Objective To investigate the resistance of Staphylococcus to erythromycin and clindamycin and detect the percentage and gene for inducible resistance. Methods Disk diffusion method was used to test the resistance phenotype of Staphylococcus aureus and coagulase-negative staphylococcus according to the standards of NCCLS. The inducible resistance of erythromycin to clindamycin was checked by D-test and the gene for erythromycin ribosome methylase was detected by polymerase chain reaction.Results Co-resistance to erythromycin and clindamycin accounted for 62.7% and 54.8% in MRSA and MRCNS respectively. D-test positive rate was 17.7% among all Staphylococcus tested. The rate of inducible resistance to clindamycin (D-test positive) was 67.6% and 45.3% in Staphylococcus aureus and coagulase-negative Staphylococcus which possessed erythromycin resistant and clindamycin sensitive by individual disk diffusion test. The predominant gene for inducible resistance was ermC with the percentage of 74.5%.Conclusion The inducible resistance of erythromycin to clindamycin in Staphylococcus should be checked by D-test in clinical microbiology laboratory in order to help physicians to select MLSB antimicrobial agents correctly.

Objective To study the detection characteristics of methicillin-resistant Staphylococcus aureus and methicillin-resistant coagulase-negative staphylococcus.Methods Disks with 1 ?g of oxacillin and 30 ?g of cefoxitin were used to detect the inhibition zone of staphylococcus aureus and coagulase-negative staphylococcus at both 35℃ and 30℃ according to the method and breakpoint recommended by CLSI.The agar surface of oxacillin plate with sodium chloride was spotted.mecA gene was amplified by PCR.Results For detection of MRSA, disks of oxacillin and cefoxitin at 30℃ have the same sensitivity of 100%, however, the sensitivity of cefoxitin( 94.7%) is a little higher than that of oxacillin (93.3%) at 35℃. For detection of MRCNS, the sensitivity of 100% can be obtained by disks of both oxacillin and cefoxitin at both 30℃ and 35℃.The sensitivity and specificity of oxacillin plate with sodium chloride are the same as those of disks of oxacillin and cefoxitin at 30℃ for detection of MRSA, its sensitivity is lower than that of disks for detection of MRCNS.Conclusion The detection of methicillin-resistant Staphylococcus can be improved by the use of cefoxitin disk.

OBJECTIVE To study the prevalance and resistance characteristics of clinical isolates of Enterobacter cloacae.METHODS Clinical isolates of E.cloacae were studied by K-B methods,and the data of MIC were(analyzed ) by WHONET 5.3 software.RESULTS Totally 416 clinical isolates of E.cloacae isolated from 2000 to 2004 were studied and they were mainly isolated from department of respiration,surgical ICU and department of(neurology) and their rate was 25.2%,9.6%,and 8.6%,respectively.The E.cloacae strain was(resistant) to ciprofloxacin,amikacin and most of penicillins,cephalosporins and ?-lactams combined with the(?-lactamase) inhibitors.It was susceptible to cefepime,imipenem and etrapenem.CONCLUSIONS The E.cloacae is resistant to many commonly used antibiotics in clinics and it is important to control antibiotic(resistance) by using antibiotics reasonably.

OBJECTIVE To investigate the phenotype and genotype of plasmid-encoded AmpC and extended spectrum beta-lactamases in Klebsiella pneumoniae.METHODS 3-Aminophenylboronic acid(APB) test and ESBLs confirmatory test were used for phenotypic detection of AmpC and ESBLs.Conjugation was conducted in order to understand the spread of plasmid in bacteria.The size and genotype of ampC and ESBL genes were studied by extraction and purification of plasmid,PCR and sequencing analysis.RESULTS A plasmid of about 15kb was extracted from K.pneumoniae.This plasmid carrying resistance genes to antibiotics could be spread from K.pneumoniae to recipient Escherichia coli NK5449 through conjugation.DHA-type ampC gene and SHV-type ESBLs gene could be amplified from plasmids extracted from both K.pneumoniae and its conjugant in E.coli,they were DHA-1 ampC gene and SHV-12 ESBLs gene confirmed by sequencing analysis.CONCLUSIONS DHA-1 ampC gene and SHV-12 ESBLs gene are detected from the plasmid of K.pneumoniae.

