COMPARATIVE SEROREACTIVITY TO BARTONELLA-HENSELAE AND BARTONELLA-QUINTANA AMONG CATS FROM ISRAEL AND NORTH-CAROLINA

Bartonella henselae, the predominant cause of cat scratch disease, and Bartonella quintana, the cause of trench fever, are closely related B artonella species that induce cross-reactivity when cat or human sera are tested using an indirect immunofluorescence antibody (IFA) test. C ats an the natural reservoir for B. henselae, whereas a mammalian rese rvoir host for B. quintana has not been identified. Serum samples from 114 cats from Israel and 114 cats from North Carolina were tested by IFA for seroreactivity to B. henselae and B. quintana antigens. Simila r numbers of cats from Israel [45 (39.5%)] and from North Carolina [46 (40.4%)] were seroreactive to both antigens, however, as compared to cats from North Carolina [8 (7%)], a significantly (P = 0.001) larger number of cats from Israel were seroreactive to B. quintana antigen on ly [23 (20.2%)]. In addition, mean antibody titers were lower to B. he nselae than to B. quintana (P = 0.0001) in the cats from Israel, where as similar mean titers to both antigens were identified in cats from N orth Carolina. Absorption of serum using whole B. henselae organisms r esulted in a significantly greater (P = 0.0001) decrease in antibody t iter to B. henselae between absorbed and non-absorbed sera, as compare d to the decrease in antibody titer following absorption with whole B. quintana organisms. There was a similar decrease in antibody titer in sera from cats experimentally infected with B. henselae and in cats n aturally exposed to Bartonella species from Israel and North Carolina. Our results indicate that absorption of serum will, in most instances , distinguish species-specific reactivity by IFA to B. henselae from c ross-reactivity to B. quintana in cats experimentally infected with B. henselae. The data support the conclusion that B. henselae is the pri ncipal Bartonella species responsible far seroreactivity against B. he nselae and B. quintana in naturally exposed cats from Israel or North Carolina. It also suggests that in Israel, cats are exposed to one or more antigenically different Bartonella species, sub-species or strain s, that seroreact by IFA more intensely with B. quintana antigen.