[A stat-method of determining antibiotic concentration in biological fluids]. / Ekspress-metod opredeleniia kontsentratsii antibiotikov v biologicheskikh zhidkostiakh.

The rapid method for measuring antibiotic concentrations in biologic substrates, developed by the authors, is based on the suppression of Staphylococcus aureus 209 P test culture dehydrogenase activity. Comparison of the rapid method and the routine agar diffusion test has shown a high correlation of the results, the correlation coefficient r being 0.84-0.93 and its probability 99.9%. The new technique permits getting an answer in 4 hours, is simple, and saves nutrient media.

[Use of a new method for restoring the type properties of atypical Vibrio cholerae]. / Ispol'zovanie novogo metoda dlia vosstanovleniia tipichnykh svoistv u atipichnykh kholernykh vibrionov.

Subcultures with a number of signs characteristic of epidemically significant strains have been isolated from cholera vibrios, nonpathogenic and atypical in a number of properties, by a new in vitro method developed by the authors. This method makes it possible to increase the virulence of poorly agglutinating cultures of V. cholerae O1 and their agglutinability with cholera antisera.

[Seasonal fluctuations in the antibiotic sensitivity of Vibrio cholerae]. / Sezonnye kolebaniia chuvstvitel'nosti k antibiotikam u kholernykh vibrionov.

Sensitivity of group 01 Vibrio cholerae to 6 antibiotics including tetracycline, ampicillin, benzylpenicillin, polymyxin M, erythromycin and novobiocin was studied during various seasons within 3 years. The antibiotic sensitivity of the cultures was assayed with the method of two-fold dilutions in solid medium AGV. The "clonal sensitivity" of the populations of the same strains was estimated by the original method developed by the authors. There were observed seasonal biorhythms in manifestation of the physiological functions by Vibrio cholerae reflected in altered "clonal sensitivity" of the populations to the antibiotics, altered multiplication intensity during various periods and seasonal dissociation with respect to the cultural and morphological features in the strains with altered properties.

[Variability of Vibrio cholerae as affected by subbacteriostatic concentrations of antibiotics]. / Izuchenie izmenchivosti kholernykh vibrionov pod vliianiem subbakteristaticheskikh kontsentratsii antibiotikov.

The effect of subbacteriostatic concentrations of some antibiotics on variation of the features characterizing the serovar and biovar of the cholera germ was studied on 10 strains of V. cholerae E1 Tor of the Inaba serovar having the typical properties. It was shown that even a single exposure to the subbacteriostatic concentrations of some antibiotics resulted in formations of clones differing from the parental strains by a number of significant features, such as the antigenic structure, phage lysability and enterotoxicity. The new features were inherited in a number of generations on multiplication in culture media and in sensitive animal hosts.

[Action of Vibrio cholerae enterotoxin on microorganisms]. / Deistvie énterotoksina Vibrio cholerae na mikroorganizmy.

The damaging of V. cholerae enterotoxin on anaerobic dehydrogenases of different species of opportunistic microorganisms has been revealed. Experiments, carried out both in vivo and in vitro, have shown that under certain conditions this enterotoxin may act as one of the factors of the intra- and interspecific antagonism of bacteria.

Investigation of populations heterogeneous according to O-antigen in Vibrio cholerae cultures.

The O-antigenic composition of 36 cultures of Vibrio cholerae agglutinating simultaneously with 01 cholera sera and 0 sera to NAG vibrios of the Sakazaki collection was investigated. It has been established experimentally that under the effect of medium and environmental conditions such cultures dissociate to subcultures differing in their affiliation to different serological groups according to 0 antigen. The passage of these cultures in the organism of susceptible animals promotes preservation of 01-group clones whereas the passage in peptone water or prolonged storage under unfavourable conditions result in the predominance of clones of different serological affiliation. The proposition has been put forward that the observed vibrio cultures are genotypically capable of producing, besides the 01 group, a number of 0 antigens. Phenotypical manifestation of the antigenic structure in the respective individuals of the population depends on the conditions of the environment.

[Model UF-2 mutant of Staphylococcus aureus 209 P for titrating Vibrio cholera enterotoxin]. / Model' UF-2 mutanta Staphylococcus aureus 209 P dlia titrovaniia énterotoksina kholernykh vibrionov.

The identical character of the action of crude V. cholerae enterotoxin on the anaerobic dehydrogenases of the UV-2 mutant of S. aureus 209 p and the surviving culture of Ehrlich's carcinoma has been revealed. The range of this action is linked with the concentration of the toxin and varies from the stimulation of cell dehydrogenases to their complete suppression. The rapid method for the titration of the enterotoxin in the dehydrogenase suppression test with the use of the bacterial model is proposed.

[In vitro determination of the biological activity of choleragen by the anaerobic dehydrogenase inhibition test in a surviving blastoma cell culture]. / Opredelenie biologicheskoi aktivnosti kholerogena in vitro po testu podavleniia anaérobnykh degidrogenaz perezhivaiushchei kul'tury blastomnykh kletok.

A rapid method for the detection and titration of choleragen in vitro in the test allowing one to evaluate dehydrogenase activity in the surviving blastoma culture has been developed. In comparison with the commonly accepted method of using the ligated loop in adult rabbits, the above method is simple, highly sensitive and economical.

[Seasonal fluctuations in the enteropathogenic properties of vibrios]. / Sezonnye kolebaniia énteropatogennykh svoistv u vibrionov.

Seasonal biorhythms with the intermittent periods of activity and rest in the manifestation of the enteropathogenic properties of cholera and NAG vibrios have been revealed. In the climatic conditions of the Rostov region the period of maximum activity in respect of this characteristic is shown to fall on spring and summer, while the period to rest is shown to fall on autumn and winter. In highly toxigenic cultures the phase of rest has been found to be considerably shorter than in cultures with low toxigenicity. The cyclic changes in the toxin-producing function of vibrios are suggested to be the main reason of the seasonal character of infections caused by cholera and NAG vibrios.

[Gentamycin sulfate in the therapy of acute and chronic pneumonias]. / Gentamitsina sul'fat v terapii ostrykh i khronicheskikh pnevmonii.

Clinical efficacy of gentamicin in treatment of acute and chronic pneumonia was shown. The wide antibacterial spectrum of the antibiotic provided its use in therapy of mixed bacterial infections. Satisfactory results were observed in 47 (93.7 per cent) out of 51 patients. The adverse reactions, such as proteinuria, hematuria, and polymorphous eruption were recorded in 5 patients and vanished after discontinuation of the drug. On the basis of the experience acquired the drug may be recommended for use in pulmonology.

[Sensitivity of Gram-negative microflora to lysozyme]. / Chuvstvitel'nost' gramotritsatel'noi mikroflory k lizotsimu.

Sensitivity to lysozyme of the representatives of various species of gramnegative microflora (476 strains) was studied with a new modified procedure, which is more exact and economic as compared to the method of serial dilutions in agar. High resistance of Eltor vibrio cholerae and Pseudomonas to lysozyme was found. Cultures of various sensitivity levels to lysozyme were detected among Aeromonas, enteropathogenic E. coli and NAG-vibrios.