Objective Using 16S rRNA gene sequencing as the gold standard method,to compare the performance of two matrix-assisted laser desorption ionization time of flight mass spectrometry system (MALDI Biotyper and VITEK MS) for identifying clinical isolates of Streptococcus spp.Methods One hundred and sixty two clinical Streptococcus isolates were collected at the Second Affiliated Hospital of Zhejiang University,from April to June,2014,and confirmed by 16S rRNA gene sequencing analysis.MALDI Biotyper and VITEK MS mass spectrometry system were used for identification and further evaluated by performance respectively.Results Of all the isolates tested,155 (155/162,95.68％) Streptococcus isolates were accurately identified to species level by MALDI Biotyper.Besides,MALDI Biotyper identified three Streptococcus mitis group as S.pneumoniae and one S.parasanguinis as S.australis.Another three S.pneumonia isolates were not identified accurately (values ＜ 1.7).Although 156 (156/162,96.30％) isolates were accurately identified to species level (including subspecies) by VITEK MS system,two S.pneumoniae as S.mitis/S.oralis and one S.euinus as S.infantarius ssp.infantarius were misidentified.The two systems showed a 100％ (51/51) accuracy in identifying all S.pyogenes and S.agalactiae isolates,and an accuracy higher than 85％ for S.pneumoniae.Conclusions Both systems showed potent identification ability for Streptococcus spp.,VITEK MS system showed more clinical significance in accurately identifying some subspecies.Mass spectrometry system can be used as a rapid identification method for Streptococcs spp.in clinical practice.

Objective To evaluate the performance and clinical utility of Verigene gram-negative blood culture ( BC-GN ) assay for a rapid identification of gram-negative bacteria and resistance genes . Methods Non-repetitive blood culture samples containing gram-negative bacteria were collected from inpa-tients in the Second Affiliated Hospital of Zhejiang University School of Medicine from June to October , 2013 .BC-GN assay was performed to identify the species and genetic resistance determinants of gram -nega-tive bacteria directly from the positive blood culture bottles .VITEK MS and the VITEK 2 Compact were used for species identification and antimicrobial susceptibility test , the results of which were considered as gold standards.The resistance genes were further validated by PCR amplification and sequencing analysis .A comparison of the results and time between the BC-GN assay and routine methods was conducted . Results The detection range of BC-GN assay almost covered all of the common gram-negative bacteria .BC-GN assay showed an advantage of high accuracy in the identification of Escherichia coli (13/13), Klebsiella pneumoniae (19/24), Klebsiella oxytoca (9/9), Pseudomonas aeruginosa (39/39), Serratia marcescens (4/5), Enterobacter spp.(6/8), Citrobacter spp.(11/11), Proteus spp.(6/6) and Acinetobacter spp. (24/24) with an overall accuracy of 94.24%for the identification of mono-microbial blood culture samples . Moreover , BC-GN assay accurately identified all of the bacteria and resistance genes from the two multi -mi-crobial samples .Species identification and resistance profiles could be 42 hours earlier available by using BC-GN assay than those by using routine methods .Conclusion BC-GN assay could simultaneously and ac-curately identify bacteria and resistance determinants from blood cultures within 2 hours.More time for clini-cally effective therapy could be achieved by using BC-GN assay for the reduction of mortality associated with bloodstream infection .

Objective To investigate the antimicrobial activity of fosfomycin combined with other antibiotics against carbapenem-resistant enterobacteriaceae(CRE).Methods A total of 233 non-repititive CRE isolates were collected from January 2010 to December 2014 from 4 hospitals, including Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou Traditional Chinese Medicine Hospital, Zhejiang Provincial People's Hospital and Second Hospital of Jiaxing.Antimicrobial susceptibility of fosfomycin, imipenem, meropenem, cefepime, ceftazidime, ceftriaxone, cefperazone-sulbactam, piperacillin-tazobactam, ciprofloxacin, amikacin, tobramycin, polymyxin B and tigecycline were determined by agar dilution method.Synergistic effect between fosfomycin and other antibiotics, including meropenem, cefepime, ceftazidime, cefperazone-sulbactam, ciprofloxacin, amikacin, tobramycin and tigecycline against 30 CRE isolates was determined by chequerboard assay.Chi-Square test was used for statistical analysis, and the difference was statistical significant when P<0.05.Results An overall 45.1%(105/233) of 233 CRE isolates were resistant to fosfomycin.Among which, Klebsiella spp.possessed the highest resistance rate (61.9%,73/118), followed by Enterobacter spp.(50%,15/30), Serratia marcescens (25%,7/28), and Escherichia coli (8.2%,4/49).Fosfomycin in combination with tigecyclin showed best activity against CRE isolates with a synergy rate of 76.7%(23/30).Fosfomycin and aminoglycosides also presented good activity against CRE isolates with synergy rate of 53.3%(16/30) to 70.0%(21/30).Synergism was observed only in 30%(9/30) of CRE isolates for the combination of fosfomycin and ciprofloxacin.As for the combination of fosfomycin and β-lactam antibiotics, even less synergism was observed ( 0%-3.3%) ( 1/30 ).No antagonism was demonstrates among all of the combinations.Conclusions Fosfomycin demonstrates certain in vitro activity against CRE isolates.A combination of fosfomycin and tigecyclin or aminoglycosides shows good activity, which suggests a new strategy in the campaign against serious infections caused by CRE.