BACKGROUND:Recently, the role of mesenchymal stem cels in aplastic anemia has been widely explored. However, its underlying mechanism remains unclearly. OBJECTIVE: To study the effect of umbilical cord blood and bone marrow mesenchymal stem cels on hematopoietic support and secretory function of T lymphocytes in patients with aplastic anemia. METHODS: Cord blood and bone marrow samples from 48 cases of aplastic anemia and 48 healthy lying-in women to isolate mesenchymal stem cels using flow cytometry. Mesenchymal stem cels from the cord blood and bone marrow were respectively co-cultured with cord blood mononuclear cels to count burst forming units-erythroid and colony forming units-granulocyte/macrophage. Mesenchymal stem cels were co-cultured with T lymphocytes from aplastic anemia patients undergoing phytohemagglutinin stimulation, and ELISA was used to detect interleukin-2, interleukin-4 and interferon-γ levels secreted from T lymphocytes. RESULTS AND CONCLUSION:The number of burst forming units-erythroid and colony forming units-granulocyte/macrophage significantly increased in normal bone marrow or umbilical cord blood mesenchymal stem cels co-cultured with cord blood mononuclear cels (P < 0.05), but reduced remarkably in umbilical cord blood mesenchymal stem cels from aplastic anemia patients co-cultured with cord blood mononuclear cels (P < 0.05). Levels of interleukin-2, interleukin-4 and interferon-γ from T lymphocytes were inhibited significantly after co-culture with normal bone marrow mesenchymal stem cels compared with phytohemagglutinin-induced T lymphocytes (P < 0.05). There was a similar inhibitory effect after co-culture with normal umbilical cord blood mesenchymal stem cels. There was a significantly reduction in the capacity of inhibiting interleukin-2, interleukin-4 and interferon-γ levels from T lymphocytes after co-culture with bone marrow mesenchymal stem cels from aplastic anemia patients (P < 0.05). Aplastic anemia patients show some functional defects in their bone marrow mesenchymal stem cels that have a weaker inhibitory role than normal bone marrow or umbilical cord blood mesenchymal stem cels in the hematopoietic support and secretory function of T lymphocytes. These findings indicate that mesenchymal stem cels from aplastic anemia patients can influence the pathological progress through weakening hematopoietic support and secretory function of T lymphocytes. Cite this article:Li GC, Song YP, Zhang YJ, Li G, Wang H, Xie J.Effects of mesenchymal stem cels on hematopoietic support and secretory function of T lymphocytes in patients with aplastic anemia. Zhongguo Zuzhi Gongcheng Yanjiu. 2016;20(1):107-112.

OBJECTIVE To analyze the related factors of blood stream infection caused by coagulase-negative staphylococci(CNS).METHODS A retrospective analysis of CNS in blood culture from 143 hospitalized patients in General Hospital of PLA from Jan 1 to Oct 31,2004 was done,and from them true cases of bacteremia were judged and true pathogens or contaminants were identified.RESULTS Seventy of 143(55.24%) hospitalized patients were diagnosed as with bacteremia.Most of them suffered from tumor(41),organs failure(19),after big operation(9),immunological system diseases(11) and so on.The rates of CNS(as true pathogens) distribution in clinical wards were as follows: 16/21 from hematological disease ward,7/11 from pediatric ward,18/27 from the old patients ward,13/17 from intensive care unit,7/16 from surgical department and 18/51 from internal medicine.The mean growth time of contaminants was significantly longer than that of the true pathogens(31.0/(20.8 h),P

OBJECTIVE To study the phenotypic existence,genetic type and gene transfer of extended spectrum beta-lactamases(ESBLs) and AmpC beta-lactamase from Klebsiella pneumoniae and K.oxytoca. METHODS Disk confirmation test and 3-aminophenylboronic acid(APB) disk potentiation test were used to detect ESBLs and AmpC beta-lactamase.The genetic types of these two kinds of beta-lactamases were examined by gene chip technology and sequence analysis.The transfer of resistance genes was conducted by conjugation. RESULTS From 72 strains of K.pneumoniae and 20 strains of K.oxytoca which were not susceptible to cefoxitin,coexistence of AmpC(beta-lactamase) with ESBLs together was very common,accounted for 54.2% and 75.0%,single ESBLs accounted for 22.2% and 25.0%,respectively.There were 12.5% single AmpC in(K.pneumoniae).DHA type ampC gene and SHV type ESBLs gene were the main molecular types.These genes could be transferred from clinical isolates to recipient E.coli J53. CONCLUSIONS ESBLs as well as AmpC(beta-lactamase) are the most important resistance mechanism in K.pneumoniae and K.oxytoca.The resistance could be transferred through the bacterial conjugation.

