The inhibitory effects of five berberines alkaloids (BAs) from rhizoma ofCoptis chinensis Franch,a traditional Chinese medicinal (TCM) herb,on Bacillus shigae(B.shigae)growth were investigated by microcalorimetry.The ...The inhibitory effects of five berberines alkaloids (BAs) from rhizoma ofCoptis chinensis Franch,a traditional Chinese medicinal (TCM) herb,on Bacillus shigae(B.shigae)growth were investigated by microcalorimetry.The power-time curves of B.shigae with and without BAswere acquired;meanwhile,the extent and duration of inhibitory effects on the metabolism wereevaluated by growth rate constants (k1,k2),half inhibitory ratio (IC50),maximum heat output(P_(max)),and peak time (t_p).The values of k1 and k2 of a shigae in the presence of the five BAsdecreased with the increasing concentrations of BAs.Moreover,P_(max) was reduced,and the value oft_p increased with increasing concentrations of the five drugs.The inhibitory activity varied withdifferent drugs.IC50 of the five BAs was respectively 75 mu g/mL for berberine,90 ng/mL forcoptisine,115 mu g/mL for palmatine,220 mu g/mL for epiberberine,and 400 mu g/mL forjatrorrhizine.The sequence of antimicrobial activity of the five BAs:berberine 】 coptisine 】palmatine 】 epiberberine 】 jatrorrhizine.The functional groups methylenedioxy at C2 and C3 on phenylring improve antimicrobial activity more strongly than methoxyl at C2 and C3 on phenylring.However,the effect of bacteriostasis is not significant with methylenedioxy or methoxyl at C9and C10 on phenyl ring.展开更多
The anti-bacterial activities of three types of di-O-caffeoylquinic acids(diCQAs) in Lonicera japonica flowers, a traditional Chinese medicine(TCM), on Bacillus shigae growth were investigated and compared by microcal...The anti-bacterial activities of three types of di-O-caffeoylquinic acids(diCQAs) in Lonicera japonica flowers, a traditional Chinese medicine(TCM), on Bacillus shigae growth were investigated and compared by microcalorimetry. The three types of diCQAs were 3, 4-di-O-caffeoylquinic acid(3, 4-diCQA), 3, 5-di-O-caffeoylquinic acid(3, 5-diCQA), and 4, 5-di-O-caffeoylquinic acid(4, 5-diCQA). Some qualitative and quantitative information of the effects of the three diCQAs on metabolic power–time curves, growth rate constant k, maximum heat-output power Pm, and the generation time tG, total heat output Qt, and growth inhibitory ratio I of B. shigae were calculated. In accordance with a thermo-kinetic model, the corresponding quantitative relationships of k, Pm, Qt, I and c were established. Also, the half-inhibitory concentrations of the drugs(IC50) were obtained by quantitative analysis. Based on the quantity–activity relationships and the IC50 values, the sequence of inhibitory activity was 3, 5-diCQA > 4, 5-diCQA > 3, 4-diCQA. The results illustrate the possibility that the caffeoyl ester group at C-5 is the principal group that has a higher affinity for the bacterial cell, and that the intramolecular distance of the two caffeoyl ester groups also has an important influence on the anti-bacterial activities of the diCQAs.展开更多
[Objective] This study aimed to establish a real-time PCR method for de- tecting stx2 gene in Shiga toxin-producing E. coli （STEC）. [Method] According to the known STEC stx2 gene sequences published in GenBank, PCR ...[Objective] This study aimed to establish a real-time PCR method for de- tecting stx2 gene in Shiga toxin-producing E. coli （STEC）. [Method] According to the known STEC stx2 gene sequences published in GenBank, PCR primers and probes were designed based on the conserved region to construct recombinant plasmid as a positive template, thus optimizing the reaction conditions and establishing the real- time PCR method. [Result] A standard curve was established based on the opti- mized real-time PCR system, indicting a good linear correlation between the initial template concentration and Ct value, with the correlation coefficient F^e of above 0.995. The established method had a good specificity, without non-specific amplifica- tion for 10 non-STEC intestinal bacterial strains; the detection limit of initial template was 1.0x102 copies/μI, indicating a high sensitivity; furthermore, the coefficients of variation within and among batches were lower than 1% and 5% respectively, sug- gesting a good repeatability. [Conclusion] In this study, a real-time PCR method was successfully established for detecting STEC stx2 gene, which provided technical means for rapid detection of STEC in samples.展开更多
