Analysis on drug-resistance and molecular epidemiology of Acinetobacter baumannii isolated from the clinical samples in two Chinese hospitals

In the present study, the drug-resistance genes encodingβ-lactamases, aminoglycoside modifying enzymes, DNA topoisomerases and integron as well as their molecular epidemiology were investigated by means of analyzing the drug-resistance and molecular epidemiology of Acinebacter bau mannii isolated from the clinical samples in two hospitals in Qiangzhou and Huzhou city of Jiangsu and Zhejiang province from July 2000 to March 2005. The minimal inhibitory concentrations (MICs) of these 307 isolates were detected by automatic microbiological system, and 35 strains against 5-fluoro-quinolones were performed by agar dilution assay. Meanwhile, the resistant genes in 80 isolates were amplified by PCR with identification by DNA sequencer. It was found that most of the 307 isolates of A . baumannii were resistant to multiple antibiotics tested, in which the resistance rates of the isolates against piperacillin, piperacillin/tazobactam, amoxacillin/clavulanic acid, cefotaxime, ceftazidime, cefepime, gentamicin, amikacin, ciprofloxacin, chloramphenicol and sulfamethoxazole/trimethoprim were all above 35% , but those of imipenem and meropenem were quite low, ranged only 2.6% and 3.3%. In addition, it was also demonstrated that the positive rates of TEM and SHVβ-lactamase genes accounted for 93.8% and 22.5% respectively, and those of the aminoglycoside-modifying enzyme genes including aacC1, aacC2, aacC3, aacC4, aacC4A, aphA6, ant(2")-I and ant(3") I were 58.8%, 8.8%, 7.5%, 28.8%, 45.0%, 2.5%, 28.8% and 65.0% respectively. The mutations in the quinolone-resistant determining region (QRDR) of gyrA and parC genes indicated that substitution in Ser-83 residue of GyrA protein was most frequently occurred among strains with MIC for ciprofloxacin of more than 4μg/ml, whereas a double mutation at Ser-83 residue of gyrA and Ser-80 of parC was found in strains with MIC of ciprofloxacin of more than 8μg/ml. As to the positive rates of class 1 integron (Int I -1) and qacE△1-sul-1, it was found to be 60.0% and 77.5% respectively, and the rates of resistant genes of strains isolated in these two hospitals varied considerably. The results obtained in the present study indicate the presence of the multiple resistant genes in strains of A. baumannii , and great measures should be taken to control the spread of the resistant strains carrying the resistant genes.     

Study of Klebsiella pneumoniae producing extendedspectrum β-lactamases against aminoglycosides

Klebsiella pneumoniae （ K. pneumoniae） is one of the main gmn-negative bacilli in clinical practice. Nosocomial infections caused by K. pneumoniae producing extended-spectrum β-lactamases （ESBLs） are very difficult to treat. This paper investigated the resistant characteristics of K. pneumoniae producing ESBLs and their aminoglycoside-modifying enzyme gene expressions including Nacetyltransferases and O-adenyltransferases. Bacteria identification and ESBLs confirmatory tests were performed by Phoenix^TM-100 system. And minimum inhibitory concentrations （MICs） of gentamicin, amikacin, kanamycin, tobranycin, netilmicin and neomycin in 53 K. pneumoniae isolates were detected by agar dilution. In addition, six aminoglycoside-modifying enzyme genes were amplified by polymerase chain reaction （PCR） and verified by DNA sequencer. It was found that imipenem and meropenem against 120 K. pneumoniae isolates produced powerful antimicrobial activities. The resistant rates of gentamicin and amikacin were 55.0% and 46.7%, respectively. Except neomycin, MIC50 and MIC90 of gentamicin, amikacin, kanamycin, tobramycin and netilmicin in 53 K. pneumoniae were all 〉 128 μg/ml, and the resistant rates were 83.0%, 52.3%, 75.5%, 81.1% and 69.8%, respectively. However, neomycin was only 39.6%. In addition, five modifying enzyme genes, including aac（3）-Ⅰ, aac（3）-Ⅱ, aac（6＇）-Ⅰb, ant（3＂）-Ⅰ, ant（2＂）-Ⅰ genes, were found in 53 isoaltes except aac （6＇）-Ⅱ, and their positive rates were 11.3%, 67.9%, 47.2%, 1.9% and 39.6%, respectively. It was also confirmed by nucleotide sequence analysis that the above resistant genes shared nearly 100% identities with GenBank published genes. The results obtained in the present study indicated that K. pneumoniae producing ESBLs strains are rapidly spreading in our hospital, and their resistance to aminoglycosides may be associated with aminoglycoside-modifying enzyme gene expressions.     

