Leclercia adecarboxylata is a Gram-negative bacterium belonging to the Enterobacteriaceae family. To our knowledge, this is the first report of a carbapenem-resistant L. adecarboxylata strain isolated from a healthy newborn. The L. adecarboxylata strain isolated in this study carried four plasmids that may serve as reservoirs for antibiotic resistance genes. Plasmids 2 and 4 did not harbor any antimicrobial resistance genes. Plasmid 3 is a novel plasmid containing three resistance genes. The bla _IMP gene harbored in the strain was most similar to bla _IMP-79 at the nucleotide level, with a similarity of 99.4% (737/741). This case highlights the importance of considering L. adecarboxylata as a potential cause of infections in children.
Infant, Newborn ; Child ; Humans ; Female ; Enterobacteriaceae Infections/microbiology* ; Enterobacteriaceae/genetics* ; Anti-Bacterial Agents/therapeutic use* ; Plasmids

OBJECTIVETo explore the therapy effects of (arginine-glycine-aspartic, RGD)(3)-truncated tissue factor (tTF) fusion protein on colorectal carcinoma in mice.

METHODSThe (RGD)(3)-tTF fusion gene, constructed with tTF and three series-wound peptides RGD, was expressed in Escherichia coli BL21 (DE(3)). The fusion protein was purified through Nickel affinity chromatography column. The coagulation activity of the (RGD)(3)-tTF fusion protein was detected by clotting assay in vitro. Mice colorectal cancer cells line CT26 were inoculated subcutaneously into mice to establish colorectal cancer model. Four mice were randomly divided into two groups to be injected with the (RGD)(3)-tTF or tTF fusion protein labeled with rhodamine B isothiocyanate (RBITC) at a single dose of 50 microg respectively. The location of the (RGD)(3)-tTF fusion protein in the colorectal carcinoma bearing mice tissue was analyzed by using in vivo optical imaging one hour after the injection and confocal microscopy twenty-four hours after the injection. Fifteen mice bearing colorectal carcinoma were randomly divided into three groups for injection with the (RGD)(3)-tTF, tTF fusion protein or phosphate buffered saline (PBS) at a single dose of 50 microg respectively. The tumor size was measured daily to calculate the tumor volume. Five days after the injection, the mice were killed to harvest tumor tissues, hearts, livers, spleens, lung, kidneys and brains to observe valid thrombogenesis and tumor necrosis.

RESULTSWith the concentration of the (RGD)(3)-tTF fusion protein increased, the clotting time was shorten correspondingly under the conditions of Ca(2+), and the clotting time was (8.6 +/- 0.2) min when the concentration was 6 micromol/L, and it was >30 min in the group of 0 micromol/L (P < 0.05). The coagulation activity of (RGD)(3)-tTF and tTF fusion protein was alike (F = 0.09, P > 0.05). The in vivo optical imaging and confocal microscopy analyses showed that RBITC fluorescence labeling (RGD)(3)-tTF fusion protein was assembled in the tumor vasculature. On the first, third, fifth day after injection, the tumor volume of (RGD)(3)-tTF fusion protein group was (120.8 +/- 4.8) mm(3), (93.8 +/- 3.4) mm(3), (132.2 +/- 7.7) mm(3) respectively, which was significantly smaller than that of the tTF group [(181.4 +/- 13.8) mm(3), (333.0 +/- 32.0) mm(3), (514.0 +/- 11.5) mm(3)] and PBS group [(182.6 +/- 11.5) mm(3), (332.8 +/- 21.0) mm(3), (524.2 +/- 16.7) mm(3)] (both P < 0.05). However, there was no significant difference in the tumor volume between the latter two groups (P > 0.05).

CONCLUSIONThe (RGD)(3)-tTF fusion protein is capable of targeting to tumor vasculature and inducing thrombogenesis for suppressing the tumor growth in the colorectal carcinoma mice model, and it's expected to be a new therapy for colorectal cancer.

