Involvement of the respiratory chain of gram-negative bacteria in the reduction of tellurite.

The terminal oxidases of the respiratory chain of seven strains of gram-negative bacteria were shown to be involved in the reduction of tellurite. The rate of tellurite reduction correlated with the intensity of respiration. The inhibitors of terminal oxidases, carbon monoxide and cyanide, inhibited the reduction of tellurite. In Pseudomonas aeruginosa PAO ML4262 and P. aeruginosa PAO ML4262 (pBS 10), the respiratory chain was found to contain three types of cytochrome c, one of which (the carbon monoxide-binding cytochrome c) was involved in the reduction of tellurite. Agrobacterium tumefaciens VKM B-1219, P. aeruginosa IBPM B-13, and Escherichia coli G0-102bd++ cells contained oxidases aa3, bb3, and bd, respectively. The respiratory chain of other strains contained two oxidases: E. coli DH5alpha of bb3- and bd-type, and Erwinia carotovora VKM B-567 of bo3- and bd-type. All the strains under study reduced tellurite with the formation of tellurium crystallites. Depending on the position of the active center of terminal oxidases in the plasma membrane, the crystallites appeared either in the periplasmic space [P. aeruginosa PAO ML4262 and P. aeruginosa PAO ML4262 (pBS10)], or on the outer surface of the membrane (A. tumefaciens VKM B-1219 and P. aeruginosa IBPM B-13), its inner surface (E. coli G0-102bd++), or on both surfaces (E. coli DHaalpha and E. carotovora VKM B-567).

Cytological aspects of resistance to potassium tellurite conferred on Pseudomonas cells by plasmids.

The ultrastructure of strains Pseudomonas putida BS228 and Pseudomonas aeruginosa ML4262 harboring plasmids pBS10, pBS31, and pBS221, which determine resistance to potassium tellurite, was studied. Bacteria were grown in media containing increasing concentrations of potassium tellurite. Crystalline structures containing tellurium appeared in their periplasmic space. The dynamics of crystal growth was studied. Crystals were released into the medium by pinching off of the outer membrane vesicles containing growing crystals. A possible mechanism of this process was described; cytobiochemical peculiarities were discussed.

[Determinant of plasmid pBS221 resistance to potassium tellurite]. / Determinant ustoichivosti k telluritu kaliia plazmidy PBS221.

The genes regulating resistance to potassium tellurite were cloned from plasmid pS221 with a broad host range. The studied DNA fragment encodes for the synthesis of two polypeptides with molecular mass of 38 and 43 kD. Metal tellurium crystals were localized in the periplasm of Pseudomonas aeruginosa ML4262 (pBS221) cells by electron microscopy. Results of colony hybridization permit us to propose that the cloned genes of potassium tellurite resistance have sites of homology with plasmids RP4(IncP), R27 (IncH), pBS38, pBS79, and R931(IncP-2).

[Resistance to metals determined by plasmids of gram-negative bacteria]. / Determiniruemaia plazmidami gram-otritsatel'nykh bakterii ustoichivost' k metallam.

The data are reviewed on plasmid determinants controlling resistance of gram-negative bacteria to heavy metals. The structural and functional arrangement of operons determining resistance to copper, zinc, cadmium, cobalt, nickel, tellurites, and chromates is emphasized. The fields of use of the genetic potential of the bacteria resistant to metals in the modern biotechnological processes are envisaged.

[Metal resistance of gram-negative bacteria isolated from soil and waste waters of industrial regions]. / Ustoichivost' k metallam gramotritsatel'nykh bakterii, izolirovannykh iz pochv i stochnykh vod promyshlennykh raionov.

Metals resistance of 112 strains of gram-negative bacteria isolated from soil and wastes around Nizniy Novgorod plants were investigated. MIC of metals varied in range between 1-10 mM Ni2+, Co2+, 1-6 mM Zn2+, 1-4 mM Cd2+, CrO4(2-), and 0.1-0.3 mM TeO3(2-). Bacteria with phenotypes NiCo and NiZnTe are revealed most frequent (25.6 and 6.4% accordingly). Plasmid DNAs with size between 2-70 kbp were found in 50% isolated strains. It was shown that resistance to cobalt of unidentified gram-negative bacterium is determined by plasmid genes. Recombinant plasmid contained fragment DNA controlling resistance to cadmium and zinc from Pseudomonas spp. strain was constructed by using helper plasmid pULB113.

[Genetic control of tetracycline resistance in bacteria]. / Geneticheskii kontrol' ustoichivosti k tetratsiklinam u bakterii.

Modern data on prevalence, structural and functional organization of the tetracycline resistance determinants in bacteria are reviewed. The three mechanisms of the antibiotic resistance are the tetracycline efflux, the ribosomal protection and the antibiotic modification. The problems of evolution of tetracycline resistance genes are discussed.