Molecular mechanism of the qnrA genemediated quionlone resistance in Gram-negative bacteria

To explore the prevalence of the plasmid-mediated quinolone resistance gene qnrA in Gramnegative bacteria and to investigate its molecular genetic background and resistance profile in isolates harboring this gene, a total of 629 nalidixic acid-resistant isolates of non-repetitive Gram-negative bacteria were collected from clinical specimens between April 2004 and April 2006 and these isolates were screened for qnrA gene by PCR using specific primers combined with DNA sequencing. The extended spectrum β-1actamase （ESBL） or AmpC-producing isolates were distinguished by the phenotypic confirmatory test combined with DNA sequencing, and the antibiotics susceptibility test for qnrA-positive isolates was carried out by Kirby-Bauer and E-test method. To detect the location of the qnrA gene, plasmid conjugation and Southern hybridization were performed and the integron structure containing the qnrA gene was cloned by PCR strategy and sequenced by primer walking. It was demonstrated that the incidence of the qnrA-positive strains in nalidixic acid-resistant bacteria was 1.9% （12/629）, in which the detection rates for Klebiesiella pneumoniae. Enterobacter cloacae, Enterobacter aerogenes, Citrobacterfreundii and Salmonella choeraesuis were 2.2% （3/138）, 17. 1% （6/35）, 9. 1% （1/11）, 12.5% （1/8）, and 14.3% （1/7）, respectively. The qnrA gene was found to be embedded in the complex sull-type integron located on plasmids with varied size （80-180 kb）. Among them, 4 qnrA-positive isolates carried integron In37 and 8 isolates carried a novel integron, temporarily desig- nated as InX. All the qnrA-positive isolates were ESBL-producing and transferable for the multi-drug resistance. It is concluded that the plasmid-mediated drug-resistance mechanism exists in the quinolone resistant strains of isolates from hospitals in Guangdong area, but the incidence was rather low. Nevertheless, it is still possible that the horizontal transfer of the resistant qnrA gene might lead to the spreading of drug-resista     

Detection of mutation in embB gene of Mycobacterium tuberculosis from clinical isolates of tuberculous patients in China by means of reverse-dot blot hybridization

The relationship between embB mutation of Mycobacterium tuberculosis and ethambutol (EMB) resistance of the clinical isolates of tuberculous patients in China was investigated by reverse dot blot hybridization (RDBH) in addition to evaluating the clinical value with application of PCR-RDBH technique to detect EMB resistance. In the present study, the genotypes of the 258 bp fragments of embB genes from 196 clinical isolates of M. tuberculosis were analysed with RDBH and DNA sequencing. It was demonstrated that 60 out of 91 phenotypically EMB-resistant isolates (65.9%) showed 5 types of missense mutations at codon 306 of embB gene, resulting in the replacement of the Met residue of the wild type strain with Val, Ile or Leu residues. In these mutations, the GTP mutation (38/91, 41.8%) and the ATA mutation (16/91, 17.6%) were the most encountered genotypes. The embB mutation at codon 306 could also be found in 69 isolates of phenotypically EMB-sensitive but resistant to other anti-tuberculous drugs, but no such gene mutation could be found in 36 strains of drug-sensitive isolates. Meanwhile, the concordance with the results of DNA sequencing for one wide-type probe and 5 probes for specific mutations was 100% . It was concluded that the EMB-resistance occurring in most M. tuberculosis is due to appearance of embB mutation at codon 306, and the PCR-RDBH assay was proved to be a rapid, simple and reliable method for the detection of gene mutations, which might be a good alternative for the drug-resistance screening.     

