Antibody prevalence and molecular identification of Babesia spp. In roe deer in France

In a region-wide serologic study carried out in 2004 on free-ranging hunted roe deer in various landscapes, we found that 58% of the animals (237 out of 406) were antibody positive for Babesia divergens antigen. Serologic and infection status was also analyzed for 327 roe deer live-trapped in two fenced forest areas over 5 yr (2004-08). For two consecutive years during this period, 92 and 94% of the deer in these closed populations were antibody-positive for B. divergens. Babesia spp. were isolated in autologous red blood cell culture for 131 of the trapped animals (40%). Molecular typing was done on 76 isolates with polymerase chain reaction (PCR)-restriction fragment length polymorphism methods targeted at the 18S ribosomal subunit gene (18 isolates) and the Bd37 gene coding for a merozoïte surface antigen implicated in a protective response (60 isolates). Results indicated continuous cocirculation of B. capreoli and B. venatorum in both forests and possible coinfection of animals with both species. No infection with B. divergens was detected. Fifteen isolates were confirmed to be B. capreoli by sequencing part of the 18S rRNA gene. Using PCR detection of the Bd37 gene, all nine isolates of B. venatorum in this study were negative, whereas the 15 confirmed and 50 putative B. capreoli isolates showed very variable restriction profiles, distinct from those known for Bd37 in B. divergens. Two isolates showed conflicting results, suggestive of mixed infection.