[Amikacin resistance of clinical strains of Enterobacteriaceae and Pseudomonas]. / Ustoichivost' k amikatsinu klinicheskikh shtammov bakterii semeistva Enterobacteriaceae i roda Pseudomonas]

Amikacin resistance was studied in 380 bacterial strains of Enterobacter, Klebsiella, Serratia, Pseudomonas and E. coli isolated in clinics of the Moscow Region. It was shown that 69 isolates were resistant to amikacin. Plasmid DNA was detected in 10 amikacin resistant isolates. Three of them belonging to Klebsiella and 3 belonging to E. coli contained plasmids controlling resistance to amikacin. The plasmids isolated from the strains of Klebsiella determined as well resistance to kanamycin and streptomycin but did not control resistance to sisomicin, tobramycin and gentamicin while the plasmids isolated from the strains of E. coli determined resistance to amikacin, kanamycin, gentamicin, tobramycin and sisomicin.

[Genetic determinants of tetracycline resistance of plasmids from the bacterial species Pseudomonas]. / Geneticheskie determinanty rezistentnosti k tetratsiklinam plasmid bakterii roda Pseudomonas.

The colony hybridization and tetracycline accumulation techniques made possible to demonstrate the majority of the 29 bacteria of Pseudomonas genera to harbour the plasmids carrying tet determinants belonging to classes A-C, while one strain contained a plasmid carrying tet determinant of class B. For the first time the determinants of classes D and E were found on R plasmids in Pseudomonas aeruginosa. The determinant of G class was identified on two plasmids identical to pBS221 plasmid described previously.

[Molecular-genetic analysis of the R2 plasmid (group IncP-9)]. / Molekuliarno-geneticheskii analiz plazmidy R2 (gruppa IncP-9).

The IncP-9 test plasmid R2 controlling resistance to streptomycin, carbenicillin, sulfanylamides and UV irradiation was studied. The plasmid (67.5 kb) was physically mapped for restriction endonucleases EcoRI, BamHI, BglII and SmaI. The aphC, sulI and bla genes were localized on the physical map of the plasmid. The resistance genes are supposed to be comprised within the ANT-R element. The regions participating in replication and mobilization of this plasmid were cloned. The cloned oriV region of the plasmid mediated synthesis of the protein with molecular weight of about 36 kD.

[Structural-functional organization of the incompatibility group P plasmid pBS221]. / Strukturno-funktsional'naia organizatsiia plazmidy pBS221 gruppy nesovmestimosti P.

Plasmid pBS221 was physically mapped for restriction endonucleases EcoRI, BamHI, BglII, HindIII. The regions essential for the plasmid existence and participating in replication (oriV trfA*) and mobilization (mob) were cloned. The tet determinant and oriV trfA* regions were localized on the physical map of the plasmid. A DNA sequence homologous to genes of Tn501 mer operon was detected in this plasmid. The studies on homology of plasmids RP4 (IncP alpha), R751 (IncP beta) and pBS221 plasmid suggest that the latter belongs to the IncP beta subgroup.

[The immunological diagnosis of peptostreptococcal infection]. / Immunologicheskaia diagnostika peptostreptokokkovoi infektsii.

The work deals with different methods for the diagnosis of anaerobic streptococcal infection, experimentally tested and clinically approved in the examination of children with acute pneumonia. The passive hemagglutination test, the immune rosette formation test and the specific lymphocyte blastogenesis test were used for diagnosis. As sensitin and antigen, the preparation of the peptostreptococcal bacterial mass was used. The diagnostic titer of antibodies to anaerobic streptococci was 1:160. A twofold and greater increase in the number of antigen-dependent rosette-forming lymphocytes and in specific blast transformation in the presence of the diagnostic antibody titer confirms the etiological role of anaerobic peptostreptococci in the development of pneumonia in children.

[The plasmids of Pseudomonas syringae]. / Plazmidy Pseudomonas syringae.

The paper deals with occurrence of plasmids in P. syringae strains belonging to seventeen pathovars: the strains were isolated in the USSR and other countries. One to four different plasmids having molecular weights of 20 to 90 Md have been found in various strains of the following twelve pathovars: holci, cerasi, aptata, tabaci, populi, pisi, lupini syringae, lachrymans, phaseolicola, glycinea, atrofaciens. Both virulent and avirulent P. syringae strains appear to carry such plasmids. Plasmids of incompatibility group P-2 do not occur in the strains studied.

[Cloning and expression of the determinant for resistance to a new class of tetracycline in Escherichia coli strains]. / Klonirovanie i ékspressiia determinanta rezistentnosti k tetratsiklinnovogo klassa v shtammakh Escherichia coli.

Tetracycline-resistance determinant of the plasmid pBS221 isolated from a Pseudomonas aeruginosa strain has been cloned on pUC19 vector plasmid. The determinant is expressed under aerobic and anaerobic conditions coding for two proteins: a 36 Kd protein conferring antibiotic resistance and 27 Kd repressor protein. The determinant is not homologous to tet-determinants of the known classes as shown by blot hybridization experiments. The determinant represents a new class--G. Determinants of the new class are widespread among Serratia marcescens strains.

