Experimental Infection of Young Specific Pathogen‐Free Cats withBartonella henselae

Abstract

Eighteen 12-week-old specific pathogen-free cats, blood culture- and serum antibody-negative for Bartonella henselae, were randomly allocated to groups and were intravenously inoculated with 10(10) (group 1), 10(8) (group 2), or 10(6) (group 3) B. henselae or with saline (group 4) or were not inoculated (group 5). Cats were humanely killed at 2, 4, 8, 16, and 32 weeks after inoculation. All B. henselae-inoculated cats were bacteremic by 2 weeks after infection. Bacteremia persisted until 32 weeks after infection in 1 cat. Cats in groups 1 and 2 had fever (>39.7 degrees C) and partial anorexia by 2 weeks after infection that lasted 2-7 days. All infected cats had Bartonella-specific IgM and IgG serum antibodies and lymphocyte blastogenic responses. Histopathologic lesions were observed in multiple organs of infected cats through 8 weeks after infection. Cats were readily infected with B. henselae by intravenous inoculation, developed histopathologic lesions that apparently resolved, and developed B and T lymphocyte responses to infection.

Experimental infection of specific pathogen free (SPF) cats with two different strains of Bartonella henselae type I: A comparative study

“…The IgG titers were similar for both antigens in the cats inoculated with B. henselae Houston I. A specific IgM antibody response was detected by ELISA in all cats within 1 to 2 weeks PI and declined rapidly, as previously reported [26,44,45]. The B. henselae feline type I strain appeared to induce a stronger antibody response in cats infected to B. henselae feline type I than in cats infected with B. henselae Houston I.…”

“…For B. henselae Houston I, it is not known exactly how many passages this strain has been submitted to, but according to an ATCC source, it was passed at least five times to make the initial culture stock (Jane Tang, personal communication). Serial passages of Bartonella strains on blood agar, even in limited numbers, could lead to the attenuation of the strains and induce a lower antigenic response when compared to freshly isolated strains from cat blood [1,26,27,44,45]. Isolates with very limited passages on blood agar could harbor antigenic components that are not present or present in smaller amounts in strains that have been submitted to more passages [4,8].…”

“…2 and 3). At least 25 prominent protein bands were identified between 14 kDa and 200 kDa for both B. henselae feline type I and B. henselae Houston I whole organism lysates, with estimated molecular weights of 14,22,26,30,33,37,39,46,49,56,65,78, and 93 kDa. For OMPs, at least 12 protein bands were identified between 20 kDa and 200 kDa, with prominent bands at approximately, 30, 33, 37, 65, 73, and 85 kDa.…”

Strategies of exploitation of mammalian reservoirs by Bartonella species

“…This process did not provoke symptoms in the infected rat [3]. Experiments using other animal models, such as a B. birtlesii -mouse model [18-20], and a B. henselae -cat model [21] have yielded results that are akin to those observed in the B. tribocorum -rat model, suggesting a common infection mode for all Bartonella species in their respective animal reservoirs [22]. Furthermore, the kinetics of bacteraemia observed in these models were similar to those observed in captured naturally-infected animals (unpublished observations), which supports the reliability of results obtained from artificial routes of inoculation.…”

Prevalence of Bartonella infection in domestic cats in Denmark

“…The reservoir of Bartonella henselae and B. clarridgeiae is the domestic cat [6,23,26,30,35], which can remain bacteremic for months to years [1,18,27]. Cat-to-human transmission occurs predominantly via a cat scratch or bite, whereas the cat flea (Ctenocephalides felis) is the primary vector of B. henselae from cat to cat [11,16,24].…”