Objective To study the effect of Mycobacterium tuberculosis (Mtb) Pro-Pro-Glu-59 (PPE59) protein on the biological function of Mycobacterium smegmatis (Ms) and the regulation of host cell immune response. Methods PPE59 gene fragment was obtained by PCR amplification, cloned into pALACE, constructed into recombinant pALACE-PPE59 vector, and electro-transformed into Ms. Western blot was applied to analyse PPE59 expression and subcellular localization. The survival of Ms_Vec and Ms_PPE59 under low acid (pH=3 and pH=5) conditions and active surface pressure sodium dodecyl sulfate (SDS) conditions and their intracellular survival in macrophages were analyzed. ELISA was used to detect the cytokine (IL-1β, IL-6, IL-12, TNF-α and IL-10) expression levels of Ms_Vec and Ms_PPE59 infected macrophages. Results PPE59 protein localized to the cell wall of Ms can enhance the acid-resistance and anti-SDS effect of Ms, which is conducive to the survival of Ms in macrophages. PPE59 significantly decreased the secretion levels of pro-inflammatory cytokines (IL-1β, IL-6, IL-12 and TNF-α), and promoted the secretion levels of anti-inflammatory cytokine (IL-10). Conclusion PPE59 enhances the survival ability of Ms under low acid and SDS pressure and promotes its intracellular survival by regulating the cytokine secretion levels.
Mycobacterium smegmatis/metabolism* ; Macrophages/metabolism* ; Cytokines/metabolism* ; Mycobacterium tuberculosis/metabolism* ; Bacterial Proteins/metabolism* ; Animals ; Mice ; Antigens, Bacterial/metabolism*

Objective To observe the inhibitory effect of quercetin on the biofilm formation of Streptococcus mutans(Sm),to preliminarily reveal the possible underlying mechanisms,and to evaluate the cytotoxicity of quercetion to human dental pulp cells so as to provide the theoretical basis for the application of quercetin in oral biomaterials.Methods Quercetin storage solution was diluted to 0,3.125,6.25,12.5,25,50,100,200,400 and 800 mg/L,and added into Sm medium for 4 h and 24 h,crystal violet staining was used to evaluate the biofilm volume.In subsequent detections,three groups were set:control(0 mg/L),200 mg/L quercetin and 400 mg/L quercetin.Confocal laser scanning microscopy was used to observe the morphology of the biofilm;qPCR for gtfB,gtfC,comD,comE,and luxS were assessed to preliminarily investigate the mechanisms.Finally,the methyl thiazolyl tetrazolium(MTT) test using human dental pulp cells was used to investigate cytotoxicity.Results Quercetin could significantly inhibit up to (86.16±0.45)％ of the biofilm formation of Sm (Compared with the control group P=0.00) and effectively removed (43.04±0.53)％ of the mature biofilm(Compared with the control group P=0.00).Confocal laser scanning microscopy photographs showed that after co-incubated for 24 h,the dense biofilm structures of the experimental group were destroyed by quercetin both at 200 mg/L and 400 mg/L.Quercetin suppressedover 50％ of the expression of gtfB,gtfC,comD,comE(compared with the control group P＜0.05) and promoted the expression of luxS up to 2.18 ±0.24 and 2.84±0.26 after 4 h and 24 h,respectively(compared with the control group P＜0.05).Quercetin also exhibited acceptable compatibility for human dental pulp cells.Conclusions Quercetin could effectively reduce the biofilm formation of Sm by inhibiting the expression of the related genes,and exhibited no cytotoxicity for human dental pulp cells.Quercetin has good potential to be applied in oral biological materials.

Objective To analyze clinical effectiveness of tigecycline for complicated intra abdominal infections (cIAIs) in surgical intensive care units.Methods The clinical data of patients diagnosed as cIAIs from Nov 2011 to Aug 2014 were retrospectively collected.Data of sex, age, severity of disease, bacterial strains and drug resistance, prior antibiotics, dosage of tigecycline were included.Results 1 862 patients were admitted into surgical intensive care unit from Nov 2011 to Aug 2014.54 patients were finally treated by tigecycline among 304 patients diagnosed as cIAIs.Acinetobacter baumannii (23.1％), Klebiella pneumonia (18.5％), Escherichia coli (16.9％) were the top three pathogenic bacteria.41/50 were of multiple bacterial infection.Previously adopted antibiotics were miscellaneous, the number of used antibiotics was up to 13 for one patient.Coverage of tigecycline averaged at 8.9 days.Tigecycline effective rate was 62％, 38％ (19/50) cIAIs were completely controlled and cured,24％ (12/50) patients showed effectiveness of tigercycline that procalcitonin decreased 50％ within 72 h.Logistic regression analysis showed that severity of disease and tigecycline dose contribute to the effectiveness within 72 h.Conclusions Tigecycline is effective alterative for patients diagnosed as complicated intra abdominal infections in surgical intensive care units.

Objective:To explore the association between HLA-DR,DQ allele polymorphisms and onset of epidemic hemorrhagic fever(EHF)among Han Nationality in Zunyi area.Methods:Using group study,HLA-DR and DQ genotyping was conducted in 100 EHF cases and 100 controls among Han Nationality in Zunyi area with polymerase chain reaction-sequence specific primer(PCR-SSP),GF(gene frequency)and RR(relative risk)were calculated and compared.Results:The frequency of HLA-DRB1 16 in patients with EHF was higher than in the control group(RR=3.58,?2=4.916,P=0.0266