Objective To evaluate the effects of Aidi injection on the short-term curative effect,pain level,quality of life and the survival time for the elderly and infirm patients with advanced cancer.Methods A total of 143 elderly patients with advanced cancer were randomly divided into two groups,71 patients in control group were treated with routine support therapies,and 72 patients in treatment group were injected with 50-60 ml Aidi injection infused in NS 250 ml by i.v drip every day combined with routine medicines,each cycle was 21 days,all patients were received for 2 cycles.Results After treatment the short-term curative effect rate (CR+PR) was 2.8 ％ (2/72) only compared with no effect of control group.But the effective and stabilization rate (CR+PR+SD) was 66.7 ％ (48/72),it was 31.0 ％ (22/71) in control group.There was significant difference between the two groups (P ＜ 0.05).The overall effective rate of easement of pain was 67.7 ％ (48/72) in treatment group versus 36.1％ (13/36) in control group (P ＜ 0.05).The median survival time (MST) was 6.2 months in treatment group versus 5.1 months in control group (P ＞ 0.05).The quality of life in treatment group was improved obviously (P ＜ 0.05).The side effects of patients in treatment group were very slight.Conclusions Aidi injection can reduce the cancer pain,improve the quality of life and prolong the survival time of the elderly and infirm patients with advanced cancer.It is safe,and effective to inhibit growth of tumor.It can be recommended widely to clinical use.

After ischemic stroke, secondary damages such as neuron loss, gliosis, and axonal degeneration occur in the nonischemic remote brain regions that have synaptic connections with the primary infarction site.These secondary damages in the remote brain regions may affect the recovery of neurological function.Several advanced neuroimaging techniques have been used to detect these secondary damages.This article reviews the research progress in this field.

Objective To investigate the molecular background of the New Delhi-metallo-1 (NDM-1)-producing Morganella morganii.Methods Two carbapenem-resistant M.morganii named 1 and 2 were isolated in the Second Hospital of Jiaxing,Zhejiang on October 4th and 29th,respectively.Antimicrobial susceptibility was determined by agar dilution method.Pulsed-field gel electrophoresis (PFGE) was performed to analyse the homololgy of isolates.Amplification with specific primers,DNA sequencing,conjugation experiments and genetic environment analysis were conducted to investigate the molecular mechanisms of resistance.Results The two M.morganii isolates were resistant to carbapenem and fluoroquinolones,while susceptible to aztreonam.PFGE analysis indicated that the two isolates were distinguishable.Amplification and DNA sequencing confirmed the coexistence of blaNDM-1,blasHv-12,qnrS1 and aac(6')-Ib-cr in both isolates.Transconjugants were detected with blaNDM.1 and qnrS1 simultaneously.Genetic environment analysis demonstrated that the blaNDM-1-bleMBL-trpF-dsbC-cutA1 structure was in consistence with those from known blaNDM-1-carrying Klebsiella pneumoniae.Conclusion The blaNDM-1 in M.morganii isolates possiblely obtained from K.pneumoniae through translatable plasmids.

Objective To study the relationship between the expression of Mycobacterium tuberculosis small heat shock protein Hsp16.3 and the apoptosis of infected mouse alveolar macrophages.Methods The laboratory mice were infected with bacterial suspension of the international standard virulent strain of Mycobacterium tuberculosis H37Rv strains (H37Rv),Hsp16.3 gene deletion mutants of the international standard virulent of Mycobacterium tuberculosis H37Rv strains(△H37Rv),or sterile saline solution (normal control)by the tail vein. After successful replication of mouse infection model in each group,we cleaved the alveolus of each group of mice and collected lavage fluid to obtain alveolar macrophages of the infected mice at days 1 ,3 ,5 ,7 ,9 ,1 1 ,1 3 and 1 5 .Then the infection status of macrophages was observed with confocal laser scanning microscopy;flow cytometry was used to detect the apoptosis rate of alveolar macrophages of the infected mice;Caspase-3 and Bcl-2 expressions were examined by Western blot.Results The apoptosis rate of Hsp16.3 gene was higher in deletion strain (△H37Rv)group and H37Rv strains (H37Rv)group than in control group.The apoptosis rate of alveolar macrophages in △ H37Rv group gradually increased,peaked at day 7 ,and then gradually decreased.It was significantly higher in H3 7 Rv group than in H3 7 Rv strain group from day 1 to 7 and from day 1 3 to 1 5 (P<0 .0 5 ).Caspase-3 and Bcl-2 protein expressions in the macrophages of△H37Rv group and H37Rv group were higher than those of control group.Caspase-3 expression in the microphages of △H3 7 Rv group and H3 7 Rv group gradually increased from day 1 to 7 and peaked at day 7;it peaked again at day 13 in H37Rv group.However,Caspase-3 expression remained significantly higher in△H37Rv group than in H3 7 Rv group (P<0 .0 5 ).Bcl-2 expression in △H3 7 Rv group did not change much at the early stage of infection (P<0 .0 5 ),but gradually increased after day 9 .Bcl-2 expression in H3 7 Rv group did did not change much from day 1 to 7 (P<0.05),but gradually increased after day 7.However,it remained lower in△H37Rv group than in H37Rv group,especially after 7 days(P<0.05).Conclusion Mycobacterium tuberculosis small heat shock protein Hsp16.3 can inhibit the apoptosis of macrophages during the early and late stages of infection,and this inhibition may be achieved by inhibiting the expression of apoptotic protease Caspase-3 and promoting the expression of Bcl-2 protein.