Animals ; Colorectal Neoplasms ; drug therapy ; Genetic Vectors ; Male ; Mice ; Mice, Nude ; Neoplasm Transplantation ; Oligopeptides ; genetics ; therapeutic use ; Plasmids ; genetics ; Recombinant Fusion Proteins ; genetics ; therapeutic use ; Thromboplastin ; genetics ; therapeutic use

OBJECTIVETo investigate the therapeutical effect of recombinant plasmid containing vasoactive intestinal peptide gene (pcDNA3.1+/VIP) on collagen-induced arthritis (CIA) in rats.

METHODSThe experimental arthritis was induced by intradermal injection of bovine type II collagen emulsified in Freund's adjuvants in male SD rats. The rats then were given intra-articular injection with recombinant plasmid (pcDNA3.1+/VIP). The levels of serum TNF-alpha, IL-4 and IL-2 were detected by Avidin-Biotin Peroxdase Complex-enzyme-linked immunosorbent assay (ABC-ELISA) and the pathological changes in the joint of rats were observed.

RESULTHistological examination showed massive inflammatory infiltration in the joint with destruction of bone and cartilage, while the severity of pathological changes in synovia of VIP-treated rats was markedly reduced. Compared with normal group, the serum TNF-alpha, IL-2 levels of CIA rats were significantly increased (P <0.05) and IL-4 level was decreased (P<0.05). Compared with control and pcDNA3.1+ -treated CIA rats, serum TNF-alpha and IL-2 levels of pcDNA3.1+/VIP-treated rats were decreased and IL-4 level was increased (P<0.05).

CONCLUSIONRecombinant plasmid containing vasoactive intestinal peptide gene (pcDNA3.1+/VIP) can reduce the clinical and histological severity of established CIA and it might be a promising candidate for treatment of rheumatoid arthritis.

Animals ; Arthritis, Experimental ; therapy ; Arthritis, Rheumatoid ; therapy ; Genetic Therapy ; Injections, Intra-Articular ; Male ; Plasmids ; therapeutic use ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Recombinant Proteins ; therapeutic use ; Vasoactive Intestinal Peptide ; biosynthesis ; genetics ; therapeutic use

beta-defensins possess a broad spectrum of antimicrobial activity. In this study its in vivo antibacterial effect was evaluated by using gene transfer. Rat beta-defensin-2 (rBD2) recombinant pBK-CMV-rBD2 and pCD-NA-3, 1-Myc-His(+)-rBD2 were constructed. Then, by use of liposome agent, the recombinants were delivered into rat airway via tracheal injection. The rBD-2 mRNA expression was detected in the trachea by RT-PCR and its protein expression was determined in the lungs by the tag His immunostaining, 24 hours after inoculation via trachea, the count of P. areuginosa in the lung of rat transfected with pBK-CMV-rBD2 markedly decreased, compared with the control (n = 8, P = 0.003). The data presented in this study provide evidence that airway beta-defensin-2-gene transfer can protect the rat against bacterial infection in vivo, suggesting the beta-defensins as part of the innate host defense system can be of potential applicability.
Animals ; Bacteria ; drug effects ; Lung ; microbiology ; physiology ; Plasmids ; genetics ; Rats ; Rats, Wistar ; Respiratory Tract Infections ; prevention & control ; Transfection ; beta-Defensins ; genetics ; pharmacology ; therapeutic use

