Espinal-Palomino Román, Montes de Oca-Aguilar Ana Celia, Ibarra-López Martha Pilar, Vidal-Martínez Víctor M, Ibarra-Cerdeña Carlos N
Departamento de Ecología Humana, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav), Unidad Mérida. Carretera Antigua a Progreso Km. 6, 97310, Mérida, Yucatán, México.
Laboratorio de Inmunología, Centro de Investigaciones Regionales "Dr. Hideyo Noguchi", Universidad Autónoma de Yucatán, Mérida, Yucatán, México.
Int J Parasitol. 2025 Feb;55(2):79-94. doi: 10.1016/j.ijpara.2024.11.001. Epub 2024 Nov 8.
Litomosoides includes filarial nematodes capable of infecting various vertebrate species. While Litomosoides has been extensively studied in rodents, research on its association with bats remains limited. The transmission dynamics of this parasite are complex, involving moving between different invertebrate hosts before reaching the final host. Most investigations concerning microfilariae have concentrated on their morphological characteristics, with scant attention paid to ecological aspects, particularly in human-altered landscapes. This study represents the first known documentation of Litomosoides in bats within an urban environment. It investigates their response to urbanization in their interaction with the synanthropic bat Artibeus jamaicensis and its ectoparasites. The objective was to explore the influence of urban landscapes on Litomosoides prevalence in synanthropic hosts. Blood samples were collected along urban-rural gradients, and parasite presence was confirmed through direct observation in blood smears and PCR. Phylogenetic analysis based on the mitochondrial cytochrome c oxidase subunit 1 gene (COX1), which exhibited robust support values, indicates that the microfilaria found in A. jamaicensis is closely related to Litomosoides chandleri. However, it also suggests the possibility of an unidentified, and therefore potentially new, species within the genus Litomosoides. Additionally, Litomosoides DNA was detected in Periglischrus iheringi (Acari: Spinturnicidae) and in the bat fly Trichobius intermedius collected from the bat. The parasite sequences obtained from these three interacting species exhibited a genetic distance as low as 0.002. The highest prevalences were recorded in forested areas (28.6%) compared with urban areas (21.2%). However, within the urban landscape, prevalence varied from 3.8% to 21.2%, being highest in densely built-up areas. Analysis of the urban landscape suggested that the prevalence of Litomosoides in A. jamaicensis is the result of a multifactorial and synergistic process involving ectoparasite load, host abundance, and the extent of impervious surfaces (NDBI).
丝状线虫属包括能够感染各种脊椎动物物种的丝虫线虫。虽然丝状线虫属在啮齿动物中已得到广泛研究，但关于它与蝙蝠关联的研究仍然有限。这种寄生虫的传播动态很复杂，在到达终末宿主之前要在不同的无脊椎动物宿主之间转移。大多数关于微丝蚴的研究都集中在它们的形态特征上，而对生态方面关注甚少，尤其是在人类改变的景观中。本研究是城市环境中蝙蝠体内丝状线虫属的首次已知记录。它调查了在与共栖蝙蝠 Jamaican fruit-eating bat（Artibeus jamaicensis）及其体外寄生虫的相互作用中，它们对城市化的反应。目的是探讨城市景观对共栖宿主中丝状线虫属流行率的影响。沿城乡梯度采集血样，并通过血涂片直接观察和聚合酶链反应（PCR）确认寄生虫的存在。基于线粒体细胞色素 c 氧化酶亚基 1 基因（COX1）的系统发育分析显示出很强的支持值，表明在 Jamaican fruit-eating bat 中发现的微丝蚴与 Chandler's filarial worm（Litomosoides chandleri）密切相关。然而，这也表明丝状线虫属内可能存在一个未鉴定的、因此可能是新的物种。此外，在从蝙蝠采集的 Ihering's bat mite（Periglischrus iheringi，蜱螨亚纲：蝠螨科）和蝙蝠蝇 Intermediate bat fly（Trichobius intermedius）中检测到了丝状线虫属的 DNA。从这三个相互作用的物种获得的寄生虫序列显示出低至 0.002 的遗传距离。与城市地区（21.2%）相比，森林地区的流行率最高（28.6%）。然而，在城市景观中，流行率从 3.8%到 21.2%不等，在密集建成区最高。对城市景观的分析表明，Jamaican fruit-eating bat 中丝状线虫属的流行率是一个多因素协同过程的结果，该过程涉及体外寄生虫负荷、宿主丰度和不透水表面（归一化差异建筑指数，NDBI）的程度。