Hemolytic uremic syndrome （HUS） is a rare disease. In this work the authors review the recent findings on HUS, considering the different etiologic and patho-genetic classifications. New findings in genetics and, in ...Hemolytic uremic syndrome （HUS） is a rare disease. In this work the authors review the recent findings on HUS, considering the different etiologic and patho-genetic classifications. New findings in genetics and, in particular, mutations of genes that encode the complement-regulatory proteins have improved our understanding of atypical HUS. Similarly, the comple-ment proteins are clearly involved in all types of thrombotic microangiopathy： typical HUS, atypical HUS and thrombotic thrombocytopenic purpura （TTP）. Fur-thermore, several secondary HUS appear to be related to abnormalities in complement genes in predisposed patients. The authors highlight the therapeutic as-pects of this rare disease, examining both “traditional therapy” （including plasma therapy, kidney and kidney-liver transplantation） and “new therapies”. The latter include anti-Shiga-toxin antibodies and anti-C5 mono-clonal antibody “eculizumab”. Eculizumab has been recently launched for the treatment of the atypical HUS, but it appears to be effective in the treatment of typical HUS and in TTP. Future therapies are in phases Ⅰ and Ⅱ. They include anti-C5 antibodies, which are more purifed, less immunogenic and absorbed orally and, anti-C3 antibodies, which are more powerful, but potentially less safe. Additionally, infusions of recombinant complement-regulatory proteins are a potential future therapy.展开更多
AIM： To investigate the selective cytotoxic effect of constructed hybrid protein on cells expressing granulocyte macrophage colony stimulating factor （GM-CSF） receptor. METHODS： HepG2 （human hepatoma） and LS174T...AIM： To investigate the selective cytotoxic effect of constructed hybrid protein on cells expressing granulocyte macrophage colony stimulating factor （GM-CSF） receptor. METHODS： HepG2 （human hepatoma） and LS174T （colon carcinoma） were used in this study. The fused gene was induced with 0.02% of arabinose for 4 h and the expressed protein was detected by Western blotting. The chimeric protein expressed in E..coli was checked for its cytotoxic activity on these cells and apoptosis was measured by comet assay and nudear staining. RESULTS： The chimeric protein was found to be cytotoxic to the colon cancer cell line expressing GM-CSFRs, but not to HepG2 lacking these receptors. Maximum activity was observed at the concentration of 40 ng/mL after 24 h incubation. The IC50 was 20 ± 3.5 ng/mL. CONCLUSION： Selective cytotoxic effect of the hybrid protein on the colon cancer cell line expressing GMCSF receptors （GM-CSFRs） receptor and apoptosis can be observed in this cell line. The hybrid protein can be considered as a therapeutic agent.展开更多
Non-O157 STEC has been shown to have a diverse ecological distribution among food-animals. It has been associated with both outbreaks and individual cases of severe illness. This group of the organisms is now consider...Non-O157 STEC has been shown to have a diverse ecological distribution among food-animals. It has been associated with both outbreaks and individual cases of severe illness. This group of the organisms is now considered as a major contributor to human disease. The clinical description of the diseases caused by these organisms is reviewed. The host specificity of these pathogens is described and discussed. These organisms appear widespread among food animals like cattle and sheep, and can therefore affect a range of foods directly from the meat and excretions of these animals being used in farming practices. This article reviews the origins, diversity and pathogenesis of non-O157 STEC.展开更多
