Vignette d'image

Gern, Lise

Nom
Gern, Lise
Affiliation principale
Fonction
Ancien.ne collaborateur.trice
Identifiants
https://libra.unine.ch/handle/123456789/303

Résultat de la recherche

Filtres

7
7
Réinitialiser les filtres

Paramètres

Voici les éléments 1 - 7 sur 7
  • Publication
    Métadonnées seulement
    PCR-reverse line blot typing method underscores the genomic heterogeneity of Borrelia valaisiana species and suggests its potential involvement in Lyme disease
    (2003)
    Godfroid, Edmond
    ;
    Hu, Chang Min
    ;
    Humair, Pierre-François
    ;
    Bollen, Alex
    ;
    Gern, Lise 
    Detection of the Borrelia burgdorferi sensu lato complex in biological samples is currently done by conventional immunological and molecular biological methods. To improve on the accuracy of these methods and to simplify the procedure for testing large numbers of samples, a solid-phase sandwich hybridization system readily applicable to the detection of PCR products has been designed. This colorimetric detection system relies on the use of polybiotinylated detection probes and of specific capture oligonucleotides covalently linked at allocated positions on nylon membrane strips. From a phylogenetic analysis on a great number of ospA gene sequences, we have designed and synthesized a set of PCR primers specific to the five Borrelia burgdorferi sensu lato genospecies present in Europe and a subset of probes (capture and detection probes) specific to these five genospecies (B. burgdorferi sensu stricto, B. garinii, B. afzelii, B. valaisiana, and B. lusitaniae). This combined PCR hybridization system was evaluated with a large number of various B. burgdorferi isolates and clinical specimens. These analyses clearly showed that the system could be used as a typing method to distinguish five genospecies belonging to the B. burgdorferi sensu lato complex. In addition, the study showed that B. valaisiana strains might be more heterologous than suspected up to now and clustered into three genomic groups.
  • Publication
    Métadonnées seulement
    Apodemus species mice are reservoir hosts of Borrelia garinii OspA serotype 4 in Switzerland
    (2002)
    Hügli, Delphine
    ;
    Hu, Chang Min
    ;
    Humair, Pierre-François
    ;
    Wilske, Bettina
    ;
    Gern, Lise 
    Among Borrelia burgdorferi sensu lato isolates, seven outer surface protein A (OspA) serotypes have been described: serotypes 1 and 2 correspond to B. burgdorferi sensu stricto and Borrelia afzelii, respectively, and serotypes 3 to 7 correspond to Borrelia garinii. In Europe, serotype 4 has never been isolated from Ixodes ricinus ticks until recently, although this serotype has been frequently isolated from cerebrospinal fluid from patients. In Europe, B. afzelii and B. burgdorferi sensu stricto were found associated with rodents and B. garinii was found associated with birds. In this study, the reservoir role of Apodemus mice for B. garinii OspA serotype 4 was demonstrated by xenodiagnosis. Apodemus mice are the first identified reservoir hosts for B. garinii OspA serotype 4.
  • Publication
    Métadonnées seulement
    Transmission of Borrelia garinii OspA serotype 4 to BALB/c mice by Ixodes ricinus ticks collected in the field
    (2001)
    Hu, Chang Min
    ;
    Wilske, Bettina
    ;
    Fingerle, Volker
    ;
    Lobet, Yves
    ;
    Gern, Lise 
    In Europe, Borrelia garinii OspA serotype 4 has been isolated from the cerebrospinal fluid of patients but, up to now, has never been identified among culture isolates from Ixodes ricinus ticks. This information raises the question of whether OspA serotype 4 is transmitted by I. ricinus in nature. In the present study, L ricinus nymphs collected in an area of endemicity in southern Germany were allowed to feed on mice. Cultivation of ear biopsy specimens showed that six of seven B. garinii-infected mice were infected by OspA serotype 4. In contrast, very few B. garinii OspA serotype 4 organisms were isolated directly from the ticks which infected the mice; most isolates were B. afzelii. The infected mice transmitted mainly OspA serotype 4 to xenodiagnostic ticks, preferentially in combination with B. afzelii.
  • Publication
    Métadonnées seulement
    Antigenic conservation of an immunodominant invariable region of the VlsE lipoprotein among European pathogenic genospecies of Borrelia burgdorferi SL
    (2000)
    Liang, Fang Ting
    ;
    Aberer, Elisabeth
    ;
    Cinco, Marina
    ;
    Gern, Lise 
    ;
    Hu, Chang Min
    ;
    Lobet, Yves
    ;
    Ruscio, Maurizio
    ;
    Voet, Pierre