Survey of O-islands in Escherichia coli O157 and Other Enteric Pathogens—O-islands of E. coli O157：H7

The genome of the enterohemorrhagic Escherichia coli O157:H7 EDL933 contains 177 “O”-islands (OIs). Tostudy their potential contribution to the O157-specific pathogenicity, we surveyed the distribution of 22 OIs by PCR and DNA hybridization in 17 isolates of Shiga toxin producing (Stx-positive) E. coli O157:H7, and compared with their distribution in 21 isolates of Stx-negative E. coli O157 and 21 isolates of non-O157 enteric pathogens. Fourteen of 22 OIs were present innon-O157 entericpathogens analyzed. Eight of 22 OIs were found only in the 17 Shiga toxin- (Stx) positive E. coli O157:H7 isolates, but they were absent from the 21 Stx-negative E. coli O157: NM and O157 Hund isolates tested. Among the 8OIs, only OI43 or OI48 were exclusively detected in Stx-positive E. coli O157 : H7, absent from neither of Stx-negative E. coli O157 and non-O157 enteric pathogens, such as Salmonella, ShigeUa, Citrobacter, Vibrio cholera, enteropathogen-ic E. coli (EPEC), enteroadherent E. coli (EAEC), enteroinvasive E. coli (E1EC) and enterotoxingenic E. coli (ETEC). The OI43 and OI48 are 83 kb in size and identical in DNA sequences, which encode genes for urease, tellurite resistance and adherence. By analyzing their junction genes with PCR and DNA hybridization, we found that 21 Chinese isolates have OI48 only. However, for 7 Japanese patient isolates, 4 have OI43 and 3 have OI48; for American isolates, 2have both of O143 and OI48, 2 have OI48 only. These data confirmed the highly plasticity of the pathogenic E. coli genome. The unique presence of OI43/OI48 in Stx-positive E. coli 0157:H7 denotes its critical role in the pathogenicity specific to this pathogen.     

A mutation in the type Ⅱ hair keratin KRT86 gene in a Han family with monilethrix

Monilethrix, a congenital disease of hair, is usually associated with mutations in keratin genes, like KRT81, KRT83 and KRT86. We conducted this study to investigate the mutation of type Ⅱ human basic hair keratin hHb/ KRT gene in a Han family with monilethrix and obtain information for potential pathogenic mechanism study of monilethrix. Peripheral blood samples were drawn for genomic DNA detection. Exon 1 and exon 7 of the KRT81, KRT83 and KRT86 genes were amplified by PCR. All PCR products were sequenced directly using an ABI 310 DNA sequencer. These sequences were aligned with the standard sequences in GenBank using the BLAST software. PCR products were digested with restriction endonuclease and restriction fragment length polymorphism (RFLP) analysis was performed. In this study, we identified one novel mutation, which is a heterozygous transitional mutation of G→A at position 1,289 in exon 7 of the KRT86 gene [R430Q (KRT86)]. RFLP assays for the novel mutation excluded the possibility of polymorphism. The R430Q mutation of the KRT86 gene may be pathogenic for monilethrix. Meanwhile, we did not find any novel mutation or recurrent mutation in exons 1 and 7 of KRT81 and KRT83 and exon 1 of KRT86. There is a potential pathogenic gene in the subjects and our results expand the spectrum of mutations in the hHb6 gene.     

联合应用实时定量RT-PCR和激光显微切割检测单个肝细胞RNA的表达（英文）

AIM: The manner in which a cell responds to and influences its environment is ultimately determined by the genes that are expressed. To better understand cellular functions, the isolation of single cells and subsequent quantification of the expressed genes is essential. METHODS: Normal liver tissue was obtained from operation, snap-frozen in liquid nitrogen and sectioned in crystat. Individual hepatocytes were microdissected. RNA was extracted, then reverse transcribed and amplified using real-time quantitative polymerase chain reaction (PCR). RESULTS: Single hepatocytes were dissected by laser beam and catapulted to the microcentrifuge cap which was put above the slide. In this way, cells were collected, RNA was extracted, reverse transcribed to cDNA and used for analysis of RNA expression by real-time quantitative PCR. The amplification results showed that quantitation of the RNA inside the cell was compatible with the number of cells. CONCLUSION: The expression of RNA in single cells can be quantitated successfully by using laser microdissection and real-time PCR. These techniques provide an opportunity to monitor in vivo gene expression levels in single hepatocytes.     

