Characterization of the Leptospira interrogans S10-spc-alpha operon.

A ribosomal protein gene cluster from the spirochaete Leptospira interrogans was characterized. This locus is homologous to the Escherichia coli S10, spc, and alpha operons. Analysis of L. interrogans RNA showed that the ribosomal protein genes within this cluster are co-transcribed, thus forming an operon. Two transcription initiation sites were mapped by primer extension, upstream of fus, the first gene in this cluster, and sequences from this region provided promoter activity in E. coli. Transcription terminates near a predicted stem-loop structure following rplQ, the last gene in the cluster. These data suggest that two promoters upstream of fus direct transcription of this 17.5-kb ribosomal protein gene cluster. Comparison of the L. interrogans S10-spc-alpha cluster to homologous loci from Borrelia burgdorferi and Treponema pallidum provided evidence that this region of the genome underwent several rearrangements during spirochaete evolution.

Identification of a serogroup bataviae Leptospira strain isolated from an ox in Zimbabwe.

A strain belonging to the genus Leptospira serogroup Bataviae, isolated from an ox at slaughter in Zimbabwe, was identified by using cross-agglutinin absorption, the monoclonal antibody, restriction fragment length polymorphism, and polymerase chain reaction analyses. Results of both serological tests used showed that the isolate (strain SBF 37) was antigenically similar to reference strain Paidjan and therefore belongs to serovar paidjan. Strain SBF 37 was, however, genetically different from strain Paidjan since their chromosomal DNA had different restriction fragment length polymorphism patterns. The Zimbabwe paidjan strain was identified as belonging to the species Leptospira kirschneri while strain Paidjan reacted as a member of one of the non-kirschneri species in the polymerase chain reaction. The Zimbabwe isolate therefore belongs to Leptospira kirschneri serovar paidjan.

Evaluation of the polymerase chain reaction for early diagnosis of leptospirosis.

Early diagnosis of leptospirosis is important because severe leptospiral infection can run a fulminant course. The polymerase chain reaction (PCR) was evaluated for the detection of leptospires in clinical samples from patients with acute leptospiral infection. Blood and urine samples from 71 patients with leptospirosis were examined by PCR, culture or serology. Samples from 44 (62%) patients with the diagnosis of leptospirosis were positive by PCR as compared to 34 (48%) by culture. The presence of leptospires was demonstrated by PCR in 13 patients before the development of antibodies, as well as in two patients who were seronegative during their illness and at autopsy. Samples from 16 patients without leptospirosis were seronegative and culture negative, and also negative by PCR. We conclude that PCR is a rapid, sensitive and specific means of diagnosing leptospiral infection, especially during the first few days of the disease.

Identification of leptospires of the Pomona and Grippotyphosa serogroups isolated from cattle in Zimbabwe.

Two strains of the genus Leptospira, isolated from kidneys of oxen slaughtered in Zimbabwe, one belonging to serogroup Pomona (strain SBF 8) and the other to serogroup Grippotyphosa (strain SBF 32), were identified by using cross-agglutinin absorption, monoclonal antibody, restriction fragment length polymorphism and polymerase chain reaction analyses. The identification of the two strains was equivocal. Strain SBF 8 showed a close similarity to both serovars mozdok and proechimys by cross-agglutinin absorption tests and to serovar pomona by monoclonal antibody analysis, but had a distinct DNA restriction pattern. Strain SBF 32 showed a close antigenic similarity to serovars ratnapura, grippotyphosa and valbuzzi by the cross-agglutinin absorption test, and to serovar ratnapura by monoclonal antibody analysis but also had a distinct DNA restriction pattern. Both strains SBF 8 and SBF 32 reacted as members of species Leptospira kirschneri by the polymerase chain reaction. It is concluded that strains SBF 8 and SBF 32 represent new genetic strains in the Pomona and Grippotyphosa groups, respectively.

The dream in midlife women: its impact on mental health.

The current study examines the Dream in midlife women and its impact on mental health functioning. Ninety midlife women filled out a questionnaire examining Dream Status, Dream Success, Dream Content, and Dream Support, as well as mental health factors of depression, anxiety, and purpose-in-life. Neither early nor current Dream Status was not found to be significantly related to mental health factors. Partial support was found for the hypothesis that Dream Success is related to mental health factors. Early Dream Content related to career and current Dream Content related to both marriage/intimacy and career are related to positive performance on mental health factors. Dream Support is positively related both to Dream Success and to mental health factors while resistance to the Dream is not. The results are discussed in light of gender differences in the developmental function and impact of the Dream.

Use of the polymerase chain reaction for rapid diagnosis of leptospirosis - abstract

Leptospirosis is endemic in Barbados with 97 percent of severe cases caused by three serovars of leptospira interrogans. Early diagnosis is important since the disease can run a fulminant course and patients may die before the appearance of characteristic clinical manifestations of Leptospirosis and/or leptospiral antibodies are detected, and therefore the disease may go unrecognized. In this study, the potential of the polymerase chain reaction (PCR) was explored for the early diagnosis of leptospirosis, with a view to detecting leptospirosis within the first ten days of the onset of the disease. Blood and urine samples from 83 patients with leptospirosis admitted to the Queen Elizabeth Hospital, Barbados, between January 1990 and December 1992, were examined serologically, by culture and by PCR. The mortality rate during the study period was 8.4 percent. PCR was more often positive than culture for the detection of leptospires in proven cases by antibody titre and detected the presence of leptospires in sera before the development of antibodies. As culture can take up to 13 weeks, it does not contribute to an early diagnosis. Seroconversion usually occurs on about the seventh day of the disease, thus diagnosis by serology can take a week or more to be decisive. PCR, on the day of admission, and the characterization of PCR products by Southern hybridization can be completed within one or two subsequent days. PCR is potentially a valuable addition to the diagnostic process in leptospirosis (AU)

Simple method for production of internal control DNA for polymerase chain reaction assays for leptospira spp. - abstract

A simple and highly versatile one-step method for the production of internal control DNA for an established polymerase chain reaction assay for Leptospira interrogans is described. The internal control was produced from DNA of serovar bim, and is amplified with the same primers used routinely in our PCR assays. The inclusion of the internal control in the reaction mixture did not affect the efficacy of amplification of the target DNA. The method is simple and rapid and should be adaptable to most PCR assays for Leptospira spp. (AU)

Detection of seven species of pathogenic leptospires by PCR using two sets of primers.

Two sets of primers derived from genomic DNA libraries of Leptospira serovars icterohaemorrhagiae (strain RGA) and bim (strain 1051) enabled the amplification by PCR of target DNA fragments from leptospiral reference strains belonging to all presently described pathogenic Leptospira species. The icterohaemorrhagiae-derived primers (G1/G2) enabled amplification of DNA from L. interrogans, L. borgpetersenii, L. weilii, L. noguchii, L. santarosai and L. meyeri, whereas the bim-derived primers (B64-I/B64-II) enabled the amplification of L. kirschneri. Southern blot and DNA sequence analysis revealed inter-species DNA polymorphism within the region spanned by primers G1 and G2 between L. interrogans and various other Leptospira species. Using a mixture of primer sets G1/G2 and B64-I/B64-II, leptospires of serovars icterohaemorrhagiae, copenhageni, hardjo, pomona, grippotyphosa and bim were detected in serum samples collected from patients during the first 10 days after the onset of illness.