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Four Bartonella species have been isolated from domestic cats, of which two serotypes/genotypes of Bartonella henselae and possibly B. clarridgeiae are human pathogens, causing cat scratch disease (CSD).Our objectives were to evaluate infection and potential cross-protection during re-infection in domestic cats with various Bartonella species or types.Thirty-six cats were primarily inoculated with B. henselae type I (n=16), B. henselae type II (n=10), B. clarridgeiae (n=6) or B. koehlerae (n=4). They were challenged with B. henselae type I (n=15), B. henselae type II (n=13) or B. clarridgeiae (n=8). All 36 cats became bacteremic (1.25x10(2)-1.44x10(6)CFU/ml) and bacteremia lasted from 37 to 582 days. Duration of bacteremia for cats inoculated with B. henselae type I was shorter than for cats inoculated with either B. henselae type II (P=0.025) or B. clarridgeiae (P=0.011). After challenge, 26 cats became bacteremic. Among the nine cats primarily inoculated with B. henselae type I and challenged with B. henselae type II, six cats stayed abacteremic. The three bacteremic cats had a transient low-level bacteremia. No bacteremia was observed in three cats primarily inoculated with B. henselae type I and challenged with another strain of B. henselae type I. Bacteremia levels in the 26 cats were significantly lower than for primary inoculation (P=0.022) and its duration was shorter (P=0.012). Among the eight cats challenged with B. clarridgeiae, duration of bacteremia in the four cats primarily inoculated with B. henselae type I was shorter than in the four cats primarily inoculated with B. henselae type II (P=0.01). Bartonella clarridgeiae inoculated cats were more likely to have relapses for both primary and secondary infections. This is the first demonstration of cross-protection, evidenced by absence of bacteremia, in cats primarily infected with B. henselae type I and challenged with B. henselae type II, whereas no cross-protection was previously shown for cats primarily infected with B. henselae type II and challenged with B. henselae type I. Such results are of major importance for future feline Bartonella vaccine development. more...

Bartonella quintana and Bartonella henselae are fastidious gram-negative bacteria responsible for bacillary angiomatosis, trench fever, cat scratch disease, and endocarditis. During a 5-year period, we received 2,043 samples for culture of Bartonella sp. We found Bartonella sp. to be the etiologic agent in 38 cases of endocarditis, 78 cases of cat scratch disease, 16 cases of bacteremia in homeless people, and 7 cases of bacillary angiomatosis. We correlated the results of positive cultures with the clinical form of the disease, type of sample, culture procedure, PCR-based genomic detection, and antibody determination. Seventy-two isolates of B. quintana and nine isolates of B. henselae from 43 patients were obtained. Sixty-three of the B. quintana isolates and two of the B. henselae isolates, obtained from patients with no prior antibiotic therapy, were stably subcultured. The sensitivity of culture was low when compared with that of PCR-based detection methods in valves of patients with endocarditis (44 and 81%, respectively), skin biopsy samples of patients with bacillary angiomatosis (43 and 100%, respectively), and lymph nodes of cat scratch disease (13 and 30%, respectively). Serological diagnosis was also more sensitive in cases of endocarditis (97%) and cat scratch disease (90%). Among endocarditis patients, the sensitivity of the shell vial culture assay was 28% when inoculated with blood samples and 44% when inoculated with valvular biopsy samples, and the sensitivity of both was significantly higher than that of culture on agar (5% for blood [P = 0.045] and 4% for valve biopsy samples [P < 0.0005]). The most efficient culture procedure was the subculture of blood culture broth into shell vials (sensitivity, 71%). For patients with endocarditis, previous antibiotic therapy significantly affected results of blood culture; no patient who had been administered antibiotics yielded a positive blood culture, whereas 80% of patients with no previous antibiotic therapy yielded positive blood cultures (P = 0.0006). Previous antibiotic therapy did not, however, prevent isolation of Bartonella sp. from cardiac valves but did prevent the establishment of strains, as none of the 15 isolates from treated patients could be successfully subcultured. For the diagnosis of B. quintana bacteremia in homeless people, the efficiency of systematic subculture of blood culture broth onto agar was higher than that of direct blood plating (respective sensitivities, 98 and 10% [P < 10(-7)]). Nevertheless, both procedures are complementary, since when used together their sensitivity reached 100%. All homeless people with positive blood cultures had negative serology. The isolation rate of B. henselae from PCR-positive lymph nodes, in patients with cat scratch disease, was significantly lower than that from valves of endocarditis patients and skin biopsy samples from bacillary angiomatosis patients (13 and 33%, respectively [P = 0.084]). In cases of bacillary angiomatosis for which an agent was identified to species level, the isolation rate of B. henselae was lower than the isolation rate of B. quintana (28 and 64%, respectively [P = 0.003]). If culture is to be considered an efficient tool for the diagnosis of several Bartonella-related diseases, methodologies need to be improved, notably for the recovery of B. henselae from lymph nodes of patients with cat scratch disease. more...