Construction and Verification of LuxS-negative Mutants of Streptococcus Mutans and the Effect of the Absence of LuxS Gene on the Acid Tolerance

Objective： To knock out the entire Luxs gene of Streptococcus mutans （S mutans） UA159 strain via homologous recombination and construct a Luxs-deleted mutant strain of S. mutans. To study the difference between the acid resistance of S. mutans Ingbritt C international standard strain and the acid resistance of LuxS mutant strain. Methods： Two DNA fragments locating in the upper and downstream of Luxs gene were amplified and a erythromycin resistance gene of PJT10 between them were engineered into PUC19 plasmid for constructing the recombination plasmid pUCluxKO. Electrotransformation of S. mutans cells with pUCluxKO-mutant resulted in isolation of erythromycin resistant S. mutans transformants, which was identified by polymerase chain reaction, V. harveyi BB170 luminescence bioassay and sequencing analysis. Solutions of S. mutans standard strain and LuxS mutant strain with same density were made and cultured at pH 3.5 to 7.0 BHI liquid for the same period. Terminal growth situation was compared. Firstly acidized in pH 5.5 BHI liquid, the two strains were cultured at pH 3.0 BHI liquid. The acid tolerance responses of the two strains were compared. Results ： Restriction endonuclease analyses showed that pUCluxKO-mutant vector had been successfully recombined. The Luxsdeleted status of S. mutans mutants was confirmed by PCR with primers which were specific for the genes of Luxs and Erythromycin resistance. S. mutans mutant can not induce bioluminescence, indiating the mutant had been successfully recombined. After twenty generations of culture, the constructed Chinese S. mutans mutants were confirmed to be stable. Significant difference of aciduricity was observed between S. mutans standard strain and LuxS mutant strain. The acid resistance of standard strain was stronger than that of LuxS mutant strain. The two strains both displayed the capability of acid tolerance responses. Conclusion：The S. mutans gene allelic exchange plasmid is constructed correctively and a Luxs-negative mutants of S. mutans is constructed, which can help to further study the role of Luxs in the pathogenesis of S. mutans. LuxS mutant strain is more sensitive to acid inactivation, but the capability of acid tolerance responses exist still.     

Analysis of the CDR3 Length Repertoire and the Diversity of TCRα Chain in Human Peripheral Blood T Lymphocytes

Analysis of complementarity determining region 3 （CDR3） length of T lymphocyte receptors （TCRs） by immunoscope spectratyping technique has been used successfully to investigate the diversity of TCR in autoimmune diseases and infection diseases. In this study, we investigated the patterns of CDR3 length distribution for all 32 TCR AV gene families in human peripheral blood lymphocytes of four normal volunteers by the immunoscope spectratyping technique. It was found that PCR products exhibited an obscure band on 1.5% agarose gel electrophoresis. Each TCR AV family exhibited more than 8 bands on 6% sequencing gel electrophoresis. The CDR3 spectratyping of all TCR AV families showed a standard Gaussian distribution with different CDR3 length, and the expression frequency of CDR3 was similar among the gene families. Most of CDR3 in TCR AV family recombine in frame. However, some of the CDR3 showed out-of frame gene rearrangement. Additionally, we found that in some of TCR AV families there were 18 amino acid discrepancies between the longest CDR3 and shortest CDR3. These results may be helpful to further study the recombination mechanism of human TCR genes, the TCR CDR3 gene repertoire, and the repertoire drift in health people and disease state. Cellular ＆ Molecular Immunology.     

