Post-examination quality management is an important part in clinical microbiology,which includes systematic review,standardized result reporting format and interpretation,protection of private infomation in accordance with the medical ethics system,consulting services,and proper storage of clinical microbial specimens in course of post-examination procedures.Only in this way,the clinical microbiology laboratory could play greater roles in guiding doctors to rational antibacterial drug usage and preventing the produce of drug-resistaut strains.

Objective To evaluate the activity of antibiotics against pan-drug-resistant (PDR) Acinetobacter baumannii by combination antimicrobial susceptibility test in viro with epsilometric methods (Etest method) and microdilution checkerboard (CB method),and to detect a good correlation between timekill curve with the above mentioned two assays.Methods Thirty-one clinical isolates of PDR Acinetobacter baumannii were selected for mono and combination antimicrobial susceptibility test in vitro by E-test and CB method,then a comparison was conducted between the test results and the time-kill curve.Mono drugs involved tigecycline,colistin,imipenem and amikacin,and combinations involved two of drugs above,and three drugs involved imipenem/tigecycline,plus amikacin combination.Results Synergistic effect was detected in imipenem plus colistin and tigecycline plus imipenem combination.A high comparability was revealed between the E-test method with antimicrobial drugs added into the culture medium and the time-kill curves.Synergy in the combination of imipenem/tigecycline,plus amikacin was detected by the CB method and time-kill curves.Conclusion The results showed that the effect of specific combination of antibiotics against PDR Acinetobacter baumannii could be predicted by testing their synergistic effect with combination antimicrobial susceptibility test.

Objective To explore the serum lipid metabolism and immunoregulation of patients with primary nephritic syndrome (PNS) .Methods 50 PNS patients were served as the test group and 50 healthy people the control group .Automatic biochemical analyzer was utilized to detect their serum low density lipid-cholesterol (LDL-C ) ,high density lipid-cholesterol (HDL-C ) , triglyceride(TG) ,total cholesterol(TC) ,apolipoprotein(Apo)A1 ,ApoB ,and lipoprotein (a) .Immunization rate nephelometry was employed to measure their serum IgG ,IgA ,IgM ,complement C3 ,complement C4 ,CD3+ ,CD4+ ,CD8+ and CD4/CD8 .Results Compared with the control group ,serum levels of TC ,TG ,LDL-C ,ApoB ,ApoA1 ,IgM and CD4/CD8 of patients in the test group were significantly higher ,while those of HDL-C ,IgG ,complement C3 ,complement C4 ,CD3+ ,CD4+ ,CD8+ were obviously lower , with both statistically significant differences (P<0 .05) .However ,the differences of serum lipoprotein (a) and IgA between the two groups was not statistical significant(P>0 .05) .Conclusion Serum lipid level of PNS patients is higher than healthy people ,and considerable loss of Ig and complements and T cell subsets disproportion results in humoral and cellular immune dysfunction .

Objective To investigate the clinical value of combined detection of anti-cyclic citrullinated peptide antibody(anti-CCP antibody),rheumatoid factor(RF),C-reactive protein(CRP)and erythrocyte sedimentation rate(ESR)in the diagnosis of rheu-matoid arthritis(RA).Methods The detection results of the four serum indicators of 290 cases of patients with RA(RA group), 286 cases of patients with non-RA autoimmune diseases(non-RA group)and 1 50 cases of healthy individuals(control group),from March 2013 to August 2014 in this hospital,were retrospectively analysed.Results The serum levels of the four indicators have significant differences among the three groups,between the RA group and non-RA group,and between the RA group and control group(P =0.000).Between non-RA group and control group,there was significant difference of serum levels of anti-CCP antibodies (P =0.013),while the other three serum indicators had no significant differences (P >0.05).The sensitivity of combined detection of anti-CCP antibody and RF,combined detection of anti-CCP antibody,RF and CRP,combined detection of anti-CCP antibody,RF and ESR,and combined detection of anti-CCP antibody,RF,CRP and ESR for RA diagnosis have statistically significant differences (P <0.05),while there was no statistically significant differences of specificity (P > 0.05 ).The area under a receiver operating characteristic (ROC) curve of anti-CCP antibody,RF,CRP and ESR were 0.873,0.893,0.678 and 0.747,respectively. Conclusion Combined detection of anti-CCP antibody and RF has good specificity and sensitivity,which could improve the clinical diagnosis of RA.Combined detection of CRP and ESR could improve the detection rate of RA.

Objective To compare the performance of 2009 and 2010 reference standards of the United States Clinical and Laboratory Standards Institute(CLSI)in antimicrobial susceptibility for Enterobacteriaceae.Methods The breakpoints of susceptibility for ceftriaxone,ceftazidime and aztreonam in CLSI M100-S19(2009)were used to analyze results of antimicrobial susceptibility of Escherichia coli (308 isolates)and Klebsiella pneumoniae(194 isolates),as well as those revised in M100-S20(2010).Results With both the breakpoints in CLSI M100-S19(2009)and CLSI M100-S20(2010),proportions of antimicmbial resistance of ceftriaxone,ceftazidime and aztreonam for isolates of extended-spectrum β-lactamases(ESBLs)-producing E. coli were 84.2 percent vs.98.0 percent and 84.9 percent vs.98.0percent,respectively:those for isolates of ESBLs negative E. coli were 4.2 percent vs.7.7 percent and 5.6percent vs.8.4 percent,respectively;those for isolates of ESBLs positive Klebsiella spp.were 67.2 percent vs.90.2 percent and 67.2 percent vs.90.2 percent,respectively:and those for isolates of ESBLs negative Klebsiella spp.were 9.8 percent vs.10.6 percent and 10.6 percent vs.10.6 percent,respectively.Conclusions Proportions of antimicrobial resistance for ceftriaxone,ceftazidime and aztreonam with the rcference breakpeints of CLSI M100-S20(2010)increase to various extent,8.8 compared to those with the old ones in 2009.Compared with ESBLs negative isolates,ESBLs positive isolates are affected much more by the breakpeints of CLSI M100-S20(2010).Proportion of affected Klebsiella spp.by the revised breakpoints of CLSI M100-S20(2010)for ceftazidime and aztreonam is higher than that of E. coli with ESBLs positive.

