Experimental infection of domestic cats with various feline Bartonella species or types

The clinical spectrum of human and animal infections caused by Bartonella species has widened. The genus Bartonella includes 20 species or subspecies, of which nine are pathogenic to humans and four have been isolated from domestic cats. B. henselae is the main etiological agent of cat scratch disease (CSD), with B. clarridgeiae being possibly another etiologic agent. Domestic cats are the main reservoir of these two Bartonella species.; We evaluated if cats primarily infected with a Bartonella species or type could be protected against a secondary or tertiary infection. Cats were primarily inoculated with various Bartonella species or types (B. henselae type I/type II, B. clarridgeiae, B. koehlerae or a wildlife Bartonella isolate). None of the cats challenged with a homologous strain became bacteremic, regardless of the time of challenge. In contrast, all but one cat challenged with a different Bartonella species became bacteremic. Among cats infected with B. henselae type I or type II, all the cats primarily infected with B. henselae type II became bacteremic when challenged with B. henselae type I, whereas, most of the cats primarily infected with B. henselae type II did not became bacteremic when challenged with B. henselae type I. Therefore, vaccine development will require the immunodominant B. henselae type I.; Cats inoculated with feline B. henselae type I presented clinical manifestations and a long lasting bacteremia. On the contrary, none of the cats inoculated with a human B. henselae type I strain had fever and the duration of bacteremia was significantly shorter. Therefore, the choice of a vaccine strain of B. henselae will be critical.; Cats experimentally infected with B. koehlerae, a newly discovered feline species, showed a prolonged bacteremia. B. koehlerae molecular profiles were different from the ones of B. henselae and B. clarridgeiae by SDS-PAGE and PFGE.; All infected cats developed substantial levels of Bartonella specific antibodies, despite the presence of bacteremia. The persistence of bacteremia could be explained by a lack of direct immunological response because of the intra-erythrocytic localization of Bartonella. This research provides essential information for the development of feline vaccines against Bartonella infection.