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Objective To study Kaposi's sarcoma-associated herpesvirus(KSHV)infection in chronic hepatitis B(CHB)patients and its correlation with hepatitis B virus(HBV)replication and treatment-related factors.MethodsEnzyme-linked immunosorbent assay(ELISA)with recombination protein KSHV ORF65 was employed to detect the KSHV antibody and real-time polymerase chain reaction(PCR)was performed to detect KSHV DNA and HBV DNA in CHB patients.Age,HBV replication and licorice preparation treatment of patients were further analyzed.Comparison of rates was done using X~2 test.Results KSHV ORF65 antibody positive rates were 27.3% in 161 male CHB patients and 30.0% in 50 female patients(X~2=0.135,P＞0.05).The KSHV infection rates were increased with age,but this tendency was not obvious in patients older than 40 years old.The highest infection rate was in age group of 31-40 years old which was 37.1%.The positive rate of HBV DNA in CHB patients with KSHV infection was 73.5%,which was 56.3% in uninfected patients(X~2=3.969,P＜0.05).The average plasma level of KSHV DNA in patients treated with licorice preparations was 204.7 copy/mL and that in patients without licorice preparation treatment was 533.9 copy/mL.Eight patients were KSHV DNA positive(KSHV DNA＞ 100 copy/mL)in 16 patients treated with licorice preparations and 23 were positive in 33 patients without licorice preparation treatment.Conclusions The KSHV infection rates are increased with age of CHB patients.KSHV infection may interfere with HBV replication and licorice preparations may suppresss KSHV replication in vivo.
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Objective To determine the structures of resistance transposons and muhilocus sequencing typing(MLST)in the vancomycin resistant enterococcus(VRE).Methods Twenty-one VRE strains were isolated from five hospitals in Hangzhou.The resistance to antimicrobial agents was determined by Etest.Polymerase chain reaction(PCR),conjugation,plasmid extract,transposon structures,pulse field gel electrophoresis(PFGE),muhilocus sequencing typing(MLST),and multiple-locus variable-number tandem repeat analysis(MLVA)were carried out.Results All of the 21 VRE strains harbored the vanA gene.These strains were divided into 10 PFGE types,7 sequence types(STs)and 5 MLVA types.All of these VRE strains were susceptible to linezolid and tigecycline.The vanA genes in two VRE strains were located in transposon Tnl546,and those in the other 19 VRE strains were located in transpeson Tnl546- like,with ISl485 inserted in vanXY.Vancomycin resistance of 1 8 VRE isolates was transferred by filter mating. All of these conjugants had a plasmid containing a molecular size of about 54 000 bo.Conclusions These 21 VRE strains were all caused by the vanA gene and divided into 7 MIST types.A novel trasnposon was detected.Most of these VRE isolates belonged to the clonal complex(CC17)by MIST,which was the hospital-adapted and pandemic VRE clonal complex.
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Objectives To investigate the properties and distributions of ampC gene among different drug-resistant strains of Serratia marcescens,and the relationship of control gene ampR with AmpC enzymes′ expressions.Methods According to the results of inducting experiment with 1/2 MIC of beta-lactam antibiotics (CTX),three-dimensional testing and isoelectric focusing electrophoresis testing,143 strains of S.marcescens were classified into three groups:including induction group, continuous low-production group and hyperproduction group. In each group, the sequences of ampC and ampR genes were amplified using the method of PCR. The products of PCR were analyzed. The plasmid-mediated beta-lactamases were detected using the method of conjugation experiment.Results Among 143 strains of S.marcescens, the continuous low -production strains, induction strains and hyperproduction strains were 14,103,and 18, respectively.125 and 99 strains were ampC and ampR gene positive, respectively.The detection rate of ampR in hyperproduction group was lower than other groups.5 sites of ampC genes and 4 sites in the Open Reading Frame (ORF) of ampR gene were easily mutated in 5 induction strains and 2 hyperproduction strains.Conclusions The production of inducing drug-resistance of some S.marcescens might be related to mutation of ampC gene encoding AmpC beta-lactamases and the ORF mutation in ampR. The continuous hyperproduction drug-resistance had something to do with deletion mutation in ampR in segmental hyperproduction strains.The plasmid-mediated AmpC enzymes hadn′t been found in S.marcescens.
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<p><b>OBJECTIVE</b>To investigate the epidemiological status of extended-spectrum beta-lactamase (ESBL) producing Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) and the drug resistance profiles of such organisms.</p><p><b>METHODS</b>A total of 282 clinical isolates of E. coli and 180 of K. pneumoniae were collected from different districts of Zhejiang Province. Inhibitor potentiated broth dilution tests were performed for detecting extended-spectrum beta-lactamases. Etests were performed to detect the drug resistance of these strains against nine commonly used antibiotics.</p><p><b>RESULTS</b>The prevalence of extended-spectrum beta-lactamases in E. coli and K. pneumoniae was 34.0% and 38.3%, respectively. The average prevalence of extended-spectrum beta-lactamases in E. coli and K. pneumoniae was 35.7%. The resistance prevalence of extended spectrum beta-lactamase producing strains to ceftazidime and cefotaxime was 40% and 26% respectively, so were those to cefepime, cefoxitin, piperacillin-tazobactam, cefoperazone-sulbactam, amikacin and ciprofloxacin. All these strains were sensitive to imipenem.</p><p><b>CONCLUSION</b>The results in this study showed that the prevalence of extended-spectrum beta-lactamases was high, while extended-spectrum beta-lactamase producing strains were resistant to most antimicrobial agents except imipenem.</p>
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Humans , Drug Resistance, Bacterial , Escherichia coli , Klebsiella pneumoniae , Microbial Sensitivity Tests , beta-LactamasesABSTRACT
Objective To analyse the encoding gene sequence of extended spectrum ? lactamase produced by Klebsiella pneumoniae E95 strain in Zhejiang Province and identify its ESBLs subtype. Methods The gene of ESBLs produced by E95 strain was amplified by PCR. The purified PCR product was cloned into pGEM Teasy vector and then sequenced by Sanger's dideoxy chain termination composition method. Results The encoded gene of ESBLs was identified as SHV by PCR. Its PCR product had 812 nucleotides. It had the same gene sequence as the gene encoding SHV 12 discovered in Swiss. Conclusions The ESBLs produced by Klebsiella pneumoniae E95 strain isolated from a patient in Zhejiang Province is SHV 12.