Objective To assess the diagnostic predictive value of Wells score and modified Geneva score for acute pulmonary embolism by prospective case series and to explore a more suitable scoring system for Chinese population.Methods All the patients suspected of pulmonary embolism (PE) and received CT pulmonary angiography (CTPA) were enrolled consecutively in Fuxing Hospital,Capital Medical University,China,from June 2009 to August 2011.Before CTPA test or on condition that test results were unknown,clinical scoring was assessed prospectively by the Wells score and the modified Geneva score.The probability of PE in each patient was assessed and the patients were divided into low,moderate and high probability groups according to the clinical scores.The result of CTPA was used as the diagnostic gold standard for PE.Diagnostic accuracy in each group was analyzed.The predictive accuracy of both scores was compared by AUCROC curve.Results A total of 139 patients met our enrollment criteria and 117 eligible patients entered our study at last.PE was diagnosed in 47 patients by CTPA with an overall prevalence of 40.2％.Prevalence of PE in the low,moderate and high pretest probability groups assessed by the Wells score and by the simplified modified Geneva score were 7.1％ (3/42),42.9％ (21/49),88.5％ (23/26)and 10.0％ (3/30),48.1％ (37/77),7/10,respectively.AUCROC curves for the Wells score and the simplified modified Geneva score were 0.872 ( 95％ CI 0.810-0.933 ) and 0.734 ( 95％ CI 0.643-0.825 )respectively,with a significant difference ( P =0.005 ).Conclusion The Wells score is more accurate for clinical predicting acute PE than the modified Geneva score.

Objective To study the mechanisms of depression by exploring expressional differences of AQPs in the tissues of chronic stress depression rats.Methods Depression model was replicated by unpredicted chronic stress.20 rats were randomly separated into normal control group and model control group,AQP4 and AQP3,AQP8 expressions on hippocampus and gastrointestinal mucosa of rat model with depression were detected by immunochemical staining method.Results Means of optical density of AQP4 of normal group and model group hippocampus were 0.28 ± 0.02,0.22 ± 0.06 respectively,and the difference between two groups was significant statistically(t value was 2.756,P＜0.05).The expression of AQP3 on gastric mucosa and colonic mucosa between two groups had no significant statistically(t value were 1.814,1.812,P＞0.05).Two groups'means of optical density of AQP3 on small intestinal mucosa were 0.15 ± 0.02,0.17 ± 0.02,and the difference was significant statistically (t value was 2.769,P＜0.05).Two groups'means of AQP8 optical density in gastric mucosa were 0.15± 0.01,0.19 ± 0.04 ;0.16 ± 0.01 and 0.21 ± 0.04 in small intestinal mucosa;0.16 ± 0.01 and 0.22 ± 0.04 in colonic mucosa,and the differences were significant statistically(t values were 3.139,5.113,4.534,P＜0.05,P＜0.01,P＜0.01).Conclusion The expression of AQP4 on depression model rat hippocampus are lower than those of the normal group ; and the expression of AQP3 on gastric mucosa and colonic mucosa are no change obviously,but it(')s up-regulation on small intestinal mucosa.The expressions of AQP8 on gastric mucosa and small intestinal mucosa and colonic mucosa are up-regulating.

Objective To evaluate the safety of mefformin in the treatment of elderly type 2 diabetes mellitus(T2DM). Methods Two hundred and forty-three cases of elderly T2DM hospitalized from Jan.1996 to Dec. 2006 were reviewed; the changes of fasting blood glucose(FBG), postprandial blood glucose (PBG), glycosylated hemoglobin (HbA1c), liver and renal function and blood lactic acid were evaluate before and after treatment. Results The mean time of treatment with mefformin was (6.6±3.9) years (3 months-21 years)in these 243 cases. The levels of FBG, PBG and HbAlc significantly reduced after treatment with mefformin only in 43 cases (17.7%), mefformin combined with other oral hypoglycemic drugs in 124 cases (51.0%) and mefformin combined with insulin in 76 cases (31.3%). There was only 18.1% of the cases with normal range ( > 80 ml/min) of creatinine clearance rate (Ccr), and 25.8% of the cases with Ccr≤50 ml/min. The liver and renal function as well as the blood lactic acid had no significant change after treatment no matter in total cases or in different groups separated by Ccr.Conclusions Mefformin is safety in the treatment of elderly T2DM patients. Ageing is not the contraindication of mefformin. To the patients with high risk, we should monitoring the level of blood lactic acid.