Assessment of Persistence of Bartonella henselae in Ctenocephalides felis

Abstract

c Bartonella henselae (Rhizobiales: Bartonellaceae) is a Gram-negative fastidious bacterium of veterinary and zoonotic importance. The cat flea Ctenocephalides felis (Siphonaptera: Pulicidae) is the main recognized vector of B. henselae, and transmission among cats and humans occurs mainly through infected flea feces. The present study documents the use of a quantitative molecular approach to follow the daily kinetics of B. henselae within the cat flea and its excreted feces after exposure to infected blood for 48 h in an artificial membrane system. B. henselae DNA was detected in both fleas and feces for the entire life span of the fleas (i.e., 12 days) starting from 24 h after initiation of the blood meal. Bartonella henselae is a Gram-negative facultative intracellular bacterium of veterinary and zoonotic importance distributed worldwide (1). At present, its major competent vector is the cat flea, Ctenocephalides felis (2). Viable B. henselae or its DNA has also been detected in several other blood-feeding arthropods, such as ticks (Dermacentor spp., Ixodes spp.) (3-6) and biting flies (Haematobia spp., Stomoxys spp.) (7); however, no evidence of the role of these insects as competent vectors exists. Cats, particularly kittens, represent the major reservoir of B. henselae (8). Infected cats are usually asymptomatic but experience chronic recurring bacteremia (9). Clinical signs observed after experimental infection of cats include febrile illness, transient anemia, neurological dysfunction, and endocarditis (10-12).In humans, B. henselae is the causative agent of cat scratch disease (CSD), a syndrome characterized by a persistent regional lymphadenopathy that is usually self-limiting within 2 to 4 months in immunocompetent patients (13). However, infected immunocompromised individuals (such as those with AIDS or organ transplant recipients) can develop severe vasoproliferative tumors known as bacillary angiomatosis and bacillary peliosis (13,14,15).Although the prevalence of B. henselae infection in cats fluctuates significantly, the highest levels of infection occur in temperate regions where conditions are most favorable for the development of C. felis (1,16,17). The seroprevalence of antibodies against B. henselae in healthy cat populations ranges from 25 to 45% throughout the world (17). Nonetheless, in North America, where C. felis is endemic, seroprevalence was reported to reach up to more than 90% in some cat colonies (18). Fleas acquire B. henselae during their blood meal on highly bacteremic cats (16). Once in the arthropod vector, the bacterium seems to replicate within the gut and is then excreted in the feces (19,20). While transmission by flea saliva still requires further investigation (21), the exposure to infected flea feces appears to be the main route of infection for cats and, accidentally, humans (22-24). B. henselae can also be inoculated into the skin of a naive host via scratching or biting by a flea-contaminated carrier animal (16,20,25).Knowledge of the kinetics of B. henselae in C. f...

Acquisition and excretion of Bartonella quintana by the cat flea, Ctenocephalides felis felis

“…Nonetheless, we observed the absence of B. quintana in all fleas and in their faeces on day 13. The absence of the Bartonella was observed in previous studies: no B. quintana DNA was detected in louse faeces on either day 5, 7, 9 or 11 after infection (Seki et al 2007) and no B. henselae DNA was detected in cat fleas and their faeces on day 9 (Bouhsira et al 2013b). Further studies are required to determine whether the B. quintana was completely eliminated after 13 dpi.…”

“…) and no B. henselae DNA was detected in cat fleas and their faeces on day 9 (Bouhsira et al . ). Further studies are required to determine whether the B. quintana was completely eliminated after 13 dpi.…”

“…However, the method of Bartonella migration (e.g. B. quintana or B. henselae) from the digestive tract of arthropods (such as the louse or flea) to other tissues has not yet been elucidated (Seki et al 2007;Bouhsira et al 2013b).…”

Rheumatological presentation of Bartonella koehlerae and Bartonella henselae bacteremias

“…If correct, flea transmission of B henselae to humans may occur independent of a cat scratch [11] and neither concurrent antibiotic therapy nor B. koehlerae antibodies prevented transmission or development of B henselae bacteremia. Experimentally, cats and dogs infected with one B henselae strain type do not develop protective immunity when challenged with a different Bartonella spp.…”

Onset of efficacy and residual speed of kill over one month of a topical dinotefuran-permethrin-pyriproxyfen combination (Vectra®3D) against the adult cat flea (Ctenocephalides felis felis) on dogs

“…After the blood meal, digestion starts immediately and the fleas excrete their first feces approximately 30 min after infestation (Wang et al, 2012). When fleas are infected with Bartonella, they can produce infective feces for several days (Bouhsira et al, 2013;Kernif et al, 2014). Due to the risks associated with flea infestations, various ectoparasiticides are available for the control and prevention of flea infestations in dogs.…”