[Antimicrobial effect of irradiation with ionized plasma]. / Antimikrobnyi éffekt izlucheniia ionizirovannoi plazmy.

Ion plasma light flux has been found to possess bacteriostatic effect in vitro and in vivo. Three-fold irradiation with ion plasma of a wound infected by a pathogenic Staphylococcus aureus strain reduced phase I of wound healing by three days and the overall time of healing by four-five days.

[Mutagenic effects of ionized plasma light flux]. / Issledovanie mutagennogo deistviia svetovogo potoka ionizirovannoi plazmy.

The effect of ion plasma light flux on the genomes of auxotrophic Escherichia coli strain and Drosophilla melanogaster has been examined. Essentially no mutagenic effect was found in doses close to therapeutic ones.

[Analysis of plasmid profile of antibiotic-resistant Enterobacteriaceae circulating in hospitals]. / Analiz plazmidnogo profilia antibiotikoustoichivykh enterobakterii, tsirkuliruiushchikh v statsionare.

Certain pheno- and genotype properties of S. typhimurium and some other representatives of Enterobacteriaceae resistant to antimicrobial drugs were studied. The strains were isolated from children with salmonellosis within 4 months when an infection hospital was subjected to microbiological observation. It was shown that by their antibiotic resistance, phagovars and molecular weights of the plasmid DNas, the strains S. typhimurium were similar to those isolated during hospital infections. The conjugative plasmids responsible for antibiotic resistance in some strains did not differ in their molecular weights and antibiotic resistance markers. The strains S. typhimurium similar in their pheno- and genotype properties were isolated only from 2 patients which allowed one to consider it possible that the patients were infected by the strains of common genesis. Analysis of nonpathogenic representatives of Enterobacteriaceae isolated from the patients along with the S. typhimurium strains confirmed the fact that the patients were infected with the same pathogenic strain.

[Resistance to antibacterial drugs of Enterobacteriaceae isolated from healthy children and from those with Salmonella infections]. / Ustoichivos't k antibakteria'lnym preparatom assotsiiatsii enterobakterii, vydelennykh ot zdorovykh i bo'lnykh sa'lmonel- lezom detei.

A total of 2329 Enterobacteriaceae strains in bacterial associations isolated from healthy children and children with salmonellosis were tested for their resistance to antimicrobial drugs. It was shown that the aerobic microbial associations isolated from the healthy children contained higher numbers of strains sensitive or resistant to 1-3 antibiotics while the microbial associations from the children patients with salmonellosis treated with antibiotics contained higher numbers of strains resistant to 6-8 antibiotics. Resistance of the aerobic bacterial associations was mainly defined by resistance of E. coli and K. pneumoniae. The feces of the healthy children never treated with antimicrobial drugs contained strains resistant to them. The use of the antibiotics in the treatment led to increasing numbers of the resistant bacteria and changing species composition of the bacterial associations.

[Effect of cyclic 3,5-adenosine monophosphate on the virulence of Salmonella typhimurium]. / Vliianie tsiklicheskogo 3,5-adenozin-monofosfata na virulentnost' Salmonella typhimurium.

To study the role of cAMP in the virulence of S. typhimurium, cAMP-producing plasmid pTG 4 was transferred to cAMP-deficient S. typhimurium mutant. The transfer of the plasmid enhanced the virulence of the microorganisms due to the increased destruction of macrophages and the intensified multiplication of salmonellae in the spleen of mice.

[Characteristics of microbial associations represented by the Enterobacteriaceae family isolated from the feces of healthy children and children with salmonellosis]. / Osobennosti predstavlennykh mikroorganizmami semeistva Enterobacteriaceae assotsiatsii, vydelennykh iz isprazhnenii zdorovykh i bol'nykh sal'monellezom detei.

Associations formed by microorganisms of the family Enterobacteriaceae in feces have been studied using the principles of ecological investigation. The study has revealed that the associations isolated from children with salmonellosis sharply differ from those isolated from healthy children in the number of species and in the variety of their combinations, as well as in changes in the proportion of different species, observed in multiple investigations.

