No abstract available.
Plasmids* ; Shigella* ; Virulence Factors* ; Virulence*

No Abstract Available.
Vibrio parahaemolyticus* ; Vibrio* ; Virulence Factors* ; Virulence*

No Abstract Available.
Vibrio parahaemolyticus* ; Vibrio* ; Virulence Factors* ; Virulence*

No abstract available.
Escherichia coli* ; Escherichia* ; HeLa Cells* ; Humans ; Virulence Factors* ; Virulence*

Monospecific B.pertussis antisera prepared at IVAC, Nha Trang, Da Lat have been used in the identifying testing for the presence of agglutinogens 1, 2 and 3 in B.pertussis strains GL353, 360E, H36, 248, 305, 18323 and in vaccine final bulks L617, L617-636, L624-628, L627-634, L634-636, L613-614. Similar results were obtained with monospecific B.pertussis antisera issued by the United Kingdom.
Virulence Factors, Bordetella ; Bordetella pertussis ; Immune Sera

Fungi ; Humans ; Rhinitis, Allergic/therapy* ; Virulence Factors

Some transcriptional regulators contribute to the expression of Streptococcus mutans (S. mutans) cariogenic virulence factors. Although the target sequence transcriptional regulators anchored on the cell wall and the molecular mechanism of the regulation of S. mutans are yet to be clarified, certain global regulators potentially associated with the cariogenicity of S. mutans have been identified. This review is about these related transcriptional regulators, their function, and possible mechanisms.
Gene Expression Regulation, Bacterial ; Myocarditis ; Streptococcal Infections ; Streptococcus mutans ; Transcription, Genetic ; Virulence ; Virulence Factors

A total of 100 Vibrio spp. strains were examined for production of various extracellular enzyme and for plasmid content plasmid were subjected to digestion with restriction enzymes. Most of them produced extracellular enzyme more than one, especially V. parahaemolyticus and V. cholerae non-01 strains were showed production of various extracellular enzymes. About the 55% Vibrio spp. have the plasmid more than one, but a lot of Vibrio spp. (about 45%) did not possess any plasmid. Most of these plasmid various derivatives ranged from 2.4 kb-23 kb, especially two strains of V. mimicus and one strain of V. furnissii carried one high-molecular weight plasmid (molecular weight ranging between 70 kb-100 kb). Results of restriction analysis for plasmid of this three strains were by no means the rule. For detection of tdh and ctx gene, the virulence factor involved in the pathogenesis, we carried out the TDH, CT assay, PCR amplification, and hybridization. A total 11 strains were produced TDH, involved in 4 strains of V. parahaemolyticus and 1 strain of V. cholerae non-01 from clinical isolates and 6 strains of environmental isolates. Nine strains of 11 strains, involved in 4 strains of V. parahaemolyticus and 1 strain of V. cholerae non-01 from clinical isolates and 4 strains of V. parahaemolyticus from environmental isolates, could be successfully amplified in 400 bp by PCR, no amplification products were obtained from TDH-negative strains. The PCR results were consistent with DNA hybridization. In the experiments of ctx gene detection, in all, 3 strains of V. cholerae non-01 from clinical isolate and 1 strains of V. cholerae non-01 from environmental isolate were observed CT- positive. These CT-producing strains amplified in 302 bp by PCR for the detection of ctx gene. All CT-producing strains hybridized with digoxigenin-labeled DNA probe, while CT-negative strains did not hybridize. Also hybridization tests results for detection of ctx gene consistent with PCR.
Cholera ; Digestion ; DNA ; Plasmids ; Polymerase Chain Reaction ; Vibrio* ; Virulence Factors* ; Virulence*

OBJEVTIVETo study the effect of spvB/spvC gene on Salmonella virulence and the Host immune.

METHODSSTM.211, STM.211-Delta;spvB, STM.211-Delta;spvC, STM.211-Delta;spvB.spvC and PBS were infected with 0.2 mL 10(5) CFU corresponding strain respectively by intraperitoneal. We observed the mental status, movement, diarrhea, weight, pelage changed hair of the infected mouse. Then the level of IL-10, IL-12, IFN-γ were detected by ELISA. Finally, we observe the pathological changes of liver and spleen with the general view and the microscope.

RESULTSInfection symptoms of STM.211, STM.211-Delta;spvB and STM.211-Delta;spvC were significantly worse than PBS group, but there was no significant difference between STM.211-spvB.spvC group and PBS group. The secretion of IFN-γ and IL-12 of STM.211, STM.211-Delta;spvB, STM.211-Delta;spvC group were significantly lower than those in the STM.211-Delta;spvB.spvC group (P<0.05), but IL-10 secretion was significantly higher than STM.211-Delta;spvB.spvC group (P<0.05). There were no statistical significance among the STM.211, STM.211-Delta;SpvB, STM.211-Delta;spvC groups (P>0.05).

CONCLUSIONSSalmonella virulence can be affected obviously by spvB combined with spvC gene, but not by spvB or spvC. spvB/spvC gene can inhibit the TH1 cytokines (IFN-γ and IL-12) secretion but promote the TH2 cytokines (IL-10) expression, leading immune response trend to TH2 shift. It shows that spvB/spvC gene can help the bacteria evade the host immune defenses, leading to aggravation of infection.

Animals ; Cytokines ; immunology ; Interleukin-12 ; Mice ; Salmonella ; genetics ; pathogenicity ; Salmonella Infections ; immunology ; Virulence ; Virulence Factors ; genetics

PURPOSE: There is a need to broaden protective coverage of M protein–based vaccines against group A streptococci (GAS) because coverage of the current 30-valent M protein vaccine does not extend to all emm types. An additional GAS antigen and virulence factor that could potentially extend vaccine coverage is M-related protein (Mrp). Previous work indicated that there are three structurally related families of Mrp (MrpI, MrpII, and MrpIII) and peptides of all three elicited bactericidal antibodies against multiple emm types. The purpose of this study was to determine if a recombinant form containing Mrp from the three families would evoke bactericidal antiserum and to determine if this antiserum could enhance the effectiveness of antisera to the 30-valent M protein vaccine. MATERIALS AND METHODS: A trivalent recombinant Mrp (trMrp) protein containing N-terminal fragments from the three families (trMrp) was constructed, purified and used to immunize rabbits. Anti-trMrp sera contained high titers of antibodies against the trMrp immunogen and recombinant forms representing MrpI, MrpII, and MrpIII. RESULTS: The antisera opsonized emm types of GAS representing each Mrp family and also opsonized emm types not covered by the 30-valent M protein–based vaccine. Importantly, a combination of trMrp and 30-valent M protein antiserum resulted in higher levels of opsonization of GAS than either antiserum alone. CONCLUSION: These findings suggest that trMrp may be an effective addition to future constructs of GAS vaccines.
Antibodies ; Humans ; Immune Sera ; Peptides ; Rabbits ; Staphylococcal Protein A* ; Streptococcal Vaccines* ; Streptococcus pyogenes ; Vaccines ; Virulence ; Virulence Factors