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Background and Purpose in recent years due to the extensive use of antibiotics, the growing problem of bacterial resistance. The rise and rapid spread of antibiotic resistance, the bacteria has become an important problem facing the treatment of clinical infections, the study of the mechanisms of resistance has become the focus of attention of the field of microbiology. The complex bacterial resistance mechanisms, including changes in drug targets, permeability changes, resulting in the inactivation of the enzyme and inactivating enzymes, to exclude system as well as the formation of biofilms, which the bacteria through the horizontal transfer of genes, exogenous resistant gene is an important reason to accelerate the clinical resistant strains. Drug resistance genes can be provided by engaging, transformation, transduction, such as transposition spread between different bacteria. Closely related to the genetic structure of bacterial resistance to horizontal gene transfer bonding plasmid, transposon, integrated phage, integrons and insertion sequence common region (ISCR). Integron gene by gene cassette capture and shear box moves itself can be located transposons, plasmids and other mobile genetic elements of the integration of the sub-moves. Integron bacteria, especially Gram-negative bacteria gene, one can identify the gene cassette capture mobility, and site-specific recombinant expression system. Integration the sub itself can not be mobile, but often appear in the transposon bonding plasmid, phage or bacterial chromosome, as jointly own mobile carrier capture and integrate resistance gene, a huge multi-locus, and with bacteria Reproduction is copied to the progeny DNA. Since the concept of integration - cassette system integron 10 types have been found and identified, but only 5 and encoding antibiotic resistance gene cassette Ⅰ, Ⅱ, Ⅲ, Ⅳ class research more. The first integron most common integron found from clinical isolates mostly belong to this category, the integrase IntI1 contains 337 amino acids. 5 'conserved region coding integration enzyme gene intI1, restructuring the locus attI1 and promoter of Pant. Pant encoding box located IntIl some integron There promoter P2. Most integron 3 'conserved region includes three open reading frame (ORF): sulfa drug resistance gene (sul-1), quaternary ammonium compounds, and bromine ethidium tolerance gene (qacE △ 1) and the ORF5 of unknown function. The variable region gene cassette, with a different number of encoding antibiotic resistance gene cassettes. The ISCR is obtained by the \It can have the characteristics of the inserted sequence, also has the characteristics of the common area. IS is highly mobile transposable elements, insertion capability of the small molecule fragment of the genome of one or more target sites, and often can be moved to a neighboring gene. ISCR is an IS91-like factor family, the lack of the inverted repeat sequences, the resistance gene transferred by rolling ring adjacent. ISCR members in ISCR1 the most widely studied, and it often appears in the complex class I integron. The the ISCR1 mediated transposition events, transposable resistance genes of different lengths, as catA2 dfrA of qnr blaCTX-M, blaCMY. The 'conservative end ISCR1 often together with the resistance gene inserted into ordinary integrin-mediated formation of complex integron, such as 1n6 and In7,. In addition, the the ring form ISCR1 factor, together with the resistance gene inserted directly with copy of a ISCR1 in integron the 3 'conservative end, mediated by a complex integron with the two copies ISCR1 factor, these will lead to strains resistant stronger medicine disseminated. Non-fermenting bacteria resistance mechanisms are a group of aerobic spores G-bacteria, can not use glucose as an energy source, or use glucose metabolic pathways other than the fermentation decomposition. It includes Pseudomonas, Acinetobacter, Flavobacterium, Alcaligenes. With the interventional treatment technology to carry out new antibiotics, the widespread use of immunosuppressive agents, the incidence of non-fermenting bacteria infection and drug resistance has an increasing trend, clinical diagnosis and treatment difficult. This topic ISCR1 against clinical isolates of non-fermented G-bacilli and class I integron resistance genes were detected, to understand ISCR1 and class I integron carrying resistance gene distribution characteristics, as well as explore both may exist series results. Research methods. Strain selection and genomic DNA extracted collect, Southern Medical University, Nanfang Hospital laboratory microbial room from January 2008 to December 2009 non-repetitive clinical isolates of non-fermenting G-bacilli, including Acinetobacter baumannii, Pseudomonas aeruginosa, Stenotrophomonas narrow food Aeromonas bacteria, Burkholderia cepacia, Pseudomonas putida, a total of 809. With SDS-proteinase K-phenol - chloroform extracted genomic DNA of the bacteria. 