[Strains of the family Enterobacteriaceae isolated from chronic bacterial carriers of Salmonella typhi and Salmonella schottmuelleri and from healthy persons]. / Izuchenie shtammov semeistva Enterobacteriaceae, vydelennykh ot khronicheskikh bakterionositelei Salmonella typhi i Salmonella schottmuelleri i ot zdorovykh liudei.

Fecal samples obtained from 51 chronic carriers of S. typhi and S. schottmuelleri and from 35 healthy persons were studied. Strains of different species of Enterobacteriaceae were isolated and identified. The resistance of the isolated strains to the most commonly used antibiotics was determined. The fecal samples of the carriers were found to yield a greater number of strains than those of the healthy persons. Among the strains isolated from the carriers a variety of species was noted. S. typhi and S. schottmuelleri strains were found to be sensitive to the tested antibiotics. Antibiotic-resistant strains were mostly isolated from members of the medical staff.

[Relation of Salmonella typhi and Salmonella gallinarum auxotrophicity to the ability to grow on Simmons' medium]. / Sviaz' auksotrofnosti Salmonella typhi i Salmonella gallinareum so sposobnost'iu rasti na srede Simmonsa.

A total of 9 S. typhi strains and 1 S. gallinarum strain isolated from clinical material are auxotrophic with respect to tryptophan. The growth of S. typhi is accelerated in a glucose- and tryptophan-containing minimal medium with cysteine and methionine added. S. typhi strains are incapable of using sodium citrate as the only source of carbon. S. typhi cannot grow on Simmons citrate agar as these organisms are auxotrophic with respect to tryptophan and incapable of using sodium citrate as the only source of carbon, and S. gallinarum cannot grow on this medium as they are auxotrophic with respect to tryptophan.

[Transfer of kanamycin resistance among familial strains of Enterobacteriaceae isolated from a chronic bacterial carrier of Salmonella schottmuelleri]. / Peredacha ustoichivosti k kanamitsinu sredi shtammov semeistva Enterobacteriaceae, vydelennykh ot khronicheskogo bakterionositelia Salmonella schottmuelleri.

Escherichia coli, Enterobacter aerogenes and S. schottmuelleri were isolated from the large intestine of a bacteriocarrier. E. coli and E. aerogenes strains proved to be resistant to a number of antibiotics. Plasmids were detected in DNA preparations obtained from E. coli strains. After the hybridization of these E. coli strains with E. coli C600 5K and S. schottmuelleri at 28 degrees C the transfer of resistance to kanamycin was found to occur. From some of the transconjugates thus obtained resistance to kanamycin was transferred to E. aerogenes. This resistance was found to be controlled by the plasmid with a molecular weight exceeding 2 Md. The fact that S. schottmuelleri in the carrier's body retained their sensitivity to antibiotics can be explained by the absence of the transfer of plasmid Kmr at a temperature exceeding 28 degrees C and by the existence of the infective agent in an ecological niche other than that of E. coli.

[Possibilities of biochemical identification of the Enterobacteriaceae family by conventional methods]. / Vozmozhnosti biokhimicheskoi identifikatsii semeistva Enterobacteriaceae obshchepriniatymi metodami.

A total of 579 strains of the family Enterobacteriaceae, isolated from differential diagnostic media, were analyzed by means of 20 standard tests. In 1.8% of the analyzed strains their species and genus could not be determined due to unusual reactions in the tests of amino acid decarboxylation and utilization of some carbohydrates.

[Biosynthetic incorporation of fluorescently labelled fatty acids in Escherichia coli]. / Biosinteticheskoe vkliuchenie fluorestsentno mechenykh zhirnykh kislot v Escherichia coli.

Escherichia coli cells were cultivated in a medium containing 1-pyrene butanoic acid, a fluorescent probe. Total lipids were extracted from the cells, and the extract was separated by thin-layer chromatography. The fluorescent fractions were examined using spectrofluorimetry. The starting 1-pyrene butanoic acid was shown to be biosynthetically incorporated into the bacterial lipid. Four fluorescent fractions appeared as a result; the fractions were derivatives of this compound modified in the chromophore and the fatty acid chain. The results indicate that the formation of 1-pyrene butanoic acid fluorescent metabolites can be used for studying the oxidation-reduction systems of the bacterium.

