The soil bacterium Agrobacterium tumefaciens is a plant pathogen that causes crown gall tumors by infecting the wounded dicotyledonous plants and subsequent integration of bacterial DNA into plant nuclear DNA. Virulent A. tumefaciens strains harbor a large Ti (tumor–inducing) plasmid that carries genes essential for tumorigenesis. In the present study, 13 strains (Malus pumila Mill; A₁₋₃, Populus monilifera; W₁₋₆, Populus tomentiglandlosa; P₁₋₃ and Rosa species; R₁) of Agrobacterium isolated in korean crown gall tumors and plasmids were observed in 6 strains (W₂, W₃, W₆, P₁, P₃ and A₂). The test for crown gall tumor formation was resulted only in ATCC15955 and KW2 strains inoculated into the stem of sun flower and the development was observed for 4 and 6 weeks after inoculation. Above two Ti plasmids (pTi) were purified by cesium chloride-ethidium bromide density gradient centrifugation and digested with restriction enzyme and fragments of pTiATCC15955 and pTiKW₂ observed by EcoR I ; 25&27, Hind III ; 23&21, BamH I ; each 20 and Hpa I ; 12&27. And sizes of pTiATCC15955 and and pTiKW₂ calculated as 200 and 87 kbases. Octopine was isolated from tumor tissue (W₁₋₆ and P₁₋₃) and these strains confirmed as octopine type.
Agrobacterium tumefaciens ; Agrobacterium* ; Carcinogenesis ; Centrifugation, Density Gradient ; Cesium ; DNA ; DNA, Bacterial ; Flowers ; Korea* ; Plant Tumor-Inducing Plasmids ; Plant Tumors ; Plants ; Plasmids* ; Populus ; Rosa ; Soil ; Solar System ; Wounds and Injuries

OBJECTIVETo observe the expression of a targeted fusion anticaries DNA vaccine pGJA-P in situ. To compare the levels of specific antibodies and anticaries efficacy generated by pGJA-P and pGLUA-P, a fusion anticaries DNA vaccine.

METHODSpGJA-P was administrated intramuscularly or intranasally to rats, and the expression of recombinant protein was detected by immunohistochemistry technique. Wistar rats were fed a cariogenic diet and orally infected with S. mutans, then immunized with pGJA-P or pGLUA-P via the intramuscular or intranasal route. All rats received a booster immunization 2 weeks later. At the termination of the experiment, blood and saliva samples were collected for assay of antibodies by ELISA and jaws were obtained for caries evaluation by the Keyes method.

RESULTSRecombinant protein could be detected in muscle in intramuscularly immunized rats and in nasal mucosa in intranasally immunized rats. Rats immunized intramuscularly with pGJA-P had significantly higher serum IgG levels than others (P < 0.01). Rats immunized intranasally or intramuscularly with pGJA-P had significantly higher salivary IgA levels than others (P < 0.01). Keyes scores of pGJA-P groups were significantly lower than those of pGLUA-P groups and pCI groups (P < 0.01).

CONCLUSIONSpGJA-P could be correctly expressed in vivo. pGJA-P generated increased humoral immune response and anticaries efficacy compared with pGLUA-P.

Animals ; Bacteriocin Plasmids ; immunology ; Dental Caries ; prevention & control ; Female ; Rats ; Rats, Wistar ; Recombinant Fusion Proteins ; immunology ; Streptococcus mutans ; immunology ; Vaccines, DNA ; immunology

Shigella sonnei KNIH104S, which was selected by Korean National Institute of Health, expresses form I-antigen as a somatic antigen. In this study, we cloned the genes responsible for form I-antigen synthesis from S. sonnei KNIH104S. A Sau3AI-generated cosmid library of S. sonnei KNIH104S plasmids were transfected into E. coli LE392 and transfectants were tested for agglutination with antiserum against S. sonnei form I-antigen. A clone, JH222, showing the strongest agglutination activity was chosen for further analysis. A recombinant cosmid, pJH222, was isolated from the strain JH222 and retransfected into E. coli LE392. All of the transfectants agglutinated with antiserum against form I-antigen, indicating that pJH222 carried the genes required for S. sonnei form I-antigen synthesis. Restriction analysis of pJH222 revealed a 38 kb insert, which was confirmed by Southern hybridization analysis to be present on a large plasmid of S. sonnei KNIH104S.
Agglutination ; Clone Cells* ; Cloning, Organism* ; Cosmids ; Plasmids ; Shigella sonnei* ; Shigella*