AIM:To identify and assess the novel makers for detection of Shiga toxin producing Escherichia coli (STEC) O157:H7 with an integrated computational and experimental approach. METHODS:High-throughput NCBI blast (E-valu...AIM:To identify and assess the novel makers for detection of Shiga toxin producing Escherichia coli (STEC) O157:H7 with an integrated computational and experimental approach. METHODS:High-throughput NCBI blast (E-value cutoff e-5) was used to search homologous genes among all sequenced prokaryotic genomes of each gene encoded in each of the three strains of STEC O157:H7 with complete genomes,aiming to find unique genes in O157:H7 as its potential markers. To ensure that the identified markers from the three strains of STEC O157:H7 can serve as general markers for all the STEC O157:H7 strains,a genomic barcode approach was used to select the markers to minimize the possibility of choosing a marker gene as part of a transposable element. Effectiveness of the markers predicted was then validated by running polymerase chain reaction (PCR) on 18 strains of O157:H7 with 5 additional genomes used as negative controls. RESULTS:The blast search identified 20,16 and 20 genes,respectively,in the three sequenced strains of STEC O157:H7,which had no homologs in any of the other prokaryotic genomes. Three genes,wzy,Z0372 and Z0344,common to the three gene lists,were selected based on the genomic barcode approach. PCR showed an identification accuracy of 100% on the 18 tested strains and the 5 controls. CONCLUSION:The three identified novel markers,wzy,Z0372 and Z0344,are highly promising for the detection of STEC O157:H7,in complementary to the known markers.展开更多
Objective:To identify the specific integration site of prophage φ297 in the host of E. coli K12 chromosome. Methods:Using molecular techniques such as Siebert PCR for walking from the int gene of prophage 297, which ...Objective:To identify the specific integration site of prophage φ297 in the host of E. coli K12 chromosome. Methods:Using molecular techniques such as Siebert PCR for walking from the int gene of prophage 297, which is similar to that of phage 933W to an unknown region in genomic DNA. A special adaptor is ligated to the ends of DNA fragments generated by digestion of genomic DNA with restriction enzymes that generates blunt ended fragments. Clone and subclone of PCR products, DNA sequencing and data analysis were used in this study. Results:The attL, attR and the core sequences were determined. The bacterial attachment site of phage φ297 was located in the yecE gene of E. coli K12. Conclusion:The phage φ297 integrates into the yecE gene of the E. coli K12 genome.展开更多
Isolation and biochemical and molecular identification of 303 strains of Escherichia coli obtained from diarrheic and healthy young alpacas of Puno-Peru, were realized. PCR amplification for 7 virulence factor genes a...Isolation and biochemical and molecular identification of 303 strains of Escherichia coli obtained from diarrheic and healthy young alpacas of Puno-Peru, were realized. PCR amplification for 7 virulence factor genes associated with STEC, STEC O157:H7, EPEC: sxt1, sxt2, rfbO157, fliCH7, hlyA, eae y bfp were determined. A total of 39 strains (12.88%) showed amplification for one or more of these genes. Twenty three strains (59%) were classified as STEC and 16 strains (41%) as EPEC. An 88.18% (34/39) of STEC and EPEC strains were obtained from healthy alpacas and only 11.82% (5/39) from diarrheic alpacas considering this specie as potential zoonotic reservoir of STEC and EPEC.展开更多
Everyone knows that cookware,as the name implies,cooks meals,but it can also incite an appetite and utmost joy.On December16,2022,a special event was held to showcase various multi-use,high-pressure cookware(designed ...Everyone knows that cookware,as the name implies,cooks meals,but it can also incite an appetite and utmost joy.On December16,2022,a special event was held to showcase various multi-use,high-pressure cookware(designed for highland use)in Yaou Village of Changlong Township in Gangpa County,Shigatse City.展开更多
