Cats are considered the main reservoir of three zoonotic Bartonella species: Bartonella henselae, Bartonella clarridgeiae, and Bartonella koehlerae. Cat fleas (Ctenocephalides felis) have been experimentally demonstrated to be a competent vector of B. henselae and have been proposed as the potential vector of the two other Bartonella species. Previous studies have reported a lack of association between the Bartonella species infection status (infected or uninfected) and/or bacteremia levels of cats and the infection status of the fleas they host. Nevertheless, to date, no study has compared the quantitative distributions of these bacteria in both cats and their fleas under natural conditions. Thus, the present study explored these relationships by identifying and quantifying the different Bartonella species in both cats and their fleas. Therefore, EDTA-blood samples and fleas collected from stray cats were screened for Bartonella bacteria.
Bartonellae are vector-borne hemotropic bacteria of numerous mammalian hosts, in which they typically establish persistent and subclinical infections (1). Several Bartonella species are considered pathogens of many incidental hosts, including humans and domesticated animals (2). Cats (Felis catus) are the reservoirs of three zoonotic Bartonella species: Bartonella henselae, Bartonella clarridgeiae, and Bartonella koehlerae (2). Of these, B. henselae is considered the main causative agent of cat scratch disease (CSD) in humans (3), while B. clarridgeiae has been implicated as a cause of a CSD-like disease in several cases (4-6), and B. koehlerae was reported to cause endocarditis in humans and dogs (7,8). Commonly, infected cats are subclinical persistent carriers of these Bartonella species (9-11). Moreover, other Bartonella species, including Bartonella quintana (12, 13), Bartonella bovis (14), and Bartonella vinsonii subsp. berkhoffii (15), were occasionally isolated from cats. Cat fleas (Ctenocephalides felis) are considered the major vector of feline bartonellae. They have been experimentally proved to be a competent vector of B. henselae (11) and have been proposed as the potential vector of B. clarridgeiae and B. koehlerae, since DNA sequences from these Bartonella species have been commonly detected in C. felis collected from cats worldwide (16).The distribution of Bartonella species in cat populations varies notably across geographic regions. Infection rates of 0 to 62% in cats have been reported worldwide (17-19) but can reach even higher percentages in isolated cat populations (11). Although the natural transmission of Bartonella species among cats requires the presence of fleas (11,20) and no vertical transmission of bartonellae has been proven in either cats (maternal transmission; 21, 22) or cat fleas (23), previous studies reported a lack of association between Bartonella infection in cats and their fleas (11,18). The presence and/or level of infection (bacterial loads) of the Bartonella species in the cats tested did not mirror the infection status of the fle...