Arvicanthis neumanni

Sadlova, Jovana, Vojtkova, Barbora, Hrncirova, Katerina, Lestinova, Tereza, Spitzova, Tatiana, Becvar, Tomas, Votypka, Jan, Bates, Paul & Volf, Petr, 2019, Host competence of African rodents Arvicanthis neumanni, A. niloticus and Mastomys natalensis for Leishmania major, International Journal for Parasitology: Parasites and Wildlife 8, pp. 118-126 : 120

3.1. Experimental infections and xenodiagnosis with A. neumanni

In total, 33 females of A. neumanni were infected by three different L. major strains, most of them (30) using sand fly-derived Leishmania . The strain Friedlin originating from the Middle East showed only very weak infectivity for A. neumanni ( Table 1). None of 12 female A. neumanni inoculated with sand fly-derived Leishmania developed lesions. Q-PCR revealed presence of Leishmania in 1 specimen only, with parasites localized in the inoculated ear pinnae in very low numbers (less than 100). All 532 P. duboscqi females exposed to biting sand flies at different times p.i. for xenodiagnoses, were negative ( Table 2).

The Sub-Saharan strain LV110 originating from Senegal infected all six female A. neumanni inoculated with sand fly-derived Leishmania ( Table 1), but animals did not show any external signs of the disease throughout the entire experiment. Q-PCR revealed the presence of parasites in left ear pinnae (site of inoculation) in all the six animals, however, the numbers of parasites were very low and all 442 females P. duboscqi used for xenodiagnoses were negative ( Table 2).

The second Sub-Saharan strain LV109 originating from Senegal was inoculated into 15 A. neumanni ( Table 1); 12 with sand fly-derived Leishmania (experimental groups A and B) and 3 with culture-derived promastigotes (experimental group C). Wet skin lesions did not develop, but hyper-pigmentations of left ear pinnae (sites of inoculation) were observed in 3 animals, two from group A and one from group C ( Fig. 1B ). PCR showed presence of parasites in 7 from 15 animals. They were localized mostly in the left ear (site of inoculation) and once in the blood. Interestingly, the numbers of detected Leishmania were higher (hundreds to thousands) in 3 animals, two of which also showed hyper-pigmentation of the ear. All three animals with hyperpigmentation were infective to sand flies, two by week 5 and the third by week 10 p. i. In total, 0.4% of 748 P. duboscqi females tested were positive ( Table 2).

Figures

Fig. 1. Xenodiagnosis and external manifestation of L. major in rodents. Direct xenodiagnosis with P. duboscqi in plastic tubes covered with fine mesh held on the ear of the anaesthetized A. niloticus (A) and external manifestation of L. major LV109 in ear pinnae (site of inoculation) of A. neumanni by week 10 p.i., (B); A. niloticus by week 30 p.i. (C, D) and M. natalensis by week 19 p.i. (E).