Voici les éléments 1 - 4 sur 4
  • Publication
    Métadonnées seulement
    Prevalence of Borrelia burgdorferi sensu lato in ticks collected from migratory birds in Switzerland
    (2006)
    Poupon, Marie-Angèle
    ;
    ;
    Humair, Pierre-François
    ;
    ; ;
    Schaad, Michael
    ;
    Jenni, Lukas
    ;
    The prevalence of ticks infected by Borrelia burgdorferi sensu lato on birds during their migrations was studied in Switzerland. A total of 1,270 birds captured at two sites were examined for tick infestation. Ixodes ricinus was the dominant tick species. Prevalences of tick infestation were 6% and 18.2% for birds migrating northward and southward, respectively. Borrelia valaisiana was the species detected most frequently in ticks, followed by Borrelia garinii and Borrelia lusitaniae. Among birds infested by infected ticks, 23% (6/26) were infested by B. lusitaniae-infected larvae. Migratory birds appear to be reservoir hosts for B. lusitaniae.
  • 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
    ;
    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
    An avian reservoir (Turdus merula) of the Lyme borreliosis spirochetes
    (1998)
    Humair, Pierre-François
    ;
    Postic, Danièle
    ;
    Wallich, Reinhard
    ;
    The reservoir competence of passerine birds for the Lyme borreliosis spirochetes was studied in an enzootic focus in Switzerland. Skin aspirates and skin biopsies were used to isolate Borrelia spirochetes from Turdus species. B. burgdorferi sensu late was isolated and/or PCR-detected in BSK medium containing skin biopsy or skin aspirate from 5 blackbirds (T. merula) and one song thrush (T. philomelos). Seven isolates were obtained from 3 different blackbirds. Either B. garinii or Borrelia from the genomic group VS116 was found in bird skin samples. Mixed infection occurred in 2 cases. Tick xenodiagnosis was used to determine whether blackbirds transmitted Borrelia to ticks. Five xenodiagnoses were performed on 3 different blackbirds. Borrelia DNA was detected in BSK medium inoculated with xenodiagnostic ticks from all the passerines tested. Isolates cultured from xenodiagnostic ticks were obtained from 2 blackbirds. Isolates belonged to group VS116 (n = 10) and to B. garinii (n = 1). Our study has shown that Turdus sp. are infected by B. garinii and by Borrelia from group VS116 and that blackbirds are implicated as reservoirs for these 2 genomic groups of Borrelia, as they transmit living borreliae to ticks. An association seems to exist between birds and Borrelia VS116, and to a lesser extent, B. garinii, similar to the association existing between small rodents and B. afzelii. Our observations emphasize the fact that different enzootic cycles maintain Lyme borreliosis spirochetes in nature.
  • 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
    ;
    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.