[Antagonistic and insecticidal properties of soil micromycetes]. / Antagonisticheskie i insektitsidnye svoistva pochvennykh mikromitsetov.

It was shown that microscopic fungi isolated in plague foci had an antagonistic effect on the plague causative agent. In the majority of the cases it was associated with their insecticidal activity against plague-transmitting fleas. It is expedient to consider the relations revealed between the burrow biocenosis components in investigation of plague enzootic aspects and development of new biological insecticides for control of the infection carriers.

[Pathways of enzymatic inactivation of levomycetin in El Tor vibrios with plasmid and chromosome resistance to the antibiotic]. / Nekotorye puti énzimaticheskoi inactivatsii levomitsetina u vibrionov El-Tor splasmidnoi i khromosomnoi rezistentnost'iu k antibiotiku.

Two possible mechanisms of enzymatic inactivation of levomycetin, i.e. acetylation of OH-groups and reduction of the n-nitrophenylic component by the cells and cell-free extracts of V. eltor 2044 with the plasmid or chromosome types of antibiotic resistance were studied in vitro. The vibrio containing the extrachromosome determinants were resistant to a number of antibiotics. The rate of levomycetin acetylation by them under conditions of intensive aeration and reduction of the antibiotic aromatic nitrogroup in the absence of oxygen was high. The cells with the chromosome resistance had a trace activity of levomycetin acetyltransferase. Still, they rather rapidly reduced levomycetin into its aminoderivative (during 2-hour incubation in the atmosphere of nitrogen 70-80% of the substrate are transformed into its summary arylamine). The antibiotic sensitive vibrio practically had no capacity for acetylation of levomycetin but could transform it into the reduced aminoderivative though to a less extent than the antibiotic resistant cells.

[Effect of several antibiotics and their combination with prodigiozan on Y. pestis EV, engulfed by macrophages]. / Vliianie mekotorykh antibiotikov i ikh sochetanii s prodigiozanom na Y. pestis EV, pogloshchennye makrofagami.

The effect of various antibiotics, such as streptomycin, gentamicin, ampicillin, benzylpenicillin, tetracycline, chlortetracycline and levomycetin on the plague bacteria (strain Y. pestis EV) located inside the cells was studied. Peritoneal macrophages of albino mice with aceptic inflammation of the abdominal cavity caused by intraperitoneal administration of 2 ml of sterile meat-peptone broth were used in the experiments. The ratio of the macrophages and microbes was 1 : 50. A part of the mice were treated with prodigiozan 24 hours before taking the exudate. The preparations of the macrophages of albino mice with the microbes absorbed by them served as the control. The effect of the antibiotics and their combinations with prodigiozan was stimated by the coefficient of multiplication suppression against the control. The observations were made in dynamics. The studies showed that the macrophage activity of the mice treated with prodigiozan after exposure to the antibiotics was reliably higher than that in the control and digestion of the microbes located inside the cells started earlier, providing more complete phagocytosis.