2. Class I integron conserved region (I int2) and variable (gene cassette) detector were amplified by conservative and variable regions of the class I integron, and then use the variable region restriction endonuclease Hinf Ⅰ and Rsa Ⅰ digestion preliminary classification of the PCR products, the selection of different types of sequencing analysis of homology and resistance gene combinations, application GenBank accession no. 3. ISCR1 conserved region (ISCR1 transposase enzyme) and the variable region (ISCR1 carrying resistance genes) detecting ISCR1 specific primers for PCR amplification, positive strains and then amplification of the variable region, and then using the restriction endonuclease the of Hinf Ⅰ and Rsa Ⅰ digestion variable region PCR products preliminary classification, selection of different types of sequencing analysis of homology and resistance gene combinations, application for GenBank accession no. 4. Series may exist of the analysis ISCR1 and class I integron structure (complex class I integron) ISCR1 often formed with the ordinary class I integron complex integron 3'-conservative end of the class I integron variable region and conserved sequence primers designed ISCR1 gene, amplified by PCR and sequenced, and analyzed for the presence of a tandem structure. Results 1. Detected 358 bacteria carrying the class I integrase enzyme, the 293 bacteria carrying the gene cassette in this experiment detected class I integron carrying genes resistant to aminoglycosides, including aacA4 aacC1 aac6-Ⅱ aadA1 aadA2, aadA5 , aadA13, aadB; trimethoprim resistance class, including dfrA1, dfrA15 dfrA17; β-lactamases, including blaIMP-9, blaoxA-10, blaoXA-30, blaIMP-25, blaPSE-1; resistant Chloamphenicol prime class, including G-non-fermenting bacteria catB8. catB3. cmlA8. 809 strains of gene cassette arrangement and distribution were: 376 Acinetobacter baumannii aacA4 catB8 aadAl 159, 18 strains of catB3 qnrVC-like aacA4 , 14 aacC1 orfP orfQ aadA1 9 strains arr3 aacA4, 4 strains of dfrA15, 1 strain aadB aadA2; 240 Pseudomonas aeruginosa 32 blaIMP-9 aacA4 blaoxA-10 aadA2 10 strains of aac (6 ') - Ⅱ aadA13 cmlA8 blaoXA-10a, 8 Zhu the aadB blaPSE-1 plants aacA4 blaIMP blaoxA-30 catB3, 3 strains of dfrA12 orfF aadA2, 2 strains aacA4 aadA2 Zhu dfrA15 1 strain aadB aac6-Ⅱ pse-1, 1 strains aacA4 catB3 dfrA1, 1 Zhu aadB aadA2; 106 Stenotrophomonas narrow food unicellular bacteria, 3 dfrA17 aadA5 the plants aacA4 blaIMP-25 blaOXA-30 catB3, 1 Zhu qacF, 1 strain dfrA15, 1 strain aadB aadA2 ; 75 Burkholderia cepacia, 7 aadB aac6-II pse-1, 2 strains aacA4 catB8 aadA1; 12 Pseudomonas putida, three aadB aac6-Ⅱ pse-1, 1 strains of aadA1 1 strain blaIMP-the 9 aacA4 blaOXA-10 aadA2 2. detected positive of 125 bacterial ISCR1 conservative District 18 ISCR1 variable area positive in 125 ISCR1 positive strains, 18 G-non-fermenting bacteria ISCR1 arrangement, and distribution: in 376 Bowman Acinetobacter, 8 ISCR1 qnrA1 the ampR qacE △ of 1,6 plants ISCR1 blaPER-1 ABC the transporter qacE △; 240 Pseudomonas aeruginosa, three ISCR1 qnrA1 the ampR qacE △ 1; 106 Stenotrophomonas maltophilia Bacteria, a ISCR1 qnrA1 the ampR qacE △ 3. detected 12 bacteria containing complex class I integron arrangement of 12 complex I integron and distribution: 4 Acinetobacter baumannii the qnrVC-like ISCR1 the containing catB3 qnrVC-likecatB3 blaPER-1 ABC tansporter qacE △ 1,4 strains of Acinetobacter baumannii and two Pseudomonas aeruginosa containing dfrA15 ISCR1 qnrA1 the ampR qacE △ 1,1 strains of Acinetobacter baumannii and one Stenotrophomonas narrow food Aeromonas The the bacteria containing aadB aadA2 ISCR1 qnrAl the ampR qacE △. Conclusions 1. Hospital clinical isolates of non-fermenting G-the bacillary I class integrated enzyme carrying rate of 14.2% to 61.7%, the gene cassette carrier rate from 17.5% to 54.5%. Hospital clinical isolates of non-fermented G-bacteria ISCR1 the transposase enzyme carrier rate from 0 to 26.2%, in ISCR1 positive strains, ISCR1 carrying resistance genes 0-16.7%. Hospital clinical isolates of non-fermenting Class I integron resistance gene of the G-bacteria is resistant to aminoglycosides, trimethoprim class, chloramphenicol, β-lactamase enzymes. Hospital clinical isolates of non the Fermented G-bacteria carrying resistance genes ISCR1 main separation qnrA1. 5. Hospital clinical complexity of class I integron non-fermented G-bacteria carrying resistance genes to catB, aacA4, aadA2, aadB, dfrA15, qnr based.
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