Analysis of drug resistance and pathogenicity of six strains of Klebsiella pneumoniae / 安徽医科大学学报

Objective @#To investigate the drug resistance and pathogenicity of six clinical isolates of Klebsiella pneu- moniae (Kp) ，and to provide a basis for prevention and treatment of Kp infection．@*Methods @#The six strains from different hospitals were isolated ，cultured ，and identified by species-specific gene khe． Their whole genome se- quences (WGS) were obtained using next-generation sequencing technology (NGS) ．Based on the WGS，the cap- sular serotypes，sequence types (ST) and drug-resistance genes of six strains were identified．The capsular sero- type genes and virulence genes were validated or identified using PCR. Broth microdilution tests were conducted to validate their drug susceptibility，and mice were challenged with Kp aerosols by MicroSprayer aerosolizer to evaluate their pathogenicity. @*Results @# The six strains were all serotype K2 but belonged to four ST types ( ST14 ，ST65， ST700，and ST86) ，and collectively carried six virulence genes and 23 drug-resistance genes．All the six strains were resistant to ampicillin，but only one strain was multidrug-resistant．Four strains exhibited high mucoid charac- teristics．Five strains could cause mortality in mice，which were preliminary identified as high virulence strains. @*Conclusion @# For the six Kp clinical isolates from different sources，only one strain named NY 13294 is both multi- drug-resistant and highly virulent，and other four highly virulent strains are resistant to one or two types of antibiot- ics.

Comparative analysis of the intestinal microbial flora diversity of adult and young African lions / 中国兽医学报

In this study,the intestinal microbial flora diversity of adult and young African lions in the same breeding environment was detected by PCR-DGGE technique.Total bacterial DNA was extracted and 16S rDNA V3 region was amplified,then conducting PCR-DGGE.Subsequently,the specific bands of DGGE were cloned and sequenced.The bacterial species were identified by comparing the sequence through BLAST.The results indicated that the intestinal microbial flora of adult African lions includes Clostridium,Lachnospiraceae bacterium,Anaerovorax,Lactococcus,Peptostreptococcus and Blautia.While the intestinal microbial flora of young African lions is lesser,most bacteria are common to adult and young lions,such as Bacteroidetes bacterium and rumen bacterium.The UPGMA clustering analysis of the DGGE fingerprint showed the similarities of the bacteria structures between adult and young African lions were only 34％.These results revealed that the intestinal microbial flora has significant difference in different stages of African lions.This study lays a foundation for the development of microecological agents in different growth stages of wild animals.

Sensitivity of esophageal squamous cell carcinoma cells to rapamycin can be improved by siRNA-interfered expression of p70S6K / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the differences in sensitivity to rapamycin of five esophageal squamous cell carcinoma cell lines with different differentiation and the changes of sensitivity of the cells after siRNA-interfered expression of p70S6K.</p><p><b>METHODS</b>Effects of rapamycin on proliferation of ESCC cell lines with different differentiation, EC9706, TE-1, Eca109, KYSE790 and KYSE450 cells, were investigated using cell counting kit 8 (CCK-8) assay, and according to the above results, the EC9706 cells non-sensitive to rapamycin were chosen to be transfected with p70S6K-siRNA. The changes in sensitivity of cells to rapamycin were measured in vitro and in vivo using CCK-8 kit, flow cytometry and tumor formation in nude mice.</p><p><b>RESULTS</b>CCK-8 results showed that all the five cell line cells were sensitive to low concentration of rapamycin (<100 nmol/L), but TE-1 and EC9706 cells, which were with poor differentiation, showed resistance to high concentration of rapamycin. After EC9706 cells were treated with 50, 100, 200, 500 and 1 000 nmol/L rapamycin and p70S6K-siRNA, the proliferation rates of EC9706 cells were (48.67 ± 1.68)%, (15.45 ± 1.54)%, (14.00 ± 0.91)%, (10.97 ± 0.72)% and (2.70 ± 0.32)%, respectively, and were significantly lower than that of cells treated with 50, 100, 200, 500 and 1 000 nmol/L rapamycin and control siRNA [(74.53 ± 1.71)%, (68.27 ± 1.35)%, (71.74 ± 2.44)%, (76.23 ± 1.02)% and (80.21 ± 2.77)%] (P<0.05 for all). The results of flow cytometry showed that the ratios of cells in G1 phase of the p70S6K-siRNA, rapamycin and p70S6K-siRNA+ rapamycin groups were (53.82 ± 1.78)%, (57.87 ± 4.01)% and (73.73 ± 3.68)%, respectively, significantly higher than that in the control group (46.09 ± 2.31)% (P<0.05 for all). The results of tumor formation test in vivo showed that the inhibitory effect of rapamycin on tumor growth was stronger after the cells were transfected with p70S6K-siRNA, and the inhibition rate was 96.5%.</p><p><b>CONCLUSION</b>ESCC cells with different differentiation have different sensitivity to rapamycin, and p70S6K-siRNA can improve the sensitivity of cells to rapamycin in vitro and in vivo.</p>

Effects of Egb761 on the Expression of Matrix Metalloproteinase-9/Tissue Inhibitor of Metallopro-teinase-1 in Asthmatic Model Rats and Its Intervention on Airway Remodeling / 中国药房

OBJECTIVE: To investigate the effects of extract of Ginkgo biloba(Egb761) on the expression of matrix metalloproteinase-9(MMP-9) and tissue inhibitor of metalloproteinase-1(TIMP-1) and evaluate its intervention effect on airway remodeling in asthmatic rats model. METHODS: Rats were randomly assigned to normal control, asmatic group, Dexamethasone (DXM) group and Egb761 group. The asmatic model was established in rats. The changes of airway morphologic parameter and the relative content of MMP-9 and TIMP-1 in bronchial epithelium in these groups were determined using immunohistochemical technique and computer assisted image analysis system. RESULTS: The thickness of airway wall and airway smooth muscle was obviously thicker in the asthmatic group than any other group (P

BCL-2 METHYLATION IN THE DEVELOPMENT OF BREAST CANCER AND THE RELATIONSHIP BETWEEN BCL-2 METHYLATION AND EXPRESSION / 解剖学报

Objective To establish MSP (methylation-specific PCR) method for detecting bcl-2 gene, to study bcl-2 methylation in the development of breast cancer and the relationship between bcl-2 methylation and expression. Methods Designing the MSP primer of bcl-2 gene, the methylations in CpG island of bcl-2 gene 5'-regulatory region in 30 cases of normal, 25 cases of atypical hyperplasia(precancerous condition), 40 cases of lymphnode(-)(low-stage) and 45 cases of lymphnode(+)(high-stage) breast tissue were detected by using MSP. The expressions of bcl-2 were detected by using SP immunohistochemical technique. Results The positive rates of bcl-2 methylation in normal, atypical hyperplasia, lymphnode(-) and lymphnode(+) breast tissue were 10.0%,32.0%,40.0% and 53.3% respectively. The methylation of bcl-2 was increased and the expression of bcl-2 was decreased in the development of breast cancer(P