Joseph Ross, Darrisaw Constance, Lloyd Aaron, Hoel David, Keyhani Nemat O
Department of Biological Sciences, University of Illinois, Chicago, IL 60607, USA.
Lee County Mosquito Control District, Lehigh Acres, FL 33971, USA.
J Fungi (Basel). 2024 Mar 5;10(3):199. doi: 10.3390/jof10030199.
Only a handful of microbial mosquito larval pathogens have been described to date. Sampling several natural enzootic infections of mosquito larvae in southwestern Florida indicated the presence of microbial pathogens capable of extensive larval mortality. A microscopic analysis of one sample site revealed extensive apparent growth of a -like microbe on mosquito larvae, with the highest degree of infection observed in the siphon and head regions. Structures consistent with sporangia were seen on infected insects after lactophenol blue staining, and higher-resolution scanning electron microscopy (SEM) micrographs showed sporangia and encysted zoospores targeting the head and siphon regions. The isolate was single-colony purified, and molecular identification targeting the ITS and COX1 loci coupled to phylogenetic reconstruction indicated that the isolate belonged to the genus but was distinct from its closest characterized species, . Morphological features were characterized, with the isolate showing rapid growth on all mycological media tested and relatively high thermotolerance, capable of robust growth at 37 °C; hence, it was designated . Sampling from a second series of natural infections of mosquito larvae resulted in the molecular identification of three isolates, one with high similarity to and the other two clustering closely with . These data highlight the occurrence of natural enzootic infections of mosquito larvae, potentially as a resource for the identification of new mosquito pathogens.
迄今为止，仅描述了少数几种微生物蚊子幼虫病原体。对佛罗里达州西南部蚊子幼虫的几种自然动物源性感染进行采样，结果表明存在能够导致大量幼虫死亡的微生物病原体。对一个采样点进行显微镜分析发现，一种类似α的微生物在蚊子幼虫上大量明显生长，在虹吸管和头部区域观察到的感染程度最高。经乳酚蓝染色后，在受感染昆虫上可见与孢子囊一致的结构，高分辨率扫描电子显微镜（SEM）显微照片显示，孢子囊和包囊游动孢子以头部和虹吸管区域为目标。该分离株经单菌落纯化，针对ITS和COX1基因座的分子鉴定以及系统发育重建表明，该分离株属于该属，但与其最接近的已鉴定物种不同。对形态特征进行了表征，该分离株在所有测试的真菌培养基上均生长迅速，且耐热性相对较高，能够在37°C下茁壮生长；因此，它被命名为。从第二批蚊子幼虫自然感染中采样，结果在分子水平上鉴定出三种分离株，一种与[具体物种1]高度相似，另外两种与[具体物种2]紧密聚类。这些数据突出了蚊子幼虫自然动物源性感染的发生情况，这可能是鉴定新的蚊子病原体的一个资源。
