Department of Genetic Research, Institute for Biological Research "Sinisa Stankovic", National Institute of the Republic of Serbia, University of Belgrade, Belgrade, Serbia.
Department of Molecular Parasitology, Humboldt University, Berlin, Germany.
Parasit Vectors. 2023 May 26;16(1):170. doi: 10.1186/s13071-023-05786-1.
Haemosporidian parasites of the genus Polychromophilus infect bats worldwide. They are vectored by obligate ectoparasitic bat flies of the family Nycteribiidae. Despite their global distribution, only five Polychromophilus morphospecies have been described to date. The two predominant species, Polychromophilus melanipherus and Polychromophilus murinus, are broadly distributed and mainly infect miniopterid and vespertilionid bats, respectively. In areas where species from different bat families aggregate together, the infection dynamics and ability of either Polychromophilus species to infect other host families is poorly characterized.
We collected 215 bat flies from two bat species, Miniopterus schreibersii and Rhinolophus ferrumequinum, which sometimes form mixed clusters in Serbia. Miniopterus schreibersii is known to be frequently infected with P. melanipherus, whereas R. ferrumequinum has been observed to be incidentally infected with both Polychromophilus species. All flies were screened for Polychromophilus infections using a PCR targeting the haemosporidian cytb gene. Positive samples were subsequently sequenced for 579 bp of cytochrome b (cytb) and 945 bp of cytochrome oxidase subunit 1 (cox1).
Polychromophilus melanipherus DNA was detected at six out of nine sampling locations and in all three examined bat fly species collected from M. schreibersii (Nycteribia schmidlii, n = 21; Penicillidia conspicua, n = 8; Penicillidia dufourii, n = 3). Four and five haplotypes were found for cytb and cox1, respectively. Evidence for multiple Polychromophilus haplotypes was found in 15 individual flies. These results point to a high diversity of P. melanipherus parasites in Miniopterus hosts and efficient transmission throughout the study area. A single Phthiridium biarticulatum bat fly collected from R. ferrumequinum screened positive for P. melanipherus, but only yielded a partial cox1 sequence fragment. Nevertheless, this result suggests that secondary hosts (both bat and fly species) are regularly confronted with this parasite.
The results of this study provide new insights into the prevalence and distribution of Polychromophilus parasites in European bats and their nycteribiid vectors. The use of bat flies for the non-invasive investigation of Polychromophilus infections in bat populations has proven to be efficient and thus represents an alternative for large-scale studies of infections in bat populations without the need to invasively collect blood from bats.
血孢子虫属的 Haemosporidian 寄生虫感染全世界的蝙蝠。它们由蝙蝠蝇科的专性外寄生虫蝙蝠蝇传播。尽管它们分布广泛，但迄今为止只描述了五种 Polychromophilus 形态种。两种主要的物种，Polychromophilus melanipherus 和 Polychromophilus murinus，分布广泛，主要分别感染迷你蝙蝠和蝙蝠。在不同蝙蝠科的物种聚集在一起的地区，任何 Polychromophilus 物种的感染动态及其感染其他宿主科的能力都没有得到很好的描述。
我们从两种蝙蝠物种，Miniopterus schreibersii 和 Rhinolophus ferrumequinum 中收集了 215 只蝙蝠蝇，它们有时在塞尔维亚形成混合群。Miniopterus schreibersii 已知经常感染 P. melanipherus，而 R. ferrumequinum 则观察到偶然感染两种 Polychromophilus 物种。所有苍蝇都使用针对血孢子虫 cytb 基因的 PCR 进行了 Polychromophilus 感染筛查。阳性样本随后对 579bp 的细胞色素 b (cytb) 和 945bp 的细胞色素氧化酶亚基 1 (cox1) 进行测序。
在九个采样地点中的六个和从 M. schreibersii 收集的三种蝙蝠蝇（Nycteribia schmidlii，n=21；Penicillidia conspicua，n=8；Penicillidia dufourii，n=3）中均检测到 Polychromophilus melanipherus DNA。分别发现了 cytb 和 cox1 的四个和五个单倍型。在 15 只单独的苍蝇中发现了多个 Polychromophilus 单倍型的证据。这些结果表明，在 Miniopterus 宿主中，P. melanipherus 寄生虫的多样性很高，并且在整个研究区域内的传播效率很高。从 R. ferrumequinum 采集的一只 Phthiridium biarticulatum 蝙蝠蝇检测出 P. melanipherus 阳性，但仅产生了 cox1 序列片段。然而，这一结果表明，次级宿主（蝙蝠和苍蝇物种）经常面临这种寄生虫。
本研究结果为欧洲蝙蝠及其蝙蝠蝇传播者中 Polychromophilus 寄生虫的流行程度和分布提供了新的见解。使用蝙蝠蝇对蝙蝠种群中 Polychromophilus 感染进行非侵入性研究已被证明是有效的，因此代表了无需从蝙蝠身上采集血液即可对蝙蝠种群感染进行大规模研究的替代方法。
