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Biomedical subjects

L I Glatman

Publications and source records attributed to L I Glatman.

At least 19 recordsLinked to original sources
PubMed1994

Genetic and molecular R-plasmid analysis of Enterobacteriaceae hospital strains at Children's Hospitals of the former USSR.

R-plasmids from Enterobacteriaceae clinical strains, mainly Klebsiella and Serratia, isolated at different neonatal and children's hospitals of different cities of the former USSR for 10 years, were studied for their possible influence on the bacterial host phenotype. Hospital R-plasmids of stable inheritance persisted in hospitals from 2 to 7 years and were disseminated among strains of different genera (Klebsiella, Serratia, Enterobacter) and among different units. The data showed a possibility of long-term molecular rearrangements of R-plasmids in the hospital settings and an acquisition of genetic determinants encoding enterotoxin production. A novel R-plasmid encoding cytotoxicity to HEp-2 cells involved in two nosocomial outbreaks due to K. pneumoniae strains was reported. K. pneumoniae population heterogeneity was evaluated by using the plasmid parameters of strains. Their heterogeneity of a bacterial population was significantly lower during nosocomial outbreaks than in interepidemic periods.

Base Sequence↗
PubMed1993

The cleavage sites and localization of genes encoding the restriction endonucleases Eco1831I and EcoHI.

The restriction endonucleases Eco1831I and EcoHI cleave before the first 5'-cytosine in the recognition sequence 5'-decreases CCSGG--3'/3'--GGSCC increases-5' (where S = G or C), generate 5-base 5' cohesive ends, and are encoded by homologous plasmids that are restricted in McrA+ hosts. Thus, they differ in their cleavage specificity from that of the BcnI isoschizomer, which cleaves after the second 5' cytosine.

Cloning, Molecular↗
PubMed1992

[The resistance plasmid of Klebsiella pneumoniae that controls its cytotoxic activity].

R-plasmid (40 MD) isolated from K. pneumoniae hospital strain makes Escherichia coli strain J62 capable of inducing a cytotoxic effect which can be detected in Hep-2 cell culture. In contrast to the initial E. coli strain J62 producing no changes in the monolayer, E. coli J62 cells containing P-plasmid induced pronounced cytotoxic changes and a sharp increase in the number of nonviable Hep-2 cells by hour 24 of interaction.

Bacterial Adhesion↗
PubMed1990

[A new site-specific endodeoxyribonuclease EcoHI].

A new sitespecific endonuclease of the II class EcoHI has been isolated from Escherichia coli strain and characterized. Restriction endonuclease EcoHI recognises the nucleotide sequence C C (C/G) G G with the cleavage site between the fourth and fifth nucleotide. It is an isoshizomer of the restriction endonuclease CauII. The yield of enzyme is 2500 units of activity per 1 g of biomass. The producing strain Escherichia coli HI is nonpathogenic, easily grown with the antibiotic resistance markers permitting to cultivate the strain under selective conditions.

Base Sequence↗
PubMed1988

[Physico-chemical and biological characteristics of Pseudomonas aeruginosa elastase].

Elastase isolated from P. aeruginosa clinical strain hydrolyzes elastin, casein, hemoglobin, ovalbumin, gelatin, fibrin, collagen. The optimum pH ensuring the activity of the enzyme is 7.8-8.0. Elastase shows maximum stability at pH 6.6-9.0. Heating at 80 degrees C for 10 minutes results in its practically complete inactivation. Elastase is a highly radiosensitive enzyme. Chelating agents and zinc, cobalt, mercury ions suppress its activity. Sodium and ammonium chlorides selectively inhibit the elastolytic, but not proteolytic activity of the enzyme. Elastase shows pronounced dermonecrotic and keratolytic action.

Animals↗
PubMed1988

[Isolation and primary characteristics of elastase from a clinical strain of Pseudomonas aeruginosa].

The homogeneous preparation of elastase has been obtained from P. aeruginosa clinical strain. The molecular weight of the isolated enzyme is 33,000 daltons, and its isoelectric point is 6.8. Two media manufactured in this country (dialyzed bovine heart hydrolysate and a dried semisynthetic medium) ensuring good production of the enzyme have been proposed. The optimum time for the cultivation of the producer strain (30-40 hours) has been established. Elastase has been shown to be widely spread among P. aeruginosa clinical strains.

Animals↗
PubMed1987

[The role of R plasmids in the resistance of bacteria in air].

The study of Escherichia coli J 53, used as a model, has revealed that some R plasmids isolated from Serratia marcescens and Klebsiella pneumoniae, found to be the cause of the outbreak of hospital infection, ensure, besides multiple drug resistance, also their viability in the air.

Air Microbiology↗
PubMed1986

[Possible use of plasmids for studying the effect of space flight factors on biological objects].

The action of space flight factors on the phenotype and certain molecular and genetic parameters of E. coli plasmids (R, Col, Hly and others) was studied. The E. coli strains were grown and multiplied in the "Cytos" apparatus during the orbital flight of "Salyut-7" in June 1982. A synchronous experiment in the "Cytos" apparatus was performed under the Earth conditions. It was shown that space flight factors had no effect on the properties of the test strains and plasmids (antibiotic resistance, capacity for production of colicin, hemolysin, restriction endonuclease, conjugative capacity, frequency of conjugative transfers and molecular weight).

