Babesia infections

Springer, Andrea, Fichtel, Claudia, Sebastien ́ Calvignac-Spencer, Leendertz, Fabian H. & Kappeler, Peter M., 2015, Hemoparasites in a wild primate: Infection patterns suggest interaction of Plasmodium and Babesia in a lemur species, International Journal for Parasitology: Parasites and Wildlife 4 (3), pp. 385-395 : 390

3.3. Filarial nematode infections

Two different filarial nematode species could be differentiated morphologically as well as genetically. Two to 3 blood smears per sample were scanned for microfilaria and on average 4.2 microfilaria were measured per sample. Microfilaria of species 1 were 268 ± 10.1 Mm long with the nerve ring located at 53 ± 4.5 Mm from the anterior end. Microfilaria of species 2 were considerably shorter, 222 ± 18.6 Mm, with the nerve ring located at 43 ± 5.4 Mm.

Sequencing of PCR products confirmed the presence of 2 different species. Species 1 produced a shorter band of about 850 bp and species 2 produced a longer band of about 900 bp. The bands could be separated out using 2% agarose gels, and individually sequenced. The sequences (EMBL accession no. LN869520 and LN869521) showed 99 ‾ 100% sequence identity to different filarial nematodes such as Mansonella sp. , Diro fi laria sp. and Onchocerca sp. in the conserved 18S and 5.8S regions, but only 84 ‾ 90% similarity to other filarial nematodes in the variable ITS1 region.

In 33 of 45 samples, the PCR results exactly confirmed the morphological diagnosis (negative sample, presence of one or both species). In 7 cases, a species was morphologically identified but not detected by PCR, while in 5 cases an infection was revealed by PCR only. Thus, neither method seems to be 100% sensitive. For statistical analyses, we considered an infection present if it was detected by one of the methods.

Prevalence of species 1 was 50%, while species 2 was found in 33.3% of animals. Nine animals (25%) were co-infected with both species. No filarial nematode infections were detected in animals under the age of one year. Probability of infection with species 1 significantly increased with age ( Table 5). We did not find any significant influences on infection with the second species ( Table 5).