The use of tumor antigen specific antibody for the delivery of therapeutic agents offers the possibility of targeting therapy with reduced toxicity to normal tissues compared to conventional treatments. In previous work, the human-mouse chimeric antibody fragment Fab' directed against CD20 was constructed from the new anti-CD20 antibody HI47 (a mouse IgG3, K). The chimeric antibody fragment Fab' could reduce its antigenicity, but the yield, quality and affinity of chimeric antibody fragment Fab' restrict its use. To improve affinity of chimeric antibody fragment Fab', a new phasmid pYZcpp3, which expresses chimeric antibody fragment F(ab')2, was constructed by adding a sequence encoding a small peptide, (CPP)3, to C-terminus of heavy chain constant region of chimeric antibody fragment Fab'. Using the pYZcpp3 to transform E. coli. 16c9, the genetically engineered bacteria 10916# was obtained. 10916# can secret the soluble chimeric antibody fragment Fab' and F(ab')2 into periplasmic. The yield was up to 360 mg/L with the percent of F(ab')2 up to 45% in 19L fermentor by the high density fermentation technology. Without denaturation and renaturation, the F(ab')2 has possessed the native three-dimensional structure. The purity of F(ab')2 was more than 90% after the purification of protein G affinity chromatography and S200 size exclusion chromatography. The F(ab')2 could distinguish and bind to Raji cells (CD20+) by FACS. F(ab')2 could inhibit the proliferation of Raji cells in vitro by MTT, IC50 was 22.8 microg/mL. HI47 and its chimeric fragments F(ab')2 induced a significant level of apoptosis (23.5%, 20.8%, respectively), independent of any cross-linking agents, in Raji cells after 24 h incubation. The chimeric antibody fragment F(ab')2 directed against CD20 is possible to apply to tumor therapy in clinic in the future.
Antigens, CD20 ; immunology ; Apoptosis ; Escherichia coli ; genetics ; Fermentation ; Humans ; Immunoglobulin Fab Fragments ; chemistry ; genetics ; isolation & purification ; therapeutic use ; Lymphoma, B-Cell ; therapy ; Plasmids ; Recombinant Fusion Proteins ; biosynthesis ; isolation & purification ; therapeutic use

OBJECTIVETo study the effects of antisense transforming growth factor beta receptor-II (TGFbetaRII) expressing plasmid on experimental liver fibrosis.

METHODSRT-Nest-PCR and gene recombinant techniques were used to construct the rat antisense TGFbetaRII recombinant plasmid which can be expressed in eukaryotic cells. Thirty-six male SD rats were randomly distributed into five groups: 10 in experimental liver fibrosis model induced by pig-serum as disease control group; 10 in antisense TGFbetaRII transfection as treatment group; 10 in pCDNA3 transfection as treatment control group and 6 in normal control group. The recombinant plasmid and empty vector (pCDNA3) were encapsulated by glycosyl-poly-L-lysine and then transducted into rats of pig serum-induced liver fibrosis model respectively. Expression of exogenous transfected plasmid was assessed by Northern blot, RT-PCR and Western blot. We also tested ELISA of serum TGF-beta1, the contents of hepatic hydroxyproline, immunohistochemistry of type I and III collagen, and VG staining for pathological study.

RESULTSThe antisense TGFbetaRII expressing plasmid could be well expressed in vivo, and could block the mRNA and protein expression of TGFbetaRII in the fibrotic liver induced by pig serum. Its expression also reduced the level of TGF-beta1 [antisense treatment group (23.16+/-3.13) ng/ml, disease control group (32.96+/-3.79) ng/ml; F=36.73, 0.01]. Compared with the disease control group, the contents of hepatic hydroxyproline [antisense treatment group (0.17+/-0.01) mg/g liver, disease control group (0.30+/-0.03) mg/g liver; F=15.48, 0.01] and the deposition of collagens type I and type III decreased in the antisense group (antisense treatment group collagen type I 650.26+/-51.51, collagen type III 661.58+/-55.28; disease control group type I 1209.44+/-116.60, collagen type III 1175.14+/-121.44; F values are 69.87, 70.46, 0.01). And its expression also improved the pathologic classification of liver fibrosis models (0.01).

CONCLUSIONThe results demonstrate that TGF-beta plays a key role in liver fibrogenesis and the prevention of liver fibrosis by antisense TGFbetaRII recombinant plasmid intervention may be therapeutically useful.

