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Objective@#To demonstrate the effects of symbiotic bacteria from lettuce on inactivation of norovirus（NV）.@*Methods@#Symbiotic bacteria were isolated from the lettuces sampled from farmlands and supermarkets. NV mixed with symbiotic bacteria was set as the experimental group,without symbiotic bacteria as the control group. After the inactivation by high temperature,ultraviolet light（UV）and chlorine dioxide,the ratio of NV amount in the experimental group and the control group was calculated to evaluate the effects of symbiotic bacteria. The mechanism of symbiotic bacteria was revealed by detecting their effects on the protection of viral capsid protein from UV and on the adsorption of NV.@*Results@#Eleven symbiotic bacteria were identified from lettuces,all of which were bacilli,mainly Pseudomonas. Ten symbiotic bacteria could improve the heat-resistant ability of NV,with Microbacterium oryzae,Cupriavidus taiwanensis（SC061204）,Pseudomonas furukawaii,Enterobacter tabaci and Pseudomonas resinovorans（SC061211）more significant. Eleven symbiotic bacteria could improve anti-UV ability of NV,with Pseudomonas putida,Microbacterium oryzae and Enterobacter tabaci more significant. Only one strain of Pseudomonas putida could improve anti-chlorine dioxide ability of NV（Class I hazard）. Pseudomonas putida,Microbacterium oryzae and Enterobacter tabaci could significantly reduce the damage of NV capsid protein. Nine symbiotic bacteria could promote NV adsorption into lettuces,with the promotion rates ranged from 1.04% to 46.73%;while Pseudomonas putida and Pseudomonas resinovorans（SC061211） could restrain NV absorption,with the promotion rates of -6.50% and -19.85%.@*Conclusion@#Symbiotic bacteria from lettuce may enhance the anti-inactivation of NV by protecting capsid protein and promoting adsorption of NV. It is recommended to control the presence of symbiotic bacteria in the process of inactivating NV.
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Methicillin-resistant staphylococcus aureus (MRSA) has become the main pathogen for hospital and community acquired infections. Based on the resistance mechanism of MRSA, this article reviews the reducing and eliminating effect of Chinese herb extracts on bacterial drug resistance, by means of PBP2a protein binding, γ-lactamase, plasmid, efflux system, cell structure and biofilmdamage.
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Objective: To study the changes of the sensitivity of the methicillin-resistant Staphylococcus aureus (MRSA) to oxacillin after Chinese herbs. effects, so as to find Chinese medicine that can enhance the sensitivity of MRSA to antibiotics and provide new ideas for the clinical treatment of MRSA infection. Methods: A total of 33 commonly used antibacterial herbs were selected to prepare extracts, which act on clinically isolated MRSA. The broth micro dilution method was used to determine the minimal inhibitory concentration (MIC) of oxacillin on MRSA before and after the action of Chinese medicine. If there is a statistically significant difference (P ＜ 0.05), the medicine is effective. Results:The MIC of oxacillin on MRSA were 128-512 μg·ml-1, after the effect of Bletilla extracts, the change of MIC showed a statistically significant difference (P ＜ 0.05), which could increase the sensitivity of MRSA (271) to oxacillin. Conclusion:Bletilla extracts can enhance the sensitivity of MRSA (271) to oxacillin and the compatibility with antibiotics is expected to restore the efficacy of antibiotic.
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Objective To investigate the genotypes of extended spectrum β-lactamases (ESBLs) and their carrying modes in Escherichia coli (E.coli) isolates,and to analyze the mechanism of protein phosphorylation and ESBLs gene expression induced by β-lactam antibiotics or inhibited by histidine kinase inhibitors.Methods The predominant genotypes of ESBLs (KPC,TEM,SHV and CTX-M) and their carrying modes were identified by PCR and sequencing analysis.E-test and micro-tube dilution method were applied to measure minimal inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs).Immobilized metal ion affinity chromatography,bacterial protein phosphorylation detection kit and real-time fluorescent quantitation RT-PCR were performed to analyze the enhancing effects of 1/4 MIC penicillin or cefotaxime or the inhibitory effects of histidine kinase inhibitors (closantel,bromized or iodized methylimidazol) on protein phosphorylation and the expression of ESBLs at mRNA level in E.coli isolates.Results In 183 β-lactam antibiotics-resistant E.coli isolates,TEM and CTX-M genes (83.1％ and 77.1％) were highly expressed than other two ESBLs genes with a prevalent carrying mode of coexisting (65.0％) (P＜0.05).Penicillin or cefotaxime at 1/4 MIC induced the protein phosphorylation and promoted the expression of TEM,SHV and CTX-M at mRNA level (P＜0.05).Closantel (200 μmol),bromized methylimidazol (2 or 10 μmol) or iodized methylimidazol (20 or 50 μmol) could neither kill E.coli isolates nor inhibit their growth,but could inhibit the protein phosphorylation induced by above mentioned antibiotics and enhance the expression of ESBLs at mRNA level (P＜0.05).Moreover,the susceptibility of antibioticresistant E.coli strains to penicillin and cefotaxime were increased (P＜0.05).Conclusion TEM and CTX-M were the predominant genotypes of ESBLs carried by β-lactam antibiotics-resistant E.coli strains isolated from Zhejiang province,which were mostly found in a TEM plus CTX-M carrying mode.Sublethal dose of β-lactam antibiotics could up-regulate the expression of ESBLs genes in E.coli isolates via TCSS,but it could be inhibited by histidine kinase inhibitors.