Objective To evaluate the etiology of Shiga-like toxin-producing Escherichia coli (SLTEC) in children with diarrhea. Methods We designed and synthesized 3 pairs of primers located in the SLT1, SLT2, and eaeA genes of ...Objective To evaluate the etiology of Shiga-like toxin-producing Escherichia coli (SLTEC) in children with diarrhea. Methods We designed and synthesized 3 pairs of primers located in the SLT1, SLT2, and eaeA genes of enterohaemorrhagic Escherichia coli (EHEC), while the virulent genes SLT1, SLT2, and eaeA from E.coli species were amplified by polymerase chain reaction (PCR). Results One strain of EHEC with SLT1, SLT2, and eaeA in 29 reference strains of diarrhea-causing E.coli (DCEC) and 10 strains of other enterobacteria detected by PCR had positive reactions, while all other DCEC and enterobacteria were negative. Of 474 strains of E. coli isolated from 1032 children with diarrhea and detected by PCR, 20 strains of SLT1 producing E. coli (4.2%) positive, and 7 strains of SLT2 producing E.coli (1.5%) positive; while of 74 strains of entero-SLTs-producing and invasive Escherichia coli (ESIEC), 15 strains of SLT1 (20.3%) and 5 strains of SLT2 (6.8%) were positive. Conclusion Shiga-like toxin E. coli has been identified as a major etiologic agent of children with diarrhea in Taiyuan, China.展开更多
基金Supported by the National Natural Science Foundation of China (Grant No. 39970911)
文摘The inhibitory effects of five berberines alkaloids (BAs) from rhizoma ofCoptis chinensis Franch,a traditional Chinese medicinal (TCM) herb,on Bacillus shigae(B.shigae)growth were investigated by microcalorimetry.The power-time curves of B.shigae with and without BAswere acquired;meanwhile,the extent and duration of inhibitory effects on the metabolism wereevaluated by growth rate constants (k1,k2),half inhibitory ratio (IC50),maximum heat output(P_(max)),and peak time (t_p).The values of k1 and k2 of a shigae in the presence of the five BAsdecreased with the increasing concentrations of BAs.Moreover,P_(max) was reduced,and the value oft_p increased with increasing concentrations of the five drugs.The inhibitory activity varied withdifferent drugs.IC50 of the five BAs was respectively 75 mu g/mL for berberine,90 ng/mL forcoptisine,115 mu g/mL for palmatine,220 mu g/mL for epiberberine,and 400 mu g/mL forjatrorrhizine.The sequence of antimicrobial activity of the five BAs:berberine 】 coptisine 】palmatine 】 epiberberine 】 jatrorrhizine.The functional groups methylenedioxy at C2 and C3 on phenylring improve antimicrobial activity more strongly than methoxyl at C2 and C3 on phenylring.However,the effect of bacteriostasis is not significant with methylenedioxy or methoxyl at C9and C10 on phenyl ring.
基金supported the National Natural Science Foundation of China(No.81073069)
文摘The anti-bacterial activities of three types of di-O-caffeoylquinic acids(diCQAs) in Lonicera japonica flowers, a traditional Chinese medicine(TCM), on Bacillus shigae growth were investigated and compared by microcalorimetry. The three types of diCQAs were 3, 4-di-O-caffeoylquinic acid(3, 4-diCQA), 3, 5-di-O-caffeoylquinic acid(3, 5-diCQA), and 4, 5-di-O-caffeoylquinic acid(4, 5-diCQA). Some qualitative and quantitative information of the effects of the three diCQAs on metabolic power–time curves, growth rate constant k, maximum heat-output power Pm, and the generation time tG, total heat output Qt, and growth inhibitory ratio I of B. shigae were calculated. In accordance with a thermo-kinetic model, the corresponding quantitative relationships of k, Pm, Qt, I and c were established. Also, the half-inhibitory concentrations of the drugs(IC50) were obtained by quantitative analysis. Based on the quantity–activity relationships and the IC50 values, the sequence of inhibitory activity was 3, 5-diCQA > 4, 5-diCQA > 3, 4-diCQA. The results illustrate the possibility that the caffeoyl ester group at C-5 is the principal group that has a higher affinity for the bacterial cell, and that the intramolecular distance of the two caffeoyl ester groups also has an important influence on the anti-bacterial activities of the diCQAs.