Characterization of integrons and novel cassette arrays in bacteria from clinical isloates in China,2000-2014

Rapid dissemination of antibiotic resistance genes among bacterial isolates is an increasing problem in China.Integron,a conserved DNA sequence,which is carried on episomal genetic structures,plays a very important role in development of antibiotic resistance.This systematic analysis was based on MEDLINE and EMBASE databases.We summarized the distribution and proportion of different types of gene cassette arrays of integrons(including class 1,2,3 and atypical class 1 integron) from clinical bacteria isolates in China.Fifty-six literatures were included in this study.Most of the strains were Gram-negative bacteria(94.1%,7,364/7,822) while only 5.9% strains were Grampositive bacteria.Class 1 integrons were detected in 54.2%(3956/7295) Gram-negative strains.aadA2 was the most popular gene cassette array detected from 60 Gram-positive bacteria while dfrA17-aadA5 were detected in 426 Gramnegative bacteria.This study identified 12 novel gene cassette arrays which have not been previously found in any species.All the novel gene cassette arrays were detected from Gram-negative bacteria.A regional characteristic of distribution of integrons was presented in this study.The results highlight a need for continuous surveillance of integrons and provide a guide for future research on integron-mediated bacteria resistance.     

人类免疫缺陷病毒-1包膜糖蛋白进化对抗原表位及病毒亲嗜性的影响

Objective To investigate the evolution of HIV-1 envelope (env) gene from the individuals infected by the virus from one donor, the entry mediated by the envelope glycoprotein and the variation in the main neutralizing epitopes of envelope. Methods The genetic distances of the HIV-1 envelope genes derived from previous studies were analyzed. A series of envelope-pseudotyped viruses were constructed by co-transfecting HEK293T cells with a HIV-1 plasmid bearing the firefly luciferase reporter gene and an envelope expression plasmid. The entry ability of the envelope-pseudotyped viruses into U87. CD4. CCR5 or U87. CD4. CXCR4 cell lines was examined. The ami-no acid sequences representing the epitopes to the broad-neutralizing antibodies within the envelope glycoproteins were also investigated. Results It was found that the genetic distance of the 24 env genes with complete open reading frame was (7.91 ±0.78)% towards HIV-1 CNHN24, and (6.90 ±0.79)% towards RL42. Among the variable regions, the genetic distance of V1/V2 showed the biggest distance, and that of V3 showed the smallest distance. There were CCR5-tropic, CXCR4-tropic and CCR5/CXCR4-dual-tropic Env-pseudoviruses. Furthermore, in these envelopes, the epitopes to IgG1 b12 2F5 and 4E10 antibody were conserved, while the epitope to 447-52D was variable. Conclusion There is definite env gene variation among the viruses derived from the same donor. The variation influences the entry ability and tropism of emelope pseudoviruses. The epitopes to the main broad-neutralizing antibodies are conserved.     

体内诱导耐碳青霉烯类鲍曼不动杆菌膜蛋白质组学研究

Objective To investigate the role of outer membrane protein in clinical isolated car-bapenem resistance Acinetobacter baumannii. Methods Carbapenem resistance and sensitive strains were collected from the same patient. After MIST and REP-PCR analysis, carbapenemases were detected by isoe-lectric focusing. Different expressed membrane proteins were identified by two-dimension electrophoresis and mass spectrometry analysis. We also used efflux pump inhibitor PAβN(Phe-Arg-β-naphthylamide) to con-firm the phenotype. Results Carbapenem resistance and sensitive strains were attributed to the same pat-tern. At positions of P17.6 and P19.0, two β-lactamases were expressed in two investigated strains, no cabapenemases were detected. Six differential expressed membrane proteins were identified, a 34 × 103 membrane protein that was confirmed by efflux pump inhibitor PAβN experiment (imiponem MIC decreased from far above 32 μg/ml to 8μ/ml) and OprD and CarO. Conclusion Up-regulation of exported protein accompanied with down-regulation of OprD and CarO other than carbaponemases are responsible for carbap-enem resistance in A. baumannii.     