    ;
    Weynants, Vincent
    ;
    Philipp, Mario T
    Lyme disease is caused by genetically divergent spirochetes, including 3 pathogenic genospecies: Borrelia burgdorferi sensu stricto, B. garinii, and B. afzelii. Serodiagnosis is complicated by this genetic diversity. A synthetic peptide (C-6), based on the 26-mer invariable region (IR6) of the variable surface antigen of B. burgdorferi (VlsE), was used as ELISA antigen, to test serum samples collected from mice experimentally infected with the 3 genospecies and from European patients with Lyme disease, Regardless of the infecting strains, mice produced a strong antibody response to C-6, which indicates that IR6 is antigenically conserved among the pathogenic genospecies. Twenty of 23 patients with culture-confirmed erythema migrans had a detectable antibody response to C-6, A sensitivity of 95.2% was achieved, with serum samples collected from patients with well-defined acrodermatitis chronica atrophicans, Fourteen of 20 patients with symptoms of late Lyme disease also had a positive anti-IR6 ELISA, Thus, it is possible that C-6 may be used to serodiagnose Lyme disease universally.
  • Publication
    Métadonnées seulement
    Infection of Ixodes ricinus (Acari : Ixodidae) by Borrelia burgdorferi sensu lato in North Africa
    (1999)
    Zhioua, Elyes
    ;
    Bouattour, Ali
    ;
    Hu, Chang Min
    ;
    Gharbi, Mohamed
    ;
    Aeschliman, Andre
    ;
    Ginsberg, Howard S
    ;
    Gern, Lise 
    Free-living adult Ixodes ricinus. were collected in Amdoun, situated in the Kroumiry mountains in northwestern Tunisia (North Africa). Using direct fluorescence antibody assay, the infection rate of field-collected I. ricinus bq Borrelia burgdorferi sensu late was 30.5% (n = 72). No difference in infection rate was observed between male and female ticks. Spirochetes that had been isolated from I. ricinus from Ain Drahim (Kroumiry Mountains) in 1988 were identified as Borrelia lusitaniae (formerly genospecies PotiB2). This is the first identification of a genospecies of Borrelia burgdorferi sensu lato from the continent of Africa.
  • Publication
    Métadonnées seulement
    Immunization with a polyvalent OspA vaccine protects mice against Ixodes ricinus tick bites infected by Borrelia burgdorferi ss, Borrelia garinii and Borrelia afzelii
    (1997)
    Gern, Lise 
    ;
    Hu, Chang Min
    ;
    Voet, Pierre
    ;
    Hauser, Pierre
    ;
    Lobet, Yves
    Sequence variability of the outer surface protein (Osp) A among Borrelia burgdorferi sl species suggests that a monovalent OspA vaccine may not protect against the various Borrelia present in Eurasia. Here, we confirmed that a monovalent recombinant OspA (rOspA) vaccine noes not protect mice against Ixodes ricinus mediated infection with B. burgdorferi ss, Borrelia garinii and Borrelia afzelii. However when mice were vaccinated with a cocktail of various rOspA from these three species, they were protected, and all challenge ricks that fed on them were cleared of their spirochetes. These results showed that a multiple OspA antigens vaccine, compatible with human use, was very efficient at protecting mice against B. burgdorferi ss, B. garinii and B. afzelii. (C) 1997 Elsevier Science Ltd.
  • Publication
    Métadonnées seulement
    Apodemus sp. rodents, reservoir hosts for Borrelia afzelii in an endemic area in Switzerland
    (1997)
    Hu, Chang Min
    ;
    Humair, Pierre-François
    ;
    Wallich, Reinhard
    ;
    Gern, Lise 
    Borrelia burgdorferi is maintained in nature in transmission cycles alternatively involving ticks and reservoir hosts. Small rodents like Apodemus mice and Clethrionomys voles are the primary reservoir of Lyme disease in Europe. In this study, we analyzed by SDS-PAGE and Western blot 20 borrelial isolates from xenodiagnostic ticks fed on four Apodemus sp. mice captured in the Staatswald forest (Switzerland). All isolates but one showed a homogeneous protein pattern expressing an outer surface protein, (Osp) A of 32 kDa and an OspB of 35 kDa and reacted with monoclonal antibody (mAb) I 17.3 specific for B. afzelii. One isolate expressed an OspA of 32.5 kDa and an OspB of 35 kDa and did not react with species-specific mAbs I 17.3, D6 and H3TS, but was shown to belong to B., afzelii by Southern blot analysis. The possibility exists that non-cultivatable borreliae are present in xenodiagnostic ticks. However, our results clearly show that Apodemus sp. are reservoir hosts for B. afzelii, since this genospecies is transmitted from Apodemus sp. to feeding larval ticks.