Evaluation of DNA colony hybridization and other techniques for detection of virulence in Yersinia species.

The virulence of yersiniae varies according to (i) species and biotype and (ii) possession of a 67- to 72-kilobase virulence plasmid. Y. pestis, Y. pseudotuberculosis, and biotypes 1B, 2, 3, 4, and 5 of Y. enterocolitica are inherently virulent but express full virulence only when in possession of a virulence plasmid. Other Yersinia species and biotypes 1A and 3B of Y. enterocolitica are seldom implicated in disease. In this study, we prepared DNA probes from eight nonoverlapping regions of the virulence plasmid of a strain of Y. enterocolitica and from the inv and ail chromosomal loci responsible for the invasive capacity of Y. enterocolitica and Y. pseudotuberculosis. The probes were used in colony hybridization experiments to investigate 156 yersiniae of various species and biotypes and of differing virulence. Probes prepared from the inv gene of Y. pseudotuberculosis hybridized with Y. pseudotuberculosis and Y. pestis only, whereas an analogous probe prepared from Y. enterocolitica hybridized with all species and biotypes of yersiniae (but not with other bacteria) regardless of virulence or potential virulence. Probes prepared from the ail region of Y. enterocolitica reacted almost exclusively with Y. enterocolitica strains of pathogenic biotypes. Probes prepared from the virulence plasmid of a serogroup O:8, biotype 1B isolate of Y. enterocolitica identified virulent yersiniae in all species with a high degree of sensitivity and specificity. These probes did not react with yersiniae of avirulent biotypes or species. Of the other assays of virulence evaluated (calcium dependence, binding of crystal violet, and pyrazinamidase activity), binding of crystal violet provided a simple means for identifying plasmid-bearing strains.     

Identification of a conjunctivitis-associated gene locus from the virulence plasmid of Yersinia enterocolitica.

The virulence plasmid (pYV) of Yersinia enterocolitica is necessary for production of conjunctivitis in guinea pigs and for mouse lethality. To identify the genes responsible for production of conjunctivitis in guinea pigs, we subcloned the BamHI and SalI restriction fragments of the virulence plasmid of Y. enterocolitica A2635 (serotype O:8) into derivatives of the broad-host-range plasmid pRK290 and introduced the constructions into plasmid-negative Y. enterocolitica strains. A mild, transient conjunctivitis was evident 24 h after inoculation with strains containing a 2.8-kilobase (kb) BamHI fragment of pYV. These strains were cytotoxic to HEp-2 cells but did not cause death in iron-loaded adult mice. When the 2.8- and adjacent 0.5-kb BamHI fragments were deleted from the virulence plasmid of a fully virulent Y. enterocolitica isolate, the resultant strain did not cause conjunctivitis in guinea pigs and was not cytotoxic to HEp-2 cells. However, the strain with the deletion appeared to be more virulent for mice, with more rapid dissemination after orogastric inoculation, compared with that of the parent strain. When the deletion was complemented by introduction of a plasmid containing the 2.8-kb BamHI fragment, the strain again caused conjunctivitis but had decreased virulence for mice.     

Genistein Supplements Might Not Induce Clitoral Modifications in Postmenopausal Women: A Prospective,Pilot Study

IntroductionVaginal dryness, low sexual desire, and low sexual arousability are critical issues for many postmenopausal women. Hormone therapy seems to improve vaginal lubrication and dyspareunia.AimTo evaluate, in postmenopausal women who refused hormonal therapy, the role of genistein in the treatment of vasomotor symptoms and its capacity to induce clitoral volumetric and vascular modifications independently from sexual stimulation.MethodsTwenty‐nine postmenopausal women who refused hormonal therapy were submitted to oral daily treatment with genistein 45 mg (Group I; N = 15); or no treatment (Group II; N = 14). The Group II patients served as controls. The patients were not randomly assigned to the two groups. The patients were studied before and after 3 months.Main Outcomes MeasuresEndometrial and clitoral ultrasonographic analysis; color Doppler evaluation of the dorsal clitoral artery; evaluation of hormonal plasma concentrations; administration of the two‐factor Italian McCoy Female Sexuality Questionnaire; compilation of a monthly diary reporting the number of hot flashes. The ultrasound, color Doppler and psychometric tests were performed by examiners blinded to the participant's group assignment.ResultsIn the genistein‐treated patients the vasomotor symptoms ameliorated at the end of the study. The use of genistein did not influence any other parameter.ConclusionsPostmenopausal women submitted to a 3‐months treatment with genistein showed an improvement of vasomotor symptoms. However, isoflavones seem to not induce any modification in the clitoral structures. Battaglia C, Cianciosi A, Mancini F, Fabbri R, Busacchi P, Nappi RE, and Venturoli S. Genistein supplements might not induce clitoral modifications in postmenopausal women: A prospective, pilot study.