Animals ; Antisense Elements (Genetics) ; therapeutic use ; Liver Cirrhosis, Experimental ; etiology ; therapy ; Male ; Plasmids ; therapeutic use ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Receptors, Transforming Growth Factor beta ; antagonists & inhibitors ; genetics ; Transforming Growth Factor beta ; physiology

The widespread of tigecycline resistance gene tet(X4) has a serious impact on the clinical efficacy of tigecycline. The development of effective antibiotic adjuvants to combat the looming tigecycline resistance is needed. The synergistic activity between the natural compound β-thujaplicin and tigecycline in vitro was determined by the checkerboard broth microdilution assay and time-dependent killing curve. The mechanism underlining the synergistic effect between β-thujaplicin and tigecycline against tet(X4)-positive Escherichia coli was investigated by determining cell membrane permeability, bacterial intracellular reactive oxygen species (ROS) content, iron content, and tigecycline content. β-thujaplicin exhibited potentiation effect on tigecycline against tet(X4)-positive E. coli in vitro, and presented no significant hemolysis and cytotoxicity within the range of antibacterial concentrations. Mechanistic studies demonstrated that β-thujaplicin significantly increased the permeability of bacterial cell membranes, chelated bacterial intracellular iron, disrupted the iron homeostasis and significantly increased intracellular ROS level. The synergistic effect of β-thujaplicin and tigecycline was identified to be related to interfere with bacterial iron metabolism and facilitate bacterial cell membrane permeability. Our studies provided theoretical and practical data for the application of combined β-thujaplicin with tigecycline in the treatment of tet(X4)-positive E. coli infection.
Humans ; Tigecycline/pharmacology* ; Escherichia coli/metabolism* ; Reactive Oxygen Species/therapeutic use* ; Plasmids ; Anti-Bacterial Agents/metabolism* ; Escherichia coli Infections/microbiology* ; Bacteria/genetics* ; Microbial Sensitivity Tests

OBJECTIVETo construct a fusion anti-caries DNA vaccine pGLUA-P carrying GLU fragment from gtfB gene of Streptococcus mutans GS-5 and A-P fragment including the A region and P region of PAc protein from a DNA anti-caries vaccine pCIA-P, and to investigate its expression in prokaryotic and eukaryotic cells.

METHODSThe sequence of GLU fragment in pGLU plasmid was testified by DNA sequencing. The fusion anti-caries DNA vaccine was constructed by ligating A-P fragment from pCIA-P to pGLU. The expression of GLUA-P fusion protein in E. coli BL21 (DE3) was induced by IPTG and checked by SDS-PAGE electrophoresis. pGLUA-P was transfected in vitro to cultured rat primary muscle cells by cation liposome Dosper, and immunohistochemical method was used to test the expression of GLUA-P fusion protein in cells.

RESULTSGLU sequence was identical with relative sequence of GTF-I (GS-5 strain) in Gene Bank. Recombinant eukaryotic expression plasmid pGLUA-P was confirmed to have both GLU and A-P fragment. After pGLUA-P was transferred into E. coli (DE3), it could express a new 115 000 protein by the induce of IPTG. Specific brown products could be found in the cytoplasm of cultured rat primary muscle cells transfected by pGLUA-P.

CONCLUSIONSFusion anti-caries DNA vaccine pGLUA-P is successfully constructed and confirmed by sequencing and enzymes digestion. Fusion GLUA-P protein can be correctly expressed in prokaryotic and eukaryotic cells.

Animals ; Animals, Newborn ; Bacterial Proteins ; genetics ; metabolism ; Cells, Cultured ; Cloning, Molecular ; Dental Caries ; prevention & control ; Electrophoresis, Polyacrylamide Gel ; Escherichia coli ; genetics ; Gene Expression ; Glucosyltransferases ; genetics ; metabolism ; Membrane Glycoproteins ; Muscle, Skeletal ; cytology ; metabolism ; Plasmids ; genetics ; Rats ; Rats, Wistar ; Recombinant Fusion Proteins ; genetics ; metabolism ; Streptococcal Vaccines ; genetics ; immunology ; therapeutic use ; Streptococcus mutans ; genetics ; immunology ; Transfection ; Vaccines, DNA ; genetics ; therapeutic use

