First experimental assessment of Phlebotomus mascittii vector competence for Leishmania infantum and Leishmania martiniquensis.

Abstract

<h4>Background</h4>Phlebotomus mascittii is one of the most widespread but least studied sand fly species in Europe, occurring from Mediterranean to Central European regions. Despite its broad distribution, its potential role in Leishmania transmission remains unknown, mainly due to the lack of laboratory colonies. This study provides the first experimental assessment of the vector competence of P. mascittii for Leishmania infantum and Leishmania martiniquensis.<h4>Methods</h4>Wild-caught P. mascittii females from Styria, Austria, were experimentally infected using membrane feeding with blood containing L. infantum and L. martiniquensis isolates of different geographical origins. Infections were evaluated 7 days post-blood meal (PBM) by microscopy and polymerase chain reaction (PCR). Morphological forms of L. infantum were quantified and compared with infections in Phlebotomus perniciosus, a known competent vector.<h4>Results</h4>Fifteen (94% of dissected) P. mascittii females developed L. infantum infections, all showing colonization of the stomodeal valve, whereas L. martiniquensis failed to establish infection. Infection patterns and parasite localization closely resembled those in P. perniciosus. Morphometric analysis revealed a significantly higher proportion of metacyclic and leptomonad forms and fewer nectomonads in P. mascittii than in P. perniciosus.<h4>Conclusions</h4>Our findings demonstrate that P. mascittii supports full development of L. infantum to the transmissible metacyclic stage and colonization of the stomodeal valve, confirming its potential vector competence. This study provides the first experimental evidence on P. mascittii vectorial competence and highlights its epidemiological relevance in Europe.