Polymerase chain reaction detection of Rickettsia felis-like organism in Archaeopsylla erinacei (Siphonaptera: Pulicidae) from Bavaria, Germany.

Fleas occur as ectoparasites of vertebrates around the world. The obligate intracellular bacterium Rickettsia felis has been detected globally in several flea species, causing a murine-typhus like disease in humans. In this study, a total of 150 hedgehog fleas (Archaeopsylla erinacei Bouché) were collected from 18 hedgehogs coming from four locations in southern Germany for the detection of R. felis. Individual DNA extracts were tested with polymerase chain reaction (PCR) for the amplification of the rickettsial ompB, gltA, ompA, and 16S rRNA genes. A total of 144 samples (96%) were positive using ompB PCR. Sequencing and phylogenetic analysis showed an organism very closely related to R. felis with 96% similarity. These results provided evidence that hedgehog fleas in Germany may be nearly 100% infected with a rickettsial species closely related to R. felis. Further studies are needed for its molecular and pathogenetic characterization. The hedgehog as a potential reservoir for the emergent pathogen R. felis or closely related strains also needs further study.

Molecular evidence for Bartonella spp. in cat and dog fleas from Germany and France.

Nine hundred and fifty-two fleas were collected from 148 cats and 133 dogs at 18 widely distributed geographic locations in Germany and France and examined for the presence of six different Bartonella spp. (Bartonella bacilliformis, Bartonella clarridgeiae, Bartonella elizabethae, Bartonella henselae, Bartonella quintana, Bartonella vinsonii subsp. berkhoffii) by PCR. Thirty-five specimens (3.7%) tested positive for either B. henselae (14 positive fleas) or B. clarridgeiae (21 positive fleas). DNA of other Bartonella spp. were not detected. Bartonella clarridgeiae was the dominating species in samples from France (19 out of 22 positive fleas), whereas B. henselae was more frequent in Germany (11 out of 13 positive fleas). With 3.5% (22 out of 632 fleas) in France and 4.1% (13 out of 320 fleas) in Germany, the overall prevalences of pathogen did not vary significantly between the flea populations of both countries. 5.4% of cats in France versus 16.1% of cats from Germany were infested by fleas carrying Bartonella, whereas 9.5% of dogs in France but none of the examined dogs from Germany were infested by Bartonella positive fleas. The molecular evidence of Bartonella infections reveals that agents of zoonotic potential are established in flea populations in Germany and France and that the spectrum of species can vary significantly from country to country.

Osp17, a novel immunodominant outer surface protein of Borrelia afzelii: recombinant expression in Escherichia coli and its use as a diagnostic antigen for serodiagnosis of Lyme borreliosis.

Western blot analyses of the human humoral response of patients with Lyme borreliosis have shown that a 17-kDa protein is an immunodominant protein in late disease. Immune electron microscopy with a monoclonal antibody against this protein revealed that the 17-kDa protein is abundantly expressed on the surface of Borrelia afzelii strain PKo. Therefore, the protein has been renamed outer surface protein (Osp) 17. Recombinant Osp 17 of strain PKo was expressed in Escherichia coli and purified by chromatography. Immunoblot analysis of human sera showed a comparable sensitivity with recombinant and natural proteins. The DNA sequences of the osp17 genes from different B. afzelii strains were determined. The DNA sequences of the different osp 17 homologues (six isolates from skin, three isolates from CSF and one isolate from synovial fluid) had high sequence identities of at least 94%. Using a polyclonal antibody against recombinant Osp 17, it was shown that Osp 17 expression varied considerably among the investigated B. afzelii strains. As previously also observed for OspA- and OspC-encoding genes, the osp 17 gene is present in strains not expressing the respective protein. It has been shown that OspA and OspC expression varies in different environments such as tick and vertebrate host. Studies are underway to examine whether this is also true for Osp 17. For diagnostic purposes the use of recombinant Osp 17 has the advantage that the amount of Osp 17 antigen can be easily standardized for immunoblotting, and that this antigen can be used in a protein-specific enzyme-linked immunosorbent assay.

An improved recombinant IgG immunoblot for serodiagnosis of Lyme borreliosis.

We have previously described the use of the following recombinant antigens for serodiagnostic immunoblots: p83/100, p39, OspC and p41 (flagellin) internal fragment [Wilske et al. (1993) Med Microbiol Immunol 182:255-270; Rossler et al. (1997) J Clin Microbiol 35:2752-2758]. In our currently used immunoblot p83/100 is derived from strain PKo (Borrelia afzelii), p39 (BmpA) and OspC from strains PKa2 (B. hurgdorferi sensu stricto), PKo and PBi (B. garinii), respectively; the p41 (flagellin) internal fragments were cloned from strains PKo and PBi. In this study we describe the use of two additional recombinantly expressed highly immunogenic proteins Osp 7 (derived from PKo) and p58 (derived from PBi). A clinically well-defined panel of sera from 147 Lyme borreliosis patients and 139 controls previously tested by a standardized whole cell lysate immunoblot [Hauser et al. (1997) J Clin Microbiol 35:1433-1444] was investigated in the recombinant immunoblot without (old recombinant immunoblot) and with Ospl7 and p58 (new recombinant immunoblot) for IgG antibodies. The sensitivity of the recombinant IgG immunoblot for diagnosis of stage II and stage III could be significantly improved by addition of Osp17 and p58 without loss of specificity. With the exception of sera from patients with erythema migrans the diagnostic sensitivity is comparable to the whole cell lysate IgG immunoblot. The main advantage of the recombinant immunoblot is the easy identification of diagnostic bands, whereas the identification of bands in the whole cell lysate immunoblot is difficult. The recombinant immunoblot is especially suitable where large series of sera need to be investigated.