Induction of tumor vasculature occlusion by targeting a thrombogen to newly formed blood vessels in tumor tissues represents an intriguing approach to the eradication of primary solid tumors. In the current study, we construct and express a fusion protein containing vascular endothelial growth factor (VEGF) and tissue factor (TF) to explore whether this fusion protein has the capability of inhibiting tumor growth in a colon carcinoma model. The murine cDNA of VEGF A and TF were amplified by reverse transcriptase polymerase chain reaction (RT-PCR), and then cloned into prokaryotic expression plasmid pQE30 with a linker. The expression product recombinant VEGF-TF (rVEGF-TF) was purified and proved to have comparable enzyme activity to a commercial TF and the capability of specific binding to tumor vessels. Significant decrease of tumor growth was found in the mice administered with rVEGF-TF on Day 6 after initiated rVEGF-TF treatment (P<0.05), and the tumor masses in 2 of 10 mice were almost disappeared on Day 14 after the first treatment. In addition, valid thrombogenesis and tumor necrosis were observed in the tumor tissues injected with rVEGF-TF. Our results demonstrate that occlusion of tumor vasculature with rVEGF-TF is potentially an effective approach for cancer therapy.
Animals ; Cell Line, Tumor ; Cloning, Molecular ; Colonic Neoplasms ; blood supply ; drug therapy ; pathology ; Disease Models, Animal ; Disease Progression ; Gene Expression ; Mice ; Mice, Inbred BALB C ; Neoplasm Transplantation ; Plasmids ; genetics ; Recombinant Fusion Proteins ; genetics ; isolation & purification ; metabolism ; therapeutic use ; Thromboplastin ; genetics ; isolation & purification ; metabolism ; therapeutic use ; Thrombosis ; drug therapy ; pathology ; Vascular Endothelial Growth Factor A ; genetics ; isolation & purification ; metabolism ; therapeutic use

OBJECTIVETo develop an oral DNA vaccine based on MG(7)-Ag mimotope of gastric cancer using attenuated Salmonella typhimurium and evaluate its efficacy and protective effect.

METHODSThe eukaryotic expression vector including the MG(7)-Ag mimotope and a Th epitope was constructed, and then transduced into an attenuated Salmonella typhimurium to get the oral DNA vaccine. C57BL/6 J mice were orally immunized with 1 x 10(8) cfu Salmonella transfectants, with Salmonella harboring empty plasmid, with phophate buffered saline (PBS) as control. At the 6th week, serum titer of MG(7) antibody was detected by ELISA. In the 8th week, a [(3)H]-thymidine incorporation assay was performed to test the proliferation of murine spleen cells to the stimulant of MG(7)-Ag mimicry peptide. At the same time, Ehrlich ascites carcinoma cells expressing MG(7)-Ag were used in tumor challenge assay to evaluate the protective effect of the immunization.

RESULTSThe oral DNA vaccine induced MG(7) antibody in mice, while in vivo unprimed proliferation assay of the spleenocytes showed no difference among the three groups. Two weeks after tumor challenge, 2 in 7 immunized mice were tumor free, while none in the control group was protected.

CONCLUSIONOral DNA vaccine based on the MG(7)-Ag momitope is immunogenic. It is able to induce specific immunity response against tumor in mice, and the vaccine is partially protective.

Administration, Oral ; Amino Acid Sequence ; Animals ; Antigens, Neoplasm ; blood ; genetics ; immunology ; Base Sequence ; Cancer Vaccines ; genetics ; immunology ; therapeutic use ; Epitopes ; genetics ; immunology ; Female ; Mice ; Mice, Inbred C57BL ; Molecular Mimicry ; genetics ; immunology ; Molecular Sequence Data ; Plasmids ; genetics ; Polymerase Chain Reaction ; Stomach Neoplasms ; drug therapy ; immunology ; Treatment Outcome ; Vaccines, DNA ; genetics ; immunology ; therapeutic use