[Identification of nonspecifically agglutinating strains of enterobacteria]. / Identifikatsiia nespetsificheski aggliutiniruiushchikhsia shtammov énterobakterii.

Eight nonspecific agglutinating enterobacterial strains have been classified with the definite taxon on the basis of the data obtained by the study of their biochemical and serological properties. The possibilities offered by the supplementary methods for the study of such strains in practical laboratories are discussed.

[Interrelation between the presence in enterobacteria of distinct biological properties and their capacity to colonize the small intestine in the early stage of the development of postradiation dysbacteriosis]. / Izuchenie vzaimosviazi mezhdu nalichiem u énterobakterii opredelennykh biologicheskikh svoistv i ikh sposobnost'iu zaseliat' tonkii kishechnik na rannei stadii razvitiia postluchevogo disbakterioza.

An increase in the percentage of antibiotic resistant and hemolysin-producing enterobacteria occurring in the process of the development of postradiation intestinal dysbacteriosis was due to a sharp increase in the number of such bacteria among the representatives of the genera inhabiting the large intestine of mice (E. coli, E. aerogenes, E. cloacae, P. morganii) and to the appearance of antibiotic-resistant and hemolysin-producing strains in the intestinal tract; these strains belonged to the genera which had not been detected in the intestines of the animals before irradiation. In postirradiation dysbacteriosis a considerable decrease in the percentage of colicin-producing strains was observed. The dissemination of enterobacteria in the small intestine of irradiated mice occurred as the result of exogenous and endogenous infection.

[Limits of the biochemical variability of the Salmonellae isolated from human beings and their possible identification]. / Granitsy biokhimicheskoi izmenchivosti vydelennykh ot liudei sal'monell i vozmozhnost' ikh identifikatsii.

The biochemical properties of 217 Salmonella strains isolated from patients, convalescents and carriers have been studied. Salmonellae with changes in a number of characteristics important for microbiological diagnosis have been found. The possibility of their identification is shown. The probable causes of their appearance are discussed. Recommendations for their detection are given.

[Change in the biological properties of salmonellae in acquiring resistance to chloramphenicol]. / Izmenenie biologicheskikh svoistv sal'monell v usloviiakh priobreteniia ustoichivosti k khloramfenikolu.

Mutants of Salmonella typhimurium and Salmonella abony resistant to 40 microgram/ml of chloramphenicol were obtained during selection according to the method of Szybalski on Hottinger broth with increasing concentrations of the antibiotic. By the colony morphology the mutants were divided into 4 groups. The study of the mutant biological properties revealed changes in the growth rate characterized by elongation of the lag-phase and exponential phase, changes in the biochemical activity evident from lower fermentation rate of some carbohydrates and production of hydrogen sulphide and changes in some amino acid dependence. Increased cross resistance to tetracycline and benzylpenicillin and decreased resistance to kanamycin were noted. The LD50 of most mutants was increased as compared to that of the initial strains. Combination of several types of the changes was observed in some mutants. It is supposed that resistance to chloramphenicol in the mutants is due to mutations in several genes. Some of such genes had pleuotropic effect because of the changes in the structure of the ribosome 50S subunits.

[Physiological characteristics of Salmonella typhimurium treated with penicillin]. / Fiziologicheskie osobennosti Salmonella typhimurium pri obrabotke penitsillinom.

Growing bacteria of the two strains of Salmonella typhimurium differing in the sensitivity levels to UV-light formed multinuclear non-septal filaments in the penicillin-containing nutrient medium. The maximum number of the lifefull filaments was formed by the 4th hour of incubation in the beaf-peptone broth at a temperature of 37 degrees C in the presence of 5 gamma/ml of penicillin. The strains exposed to penicillin were less sensitive to UV-light. Exclusion of penicillin from the nutrient medium resulted in a new division of the filamentous cells and reduction of the initial UV-light sensitivity level. It was concluded that the low UV-light sensitivity level of the filaments induced by penicillin was associated with their multinuclear state.