Leonora H. Pugh

Observations on Antiviral Activity of Viscosin.

Summary Viscosin was found to exert a marked protective effect in embryonated eggs subsequently infected with infectious bronchitis virus. A slight but detectable suppressive effect on the progress of infection in mice infected with influenza A virus was demonstrated.

In vivo Activity of Streptothricin Against Brucella abortus.

Summary Streptothricin, an antibiotic substance obtained from a soil Actinomyces, has been tested against Brucella abortus both in vitro and in vivo with favorable results. Experiments with incubating eggs established that the toxicity of streptothricin is low enough to make possible the administration of doses sufficient to destroy Br. abortus in the living tissues. Studies with guinea pigs indicated that streptothricin offers considerable promise as an antibiotic agent against brucellosis in animals.

Suppression of Viral Pneumonia in Mice by a Microbial Product (APM)

Summary A material (APM) produced by a culture of Achromobacter sp., was found to possess a unique combination of biological characteristics, (a) APM was not inhibitory to representative species of bacteria or fungi in vitro, (b) Preparations capable of suppressing the development of pulmonary lesions in mice previously infected with influenza A virus were found to be devoid of virucidal activity in vitro and failed to affect the production of infectious virus in lung tissue or allantoic fluid. (c) The mouse was a far better host than the embryonated egg for the demonstration or detection of inhibitory effects of APM on influenza A virus. (d) Hemagglutination in vitro by influenza A or B virus was not affected by the presence of APM. (e) The most interesting characteristic of APM was its capacity to suppress the development of non-transmissible pneumonia in mice induced by intranasal inoculation of Newcastle disease virus.

Effect of gonadal hormones on experimental infection of rats with Brucella abortus.

Summary Testosterone propionate significantly increased the resistance to experimental Br. abortus infection in the small number of rats used in this experiment. The effect was more pronounced in the females than in the males. This correlates with the fact that A.L.D. for Br. abortus for mature male rats is twice that for mature females and immature male and female rats.

Auto-interference associated with influenza B virus.

Summary Experiments are described illustrating (a) the use of death of the embryo as a criterion for the measurement of infectivity and interference, (b) an increase in the amount of interfering material present in allantoic fluid following death of the embryo and (c) the absence of demonstrable auto-interference following inoculation into the yolk sac.