Snježana Ćurković

Molecular detection of Theileria annae and Hepatozoon canis in foxes (Vulpes vulpes) in Croatia.

An epizootiological field study on tick-borne protozoan infections in foxes (Vulpes vulpes) was carried out in different parts of Croatia. Spleen samples of 191 carcasses of red foxes killed in sanitary hunting, were examined for the presence of hematozoa by polymerase chain reaction (PCR) and subsequent sequencing. The investigation revealed four species of hematozoa in 57 foxes (30%), namely Theileria annae, Theileria sp. 3182/05 and Hepatozoon canis. T. annae was found in 10 foxes (5%), Theileria sp. 3182/05 in a single animal (1%), H. canis in 44 (23%) and Hepatozoon sp. was detected in two foxes (1%). T. annae and H. canis were distributed through all the studied regions, while Theileria sp. 3182/05 and Hepatozoon sp. were restricted to the Zagreb and Zagorje, and Istria regions, respectively. Detection of T. annae in all regions of Croatia indicates the presence of the natural cycle of the parasite and raises the possibility of other vectors other than the proposed Ixodes hexagonus.

Molecular epizootiology of canine hepatozoonosis in Croatia.

An epizootiological survey was conducted to investigate the prevalence of hepatozoonosis in a population of 924 apparently asymptomatic dogs from different regions of Croatia. DNA was isolated from canine blood and screening PCR on the 666 bp fragment of 18S rRNA revealed that 108 (11.8%) of dogs were infected. Positive samples were confirmed by partial sequencing of the 18S rRNA gene. The consensus sequences, derived from various sequence data sets, were compared with sequences of 18S ssrRNA of Hepatozoon spp. available in GenBank. The alignments revealed 106 Hepatozoon canis and two Hepatozoon sp. sequences. Among H. canis isolates, we found a certain amount of heterogeneity, while both Hepatozoon sp. isolates were identical to the Spanish isolate (Accession No. AY600625) from Clethrionomys glareolus. On the basis of eight commonly mutated nucleotide positions in the partial 18S rRNA gene sequence, we divided the H. canis isolates into five groups. The results obtained indicate a higher prevalence and significance of hepatozoonosis in Croatia than previously believed and demonstrate that the organisms belonging to H. canis that infect European dogs are genetically very heterogeneous.

Molecular Survey of Babesia microti in Wild Rodents in Central Croatia

Babesia divergens and B. divergens-like organisms are the main causative agents of human babesiosis in Europe. Recently, the first case of human infection with Babesia microti was confirmed in Germany, implicating the presence of zoonotic isolates. To estimate the presence of zoonotic B. microti in Croatia we analyzed 120 small wild mammals that serve as its reservoir by polymerase chain reaction. Yellow-necked mice (Apodemus flavicollis) and bank voles (Myodes glareolus) were both found to be infected with prevalence of 16.2%. Sequence analysis of the portion of 18S rDNA gene demonstrated that six polymerase chain reaction-positive samples, detected in both rodent species, were identical to that of the human Jena/Germany strain (EF413181). The other two isolates were identical to the nonzoonotic Munich strain (AB071177). The results of this study indicate the presence of zoonotic B. microti in A. flavicollis and M. glareolus in Croatia and a potential risk for human health.