Protection of Immuno-Compromised Mice from Lethal Infection of KlebsieUa pneumonia by rAAV2-BPI23-Fcγ1 Gene Transfer

In previous research, chimerical BPI23-Fcy1 gene which consisted of human bactericidal/permeability increasing protein （BPI） gene of encoding the functional N terminus （amino acid residues 1 to 199） of human BPI and Fcy1 gene of encoding the Fc segment of human immunoglobulin G1 was successfully reconstructed within a recombinant adeno-associated virus serotype 2 （rAAV2） vector as rAAV2-BPI23-Fcy1. Here, to evaluate the potentiality of applying gene therapy to gram negative bacterial （GNB） infection in high-risk patients, we investigated protection of immuno-compromised mice and immunocompetent mice from challenge with minimal lethal dose （MLD） Klebsiella pneumonia infection after rAAV2-BPI23-Fcy1 gene transferred. The results showed that the survival rate of rAAV2-BPI23-Fcy1 transferred immunocompetent mice as well as immuno-compromised mice （40.0% and 44.4%, respectively） were significant higher than that of corresponding control mice （6.7% and 4.4%, respectively）; the bacteria counting, level of endotoxin and proinflammatory cytokines in the rAAV2-BP123-Fcy1 transferred immuno-compromised mice were markedly lower than that of rAAV2-EGFP and rAAV2-Null transferred immuno- compromised mice. Our data suggest that rAAV2-BPI23-Fcy1 gene transferring offered immuno-compromised mice with resistance against GNB infection, so it is quite potential in preventing GNB infection of clinical high-risk patients. Cellular ＆ Molecular Immunology. 2008;5（6）：439-445.     

Protection of Immuno-Compromised Mice from Lethal Infection of Klebsiella pneumonia by rAAV2-BPI23-Fcγ1 Gene Transfer

In previous research, chimerical BPI23-Fcγ1 gene which consisted of human bactericidal/permeability increasing protein (BPI) gene of encoding the functional N terminus (amino acid residues 1 to 199) of human BPI and Fcγ1 gene of encoding the Fc segment of human immunogiobulin G1 was successfully reconstructed within a recombinant adeno-associated virus serotype 2 (rAAV2) vector as rAAV2-BP123-Fcγ1. Here, to evaluate the potentiality of applying gene therapy to gram negative bacterial (GNB) infection in high-risk patients, we investigated protection of immuno-compromised mice and immunocompetent mice from challenge with minimal lethal dose (MLD) KiebsieUa pneumonia infection after rAAV2-BPI23-Fcγ1 gene transferred. The results showed that the survival rate of rAAV2-BPI23-Fcγ1 transferred immunocompetent mice as well as immuno-compromised mice (40.0% and 44.4%, respectively) were significant higher than that of corresponding control mice (6.7% and 4.4%, respectively); the bacteria counting, level of endotoxin and proinflammatory cytokines in the rAAV2-BPI23-Fcγ1 transferred immuno-compromised mice were markedly lower than that of rAAV2-EGFP and rAAV2-Null transferred immuno- compromised mice. Our data suggest that rAAV2-BPI23-Feγ1 gene transferring offered immuno-compromised mice with resistance against GNB infection, so it is quite potential in preventing GNB infection of clinical high-risk patients. Cellular & Molecular lmmunology. 2008;5(6):439-445.     

