Canine experimental infection: intradermal inoculation of Leishmania infantum promastigotes

Abstract

Five mixed breed dogs were inoculated intradermally (ID)

Clinical, Parasitologic, and Immunologic Evolution in Dogs Experimentally Infected with Sand Fly-Derived Leishmania chagasi Promastigotes

“…6,[14][15][16][17] Previous studies showed that experimental IV infection was more likely to lead to overt disease than intradermal inoculation, which typically led to subclinical infection. 11,12,28 Our finding of small liver granulomas, an indication of an active cell mediated immune response, in the intradermally infected dogs is consistent with what was observed in resistant dogs naturally infected in endemic areas. [29][30][31] However, the previous work by Killick-Kendrick and others 10 showed development of severe disease (timing or nature not specified) in 48% of dogs infected intradermally with approximately 10 5 L. infantum promastigotes isolated from the mid guts of infected sand flies.…”

“…[3][4][5] Experimental infections of dogs have been carried out using a wide range of strategies that included the use of cultured promastigotes [6][7][8] or tissue-derived amastigotes. 6,7,9 Studies have used numbers of parasites that ranged from a few thousand to several million, delivered by the intradermal [10][11][12][13] or intravenous routes. 6,[14][15][16][17] Some of these inoculations included an extract of Lutzomyia longipalpis salivary glands in an unsuccessful attempt to increase parasite pathogenicity.…”

Canine neutrophils cooperate with macrophages in the early stages of Leishmania infantum in vitro infection

“…Studies addressing the interaction between canine MØ and PMN are limited. In a previous study, our group showed that 3‐4 hours after dermal experimental inoculation promastigotes had already been internalized by PMN, proving the early involvement of these cells in dog infection . Recently, in an in vitro study, we proved that some parasites internalized by PMN maintained the viability and the replication ability, and thus the capacity to infect MØ.…”

“…Polymorphonuclear neutrophils (PMN) are the first cells to be recruited to the inoculation site, phagocytizing the parasite . Circulating monocytes infiltrate the canine dermis just a few hours after L infantum intradermal inoculation, where acquire the macrophage (MØ) functional phenotype.…”

“…Polymorphonuclear neutrophils (PMN) are the first cells to be recruited to the inoculation site, phagocytizing the parasite . Circulating monocytes infiltrate the canine dermis just a few hours after L infantum intradermal inoculation, where acquire the macrophage (MØ) functional phenotype. These cells are recognized as Leishmania host cells and internalize the parasite through a classical receptor‐mediated process, involving Leishmania and MØ surface receptors .…”