ABSTRACT
To investigate the distribution of the genes of two major metallo-beta-lactamases (MBL; i.e., IMP and VIM) and class 1 integrons (intI) in the clinical imipenem-resistant Pseudomonas aeruginosa, a total of 65 isolates, from a university hospital in Sichuan between December 2004 and April 2005 were screened for MBL genes by PCR using primers specific for bla ( IMP-1 ), bla ( VIM ) and bla ( VIM-2 ) genes. The MBL-positive isolates were further assessed for class 1 integrons by PCR using specific primers. The nucleotide sequences of several PCR products were also determined. The results revealed that the bla ( VIM ) gene was found in 81.5% (53/65) of all isolates, bla ( VIM-2 ) gene was found in only 1 isolate and the intI gene was observed in 45.3% (24/53) of bla ( VIM )-positive isolates. One isolate carried simultaneously both bla ( IMP-1 ) and intI genes, and to the best of our knowledge this is the first report of such isolate in southwest China. These observations highlight that the genes for VIM beta-lactamase and class 1 integrons were predominantly present among the imipenem-resistant P. aeruginosa tested, confirming the current widespread threat of imipenem-resistant, integron-borne P. aeruginosa.
Subject(s)
Anti-Bacterial Agents/pharmacology , China , DNA Primers/chemistry , Drug Resistance, Bacterial , Gene Expression Regulation, Bacterial , Imipenem/pharmacology , Integrons , Microbial Sensitivity Tests , Models, Genetic , Pseudomonas Infections/genetics , Pseudomonas Infections/microbiology , Pseudomonas aeruginosa/metabolism , Sequence Analysis, DNA , beta-Lactamases/metabolismABSTRACT
A total of 50 clinical imipenem-resistant isolates of Pseudomonas aeruginosa and Acinetobacter baumannii were subjected to the ceftazidime-2- mercaptoethanol -double-disk synergy test and to the PCR assays with primers specific for bla(IMP-1). After the process of sequencing the positive one to identify the results, PCR analysis was conducted with primers specific for class 1 integrons. For synergy test, 28 isolates gave positive results, among which were 27 Pseudomonas aeruginosa and Acinetobacter baumannii. Only one Pseudomonas aeruginosa was found to carry bla(IMP-1), and bla(Int1) at the same time. This is the first ascertainment of IMP-1 producing Pseudomonas aeruginosa isolate carrying bla(IntI1) in West China, which is of significance to the research on the clinical spread of these drug-resisitant genes.
Subject(s)
Acinetobacter baumannii , Genetics , Anti-Bacterial Agents , Pharmacology , Ceftazidime , Pharmacology , Drug Resistance, Multiple, Bacterial , Genetics , Fermentation , Imipenem , Pharmacology , Mercaptoethanol , Pharmacology , Microbial Sensitivity Tests , Pseudomonas aeruginosa , Genetics , beta-Lactamases , GeneticsABSTRACT
This is a study on the biodegradable polymers as gene controlled-released coatings for gene transfer. The PELA (poly (Dl-lactic acid)-co-poly (ethylene glycol), and PLGAE (poly (lactic acid)-co-poly (ethylene glycol)-co-poly (glycolic acid) random copolymer) were synthesized and prepared as the coatings of plasmid pCH110 in the transfection. All kinds of factors affecting the loading efficiency, cytotoxicity, transfection efficiency and the course of the degradation and release in vitro were discussed. The average diameters of microspheres of PELA and PLGAE were 1-3 microm and 0.72 microm respectively. The loading efficiency levels of them were 62% and 70% respectively. The transfection efficiency levels of two kinds of pCH110 delivery system for COS-1 cells were higher and two of them had few cytotoxicity. After transfection, the X-gal assay was performed and reported positive for 96 h. The biodegradable polymeric materials as gene carriers possess their potential superiority.
Subject(s)
Biocompatible Materials , DNA , Chemistry , Drug Carriers , Chemistry , Toxicity , Gene Transfer Techniques , Lactates , Chemistry , Toxicity , Lactic Acid , Chemistry , Toxicity , Polyethylene Glycols , Chemistry , Toxicity , Polyglycolic Acid , Chemistry , Toxicity , Polymers , Chemistry , Toxicity , TransfectionABSTRACT
New strategies are needed for prevention of Pseudomonas aeruginosa (P. aeruginosa) infections, a widespread disease caused by P. aeruginosa with strong drug resistance. The immunoprotective capacity of the receptor of autoinducers protein LasR/RhlR was examined in the BALB/c mice. At first, specialized expression plasmids were developed to facilitate expression of LasR/RhlR proteins in Escherichia coli (E. coli). Then, biofilms were grown from clinical isolated P. aeruginosa PA0305 to investigate the relative contributions of cell signaling for biofilm formation. Morphological characters of biofilm were quantified using Image-Pro Plus software. Fluorescence analysis demonstrated that cell signal molecule LasR/RhlR significantly (P ＜ 0.05) influenced development of P. aeruginosa biofilm. Active immunization of mice with LasR/RhlR was found to provide significant protection against homologous challenge with P. aeruginosa in mice lungs. In 10 days after lungs inoculation, the bacterial clearance rate of the immunized mice was clearly higher than that of non-immunized groups on the basis of microbiological and histological assays. The protective effects of immunization with LasR and Rh1R together were the same as the result of LasR or Rh1R immunized mice alone. These data indicate that the manner ofLasR, Rh1R or both is an important determinant of immunoprotection in mice lungs infection.
