Bartonella infection in sylvatic small mammals of central Sweden

Abstract

Sylvatic small mammals were captured in rural habitats near Uppsala, Sweden, to measure the prevalence of bartonella infections, characterize bacterial isolates and identify their host range, and increase our understanding of host-pathogen ecology. During 7 nights of trapping at 3 localities, 236 small mammals were captured (trap success 30%). Bartonella were isolated from bloods of Apodemus flavicollis (19 of 110 tested), Apodemus sylvaticus (6/25), Clethrionomys glareolus (9/60), Microtus agrestis (1/3), Mus musculus (1/18), and Sorex araneus (3/20). Nucleotide sequencing (a 338 bp fragment of the gltA gene) of 40 isolates yielded 6 unique genotypes. Five of the 6 genotypes were most similar to other known bartonella isolated from Old World small-mammal hosts. The most frequent genotype (83%) was isolated from A. flavicollis and M. musculus and was identical to Bartonella grahamii, a recently demonstrated human pathogen. These two hosts were most frequently captured in and around human structures and work places, thus providing conditions that could potentially lead to frequent human infections.

Demographic Features of Bartonella Infections in Richardson's Ground Squirrels (Spermophilus Richardsonii)

“…Many studies have reported similar, or even higher, prevalence of Bartonella in wild rodents in a variety of geographical locations (Kosoy et al, 1997;Fichet-Calvet, 2000;Ying et al, 2002;Holmberg et al, 2003).…”

Factors associated with the rapid emergence of zoonotic Bartonella infections

“…In Thailand, a number of the Bartonella isolates from Thai rodents are closely related to B. grahamii and B. elizabethae, two species that have been associated with human illness [36]. Bartonella grahamii has been mainly isolated from bank voles (Clethrionomys glareolus) in the United Kingdom [20] and Poland [10] and from yellow-necked mice (Apodemus flavicollis) in Sweden [110], but has also been isolated from rats in the USA and a domestic mouse captured in California [77]. The rodent flea Ctenophthalmus nobilis was recently shown to be a competent vector of at least two Bartonella species, B. grahamii, which has previously been associated with human ocular infection (neuroretinitis and retinal artery occlusion) [123,208], and B. taylorii [23].…”

Phylogenetic Analysis of Bartonella Detected in Rodent Fleas in Yunnan, China

“…These gltA amplicon sequences differed from those described for all the known Bartonella variants. F15YN had the highest BLAST sequence similarity (97%) to Bartonella strains detected from rodents from Greece (Tea et al, 2004) and Sweden (Holmberg et al, 2003) and 95% similarity to B.…”