基金Supported by Agricultural Science and Technology Support Program(Social Development)of Jiangsu Province(BE2011771)~~
文摘[Objective] This study aimed to establish a real-time PCR method for de- tecting stx2 gene in Shiga toxin-producing E. coli （STEC）. [Method] According to the known STEC stx2 gene sequences published in GenBank, PCR primers and probes were designed based on the conserved region to construct recombinant plasmid as a positive template, thus optimizing the reaction conditions and establishing the real- time PCR method. [Result] A standard curve was established based on the opti- mized real-time PCR system, indicting a good linear correlation between the initial template concentration and Ct value, with the correlation coefficient F^e of above 0.995. The established method had a good specificity, without non-specific amplifica- tion for 10 non-STEC intestinal bacterial strains; the detection limit of initial template was 1.0x102 copies/μI, indicating a high sensitivity; furthermore, the coefficients of variation within and among batches were lower than 1% and 5% respectively, sug- gesting a good repeatability. [Conclusion] In this study, a real-time PCR method was successfully established for detecting STEC stx2 gene, which provided technical means for rapid detection of STEC in samples.
文摘Hemolytic uremic syndrome （HUS） is a rare disease. In this work the authors review the recent findings on HUS, considering the different etiologic and patho-genetic classifications. New findings in genetics and, in particular, mutations of genes that encode the complement-regulatory proteins have improved our understanding of atypical HUS. Similarly, the comple-ment proteins are clearly involved in all types of thrombotic microangiopathy： typical HUS, atypical HUS and thrombotic thrombocytopenic purpura （TTP）. Fur-thermore, several secondary HUS appear to be related to abnormalities in complement genes in predisposed patients. The authors highlight the therapeutic as-pects of this rare disease, examining both “traditional therapy” （including plasma therapy, kidney and kidney-liver transplantation） and “new therapies”. The latter include anti-Shiga-toxin antibodies and anti-C5 mono-clonal antibody “eculizumab”. Eculizumab has been recently launched for the treatment of the atypical HUS, but it appears to be effective in the treatment of typical HUS and in TTP. Future therapies are in phases Ⅰ and Ⅱ. They include anti-C5 antibodies, which are more purifed, less immunogenic and absorbed orally and, anti-C3 antibodies, which are more powerful, but potentially less safe. Additionally, infusions of recombinant complement-regulatory proteins are a potential future therapy.
文摘AIM： To investigate the selective cytotoxic effect of constructed hybrid protein on cells expressing granulocyte macrophage colony stimulating factor （GM-CSF） receptor. METHODS： HepG2 （human hepatoma） and LS174T （colon carcinoma） were used in this study. The fused gene was induced with 0.02% of arabinose for 4 h and the expressed protein was detected by Western blotting. The chimeric protein expressed in E..coli was checked for its cytotoxic activity on these cells and apoptosis was measured by comet assay and nudear staining. RESULTS： The chimeric protein was found to be cytotoxic to the colon cancer cell line expressing GM-CSFRs, but not to HepG2 lacking these receptors. Maximum activity was observed at the concentration of 40 ng/mL after 24 h incubation. The IC50 was 20 ± 3.5 ng/mL. CONCLUSION： Selective cytotoxic effect of the hybrid protein on the colon cancer cell line expressing GMCSF receptors （GM-CSFRs） receptor and apoptosis can be observed in this cell line. The hybrid protein can be considered as a therapeutic agent.
文摘Non-O157 STEC has been shown to have a diverse ecological distribution among food-animals. It has been associated with both outbreaks and individual cases of severe illness. This group of the organisms is now considered as a major contributor to human disease. The clinical description of the diseases caused by these organisms is reviewed. The host specificity of these pathogens is described and discussed. These organisms appear widespread among food animals like cattle and sheep, and can therefore affect a range of foods directly from the meat and excretions of these animals being used in farming practices. This article reviews the origins, diversity and pathogenesis of non-O157 STEC.