ABSTRACT
Salmonella Typhi capsular polysaccharide vaccines were encapsulated in the Micro-particles made from polyethylene glycol-poly-DL-lactide (PELA). BALB/c mouse were divided into three groups with 20 mice in each. Mouse were immunized respectively with controlled release microencapsulated Salmonella Typhi capsular polysaccharide vaccines and Salmonella Typhi capsular polysaccharide vaccines by oral and subcutaneous administration. The mice blood and salvia were collected at the 2nd, 4th and 8th weeks respectively for the titrating of IgG and sIgA antibodies by RIA. At the 8th week, live typhoid bacteria were injected into the immunized mice for the calculation of the rate of immunization protection. The IgG titers of the controlled release microencapsulated Salmonella Typhi capsular polysaccharide vaccines group were higher than those of the other groups(P < 0.05). The IgA titers of the low groups of controlled release microencapsulated Salmonella Typhi capsular polysaccharide vaccines (oral and subcutaneous) were higher than those of the group of Salmonella Typhi capsular polysaccharide vaccines (P < 0.05). The immunization protection rates of the three groups were 40%, 100% and 60% respectively. The controlled release microencapsulated Salmonella Typhi capsular polysaccharide vaccines possess the advantages of releasing slowly in vivo and persisting long time immunogenicity.
Subject(s)
Animals , Female , Mice , Administration, Oral , Delayed-Action Preparations , Immunoglobulin A, Secretory , Immunoglobulin G , Blood , Injections, Subcutaneous , Mice, Inbred BALB C , Microspheres , Polysaccharides, Bacterial , Allergy and Immunology , Typhoid-Paratyphoid Vaccines , Allergy and Immunology , VaccinationABSTRACT
<p><b>OBJECTIVE</b>Streptococcus mutans has been proved as a causative bacteria of human dental caries. The surface protein antigen is one of the important pathogenic factors. The A region of the surface protein antigen pac gene (pacA) can enrich T-cells and B-cells epitope. In this study, a DNA vaccine carrying pacA and gfp gene (a reporter gene) for caries prevention was constructed. The DNA vaccine was liable to be traced in vitro and in vivo.</p><p><b>METHODS</b>The fragment of pacA (1.3 kb) was amplified by PCR with the plasmid pPC41 as template, and inserted into a pEGFP-C1 vector. The recombinant plasmid produced was named as pEGFPC1-pacA. After the COS1 cell line was transfected by the recombinant plasmid, the expression of gfp was detected by observing the green fluorescence and measuring the fluorescence intensity, and the expression of pacA was detected by RT-PCR.</p><p><b>RESULTS</b>Restricted analyzing, sequencing and PCR technique were employed to identify the recombinant plasmid. The phase and orientation of the pacA gene inserted into the vector pEGFPC1 were correct and no changes of their open reading frames were discovered. The transfected COS1 carrying green fluorescent protein (GFP) was observed; the GFP expression level of transfected cells was higher than that of controlled cell. The transcript of pacA gene was confirmed by RT-PCR.</p><p><b>CONCLUSION</b>Construction of the recombinant plasmid was successful. The gfp gene and pacA gene in the plasmid was transcribed and expressed simultaneously in the transfected cells. Moreover, detection of GFP is simple, safe and effective for living cells.</p>
Subject(s)
Humans , Dental Caries , Escherichia coli , Genetics , Fluorescence , Gene Expression , Gene Transfer Techniques , Genes, Bacterial , Genes, Reporter , Genetics , Green Fluorescent Proteins , Luminescent Proteins , Genetics , Recombinant Fusion Proteins , Genetics , Metabolism , Recombination, Genetic , Streptococcal Vaccines , Genetics , Allergy and Immunology , Streptococcus mutans , Genetics , Allergy and Immunology , Vaccines, DNA , Genetics , Allergy and ImmunologyABSTRACT
0.01). The result confirmed he research work of Kennedy that anti-idiotypic antibodies against anti-HBs can be function as the internal image of HBsAg.It is worth to further study the idiotype networks and regulation of the immune response in the field of HBV infection,especially,it can serve as vaccine of HBV.
ABSTRACT
The anti-idiotypic antibodies Specific for anti-HBs were prepared by Immunizing New Zealand white rabbits with anti-HBs according to the method of Kennedy. The serum was first purified through IgG of normal human-Sepharose 4B affinity Column.The anti-idiotypic Specificity of the antibodies obtained was identified with ELISA or RIA inhibition test.The resultshowed that the anti-idiotypic antibodies were directed at the idiotypic determinants on anti-HBs,and no cross reaction between anti-idiotypic antibodies and normal human IgG.