Coyotes (Canis latrans) as the reservoir for a human pathogenic Bartonellasp.: Molecular epidemiology of Bartonella vinsonii subsp berkhoffii infection in coyotes from central coastal California

Bartonella vinsonii subsp. berkhoffii was originally isolated from a dog su ffering infectious endocarditis and was recently identified as a zoonotic a gent causing human endocarditis. Following the coyote bite of a child who d eveloped clinical signs compatible with Bartonella infection in Santa Clara County, Calif., this epidemiological study was conducted. Among 109 coyote s (Canis latrans) from central coastal California, 31 animals (28%) were fo und to be bacteremic with B. vinsonii subsp. berkhoffii and 83 animals (76% ) had B. vinsonii subsp. berkhoffii antibodies. These findings suggest thes e animals could be the wildlife reservoir of B. vinsonii subsp. berkhoffii. PCR-restriction fragment length polymorphism (PCR-RFLP) analysis of the gl tA and 168 rRNA genes for these 31 isolates yielded similar profiles that w ere identical to those of B. vinsonii subsp. berkhoffii. Partial sequencing of the gltA and 16S rRNA genes, respectively, indicated 99.5 and 100% homo logy between the coyote isolate and B. vinsonii subsp. berkhoffii (ATCC 516 72). PCR-RFLP analysis of the 16S-23S intergenic spacer region showed the e xistence of two different strain profiles, as has been reported in dogs. Si x (19%) of 31 Bartonella bacteremic coyotes exhibited the strain profile th at was identified in the type strain of a canine endocarditis case (B. vins onii subsp. berkhoffii ATCC 51672). The other 25 bacteremic coyotes were in fected with a strain that was similar to the strains isolated from healthy dogs. Based on whole bacterial genome analysis by pulsed-field gel electrop horesis (PFGE) with SmaI restriction endonuclease, there was more diversity in fingerprints for the coyote isolates, which had at least 10 major varia nts compared to the two variants described for domestic dog isolates from t he eastern United States. By PFGE analysis, three Bartonella bacteremic coy otes were infected by a strain identical to the one isolated from three hea lthy dog carriers. Further studies are necessary to elucidate the mode of t ransmission of B. vinsonii subsp. berkhoffii, especially to identify potent ial vectors, and to determine how humans become infected.