Anti-Bacterial Agents↗
PubMed1985

[Biological characteristics of bacteria during the Cytos-2 Soviet-French space experiment].

The experiment "Cytos-2" made it possible to reveal a certain increase in the antibiotic resistance of bacteria constituting the opportunistic pathogenic microflora of man (Staphylococcus, Escherichia coli and Pseudomonas aeruginosa) to oxacillin, erythromycin, colistin and kanamycin under the conditions of space flight. The electron-microscopic study of the postflight staphylococcal cultures revealed the thickening of the cell membrane in staphylococci. The conditions of the experiment did not affect the stability of the biochemical characteristics of P. aeruginosa cultures, as well as their virulence, immunogenic properties and type specificity.

Anti-Bacterial Agents↗
PubMed1984

[Use of genetic and molecular characteristics of R plasmids as an epidemiological marker in an outbreak of hospital infection].

Antibiotic sensitivity of 38 strains of enteric bacteria, such as Serratia marcescens Klebsiella pneumoniae and others and Ps. aeruginosa isolated during an outbreak of meningitis in a premature infant resuscitation department was studied. It was shown that all the isolates were multiple resistant, most frequently to 7 antibiotics. All the resistance markers were transferred on conjugation, segregation of some markers being observed. Investigation of the plasmid composition of the clinical strains and transconjugants of E. coli revaled the presence of 2 plasmids with the molecular weights of 40 and 60 Md or one of them. The restriction analysis demonstrated that the plasmids with the same molecular weights isolated from different strains were identical. It was suggested that such plasmids originated from the same source and were distributed by conjugation. The possible part of R plasmids in epidemiological analysis of hospital infections is discussed: the possible part as an additional marker in determination of the infection source and the possible part through its ability to change the host cell phenotype, including the phage and bacteriocin types.

Conjugation, Genetic↗
PubMed1983

Restriction of bacteriophage T3 and T7 ocr+ strains by the type II restriction endonuclease EcoRV.

When E. coli cells carrying the plasmid pLG13 (coding for the newly discovered type II restriction endonuclease EcoRV) are infected with phage T3 or T7, only T7 is able to replicate normally. T3 wild-type as well as its ocr- mutants are subject to DNA restriction in vivo and in vitro. The EcoRV enzyme cuts T3 DNA at 5 sites. T7 and its ocr- mutants have no EcoRV sites in their DNA. In contrast to the anti-restriction activity of the T3 and T7 ocr+ gene function against type I and III restriction enzymes, the ocr+ protein is unable to inactivate the type II restriction endonuclease EcoRV.

DNA Replication↗
PubMed1983

[Possible dependence of the results of phage typing Ps. aeruginosa strains on the presence of R plasmids].

The plasmid composition of 209 strains of Ps. aeruginosa was determined. The strains were isolated from patients, animals and environment in different geographical areas. The number of the plasmid-containing strains averaged 26.8 per cent. The molecular weights of the plasmids varied from less than 10 to more than 150 MD. 41 conjugative plasmids were transmitted to the recipients of Ps. aeruginosa RAO 303. 66 per cent of them had a restrictive effect on the development of phages used in genetic studies, epidemiological phage typing (Lindberg Collection), and medical practice. This resulted in the changing of the phage type of the host strain. Similar results were obtained in the studies with 10 standard R plasmids representing different incompatibility groups. No relation between the spectrum of the phage restriction, group specificity and the other properties of the plasmids was observed. About 50 per cent of the plasmids markedly lowered the sensitivity level of Ps. aeruginosa RAO 303 to the therapeutic pyocyanic phage. The systems of restriction and modification of DNA coded with plasmids were not detected. A possible changing of the phage type of Ps. aeruginosa strains under the effect of R plasmids should be considered in epidemiological assays and respective treatment measures.

Bacteriophage Typing↗
PubMed1981

[Antibiotic resistance of uropathogenic strains of E. coli isolated from patients in the USSR and the People's Republic of Bulgaria].

The MIC of benzylpenicillin, ampicillin, ceporin, streptomycin, kanamycin, gentamicin, tetracycline, rondomycin, rifampicin, chloramphenicol, nalidixic acid, orafuran, furacin and furazolidon with respect to E. coli strains isolated from urological patients were determined and compared with those isolated from patients with other localization of inflammatory processes and the feces of healthy persons. It was shown that the strains isolated from the urine of the urological patients were characterized by higher levels of the drug resistance and as a rule were polyresistant. The bacterial resistance was due to the presence of conjugative R plasmids in 26-32 per cent of the cases and nonconjugative R plasmids in 37-38 per cent of the cases. The total number of the cultures with the drug resistance controlled by the plasmid markers amounted to 64-69 per cent. Ceporin, gentamicin, and furacin had the highest inhibitory effect.

Anti-Bacterial Agents↗