota (4). Further investigations carried out in this laboratory revealed that pneumonia virus of mice could be obtained from numerous different stocks of mice, and that latent infection by it was not confined solely to Swiss mice.…”