Phenotypic analysis of outer surface protein C (OspC) of Borrelia burgdorferi sensu lato by monoclonal antibodies: relationship to genospecies and OspA serotype.

Molecular analyses of the genes encoding OspC, a major immunodominant protein of Borrelia burgdorferi sensu lato, revealed a considerable degree of heterogeneity. In the present study, we investigated whether a similar heterogeneity of the OspC phenotype can be shown by analysis with monoclonal antibodies (MAbs). Thirteen OspC-specific MAbs (L22 MAbs) were produced by immunizing mice with either different combinations of whole-cell antigens or recombinantly expressed OspCs cloned from strains belonging to different Borrelia spp. Ten of them differed in their reactivities with various strains. Western blot (immunoblot) analyses of 38 B. burgdorferi sensu lato strains resulted in 13 different reactivity patterns. These 13 different patterns were observed among only six different OspA serotypes, indicating that OspC is more heterogeneous than OspA. Patterns 1 to 4 were present only in B. burgdorferi sensu stricto, patterns 5 to 7 were present only in Borrelia afzelii, and patterns 9 to 13 were present only in Borrelia garinii. Pattern 8 was observed among B. afzelii and B. garinii strains but not among B. burgdorferi sensu stricto strains. One L22 MAb (2B8) recognized a common OspC-specific epitope of all 38 B. burgdorferi sensu lato strains analyzed, and another one (22C11) recognized a common epitope of OspC from both B. afzelii and B. garinii and was not reactive with OspC from B. burgdorferi sensu stricto. Western blot and sequence analysis of truncated OspCs located the 22C11 epitope as well as a species-specific sequence motif between amino acids 20 and 35. Other broadly reactive L22 MAbs were 10D3, 1F8, and 7G5. Some L22 MAbs (1C3, 1C3, 12E5, 1B11, 1F10, and 6C8) bound to epitopes present only in a few strains. Relapsing fever borreliae (Borrelia hermsii, Borrelia turicatae, and Borrelia duttoni) were nonreactive, with the following exception: three L22 MAbs (2B8, 6C4, and 10C5) recognized an abundantly expressed 20-kDa-range protein of B. turicatae. Because OspC is an immunodominant protein during the early immune response in Lyme borreliosis and has been shown to be effective as a vaccine in an animal model, our findings have important implications for the development of diagnostic reagents as well as vaccine research.

Immunological and molecular polymorphisms of OspC, an immunodominant major outer surface protein of Borrelia burgdorferi.

The gene of the immunodominant major protein pC of Borrelia burgdorferi was previously cloned and sequenced (R. Fuchs, S. Jauris, F. Lottspeich, V. Preac-Mursic, B. Wilske, and E. Soutschek, Mol. Microbiol. 6:503-509, 1992). pC is abundantly expressed on the outer surface of B. burgdorferi, as demonstrated by immunoelectron microscopy with monoclonal antibody L22 1F8. Accordingly, pC is renamed OspC, by analogy to the outer surface proteins OspA and OspB. Western immunoblot analysis of 45 B. burgdorferi isolates with monoclonal antibodies revealed that OspC is immunologically heterogeneous. Partial sequence analysis of the ospC gene confirmed the protein heterogeneity at the genetic level. We found that the degree of identity between the ospC partial sequences of five strains representing different OspA serotypes was only 63.3 to 85.4%. Immunological heterogeneity was also observed among representatives of the three newly designated genospecies of B. burgdorferi sensu lato, B. burgdorferi sensu stricto, B. garinii, and group VS461. Heterogeneity was confirmed for B. garinii at the genetic level. The ospC gene was also cloned from strains that did not express OspC, and antibody-reactive OspC was expressed in Escherichia coli. In addition, OspC-expressing variants were obtained from a nonexpressing strain by plating single colonies on solid medium. These findings confirm that the ospC gene is also present in nonexpressing strains. Because OspC is an immunodominant protein for the early immune response in Lyme borreliosis and was effective as a vaccine in an animal model, the immunological and molecular polymorphisms of ospC and OspC have important implications for the development of diagnostic reagents and vaccines.

Excretion patterns of alkylating metabolites in urine following cyclophosphamide treatment of tumor patients: influence of application route, dosage, liver and kidney function.

The excretion patterns of cyclophosphamide (CP) in urine were studied in 54 tumor patients aged between 21 and 61 years, using the nitrobenzyl-pyridine (NBP) reaction, with regard to the route of application (i.v., i.m. or oral), the CP dose and the functional state of the liver and kidney. The studies were carried out in nephrectomized patients and patients with liver affections caused by the basic disease, in particular with malignant lymphomas and mammary carcinomas. The following results were obtained: 1. There exists a direct relationship between the dose of CP applied and the quantitative excretion of alkylating metabolites in urine. According to these studies in which the patients received up to 2.8 g CP/m2 body surface, the upper CP dose was limited by the generally toxic side effects rather than by the metabolization rate. 2. At comparable CP doses the route of application (i.v., i.m. or oral) has no appreciable influence on the excreted NBP activity. 3. Disorders of the liver function without signs of icterus are not a contraindication to CP treatment. 4. The functional failure of one kidney has no statistically significant influence on the excretion of alkylating metabolites in urine.