Effect of Tran on virulence through regulating metabolism and stress tolerance of Streptococcus suis serotype 2.

Streptococcus suis (SS) is an important zoonotic pathogen causing a variety of life-threatening infections in pigs and humans. Tran, a novel transcriptional regulator which was identified to be an infection-related factor in S. suis serotype 2 using suppression subtractive hybridization (SSH), has been reported by our group. In this study, a tran deletion mutant was constructed to compare with the wild-type ZY05719 in some biological characteristics. It is suggested that longer chains and relatively slower growth could be observed in tran deletion mutants. In order to identify gene transcription profiles, microarray analysis was performed. It indicated that the inactivation of Tran led to 130 differentially expressed genes spread throughout the genome. Among these, 21 genes were upregulated, and 109 genes were downregulated. Most of the differentially expressed genes were involved in bacterial metabolism, such as the phosphotransferase system (PTS), and heat shock proteins. In the case of glucose scarcity, the growth characteristics of tran deletion mutants were impacted significantly, meanwhile Δtran mutant was highly sensitive to environmental stresses. Moreover, cell adherence decreased by 22.2%, and virulence in zebrafish declined to more than five times in Δtran mutants. These data demonstrate the role of Tran in regulation in S. suis serotype 2, that is affect bacterial virulence by influencing bacterial metabolism and stress tolerance of external environment.

Biofilm formation of Streptococcus equi ssp. zooepidemicus and comparative proteomic analysis of biofilm and planktonic cells.

Streptococcus equi ssp. zooepidemicus (SEZ) is responsible for a wide variety of infections in many species, including pigs, horses and humans. Biofilm formation is essential for pathogenesis, and the ability to resist antibiotic treatment results in difficult-to-treat and persistent infections. However, the ability of SEZ to form biofilms is unclear. Furthermore, the mechanisms underlying SEZ biofilm formation and their attributes are poorly understood. In this study, scanning electron microscopy (SEM) demonstrated that SEZ strain ATCC35246 formed biofilms comprising a thick, heterogeneous layer with clumps on the coverslips when incubated for 24 h. In addition, we used a two-dimensional gel electrophoresis (2-DE) based approach to characterize differentially expressed protein in SEZ biofilms compared with their planktonic counterparts. The results revealed the existence of 24 protein spots of varying intensities, 13 of which were upregulated and 11 were downregulated in the SEZ biofilm compared with the planktonic controls. Most of proteins expressed during biofilm formation were associated with metabolism, adhesion, and stress conditions. These observations contribute to our understanding of the SEZ biofilm lifestyle, which may lead to more effective measures to control persistent SEZ infections.

Identification and characterization of a novel hemolysis-related gene in Streptococcus suis serotype 2.

Streptococcussuis serotype 2 (SS 2) is an important zoonotic pathogen that has caused two major infectious outbreaks of streptococcal toxic shock syndrome (STSS) in China. A novel gene located in the 89K pathogenicity island (PAI) encoding a putative hemolysin-III-related protein (Hhly3) has been previously characterized. In this study, the SS2 deletion mutant of the exogenous gene hhly3 was constructed by homologous recombination. This protein was found to exhibit cytolytic activity, and hemolytic activity of the hhly3 gene knockout mutant (Δhhly3) was significantly lower than that in the wild-type strain ZY05719. In addition, qRT-PCR revealed that Hhly3 played an important role in the expression of the secreted hemolysin SLY, which may be the key reason for the decreased hemolytic activity. Consequently, compared with the WT strain, the infection and pathogenicity of Δhhly3 was also decreased, as evidenced by in vitro bacterial growth in whole blood and by the in vivo zebrafish test, suggesting that hhly3 is a novel exogenous hemolysis-related gene in SS2 strains.

Contribution of fibronectin-binding protein to pathogenesis of Streptococcus equi ssp. zooepidemicus.

Streptococcus equi ssp. zooepidemicus (S. zooepidemicus) is responsible for a wide variety of infections in many species. Fibronectin-binding protein is a bacterial cell surface protein, which specifically binds fibronectin (FN). Considering the specific role of FN-binding protein in host-pathogen interactions, we investigated the function of a novel FN-binding domain in the FN-binding protein (FNZ) of S. zooepidemicus. Five recombinant FNZ gene fragments [N1 (amino acids, 38-197), N2 (amino acids, 38-603), N3 (amino acids, 41-315), N4 (amino acids, 192-370), and N5 (amino acids, 38-225)] were expressed in Escherichia coli, and their FN-binding activities were tested. The results showed that amino acids 192-225 in the NH2 -terminal region of FNZ could be responsible for binding fibronectin. The FNZ knockout mutant was constructed in S. zooepidemicus, which results in the reduced capacity to adhere to HEp-2 cell, defective virulence in vivo, decreased biofilm formation, and decreased colonization capacity in blood, liver, lung, and spleen tissues of mice as compared to the wild type. These results suggest that FNZ participates in biofilm formation, FN binding, cell adhesion, and pathogenesis of S. zooepidemicus. Furthermore, this work offers a novel FN-binding domain within FNZ, which will help in further characterization of S. zooepidemicus FN-binding properties.

