Dipartimento di Scienze e Tecnologie Agro-Alimentari (DISTAL), University of Bologna, Bologna, Italy.
Centro de Investigación en Abejas Sociales (CIAS), Faculty of Exact and Natural Sciences (FCEyN), National University of Mar del Plata (UNMdP), Mar del Plata, Buenos Aires, Argentina.
Front Cell Infect Microbiol. 2024 May 13;14:1323157. doi: 10.3389/fcimb.2024.1323157. eCollection 2024.
The genus harbors opportunistic pathogenic species, among which is pathogenic for honeybees although little studied. Recently, virulent strains of colonizing the mite's mouth were found vectored into the honeybee body, leading to septicemia and death. also occurs as an opportunistic pathogen in the honeybee's gut with a low absolute abundance. The population seems controlled by the host immune system, but its presence may represent a hidden threat, ready to arise when honeybees are weakened by biotic and abiotic stressors. To shed light on the pathogen, this research aims at studying 's development dynamics in the honeybee body and its interactions with the co-occurring fungal pathogen . Firstly, the degree of pathogenicity and the ability to permeate the gut epithelial barrier of three strains, isolated from honeybees and belonging to different species (, , and ), were assessed by artificial inoculation of newborn honeybees with different doses (10, 10, and 10 cells/mL). The absolute abundance of in the gut and in the hemocoel was assessed in qPCR with primers targeting the gene. Moreover, the absolute abundance of was assessed in the gut of honeybees infected with at different development stages and supplied with beneficial microorganisms and fumagillin. Our results showed that all tested strains could pass through the gut epithelial barrier and proliferate in the hemocoel, with being the most pathogenic. Moreover, under cage conditions, better proliferates when a infection is co-occurring, with a positive and significant correlation. Finally, fumagillin and some of the tested beneficial microorganisms could control both and development. Our findings suggest a correlation between the two pathogens under laboratory conditions, a co-occurring infection that should be taken into consideration by researches when testing antimicrobial compounds active against , and the related honeybees survival rate. Moreover, our findings suggest a positive control of by the environmental microorganism in a in vivo model, confirming the potential of this specie as beneficial bacteria for honeybees.
该属包含机会致病性物种，其中 对蜜蜂具有致病性，但研究较少。最近，在 螨的口中发现了具有感染力的 菌株，这些菌株被载体进入蜜蜂体内，导致败血症和死亡。 也作为一种机会性病原体存在于蜜蜂的肠道中，其绝对丰度较低。 种群似乎受到宿主免疫系统的控制，但它的存在可能代表着一种隐藏的威胁，当蜜蜂因生物和非生物胁迫而减弱时，它随时可能出现。为了阐明 病原体，本研究旨在研究 在蜜蜂体内的发育动态及其与共发生真菌病原体 的相互作用。首先，通过用不同剂量（10、10 和 10 个细胞/mL）的 人工接种新生蜜蜂，评估了从蜜蜂中分离出的三种属于不同物种的 菌株（ 、 和 ）的致病性和穿透肠上皮屏障的能力。用针对 基因的引物通过 qPCR 评估了 在肠道和血腔中的绝对丰度。此外，还评估了在不同发育阶段感染 并提供有益微生物和腐霉素的蜜蜂肠道中 的绝对丰度。我们的结果表明，所有测试的 菌株都可以穿透肠上皮屏障并在血腔中增殖，其中 是最具致病性的。此外，在笼养条件下，当 感染同时发生时， 更好地增殖，两者之间存在正相关。最后，腐霉素和一些测试的有益微生物可以控制 和 的发育。我们的研究结果表明，在实验室条件下，这两种病原体之间存在相关性，在测试对 有效的抗菌化合物时，应考虑到这种共同感染及其相关的蜜蜂存活率。此外，我们的研究结果表明，在体内模型中，环境微生物 对 有正向控制作用，证实了该物种对蜜蜂有益细菌的潜力。
