The aim of the research is to investigate the genetic characteristics of Legionella pneumophila serogroup1 (LP1)in Sichuan Province.The sequence-based typing (SBT) and multiple-locus VNTR analysis (MLVA) were used to describe the genetic polymorphism of 42 strains which were isolated from 1989-2016 in Sichuan Province,China.According to the reference,PCR was used to detect the 8-VNTR loci and 7 housekeeping genes respectively.The VNTR results were determined by using capillary electrophoresis,and the SBT results were sequenced and compared with the database of EWGLI.Results showed that totally 42 stains were divided into 8 MLVA types with the advantage types were M08 (47.6 ％) and M07 (23.8 ％).Twelve ST types were obtained with 3 main clonal complex and 2 singleton,including 2 novel ST types,among those,ST1 was the predominant type,accounting for 52.3 ％,following by ST630 (14.2 ％).In conclusion,our results demonstrated MLVA and SBT were both applied to the research for molecular epidemiological investigation of LP1 and showed the high genetic polymorphism and the regional specificity.The results also suggest that the isolates are a potential threat to the public,effective control and prevention strategies are urgently needed.

Objective To optimize the serum bactericidal assay (SBA) , detect and analyze the bactericidal antibody level against Neisseria meningitidis serogroup C strains after divalent polysaccharide (A plus C) vaccine immunization. Methods Two Neisseria meningitidis serogroup C strains, vaccine candidate strain (C11) and epidemic strain (053442), were selected as targets. The national Neisseria meningitidis standardized serum was used as reference serum. Pel-Freez infant rabbit complements was available. The optimized SBA method was used to detect bactericidal antibody against strain C11 and 053442 for 122 pairs of sera before and after immunization with a divalent polysaccharide (A and C) vaccine. Results The strain C11 and 053442 both could be used as targeted strain for SBA. The optimized concentration of targeted strain was achieved when a whole-cell suspension of 0.35 A at 600 nm was diluted 4×104 times. Before immunization, SBA geometric mean titers(GMT) of 122 sera against strain C11 and 053442 were 1: 1.75 and 1:2.63 respectively, and the protective rates were 9.8% and 17.2% respectively. After immunization, the GMTs and the protective rates of 122 sera both rose significantly (P<0.01), the GMTs against strain C11 and 053442 were 1:483.73 and 1:412.57 respectively. The protective rates against strain C11 and 053442 were 100% and 95.9% respectively. Conclusion Immunization with a divalent polysaccharide (A and C) vaccine could elevate remarkably the population SBA titer against Neisseria meningitidis serogroup C strains of different subtypes, but the surveillance of vaccine effect against different targeted strains remains necessary.

OBJECTIVETo evaluate the influence of Fuzhenghuayu decoction on fibrotic liver tissue and activated hepatic stellate cells (HSCs) using a carbon tetrachloride (CCl4)-induced liver cirrhosis rat model system.

METHODSSixty-four Sprague-Dawley rats were randomly divided into the following groups: normal (non-model, non-drug intervention), CCl4 liver fibrosis model, and CCl4 liver fibrosis model Fuzhenghuayu drug intervention at low dose (0.75 g/kg/d) and high dose (1.5 g/kg/d). The drug intervention was administered via oral-gastric irrigation once daily for 6 times per week over a 6-week period. Four rats from each group were sacrificed at the end of week 2, 4, and 6 for serum and liver tissue collection. Liver fibrosis was evaluated by histology, and expression of a-smooth muscle actin (a-SMA) was determined by immunohistochemistry. Liver function was assessed by measuring levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin (TBil). Between-group comparisons were made by completely random design and ANOVA with Bonferroni correction.

RESULTSAt the end of weeks 2, 4 and 6, all four groups showed significantly different levels of ALT, AST, and TBil; in addition, the model group and drug intervention groups had significantly higher levels of ALT, AST, and TBil than the control group, the drug intervention groups showed significantly lower levels of ALT, AST, and TBil than the model group (P less than 0.01 or less than 0.05), and the differences between the low dose and high dose groups reached statistical significance (P less than 0.01 or less than 0.05). At the end of weeks 2, 4 and 6, the model group and drug intervention groups had significantly higher area ratio of liver fibrosis than the normal group (F = model: 18.68, low dose: 49.95, high dose: 82.44, P less than 0.01), but the two drug intervention groups had significantly less area ratio of liver fibrosis than the model group (P less than 0.05) and the high dose group showed the most robust decrease. In addition, the model group and drug intervention groups showed higher expression of a-SMA than the normal group (F = model: 18.68, low dose: 49.95, high dose: 82.44, P less than 0.01), but two drug intervention groups had significantly less a-SMA than the model group (F = model: 46.32, low dose: 40.30, high dose: 58.42, P less than 0.05) and the high dose group showed the most robust decrease.

CONCLUSIONThe Fuzhenghuayu decoction reduces the numbers of activated HSCs, thereby leading to down-regulated a-SMA expression and reduced degree of liver fibrosis; these effects may represent the mechanism by which this drug suppresses hepatic fibrosis.

