Abstract：
Symbiosis with intracellular bacteria is essential for the nutrition of ticks, particularly through the biosynthesis of B vitamins. Yet, ticks of the genus Ixodes, which include major vectors of human pathogens, lack the nutritional symbionts usually found in other tick genera. This paradox raises questions about the mechanisms that Ixodes ticks use to prevent nutritional deficiencies. Nonetheless, Ixodes ticks commonly harbor other symbionts belonging to the order Rickettsiales. Although these obligate intracellular bacteria are primarily known as human pathogens, Rickettsiales symbionts often dominate the Ixodes microbial community without causing diseases. They also significantly influence Ixodes physiology, synthesize key B vitamins, and are crucial for immatures. These findings underscore unique associations between Rickettsiales and Ixodes ticks distinct from other tick genera.
摘要：
与细胞内细菌的共生对于蜱的营养至关重要，特别是通过B族维生素的生物合成。然而，Ixodes属的蜱，其中包括人类病原体的主要媒介，缺乏通常在其他蜱属中发现的营养共生体。这种悖论引发了人们对Ixodes用来预防营养缺乏的机制的疑问。尽管如此，Ixodes通常带有属于Rickettsiales的其他共生体。尽管这些专性细胞内细菌主要被称为人类病原体，Rickettsiales共生体通常在Ixodes微生物群落中占主导地位，而不会引起疾病。它们也显著影响Ixodes生理学，合成关键B族维生素，对不成熟至关重要。这些发现强调了Rickettsiales和Ixodes蜱之间与其他蜱属不同的独特关联。