应用抑制性消减杂交技术筛选结核分枝杆菌差异基因

Objective To screen differential Mycobacterium tuberculosis genes between Xinjiang clinical strains and H37Rv by suppression subtractive hybridization( SSH), and to analyze the function of these specifically pathopoiesis genes. Methods Both M. tuberculosis Xinjiang clinical strains and H37Rv as tester and driver each other, most identical genome was drived whereas some distinctive genes was re-mained and enriched by utilization SSH technique. Meanwhile through inserting differential genes to E. coli all of sequences that we have cloned were determined by BLAST in GenBank. The function of differential genes between M. tuberculosis H37Rv and Xinjiang clinical strains were analyzed. Results We cloned and analyzed six different DNA fragments that only existed in Xinjiang clinical strains. One is the fragment of a gene ceding monooxygenase, flavin-binding family identified by Glimmer2. One fragment belongs to acyl-transferase family protein. One for aminotransferase, class Ⅱ, acyl carrier protein. One fragment belongs to chromosomal replication initiator protein DNA and one for M. tuberculosis paralogous family 11-pyridoxamine 5'-phosphate oxidase-related. Meanwhile, we cloned ten DNA fragments only in H37Rv. Conclusion SSH technique can efficiently screen differential genes in M. tuberculosis in Xinjiang clinical strains. They are possible key genes that M. tuberculosis survive and fortify virulence in mal-environment as same as their ho-mogenic genes, such as enhanced adsorbability in wall-held protein, counteracted digestion by nitro-oxygen-ase, elevated composition capability in the acyhransferase, control chromosomal replication initiator protein, synthesized aminotransferase acyl cartier protein and pyridoxamine 5'-phosphate oxidase.     

应用抑制性消减杂交技术筛选结核分枝杆菌差异基因

Objective To screen differential Mycobacterium tuberculosis genes between Xinjiang clinical strains and H37Rv by suppression subtractive hybridization( SSH), and to analyze the function of these specifically pathopoiesis genes. Methods Both M. tuberculosis Xinjiang clinical strains and H37Rv as tester and driver each other, most identical genome was drived whereas some distinctive genes was re-mained and enriched by utilization SSH technique. Meanwhile through inserting differential genes to E. coli all of sequences that we have cloned were determined by BLAST in GenBank. The function of differential genes between M. tuberculosis H37Rv and Xinjiang clinical strains were analyzed. Results We cloned and analyzed six different DNA fragments that only existed in Xinjiang clinical strains. One is the fragment of a gene ceding monooxygenase, flavin-binding family identified by Glimmer2. One fragment belongs to acyl-transferase family protein. One for aminotransferase, class Ⅱ, acyl carrier protein. One fragment belongs to chromosomal replication initiator protein DNA and one for M. tuberculosis paralogous family 11-pyridoxamine 5'-phosphate oxidase-related. Meanwhile, we cloned ten DNA fragments only in H37Rv. Conclusion SSH technique can efficiently screen differential genes in M. tuberculosis in Xinjiang clinical strains. They are possible key genes that M. tuberculosis survive and fortify virulence in mal-environment as same as their ho-mogenic genes, such as enhanced adsorbability in wall-held protein, counteracted digestion by nitro-oxygen-ase, elevated composition capability in the acyhransferase, control chromosomal replication initiator protein, synthesized aminotransferase acyl cartier protein and pyridoxamine 5'-phosphate oxidase.     

Analysis of genetic markers of N. Gonorrhoeae resistance to β-lactam antibiotics

A complex method for detection of genetic markers of N. gonorrhoeae resistance to penicillin was developed. Mutations in penA and ponA genes were detected by minisequencing reaction with subsequent detection of reaction products by MALDI-TOF mass spectrometry. This approach was tested on 31 clinical strains of N. gonorrhoeae with minimum inhibitory concentration of penicillin from 0.03 to 8 μg/ml and higher. Mutations in penA and ponA genes in moderately resistant strains were shown (minimum inhibitory concentration up to 0.5 μg/ml) and mutations in penA, ponA, and penB genes in resistant strains (minimum inhibitory concentration more than 1.0 μg/ml). β-Lactamase genes were detected in 4 strains with high resistance (minimum inhibitory concentration 4–8 and more μg/ml). Correlation between microbiological resistance and presence of respective mutations in the studied locuses was detected. __________ Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 141, No. 5, pp. 549–554, May, 2006     