Objective To analyze the clinical effects of thrombolytic therapy in patients with ischemic in-hos-pital stroke (IHS). Methods The clinical data were collected from patients with ischemic IHS in the last five years. The patients were divided into thrombolysis group and non-thrombolysis group, according to the use of recombinant tissue plasminogen activator (r-tPA) treatment. The clinical outcomes were measured by the modified Rankin scale (mRS) at discharge. Results There were a total of 121 patients in this study. There were 6 patients in thrombolysis group and 115 patients in the non-thrombolysis group, respectively. Six patients (100%) in the thrombolysis group achieved favor-able outcomes (mRS 0~2) at discharge whereas only 42 patients (36.5%) in the non-thrombolysis group achieved fa-vourable outcomes. The rate of favorable outcomes was significantly higher in the thrombolysis group than in the non-thrombolysis group (P<0.05). Conclusions R-tPA thrombolytic therapy can improve the prognosis of patients with ischemic IHS.

Objective To construct the risk model for healthcare-associated infection (HAI)with multidrug-re-sistant organisms(MDROs)in intensive care unit (ICU).Methods 836 patients who were admitted to ICU for more than 48 hours between October 2012 and September 2015 were analyzed retrospectively,logistic regression model of HAI was constructed,the model was conducted goodness of fit tests and the area under ROC curve analysis. Results Among 836 patients,incidence of HAI with MDROs was 14.23%(n=119).15 variables that were statis-tically significant in univariate analysis were included in logistic multivariate analysis,the results showed that the following variables entered into logistic regression equation:length of ICU stay (OR,2.493 [95%CI ,1 .816 -3.494]),underlying diseases (OR,1 .536 [95%CI ,1 .243 - 1 .898 ]),hypoproteinemia (OR,87.211 [95%CI , 36.165-210.304]),ventilator days (OR,1 .723 [95%CI ,1 .399-2.121 ]),fever(OR,20.639 [95%CI ,3.462 -123.043]),and primary pulmonary infection (OR,0.295 [95%CI ,0.133 -0.664]).Evaluation of model effect:sensitivity 95%,specificity 87.9%,the area under ROC curve 0.973.Conclusion Logistic regression model has a high goodness of fit in predicting HAI among ICU patients.

Objective:To evaluate the clinical value of NG-Test Carba5 for rapid detection of carbapenemases produced by carbapenem-resistant Enterobacteriaceae (CRE) strains. Methods:A total of 1 210 CRE strains were collected during 2018-2022 from 77 hospitals in 21 provinces of China and were subjected to NG-Test Carba5 for rapid detection of carbapenemase. The whole genome sequencing (WGS) analysis was referenced as the gold standard method.Results:Overall, the NG-Test Carba5 demonstrated excellent performance in detection of five kinds of carbapenemases [Klebsiella pneumoniae carbapenemase (KPC), New Delhi metallo-β-lactamase (NDM), imipenemase metallo-β-lactamase (IMP), Verona integron-encoded metallo-beta-lactamase (VIM) and oxacillinase-48-type carbapenemases(OXA-48)] from CRE strains, with a sensitivity of 98.47% (1 161/1 179), specificity of 100% (31/31), and positive predictive value of 100% (1 161/1 161). The sensitivity for detection of NDM, IMP, OXA and VIM reached 100% (307/307), and 97.70% (763/781) for KPC. For 11 strains carrying blaKPC-25, blaKPC-78, or blaKPC-93, NG-Test Carba5 reported positive KPC detection (11/11). For strains carrying blaKPC-33 and blaKPC-77, however, NG-Test Carba5 delivered negative results. Additionally, for those strains co-producing two or three kinds of carbapenemases, NG-Test Carba5 was able to report all of the targets with a sensitivity of 100% (91/91). Conclusions:NG-Test Carba5 showed excellent performance in rapid and accurate detection of carbapenemases from CRE strains. Nonetheless, for those strains with negative results, some other phenotypic and genotypic methods should be implemented alongside to avoid missing targets.