Experimental feeding of Sergentomyia minuta on reptiles and mammals: comparison with Phlebotomus papatasi

Abstract

Background Sergentomyiaminuta (Diptera: Phlebotominae) is an abundant sand fly species in the Mediterranean basin and a proven vector of reptile parasite Leishmania (Sauroleishmania) tarentolae. Although it feeds preferentially on reptiles, blood meal analyses and detection of Leishmania (Leishmania) infantum DNA in wild-caught S.minuta suggest that occasional feeding may occur on mammals, including humans. Therefore, it is currently suspected as a potential vector of human pathogens. Methods A recently established S.minuta colony was allowed to feed on three reptile species (i.e. lizard Podarcissiculus and geckos Tarentolamauritanica and Hemidactylusturcicus) and three mammal species (i.e. mouse, rabbit and human). Sand fly mortality and fecundity were studied in blood-fed females, and the results were compared with Phlebotomuspapatasi, vector of Leishmania (L.) major. Blood meal volumes were measured by haemoglobinometry. Results Sergentomyiaminuta fed readily on three reptile species tested, neglected the mouse and the rabbit but took a blood meal on human. However, the percentage of females engorged on human volunteer was low in cage (3%) and feeding on human blood resulted in extended defecation times, higher post-feeding mortality and lower fecundity. The average volumes of blood ingested by females fed on human and gecko were 0.97 µl and 1.02 µl, respectively. Phlebotomuspapatasi females readily fed on mouse, rabbit and human volunteer; a lower percentage of females (23%) took blood meal on the T.mauritanica gecko; reptilian blood increased mortality post-feeding but did not affect P.papatasi fecundity. Conclusions Anthropophilic behaviour of S.minuta was experimentally demonstrated; although sand fly females prefer reptiles as hosts, they were attracted to the human volunteer and took a relatively high volume of blood. Their feeding times were longer than in sand fly species regularly feeding on mammals and their physiological parameters suggest that S.minuta is not adapted well for digestion of mammalian blood. Nevertheless, the ability to bite humans highlights the necessity of further studies on S.minuta vector competence to elucidate its potential role in circulation of Leishmania and phleboviruses pathogenic to humans. Graphical abstract

Phlebotomine sand fly (Diptera: Phlebotominae) diversity in the foci of cutaneous leishmaniasis in the Surxondaryo Region of Uzbekistan: 50 years on

“…In this study, our primary question focused on whether the increase in leishmaniasis cases in the Surxondaryo Region is linked to the population dynamics of Leishmania vectors. In comparison with 1966–1971 studies (Dzhabarov 1972 ; Zviagintseva 1968 ), we noted the following: (i) the implicated ZCL vector, P. papatasi , remained eudominant (with a sole exception of Boysun), where it was shown to be subdominant, but this locality has not been studied previously; (ii) the proportion of implicated ACL vector, P. sergenti (now, eudominant in all the sampled locations), rose significantly from averaged 5.4% (Dzhabarov 1972 ) to 41.4%; (iii) neither P. andrejevi nor P. caucasicus , P. mongolensis , or S. arpaklensis were detected in 2021–2022; (iv) the proportion of two Sergentomyia spp., S. grecovi and S. sogdiana , implicated in transmission of reptile parasites of the subgenus Leishmania ( Sauroleishmania ) (Maroli et al 1988 ; Ovezmukhammedov and Saf’janova 1989 ; Tichá et al 2023 ) became more prominent while S. arpaklensis has not been found even in Termiz, where it was previously eudominant; (v) Phlebotomus alexandri , a suspected VL vector, was eudominant at two sites and a second suspected vector for the VL-causing L. infantum , P. longiductus , was newly recorded in the region.…”

Evolution of RNA viruses in trypanosomatids: new insights from the analysis of Sauroleishmania

“…Interestingly, this intergeneric transfer of viruses became possible because of the ability of some sand flies (e.g., Sergentomyia spp.) to feed on both reptiles and mammals (Polanská et al 2020 ; Tichá et al 2023 ). The repeated events of viral transition between Blechomonas and Leishmania (one for narnaviruses and at least two for leishmania viruses) suggest that these might also involve Leishbuviridae (LBVs), which have been documented in the flea-infecting Blechomonas .…”

Sand fly blood meal volumes and their relation to female body weight

“…However, extensive prediuretic excretion enables some small-sized species increase considerably amount of ingested blood [16]. In sand ies, the results of previous studies [7,15] suggest that the blood meal volume does not interspeci cally correlate with body size, however, this relationship has not been closely studied so far. Similarly, the data of sand y body weight are scarce [10,22].…”

“…Sand y females were fed either on anesthetized BALB/c mice (P. argentipes, P. duboscqi, P. papatasi, L. longipalpis, S. schwetzi), or mechanically restrained New Zealand White (NWZ) rabbits (P. orientalis, P. perniciosus, P. tobbi, M. migonei) or leopard geckos (S. minuta). The blood-feeding was routinely carried out on the animal host for about 60 min in most colonies; S. minuta females need more time for full engorgement [15], thus they were allowed to feed on reptile for 2 h.…”