Actins ; metabolism ; Animals ; Drugs, Chinese Herbal ; pharmacology ; Hepatic Stellate Cells ; drug effects ; Liver ; drug effects ; pathology ; Liver Cirrhosis, Experimental ; pathology ; Male ; Rats ; Rats, Sprague-Dawley

BACKGROUND:A new-type nano-bionic anti-adhesion hernia mesh was developed in our previous research.OBJECTIVE:To investigate the mechanical properties and cytocompatibility of the new-type nano-bionic anti-adhesion hernia mesh.METHODS:The tensile strength of the compound hernia mesh was detected using a textile detector.Mouse fibroblasts (L929) were cultured with the compound hernia mesh,and cell structures on the mesh surface were observed under electron microscope at 1,3,5 days after culture.In addition,L929 cells were co-cultured with compound hernia mesh,polypropylene patch,and polyester patch,respectively.Cells cultured alone were used as negative controls.After 1,3,5 days of culture,MTS array was used to detect cell proliferation and evaluate cytotoxicity;after 3 days of culture,western blot was used to detect the content of type Ⅰ and Ⅲ collagens.RESULTS AND CONCLUSION:The average tensile strength of the compound hernia mesh was 31.2 N The number of fibroblasts on the nanofibrous layer of the compound hernia mesh increased as long as cultured.The cells spread along the nanofibers and pseudopodia extended from the cells formed polygon and fusiform structures,with a good cross-linking with the mesh.A complete cell layer covered all pores of the nanofibers at 5 days.The cytotoxicity of the nanofibrous layer of the compound hernia mesh was graded 0,and the cytotoxicity was graded 1 of polypropylene and polyester patches.All the three kinds of patches fulfilled the implantation requirements,and the compound hernia mesh had better biological properties.No significant differences were found among groups in the contents of type Ⅰ and Ⅲ collagens at 3 days of culture.To conclude,the new-type nano-bionic anti-adhesion hernia mesh has good mechanical properties and cytocompatibility.

OBJECTIVEIn mid-July 2005, five patients presented with septic shock to a hospital in Ziyang city in Sichuan, China, to identify the etiology of the unknown reason disease, an epidemiological, clinical, and laboratory study were conducted.

METHODSAn enhanced surveillance program were established in Sichuan, the following activities were introduced: active case finding in Sichuan of (a) laboratory diagnosed Streptococcus suis infection and (b) clinically diagnosed probable cases with exposure history; supplemented by (c) monitoring reports on meningococcal meningitis. Streptococcus suis serotype 2 infection was confirmed by culture and biochemical reactions, followed by sequencing for specific genes for serotype and virulence factors.

RESULTSFrom June 10 to August 21, 2005, 68 laboratory confirmed cases of human Streptococcus suis infections were reported. All were villagers who gave a history of direct exposure to deceased or sick pigs in their backyards where slaughtering was performed. Twenty six (38%) presented with toxic shock syndrome of which 15 (58%) died. Other presentations were septicaemia or meningitis. All isolates were tested positive for genes for tuf, species-specific 16S rRNA, cps2J, mrp, ef and sly. There were 136 clinically diagnosed probable cases with similar exposure history but incomplete laboratory investigations.

CONCLUSIONAn outbreak of human Streptococcus suis serotype 2 infections occurred in villagers after direct exposure to deceased or sick pigs in Sichuan. Prohibition of slaughtering in backyards brought the outbreak to a halt. A virulent strain of the bacteria is speculated to be in circulation, and is responsible for the unusual presentation of toxic shock syndrome with high case fatality.

Animals ; Bacteremia ; epidemiology ; microbiology ; China ; epidemiology ; Disease Outbreaks ; Humans ; Meningitis, Bacterial ; epidemiology ; microbiology ; Shock, Septic ; epidemiology ; microbiology ; Streptococcal Infections ; epidemiology ; microbiology ; veterinary ; Streptococcus suis ; isolation & purification ; Swine ; Swine Diseases ; microbiology

OBJECTIVE: To investigate the molecular characteristics and intracellular growth ability of Legionella pneumophila (L. pneumophila) strains from 1989 to 2016 in Sichuan Province, China. METHODS: Seventy-nine isolates of L. pneumophila were collected from environmental and clinical sources, including cooling towers, hot springs, bath water, fountains, and patients, and identified with 16S rRNA gene analysis and serum agglutination assay. The isolates were then typed by Sequence-Based Typing (SBT), and Genotyping of forty-two LP1 strains were analyzed by means of multiple-locus VNTR analysis with 8 loci (MLVA-8). All strains were further analyzed for two virulence genes: Legionella vir homologue (lvh) and repeats in structural toxin (rtxA). The intracellular growth ability of 33 selected isolates was determined by examining their interaction with J774 cells. RESULTS: All isolates were identified to L. pneumophila including 11 serogroups, among which the main serogroup were LP1, accounting for 54.43%. Thirty-three different sequence types (STs) from five main clonal groups and five singletons were identified, along with 8 different MLVA patterns. Both the lvh and rtxA loci were found in all 79 strains. Thirty isolates showed high intracellular growth ability in J774 cells. CONCLUSION L. pneumophila is a potential threat to public health, and effective control and prevention strategies are urgently needed.
Bacterial Proteins ; genetics ; Bacterial Toxins ; genetics ; China ; Genotyping Techniques ; Humans ; Legionella pneumophila ; genetics ; growth & development ; isolation & purification ; RNA, Ribosomal, 16S ; genetics ; Water Microbiology