[Pathomorphological changes in albino mice infected with plague and treated with cefotaxime]. / Patomorfologicheskie izmeneniia v organizme belykh myshei, zarazhennykh chumoi i lechennykh tsefotaximom.

Pathomorphological and bacteriological changes in albino mice infected with plague and treated with cefotaxime were investigated. The control animals which died within 3 days had structural changes characteristic of generalized plague with lesions in the infection site, regional lymph nodes, spleen, liver and lungs. The plague microbe was isolated from the tissues of all the organs and blood. The animals treated with cefotaxime (200 mg/kg for 7 days) survived. The histological examination conclusively demonstrated the absence of the changes characteristic of generalized plague in their internal organs. The infection process was mainly restricted by the primary complex and was strictly localized. The tissue reaction around the focus in the second part of the experiment developed in accordance with the productive type inflammation followed by the organization and cicatrization. In the bacteriological investigation the plague causative agent was detectable during the first days of the treatment in the site of the infection. During the subsequent days the plague microbe was not detected.

[The protective activity of the adhesion pili of Yersinia pestis]. / Izuchenie protektivnoi aktivnosti pilei adgezii Yersinia pestis.

Y. pestis adhesion pili (AP) in the native form and in the subunit form, used for immunization in one or two injections in a dose of 12-100 mu g on aluminum hydroxide, did not protect white mice and guinea pigs from experimental Y. pestis infection. The study revealed that AP produced a pronounced cytotoxic effect on macrophages and practically no influence on leukocytes. This result was confirmed in the study of luminol-dependent chemiluminescence and in the analysis of 5'-nucleotidase activity of phagocytes. These data make it possible to regard AP as Y. pestis antimacrophagal pathogenicity factor.

[Effectiveness of doxycycline in experimental plague]. / Effektivnost' doksitsiklina pri éksperimental'noi chume.

The activity of doxycycline and tetracycline against natural strains of the plague microbe of different origin was studied in vitro. The MICs of doxycycline and tetracycline for the majority of the strains were 0.8 and 3.2 micrograms/ml respectively. The efficacy of doxycycline and tetracycline in the prophylaxis and treatment of experimental plague infection was studied comparatively on albino mice. Doxycycline proved to be superior to tetracycline. By using short-term schemes of the treatment and longer intervals between the drug administrations it was shown that doxycycline had a prolonged action. Moreover, the injectable doxycycline was found to be superior to the oral one. The high efficacy of doxycycline in the treatment of the albino mice with experimental plague infection was confirmed by the pathohistological findings. The pathomorphological changes in the animals were limited by local affections in the site of the contamination and the regional lymph nodes followed by the development of infiltration foci.

[Avian CELO adenovirus as a possible contaminant in cell cultures of Japanese quail embryos]. / Adenovirus ptits CELO kak vozmozhnyi kontaminant kul'tur kletok émbrionov iaponskikh perepelov.

Avian adenovirus CELO was found to replicate poorly in Japanese quail embryos (JQE) and cell cultures of them. The infectious process in these systems was latent. The antigen of adenovirus CELO in JQE cell culture was detectable by the fluorescent antibody method (FAM) within the first 24-72 hours after inoculation as fluorescent cytoplasmic granules. Subsequently, fluorescence of nuclei and macrophage cytoplasm was observed. The results indicate that JQE and their cell cultures are not contaminated with avian adenovirus CELO despite regular circulation of this agent among avian populations. The advantages of FAM (rapidity and clearness) for identification of adenovirus as substrates contaminant as compared with other biological methods have been demonstrated.