Objective To evaluate the activities of 18 pairs of antimicrobials combinations against non - duplicate clinical isolates of multidrug resistant Acinetobacter baumannii (MDRAB) in vitro.Methods Collect isolates of Acinetobacter baumannii from different patients from October 2009 to May 2010,which were isolated in Clinical Laboratory Center of Beijing Friendship Hospital,Capital Medical University.Use broth microdilution method to detect MIC of mono-antimicrobial,and checkerboard broth microdilution method to detect combinatied MIC,and calculate fractional inhibitory concentration (FIC) index to determine drug combinations effects.When the performance of the same drug combinations conflicted,appropriate strains were selected for screening of drug-resistant mechanisms by polymerase chain reaction( PCR),including efflux pump genes.Results In tests in vitro,rifampicin and polymyxin B,imipenem and gentamicin,cefepime and levofloxacin showed synergy at high proportion,68.1％,45.5％,40.9％,respectively.Minocycline and rifampicin,ampicillin/sulbactam and tobramycin.Ceftazidime and ciprofloxacin showed additive effect at high proportion,81.8％,68.2％,68.2％,respectively.There were several combinations which appeared the opposite effects to tested strains.Strains No.19 corresponding reaction was synergy and No.21,No.26 corresponding reactions were antagonism.The three strains above were selected for screening resistant mechanisms.The difference is that genotypes of adeS were negative in No.19 and positive in No.21 and No.26.Conclusion Rifampicin and polymyxin B combination showed synergy against the MDRAB in vitro,which can be considered as the treatment choice for critical infections caused by MDRAB.Imipenem and gentamicin,cefepime and levofloxacin also showed synergy in vitro,but in some isolates showed antagonism.This phenomenon may be due to the gene adeS activated by certain antibiotics,and the activated adeS drived efflux pump express or overexpress,which made the drugs in bacterial cells pumped out,causing antagonistic effect.The individual differences in strains should be considered when clinic strain apply these two combinations above.

Although echinocandins,a new generation of antifungal drugs,shows good fungicidal activity against distinct species of Candida,with the extending usage,the activity of echinocandins is gradually to decline,which is caused by different resistance mechanisms.Also,a number of factors may influence its results of susceptibility in vitro (e.g.,human serum,culture temperature in vitro,the pH of the culture medium,and others).Paradoxical effect of echinocandins has its own characteristics and need a further study.In China,there are a few reports about the instances of drug resistance because of the limited clinic application.The study on the echinocandins in prevalence rate of drug resistance and antifungal activity under different status has important clinical significance.

Objective To investigate the resistance and infection case for the Multidrug-Resistant Acinetobacter baumanii (MDRAb) strains.Methods Retrospective study.Thirty-eight MDRAb strains were collected in Beijing Friendship Hospital from February to August 2008.VITEK2-compact system was used to detect the MDRAb.PCR was carried out to detect their resistance related genes and look up the medical records those who were infected by MDRAb.Results The resistance rate of the MDRAb is the highest in ICU.PCR confirmed that OXA-23 and OXA-51 were 100％ related with the MDRAb.Combination drug therapy such as sulbactam combined with β-lactam antibiotics was more effective than β-lactam antibiotics only to treat the infection with MDRAb.Cases analysis showed that a number of patients infected by MDRAb were the aged with basic diseases,low immunity,received a variety of antibiotic therapy even traumatic operation,and they had a poor prognosis finally.Conclusions The resistance rate of the MDRAb is the highest in ICU,OXA-23 is closely related to multidrug-resistance.Combination drug therapy is necessary and sulbactam can play a great role in curing the inpatients infected with MDRAb.

Objective To study the expression of homocysteine in serum of patients with common malignant tumor,and initially investigate the possibility of serum homocysteine as cancer biomarker.Methods Expression levels of homocysteine and caner biomarkers (CEA,AFP,CA125,CA199) in serum of 180 patients with established malignant tumor and 30 healthy controls (control) were measured,the results of homocysteine were compared with that of the cancer biomarkers based on the cutoff value used in clinic.Results The expression levels of homocysteine was significantly higher in patients with malignant tumor than in controls [(13.89 ± 4.95) μmol/L-(21.40 ± 9.38) μ mol/L vs (11.40 ± 3.13) μmol/L,P ＜ 0.05)].Conclusions The positive predictive rate of homocysteine is higher than the four kind of cancer biomarkers in lung cancer,breast cancer,esophageal cancer.The increase of homocysteine in tumors may be universal,and Homocysteine may be used as cancer biomarker in lung cancer,breast cancer and esophageal cancer.

Objective To establish a perfect method that is based on the complexes of DNA-binding-C/EBP? for detection of nuclear transcription factor C/EBP? (CCAAT enhancer binding protein ?). Methods To search specific oligonucleotides sequence and establish a labeling method of consensus oligonucleotides and the standard curve was regressed.The electrophoresis conditions were optimized.Results The combination of 20pmol of ?- 32 P-ATP and 4 pmol of C/EBP? oligonuleotides in reaction can express the highest probe activity and corporation effect.The linearity was established (r2=0.975). 0.5?g of nuclear extract can be detected and bands are clear and specific.Conclusion The method is good at specificity. It can be a method to detecting nuclear factor C/EBP? or its DNA-binding site.