[Plasmids and genetic determinants of antibiotic resistance of gram-negative bacteria]. / Plazmidy i geneticheskie determinanty rezistentnosti k antibiotikam gramotritsatel'nykh bakterii.

Distribution of plasmids and genetic determinants of antibiotic resistance was studied in 129 strains of Pseudomonas, Klebsiella, Serratia and Enterobacter isolated from oncological patients. It was shown that 56 isolates contained the plasmids, 9 conjugative plasmids being plasmids with broad bacterial host spectrum. A significant part of the strains contained genes controlling production of APH (3"), type II APH (3'), type I and II DHPS and type type II DHFR. Genetic determinants of tetracycline resistance of classes D and E were detected for the first time in the strains of Klebsiella, Serratia and Pseudomonas aeruginosa.

[Immunologic status of children living in a region with an increased level of nitrates in the drinking water]. / Immunnyi status detei, prozhivaiushchikh v raione s povyshennym soderzhaniem nitratov v pit'evoi vode.

Practically healthy schoolchildren living in the district with a high content of nitrates in drinking water experienced distinct quantitative and functional changes of immune indicators: violation of the ratio of immunoregulatory lymphocyte subpopulations, the high level of spontaneous T-lymphocyte blastogenesis, IgE-hyperglobulinemia. The above changes of the immune system could indicate both body sensitization and its desadaptation under unfavourable conditions.

[Antibiotic resistance in clinical strains of Pseudomonas aeruginosa isolated from 1979-1984]. / Rezistentnost' k antibiotikam klinicheskikh shtammov Pseudomonas aeruginosa, vydelennykh v 1979-1984.

The levels and spectra of drug resistance were determined in 530 strains of P. aeruginosa isolated in hospitals of three cities of the USSR within 1979-1984. Their conjugative R plasmids were searched for and distribution of various type resistance determinants in the composition of these plasmids was investigated. The results were compared with the findings of analogous studies on clinical strains of P. aeruginosa isolated within 1976-1979. It was shown that there were a rise in the relative number of the strains resistant to kanamycin and a decrease in the occurrence of the P. aeruginosa strains resistant to streptomycin, tetracycline and sulfanilamides. The frequency of the kanamycin, carbenicillin and gentamicin resistance genes in the composition of the detected conjugative R plasmids increased. Hybridization of 32P-labeled probes containing various type antibiotic resistance determinants with strains of P. aeruginosa ML (PAO) containing conjugative R plasmids was indicative of wide spread of genes determining APH(3')II and APH(3") and determinants of classes A and C in the composition of the studied plasmids.

[Genetic determinants of antibiotic resistance in gram negative bacteria]. / Geneticheskie determinanty rezistentnosti k antibiotikam gramotritsatel'nykh bakterii.

Modern data on spreading, structural and functional organization and evolution of the genetic determinants of antibiotic resistance in the gram-negative bacteria are reviewed. Some mechanisms for resistance to trimethoprime, sulphonamides, tetracyclines, chloramphenicol aminoglycosides, beta-lactam antibiotics controlled by the plasmid and chromosomal genes are presented. The problem of using the molecular DNA-probes containing the genetical determinants for antibiotic resistance in the practical work of clinical laboratories is discussed.

[Characteristics of Tn3611 and Tn3613 transposons discovered in the chromosome of the BS205 strain of Pseudomonas aeruginosa]. / Kharakteristika transpozonov Tn3611 i Tn3613, obnaruzhennykh v khromosome shtamma Pseudomonas aeruginosa BS205.

The transposons Tn3611 (HgR, 9.0 kb) and Tn3613 (SmRCmRKmRSuRHgR, 24.0 kb) were discovered in the chromosome of Pseudomonas aeruginosa BS205. The physical and genetic maps of these transposons were constructed using restriction endonucleases EcoRI, BamHI, SalI, HindIII. Genes of the mer operon, tnpA and tnpR were localized in the Tn3611 transposon, the genes DHPS-II, aad, tnpA, tnpR being situated in the map of the Tn3613 transposon. It was established that the Tn3611 belongs to the class of Tn3-like transposons and the Tn3613 is a complex transposon flanked by inverted repeats 2.2 kb in size, the transposon comprising both Tn3611 and a migrating sequence.

[Genetic determinants of antibiotic resistance in enterobacteria]. / Geneticheskie determinanty rezistentnosti k antibiotikam énterobakterii.

Antibiotic resistance of enterobacterial strains from population isolated in Krasnodar region is rather often controlled by the "plasmid" genes. The conclusion is based on using the colony hybridization with [32P]-DNA fragments of plasmids, carrying the genetic determinants of antibiotic resistance, as a method for antibiotic resistance, genes screening. Kanamycin resistance in the majority of strains is coded by APH (3') II gene, streptomycin resistance by APH (3") gene, chloramphenicol resistance by CATI, sulphonilamide resistance by DHPS type II gene. Tetracycline resistance of the studied enterobacterial strains is not connected with the widespread genetic determinants of a new class tetracycline resistance.