Horizontal transmission of a human rotavirus vaccine strain--a randomized, placebo-controlled study in twins.

Transmission of excreted vaccine-derived infectious virus from vaccinated to unvaccinated individuals is possible within close contacts. This randomized (1:1), double-blind study evaluated the potential for transmission of human rotavirus vaccine strain, HRV (Rotarix™) from vaccine recipients to unvaccinated close contacts (twins). 100 pairs of healthy twins aged 6-14 weeks at the time of Dose 1 of HRV vaccine/placebo were enrolled and one randomly selected twin from each pair received two vaccine doses and the other received placebo doses (at 2 and 4 months of age).

Detection and genotyping of human rotavirus VP4 and VP7 genes by reverse transcriptase PCR and reverse hybridization.

Rotavirus infections can be diagnosed in stool samples by serological and molecular methods. We developed a novel reverse transcriptase PCR (RT-PCR) method for the amplification of rotavirus RNA and a reverse hybridization assay on a strip to detect amplimers and identify the specific G and P genotypes present in human stool specimens. An additional aim was to permit specific identification of the rotavirus G1P[8] strain, used in the Rotarix vaccine.

YscP, a Yersinia protein required for Yop secretion that is surface exposed, and released in low Ca2+.

The Yersinia Ysc apparatus is made of more than 20 proteins, 11 of which have homologues in many type III systems. Here, we characterize YscP from Yersinia enterocolitica. This 515-residue protein has a high proline content, a large tandem repetition and a slow migration in SDS-PAGE.

The virulence plasmid of Yersinia, an antihost genome.

The 70-kb virulence plasmid enables Yersinia spp. (Yersinia pestis, Y. pseudotuberculosis, and Y.

The Yersinia Yop virulon: LcrV is required for extrusion of the translocators YopB and YopD.

LcrV, an essential piece of the Yop virulon, is encoded by the large lcrGVsycDyopBD operon. In spite of repeated efforts, the role of LcrV in the Yop virulon remains elusive. In an attempt to clarify this, we engineered a complete deletion of lcrV in the pYV plasmid of Yersinia enterocolitica E40 and characterized the phenotype of the mutant.

YscM1 and YscM2, two Yersinia enterocolitica proteins causing downregulation of yop transcription.

Synthesis of the Yop proteins by yersiniae is downregulated when secretion is prevented by closure or destruction of the contact (type III) secretion channel. In Yersinia pseudotuberculosis, a mutation in the IcrQ gene, encoding a secreted protein, reduces this feedback inhibition mechanism. Surprisingly, mutation in the yscM gene, the IcrQ homologue in Y.

The fliA gene encoding sigma 28 in Yersinia enterocolitica.

Yersinia enterocolitica is an enterobacterium responsible for gastrointestinal syndromes. Its pathogenicity depends on the presence of the 70-kb pYV plasmid, which directs Yop secretion. The Yop secretion machinery, consisting of the YscA-U and LcrD proteins, presents some structural similarity with the flagellum assembly machinery characterized in other bacteria.

The rpoS gene from Yersinia enterocolitica and its influence on expression of virulence factors.

The chromosome of Yersinia enterocolitica encodes a heat-stable enterotoxin called Yst and a surface antigen called Myf, which closely resembles enterotoxin-associated fimbriae. Both factors could act in conjunction to produce diarrhea. Production of the enterotoxin is regulated by temperature, osmolarity, and pH and occurs only when bacteria reach the stationary phase.