Objective To investigate the distribution and resistance of clinical isolates obtained from the second affiliated hospi-tal of Chongqing medical university in 2012 .Methods The bacteria strains isolated from clinics were collected .Identification and drug susceptibility test were performed by automatic analysis system and API manual identification system .The date was analyzed according with software WHONET 5 .6 .Results A total of 3 454 bacterial isolates were obtained ,which included 36% gram-posi-tive strains ,64% gram-negative strains and 1% Anaerobic bacteria .The detection rates of methicillin-resistant S .aures was 33% , the detection rate of vancomycin -resistant enterococci was 1 .6% .In enterobacteriaceae ,ESBLs producing strains accounted for 60 .6% and 35 .8% in E .coil and K .pneumonia respectively .The drug resistance of A .baumannii and P .aeruginosa was increased . Conclusion Drug resistance of bacterial isolated from our hospital is universal .Drug monitoring data is important for clinical treat-ment .

Objective To investigate the distribution of carbapenemase-resistant genes carried by multi-drug resistant Acineto-bacter baumannii .Methods 80 strains of multi-drug resistant Acinetobacter baumannii were collected .Polymerase chain reaction (PCR)wasusedtodetectcarbapenemase-resistantgenes,suchasOXA-23,OXA-24,OXA-51,OXA-58,SIM,IMP,VIM ,GIMand SPM ,in multi-drug resistant Acinetobacter baumannii .Results Drug resistant gene OXA-23 [49 (61 .3% )] ,OXA-51 [73 (91 .3% )] ,OXA-58[7(8 .8% )] ,OXA-24[1(1 .3% )] ,IMP[17(21 .3% )] and VIM[2(2 .5% )] were found in 80 strains of multi-drug resistant Acinetobacter baumannii ,while GIM ,SIM and SPM gene were not found .Conclusion IMP ,OXA ,VIM is the main genotypes carried by multi-drug resistant Acinetobacter baumannii .

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Objective To investigate the molecular epidemiology and infectious risk factors of linezolid-resistant Enterococci (LRE) isolates in the First Affiliated Hospital of Chongqing Medical University.Methods Thirteen LRE isolates were collected from 2011 to 2013 and confirmed by broth dilution susceptibility testing.The minimum inhibitory concentrations (MIC) of twelve antimicrobial agents were analyzed using Vitek 2 compact.The molecular epidemiology of LRE isolates was determined by multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE) and the Diversilab.A casecontrol study was conducted for the analysis of risk factors, and Logistic regression was performed to evaluate the independent risk factors.Results All thirteen LRE isolates showed low-level resistance to linezolid, and most of these isolates were resistant to tetracycline, erythromycin and ciprofloxacin.However, they had high sensitivity to penicillin, ampicillin and tigecycline.Sequence type 480 was predominant in the hospital, and three isolates (isolates 3, 4, and 5) from July to September 2013 were found to have the same ST, PFGE pattern and rep-PCR group, indicating the same resistance clone.Admission to intensive care unit (ICU), peripheral vascular disease, males, hypoalbuminaemia, enema and linezolid therapy were identified as significant risk factors for LRE infections.Among these factors, admission to ICU, enema and linezolid therapy were independent risk factors for the acquisition of LRE.Conclusions Thirteen LRE isolates collected in the hospital showed a multidrug-resistant phenotype, and a small-scale prevalence was detected from 2011 to 2013.Therefore, attention should be paid to monitor the LRE in the hospital to decrease the prevalence of LRE infections.

Objective: To evaluate and compare the safety and efficiency of the combined therapy of 89Sr plus zoledronic acid and those of 89Sr-chloride alone, in patients with painful bone metastases. Methods: A total of 87 patients with osseous metastasis were ran-domly divided into treatment groups of 89Sr-chloride alone (group A, 53 patients) and 89Sr plus zoledronic acid (group B, 34 patients). A total of 17 patients in group B received zoledronic acid 2-14 days after 89Sr therapy, and 13 other patients in the group received 89Sr 4-7 days after zoledronic-acid therapy. Pain response and KPS score were evaluated after the different treatments. Results: No obvious bone marrow suppression and liver damage were found in all cases. All patients who received both 89Sr-chloride and 89Sr plus zoledronic acid showed reduced bone pain and total discomfort, as well as improved KPS score, but the response was more pronounced in group B (P=0.047; P=0.036). No statistical differences in pain score and KPS scores were observed between the groups treated with zoledronic acid first and 89Sr therapy first (P=1.000; P=0.667). Comparison of bone pain relief and changes in the KPS score of different primary tumors after treatment with 89Sr-chloride or 89Sr plus zoledronic acid showed no statistical significance. Conclusion: Compared with 89Sr-chloride, treatment with 89Sr plus zoledronic acid was more effective in patients with painful bone metastases. The safety of these two treatments are similar.

Objective To evaluate the real-time genotyping and quantitative PCR(RT-GQ-PCR)method by comparing it with direct sequence analysis and the multiplex-PCR method.Methods RT-GQ-PCR,direct sequence analysis and the multiplex-PCR method were used to detect HBV genotypes of 113 patient samples with HBV-DNA positive.ResultsThe detection rate of RT-GQ-PCR and direct sequence analysis was 100%,and the multiplex-PCR is 94.69%.The concordance between RT-GQ-PCR and the multiplex-PCR is perfect(Kappa value =0.915),and the consistency of RT-GQ-PCR and direct sequence analysis is pretty good(Kappa value = 0.742),specially at detecting single genotype.Twenty-eight samples with genotypes B and C dual infections were detected by RT-GQ-PCR,but only 19 samples by the multiplexPCR and 13 samples by direct sequence analysis.Conclusion The RT-GQ-PCR is convenient,rapid and accurate in HBV genotyping,especially more sensitive than direct sequence analysis and the multiplex-PCR for detecting dual genotypes.The method is applicable for large-scale epidemiological study.

