Identification of Bartonella species in rodents, shrews and cats in Denmark: detection of two B. henselae variants, one in cats and the other in the long‐tailed field mouse

Abstract

Small mammals and stray cats were trapped in two areas of North Zealand, Denmark, and their blood cultured for hemotrophic bacteria. Bacterial isolates were recovered in pure culture and subjected to 16S rDNA gene sequencing. Bartonella species were isolated from five mammalian species: B. grahamii from Microtus agrestis (field vole) and Apodemus flavicollis (yellow-necked field mouse); B. taylorii from M. agrestis, A. flavicollis and A. sylvaticus (long-tailed field mouse); B. tribocorum from A. flavicollis; B. vinsonii subsp. vinsonii from M. agrestis and A. sylvaticus; and B. birtlesii from Sorex vulgaris (common shrew). In addition, two variant types of B. henselae were identified: variant I was recovered from three specimens of A. sylvaticus, and B. henselae variant II from 11 cats; in each case this was the only B. henselae variant found. No Bartonella species was isolated from Clethrionomys glareolus (bank vole) or Micromys minutus (harvest mouse). These results suggest that B. henselae occurs in two animal reservoirs in this region, one of variant I in A. sylvaticus, which may be transmitted between mice by the tick Ixodes ricinus, and another of variant II in cats, which may be transmitted by the cat flea (Ctenocephalides felis). To our knowledge, this is the first report of the occurrence of B. henselae and B. tribocorum in Apodemus mice.

Identification of Diverse Bartonella Genotypes among Small Mammals from Democratic Republic of Congo and Tanzania

“…This prevalence was comparable to previous reports from other countries; ranging from 9% to 44% in Asia, 17% to 64% in Europe, 42% in North America, 44% in South Africa, and 29% in Australia. 5,8,9,11,[13][14][15]20,22,24,[38][39][40][41] Such high rates of Bartonella prevalence could be significant with respect to the risks of humans becoming infected with these agents. The commensal mammals harboring pathogenic microorganisms are often found in biotopes where they can come into close contact with humans who might therefore be at some risk of exposure.…”

“…20 Bartonella species associated with small mammals have been detected in Asia, Australia, North America, and Europe. 11,15,[20][21][22][23][24][25][26][27] Recent studies showed that bartonellae were widely distributed among rodents in South Africa 14 and among fleas in Democratic Republic of the Congo (DR Congo). 28 However, no study was conducted in small mammals of DR Congo or Tanzania.…”

Factors associated with the rapid emergence of zoonotic Bartonella infections

“…California ground squirrels (Spermophilus beecheyi) are the main reservoir of B. washoensis, which has been identified in a human case of myocarditis [139] and in a case of endocarditis in a dog [50]. Finally, isolation of B. henselae type Houston I from three long-tailed field mice (Apodemus sylvaticus) was very recently reported [75] and raises an interesting question about the possibility of natural infection of wild rodents with B. henselae. Further studies will be required to determine if rodents could be another natural reservoir of this bacterium beside its feline reservoir.…”

Detection of Bartonella spp. in field mice (Microtus socialis) by culture and PCR

“…In addition, because the Bartonella species are generally intra-erythrocytic agent, blood is used as a culture material (4,12,15,23). Liver tissue was used as blood supplement in this study due to the unavailability of mice blood samples.…”