Expression strain of des-pGlu1-brazzein was constructed and the conditions using lactose as inducer was also optimized. The Influences of three factors which were lactose concentration, induction time and inducing temperature on the growth of strain and on the yield of des-pGlul-Brazzein was analyzed in detail. The result indicated that high lactose concentration inhibit the growth of strains (P < 0.01) but made no difference on expression of target protein between 0.5%-5% (P > 0.05), Biomass would be improved as time passed (P < 0.01), but the yield of target protein didn't increase obviously at 30 degrees C compared with at 37 degrees C. Further result showed that the greater expressed level of des-pGlul-Brazzein, as high as about 20% of total cell protein, could be achieved after the strain had been induced with 0.5% lactose under 28 degrees C - 30 degrees C for 4 h.
Dose-Response Relationship, Drug ; Escherichia coli ; drug effects ; genetics ; Isopropyl Thiogalactoside ; pharmacology ; Lactose ; pharmacology ; Plant Proteins ; genetics ; Plasmids ; genetics ; Temperature ; Time Factors ; Up-Regulation ; drug effects

No abstract available.
DNA* ; Kidney* ; Plasmids*

This study aimed to extract and type the plasmids of S. typhi strains and antibiogram. 2 S. typhi strains were selected. One multi-antibiotic resistant strain carried only R-plasmid and the other sensitive strain carried 2 smaller plasmids. Both of them were cultured and extracted DNA plasmid. Then 20 different enzymes were analysed to choose proper enzymes. There were 7 enzymes met the requirements. For DNA of larger plasmid, Kpn 1 and Sca 1 cut to 11 fractions. All of them had lower molecular weight than standard DNA. For DNA of smaller plasmid, Kpn 1 enzyme cut to 16 fractions, BamH 1 cut to 10 fractions, Mlu cut to 9 fractions, Cla cut to 11 fractions, and Bgl II cut to 7 fractions. All these fractions had lower weight than standard DNA. Molecular weight of larger plasmid is 188 206bp X 660D = 124 215 960D (124MD). That of smaller plasmid is 99 731bp X 660D = 65 822 460D.
Plasmids ; Molecular Weight

We investigated the effect of toxin-antitoxin (TA) systems in bla(CTX-M-15)-bearing plasmids of Klebsiella pneumoniae on persister formation. The persister formation rate was notably high in transconjugants in plasmids bearing TA system than the transconjugants in plasmids bearing no TA systems. Activation of relA and spoT expression was higher in transconjugants with plasmids bearing TA systems. Thus, TA systems in plasmids may contribute to the maintenance of bla(CTX-M-15)-bearing plasmids and host survival via persister formation.
Klebsiella pneumoniae ; Klebsiella ; Plasmids

Forty-seven ampicillin-resistant R plasmids derived from 218 Shigella sonnei isolates from Daegu and Gwangju areas from 1980 to 2000 were epidemiologically compared by fragments of restriction endonuclease patterns by EcoRI and SmaI, and by Southern hybridization with a blaTEM-1 probe. All the ampicillin-resistant strains isolated in the 1980S carried a conjugative R plasmid responsible for multiple resistance other than ampicillin, and an ampicillin-resistance plasmid. Ampicillin-resistant strains isolated in the 1990S harbored single conjugative R plasmid encoding ampicillin resistance along with variable antimicrobial resistances. The restriction endonuclease digestion patterns and Southern hybridiztion analysis of conjugative R plasmids showing identical resistance pattern and a same size showed different fragment and Western blotting patterns according to different isolation years and areas, while identical patterns were observed among the plasmids derived from a same isolation year and area. These findings suggest that ampicillin resistance among S. sonnei isolates was due to introduction of ampicillin-resistant R plasmids originated from different sources.
Ampicillin Resistance* ; Ampicillin* ; Blotting, Western ; Daegu ; Digestion ; DNA Restriction Enzymes ; Gwangju ; Plasmids ; R Factors ; Shigella sonnei* ; Shigella*

No abstract available.
Drug Resistance, Microbial* ; Plasmids* ; Pneumonia*

No abstract available.
Plasmids* ; Shigella* ; Virulence Factors* ; Virulence*