Objective: To investigate the gene frequency of HLA-B* 5801 in the population of Chinese Minnan region.Methods:In this study,we enrolled 178 patients requiring allopurinol therapy( including 40 patients with gout,89 patients with hyperuricemia and 49 patients with gouty arthritis) and 100 healthy people.We isolated genomic DNA from their blood and screened for HLA-B*5801 with both PCR and gene sequencing.Results:We found 22%patients and 16%healthy people with HLA-B*5801.The frequencies of HLA-B*5801 in patients and healthy people are 0.13 and 0.09,respectively.The results from PCR and gene sequencing were consistent.Conclusion:The frequency of HLA-B*5801 in the population of Chinese Minnan region is relatively high.Therefore,it is necessary to screen for HLA-B*5801 in allopurinol users before taking the medicine.

Objective To investigate the genotype and epidemiology of plasmid‐mediated AmpC β‐lactamases produced by the clinical strains of Escherichia coli and Klebsiella pneumoniae .Methods A total of 176 clinical nonrepetitive cefoxitin non‐sensitivity isolates of Escherichia coli and Klebsiella pneumoniae was collected from July 2011 to August 2012 .Polymerase chain reaction (PCR) for AmpC enzyme gene amplification and DNA sequencing were carried out for genotype of AmpC beta‐lactamases .Results The results of PCR showed that the positive rate of ampC of the 176 strains of Escherichia coli and Klebsiella pneumoniae AmpC was 18 .2% ,mainly DHA type ,counting for 59 .4% ,CIT counting for 37 .5% ,EBC counting for 3 .1% .The positive rate of ampC of Escherichia coli was 11 .4% ,mainly CIT type ,counting for 77 .8% ,the positive rates of DHA type and EBC type both were 11 .1% .The positive rate of ampC of Klebsiella pneumoniae were 23 .7% ,mainly DHA type ,counting for 78 .3% ,CIT type count‐ing for 21 .7% .The results of DNA sequencing showed that there were 18 strains DHA‐1 type and 1 strain ampC gene type of Morganella morganii in DHA type strains ,the concordance rate was 97 .0% ,10 CIT type strains was CMY‐2 type ,1 strain was CMY‐42 ,one strain was CMY‐4 type ,EBC type was ampC gene type of Enterobacter cloacae ,the concordance rate was 99 .0% .A total of 32 strains of gene sequencing were registered as KJ127248 - KJ127279 in GenBank .Conclusion The main genotypes of plasmid‐mediated ampC enzyme produced by Escherichia coli and Klebsiella pneumoniae were CMY‐2 and DHA‐1 respectively .

Objective To construct a mutant strain of Streptococcus mutans ( S.mutans ) with clpC-deletion and to investigate the role of clpC gene in genetic competence.Methods The fragment of clpC gene and the kanamycin resistant cassette flanked by two loxP sites were amplified by PCR.The purified fragment of clpC gene was cloned into pMD-19T simple vector to construct pCKX1.The pCKX1 vector was digested with ClaⅠ/EcoRⅠ, then blunted and introduced into lox71-KMR-lox66 to obtain pCKX2 vector via homologous recombination.The pCKX2 vector was linearized with SalⅠ and transformed into S.mutans UA159 strain.The positive strains constructed via homologous recombination were screened with kanamycin and transformed with the thermosensitive plasmid pCrePA.The KMR cassette was excised after incubating at 30℃ for 48 hours.Then the pCrePA plasmid was removed after overnight incubating at 37℃for the prepara-tion of clpC-deletion mutant.Total RNA were extracted from the S.mutans UA159 strain and the clpC-dele-tion mutant strain respectively, and then reverse transcribed into first strand cDNA.The target gene frag-ments were amplified by RT-PCR and analyzed by the agarose gel electrophoresis and sequencing.After be-ing verified by PCR and sequencing, the S.mutans UA159 strain and the clpC-deletion mutant strain were re-spectively transformed with E.coli-S.mutans shuttle vector pDL276 to observe the competence development induced by the competence-stimulating peptide (CSP).Results The PCR and sequencing results showed that the pCKX2 vector and the mutant strain with clpC-deletion were constructed successfully via homologous recombination.No clpC gene was detected in the clpC-deletion mutant as indicated by RT-PCR analysis.The formation of competent clpC-deletion mutant was delayed and the competence state was prolonged as com-pared with its parent strains.Conclusion The clpC gene negatively regulated the formation of competent S.mutans.

Objective To investigate the prevalence of qepA, quinolone efflux protein, among 41 unique clinical strains of K. pneumoniae producing ESBLs and to study the qepA-bearing isolates using the Diversilab system. Methods Identification and antimicrobial susceptibility were performed by Vitek-2 Compact System. Screening of qepA was carried out by PCR amplification. The NCBI BLAST program was utilized for sequence comparisons. qnr-bearing strains was evaluated by the Repetitive-sequence-based PCR(Rep-PCR) employing the Diversilab system. And the existence of rmtB was detected among these qepA contained isolates. Results qepA were detected in 5 isolates( 12.2% ). The Rep-PCR profiles produced by the Diversilab system showed that 2/5 of isolates were indistinguishable. And 60% of qepA-positive isolates were detected to harbor rmtB gene. Conclusion The data suggest the emergence of qepA-borne K. pneumoniae.