Bezerra-Santos Marcos Antonio, Ricci Alessia, Carbonara Mariaelisa, Mendoza-Roldan Jairo Alfonso, Gusatoaia Oana, Palazzo Natalizia, Volf Petr, Otranto Domenico
Department of Veterinary Medicine, University of Bari, Valenzano, Bari, Italy.
Department of Parasitology, Faculty of Science, Charles University, Czech Republic.
Acta Trop. 2025 Aug;268:107704. doi: 10.1016/j.actatropica.2025.107704. Epub 2025 Jun 22.
Sand flies are blood feeding insects known as vectors of Leishmania spp. worldwide, with Leishmania infantum being the most relevant species in Southern Europe. The sympatric occurrence of L. infantum, which causes canine leishmaniasis (CanL), along with the reptile-associated Leishmania tarentolae, triggered the interest to investigate their transmission dynamics in sand fly vectors. Sand flies were collected over two consecutive years (2023-2024) in a CanL endemic area using CDC light traps and were morphologically identified. Female specimens were either screened for Leishmania spp. DNA by quantitative PCR (qPCR) or dissected alive for microscopic detection of flagellates. A total of 3477 sand flies (2076 males and 1401 females) were collected, and the most prevalent species were Sergentomyia minuta (n = 2379) and Phlebotomus perniciosus (n = 1020), followed by Phlebotomus neglectus (n = 44), Phlebotomus perfiliewi (n = 12), andPhlebotomus papatasi (n = 2). Promastigotes were observed microscopically in 13 S. minuta and one P. perniciosus, with L. infantum isolated from the latter. The qPCR analysis revealed that 50.0 % (n = 55/110) and 1.8 % (n = 2/110) of the S. minuta pools scored positive for L. tarentolae and L. infantum, respectively, whereas 25.0 % (n = 3/12) of P. perniciosus pools were positive for L. infantum. Among the individually tested engorged female sand flies, L. tarentolae and L. infantum were amplified from 35.8 % (n = 24/67) and 3.0 % (n = 2/67) of S. minuta, respectively, while 15.5 % (n = 9/58) of the Phlebotomus spp. (i.e., eight P. perniciosus and one Phlebotomus sp.) were positive for L. infantum. These findings confirm the co-circulation of L. infantum and L. tarentolae in sand flies, with a notably high detection rate of trypanosomatids in S. minuta through molecular and microscopic methods.
白蛉是吸血昆虫，在全球范围内被认为是利什曼原虫属的传播媒介，婴儿利什曼原虫是南欧最主要的相关物种。引起犬利什曼病（CanL）的婴儿利什曼原虫与爬行动物相关的塔兰托利什曼原虫在同一地区共存，引发了人们对研究它们在白蛉传播媒介中传播动态的兴趣。在一个CanL流行地区，于连续两年（2023 - 2024年）使用疾控中心（CDC）诱虫灯诱捕白蛉，并进行形态学鉴定。对雌性标本要么通过定量聚合酶链反应（qPCR）筛查利什曼原虫属DNA，要么进行活体解剖以显微镜检测鞭毛虫。总共收集了3477只白蛉（2076只雄性和1401只雌性），最常见的物种是微小赛氏白蛉（n = 2379）和有害白蛉（n = 1020），其次是疏忽白蛉（n = 44）、佩氏白蛉（n = 12）和巴氏白蛉（n = 2）。在13只微小赛氏白蛉和1只有害白蛉中通过显微镜观察到前鞭毛体，从后者中分离出婴儿利什曼原虫。qPCR分析显示，微小赛氏白蛉样本中分别有50.0%（n = 55/110）和1.8%（n = 2/110）对塔兰托利什曼原虫和婴儿利什曼原虫呈阳性，而有害白蛉样本中有25.0%（n = 3/12）对婴儿利什曼原虫呈阳性。在单独检测的饱血雌性白蛉中，微小赛氏白蛉分别有35.8%（n = 24/67）和3.0%（n = 2/67）扩增出塔兰托利什曼原虫和婴儿利什曼原虫，而白蛉属（即8只有害白蛉和1只未鉴定白蛉）中有15.5%（n = 9/58）对婴儿利什曼原虫呈阳性。这些发现证实了婴儿利什曼原虫和塔兰托利什曼原虫在白蛉中共循环，通过分子和显微镜方法在微小赛氏白蛉中锥虫的检出率显著较高。