Construction of cDNA library from NPC tissue and screening of antigenic genes

To construct cDNA library of nasopharyngeal carcinoma (NPC) and obtain the NPC associated or specific antigens from it, we used a powerful new method to identify the antigens eliciting humoral immune response, which is SEREX (serological identification of antigen by recombinant cDNA expression library). Autologous serum of NPC patient was used to screen the reactive clones in the human NPC tissue cDNA library consisted of 3.64×106 recombinants. The 23 exact positive clones were subcloned to monoclonality and the size of cDNA inserts was identified by PCR. Then the nucleotide sequence of cDNA inserts was determined, and the sequence alignments were performed with BLAST software on GenBank database. They represented 16 different antigens. A detailed sequence analysis showed that 10 of 16 genes were high homologous to genes known in GenBank, such as RPL31, S100 A2, MT2A, etc. However, there were also 6 genes with low homology to genes in GenBank. Furthermore, 3 of 6 genes may be novel genes. The associations of these genes to NPC and the roles that they played in the occurrence and development of NPC should be further revealed.     

应用抑制性消减杂交技术筛选结核分枝杆菌差异基因

Objective To screen differential Mycobacterium tuberculosis genes between Xinjiang clinical strains and H37Rv by suppression subtractive hybridization( SSH), and to analyze the function of these specifically pathopoiesis genes. Methods Both M. tuberculosis Xinjiang clinical strains and H37Rv as tester and driver each other, most identical genome was drived whereas some distinctive genes was re-mained and enriched by utilization SSH technique. Meanwhile through inserting differential genes to E. coli all of sequences that we have cloned were determined by BLAST in GenBank. The function of differential genes between M. tuberculosis H37Rv and Xinjiang clinical strains were analyzed. Results We cloned and analyzed six different DNA fragments that only existed in Xinjiang clinical strains. One is the fragment of a gene ceding monooxygenase, flavin-binding family identified by Glimmer2. One fragment belongs to acyl-transferase family protein. One for aminotransferase, class Ⅱ, acyl carrier protein. One fragment belongs to chromosomal replication initiator protein DNA and one for M. tuberculosis paralogous family 11-pyridoxamine 5'-phosphate oxidase-related. Meanwhile, we cloned ten DNA fragments only in H37Rv. Conclusion SSH technique can efficiently screen differential genes in M. tuberculosis in Xinjiang clinical strains. They are possible key genes that M. tuberculosis survive and fortify virulence in mal-environment as same as their ho-mogenic genes, such as enhanced adsorbability in wall-held protein, counteracted digestion by nitro-oxygen-ase, elevated composition capability in the acyhransferase, control chromosomal replication initiator protein, synthesized aminotransferase acyl cartier protein and pyridoxamine 5'-phosphate oxidase.     

应用抑制性消减杂交技术筛选结核分枝杆菌差异基因

Objective To screen differential Mycobacterium tuberculosis genes between Xinjiang clinical strains and H37Rv by suppression subtractive hybridization( SSH), and to analyze the function of these specifically pathopoiesis genes. Methods Both M. tuberculosis Xinjiang clinical strains and H37Rv as tester and driver each other, most identical genome was drived whereas some distinctive genes was re-mained and enriched by utilization SSH technique. Meanwhile through inserting differential genes to E. coli all of sequences that we have cloned were determined by BLAST in GenBank. The function of differential genes between M. tuberculosis H37Rv and Xinjiang clinical strains were analyzed. Results We cloned and analyzed six different DNA fragments that only existed in Xinjiang clinical strains. One is the fragment of a gene ceding monooxygenase, flavin-binding family identified by Glimmer2. One fragment belongs to acyl-transferase family protein. One for aminotransferase, class Ⅱ, acyl carrier protein. One fragment belongs to chromosomal replication initiator protein DNA and one for M. tuberculosis paralogous family 11-pyridoxamine 5'-phosphate oxidase-related. Meanwhile, we cloned ten DNA fragments only in H37Rv. Conclusion SSH technique can efficiently screen differential genes in M. tuberculosis in Xinjiang clinical strains. They are possible key genes that M. tuberculosis survive and fortify virulence in mal-environment as same as their ho-mogenic genes, such as enhanced adsorbability in wall-held protein, counteracted digestion by nitro-oxygen-ase, elevated composition capability in the acyhransferase, control chromosomal replication initiator protein, synthesized aminotransferase acyl cartier protein and pyridoxamine 5'-phosphate oxidase.