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<p><b>OBJECTIVE</b>To construct a prokaryotic expression system of groEL gene of Leptospira interrogans serogroup Icterohaemorrhagia serovar Lai strain Lai, and to determine the immunoprotective effect of recombinant GroEL protein (rGroEL) in LVG hamsters.</p><p><b>METHODS</b>The groEL gene was amplified by high fidelity PCR and the amplification products were then sequenced. A prokaryotic expression system of groEL gene was constructed using routine genetic engineering technique. SDS-PAGE plus Bio-Rad Gel Image Analyzer was applied to examine the expression and dissolubility of rGroEL protein while Ni-NTA affinity chromatography was used to extract the expressed rGroEL. The immunoprotective rate in rGroEL-immunized LVG hamsters was determined after challenge with L.interrogans strain Lai. The cross agglutination titers of sera from immunized hamsters with different L.interrogans serogroups were detected using MAT.</p><p><b>RESULTS</b>The nucleotide and amino acid sequences of the cloned groEL gene were the same as those reported in GenBank. The constructed prokaryotic expression system of groEL gene expressed soluble rGroEL. The immunoprotective rates of 100 and 200 μg rGroEL in LVG hamsters were 50.0 % and 75.0%, respectively. The sera from the rGroEL-immunized LVG hamsters agglutinated all the L.interrogans serogroups tested with different levels.</p><p><b>CONCLUSION</b>The GroEL protein is a genus-specific immunoprotective antigen of L.interrogans and can be used to develop an universal genetically engineering vaccine of Leptospira.</p>
Subject(s)
Animals , Cricetinae , Agglutination Tests , Antigens, Bacterial , Allergy and Immunology , Chaperonin 60 , Genetics , Allergy and Immunology , Gene Expression , Leptospira interrogans , Genetics , Allergy and Immunology , Recombinant Proteins , Genetics , Allergy and ImmunologyABSTRACT
Curcumin,the active substance of turmeric.has multiple therapeutic activities.However,its water solubility and bio-availability in vivo is very low,which limits the utility of curcumin.This article reviewed recent approaches of the bioactivity and the structure-function relationship of curcumin.The authors suggest that new methods should be tried to modify the structure of cureumin and further studies of therapeutic activities of the homologues are needed.
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Objective To research the antibacterial effect in vitro of different extract of Wikstroemia indica.Methods Double dilution method was used to determine the MIC of 11 species bacterium.Results The acetic ether extract had much obvious effect than n-butanol extract,both of them had high effect on staph.,but the aqueous extract had little antibacterial effect.Conclusion The acetic ether extract has obvious antibacterial effect,also has broad-spectrum antibacterial activity.
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Objective To detect the levels of soluble vascular cell adhesion molecule-1 (sVCAM-1) and soluble intercellular adhesion molecule-l (sICAM-1) in the sera of patients with systemic lupus erythe-matosus (SLE) and their clinical significance was analysed. Methods Serum level of sVCAM-1 and sICAM-1 of 30 controls and 60 SLE patients were measured by enzyme linked immunosorbent assay (ELISA). Results 1 Serum levels of sVCAM-1 were significantly increasd in patients with SLE compared with those in normal controls (P
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Objective To investigate the relationship between the serum level of soluble vascular cell adhesion molecule-1(sVCAM-1) and soluble intercellular adhesion molecule-1(sICAM-1) and the disease activity in systemic lupus erythematosus(SLE). Methods The serum concentrations of sVCAM-1 and sICAM-1 were measured by ELISA in 60 SLE patients and age- and sex-matched normal controls. Results ① Serum levels of sVCAM-1 and sICAM-1 were significantly increased in SLE patients compared with those in normal controls (P