Unusual expression and molecular mechanisms of E-cadherin, beta-catenin in correlation with clinicopathologic parameters in neuroblastoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the expression of E-cadherin and beta-catenin in neuroblastomas of various degrees of differentiation, and to investigate their molecular mechanisms in correlation with clinicopathologic parameters.</p><p><b>METHODS</b>Immunohistochemistry EnVision method was used to detect E-cadherin and beta-catenin expression in 90 paraffin-embedded tissue samples of neuroblastomas. The methylation status of CpG islands of E-cadherin promoter was investigated by MSP in 7 fresh tissue and 24 paraffin-embedded tissue samples. The mutation status of exon 3 of beta-catenin gene was studied by PCR in 7 fresh tissue samples. Statistical analysis of the data was performed by SPSS software.</p><p><b>RESULTS</b>E-cadherin and beta-catenin were abnormally expressed in neuroblastomas in general. The expression of beta-catenin in well-differentiated neuroblastoms was markedly higher (47/70, 67.1%) than that of the poorly differentiated tumors (8/20, 40.0%). There was a markedly decreased expression of both genes in tumors with lymph node metastasis than those without. Demethylation was seen in some regions of the promoter of E-cadherin in 31 cases of nuroblatomas. PCR of the exon 3 of beta-catenin followed by DNA sequencing demonstrated rearrangements and mutations in 7 cases, including 2 cases harboring identical point mutation at gene position 27184, leading to a T-->A alteration.</p><p><b>CONCLUSIONS</b>The abnormal over-expression of E-cadherin in neuroblastomas is independent of the methylation status of their promoter sequences. The abnormal expression of beta-catenin may be related to mutational changes at exon 3 of the gene.</p>

Influence of Magnolia Biondii Pamp Volotile Oil Nanometer on Nasal Membrane and Clliary / 中国中医药信息杂志

Objective To investigate the toxicity of nasal membreane and ciliary of the Magnolia biondii Pamp volotile oil nanometer bangosome.Methods Toad palate and rat nasal membrane were used as experimental material,physiological saline and hydrochloride ephedrine as negative control.The Magnolia biondii Pamp volotile oil nanometer bangosome on ciliary movement were carried out using in vitro and electron microscope technique.Results The Magnolia biondii Pamp volotile oil nanometer bangosome had little cilitoxicity to toad palate and rat nasal membrane.Conc(?)sion The Magnolia biondii Pamp volotile oil nanometer bangosome had little cilitoxicity to membrane.

Toxicity tests of Magnolia biondii Pamp volatile oil nanometer bangosome / 上海第二医科大学学报

Objective To investigate the acute toxicity, subacute toxicity, nasal membrane local toxicity of the Magnolia biondii Pamp volatile oil nanometer bangosome. Methods Kunming mice and SD rats were selected as experimental material. Kunming mice were used in the acute and subacute toxicity tests by intragastric administration of Magnolia biondii Pamp volatile oil nanometer bangosome with different dosage and different time, and SD rats were used in the nasal membrane local toxicity test by nose dropping, while the control group was treated with intragastric administration of or nose dropping with normal saline for the same dosage. The treatment course lasted fifteen days. At the end of the tests, the general condition, routine blood test, function index of live and kidney, organ humid weight index, histological changes of liver and kidney and ultra microstructure change of rat nasal membrane were obtained and compared with the control group. Results In the acute toxicity test, the daily maximum tolerant dosage by intragastric administration was equal to 222.7 times of the clinical routine, with no marked toxic reaction. In the subacute toxicity test, the general condition, blood test, organ humid weight index and histological changes of live and kidney in different dosage groups were similar to the control group. While in the function index of live and kidney, uric acid was stepped down in the middle and large dose groups, and total bilirubin was decreased in the large dose group. The nasal membrane local toxicity test revealed that there was little change in the ultra microstructure of rat nasal membrane.Conclusion The Magnolia biondii Pamp volatile oil nanometer bangosome may have little toxicity by intragastric administration and nose dropping.

Expression of Gastrin,Somatostatin,Proliferating Cell Nuclear Antigen and Fas-Ligand in Mucosa of Gastric Antrum in Children with Chronic Gastritis / 实用儿科临床杂志

Objective To investigate the expression of immunohistochemistry of gastrin(GAS),somatostatin(SS),proliferating cell nuclear antigen(PCNA) and Fas-ligand(Fas-L) in the sinus ventriculi of children with pediatric gastritis and to explore the significance of their expression in the pathogenesis of pediatric chronic gastritis.Methods Fifty cases of the sinus ventriculi mucosa samples were enrolled in 3 groups:chronic gastritis,helicobacter pylori(Hp) positive(group A,n=20);chronic gastritis,Hp negative(group B,n=19);control group,normal sinus ventriculi mucosa,Hp negative(group C,n=11).Immunohistochemistry En Vision were carried out including GAS,SS,PCNA and Fas-L.Results In the expression of GAS and SS,the values of group A and B were comparatively higher than those of group C,but there was no significant difference among them in statistics.In the expression of PCNA,the value of group A was comparatively higher and that of group B.The value difference between 2 groups was significant(P=0.019);in the expression of Fas-L,no significant difference was found among these 3 groups.Conclusions Expressions of GAS and SS both increase in children with chronic gastritis and maybe the increase of GAS and SS play a role in the pathogenesis of pediatric chronic gastritis;Hp infection promotes the multiplication of the sinus ventriculi membrana mucosa epithelium cell in pediatric chronic gastritis.