基金Supported by National Natural Science Foundation of China, No. 30872415National Science Foundation, No. DBI-0354771, ITR-IIS-0407204, DBI-0542119, CCF0621700+1 种基金National Institutes of Health, No. 1R01GM075331 and 1R01GM081682BioEnergy Science Center, US Department of Energy BioEnergy Research Center supported by the Office of Biological and Environmental Research in DOE Office of Science
文摘AIM:To identify and assess the novel makers for detection of Shiga toxin producing Escherichia coli (STEC) O157:H7 with an integrated computational and experimental approach. METHODS:High-throughput NCBI blast (E-value cutoff e-5) was used to search homologous genes among all sequenced prokaryotic genomes of each gene encoded in each of the three strains of STEC O157:H7 with complete genomes,aiming to find unique genes in O157:H7 as its potential markers. To ensure that the identified markers from the three strains of STEC O157:H7 can serve as general markers for all the STEC O157:H7 strains,a genomic barcode approach was used to select the markers to minimize the possibility of choosing a marker gene as part of a transposable element. Effectiveness of the markers predicted was then validated by running polymerase chain reaction (PCR) on 18 strains of O157:H7 with 5 additional genomes used as negative controls. RESULTS:The blast search identified 20,16 and 20 genes,respectively,in the three sequenced strains of STEC O157:H7,which had no homologs in any of the other prokaryotic genomes. Three genes,wzy,Z0372 and Z0344,common to the three gene lists,were selected based on the genomic barcode approach. PCR showed an identification accuracy of 100% on the 18 tested strains and the 5 controls. CONCLUSION:The three identified novel markers,wzy,Z0372 and Z0344,are highly promising for the detection of STEC O157:H7,in complementary to the known markers.
文摘Objective:To identify the specific integration site of prophage φ297 in the host of E. coli K12 chromosome. Methods:Using molecular techniques such as Siebert PCR for walking from the int gene of prophage 297, which is similar to that of phage 933W to an unknown region in genomic DNA. A special adaptor is ligated to the ends of DNA fragments generated by digestion of genomic DNA with restriction enzymes that generates blunt ended fragments. Clone and subclone of PCR products, DNA sequencing and data analysis were used in this study. Results:The attL, attR and the core sequences were determined. The bacterial attachment site of phage φ297 was located in the yecE gene of E. coli K12. Conclusion:The phage φ297 integrates into the yecE gene of the E. coli K12 genome.
文摘Isolation and biochemical and molecular identification of 303 strains of Escherichia coli obtained from diarrheic and healthy young alpacas of Puno-Peru, were realized. PCR amplification for 7 virulence factor genes associated with STEC, STEC O157:H7, EPEC: sxt1, sxt2, rfbO157, fliCH7, hlyA, eae y bfp were determined. A total of 39 strains (12.88%) showed amplification for one or more of these genes. Twenty three strains (59%) were classified as STEC and 16 strains (41%) as EPEC. An 88.18% (34/39) of STEC and EPEC strains were obtained from healthy alpacas and only 11.82% (5/39) from diarrheic alpacas considering this specie as potential zoonotic reservoir of STEC and EPEC.
文摘Everyone knows that cookware,as the name implies,cooks meals,but it can also incite an appetite and utmost joy.On December16,2022,a special event was held to showcase various multi-use,high-pressure cookware(designed for highland use)in Yaou Village of Changlong Township in Gangpa County,Shigatse City.
文摘Objective To evaluate the etiology of Shiga-like toxin-producing Escherichia coli (SLTEC) in children with diarrhea. Methods We designed and synthesized 3 pairs of primers located in the SLT1, SLT2, and eaeA genes of enterohaemorrhagic Escherichia coli (EHEC), while the virulent genes SLT1, SLT2, and eaeA from E.coli species were amplified by polymerase chain reaction (PCR). Results One strain of EHEC with SLT1, SLT2, and eaeA in 29 reference strains of diarrhea-causing E.coli (DCEC) and 10 strains of other enterobacteria detected by PCR had positive reactions, while all other DCEC and enterobacteria were negative. Of 474 strains of E. coli isolated from 1032 children with diarrhea and detected by PCR, 20 strains of SLT1 producing E. coli (4.2%) positive, and 7 strains of SLT2 producing E.coli (1.5%) positive; while of 74 strains of entero-SLTs-producing and invasive Escherichia coli (ESIEC), 15 strains of SLT1 (20.3%) and 5 strains of SLT2 (6.8%) were positive. Conclusion Shiga-like toxin E. coli has been identified as a major etiologic agent of children with diarrhea in Taiyuan, China.
