Royal jelly (RJ), a brood food of honey bees, has strong antimicrobial activity. Melissococcus plutonius , the causative agent of European foulbrood of honey bees, exhibits resistance to this antimicrobial activity and infects larvae orally. Among three genetically distinct groups (CC3, CC12 and CC13) of M . plutonius , CC3 strains exhibit the strongest RJ resistance. In this study, to identify genes involved in RJ resistance, we generated an RJ‐susceptible derivative from a highly RJ‐resistant CC3 strain by UV mutagenesis. Genome sequence analysis of the derivative revealed the presence of a frameshift mutation in the putative regulator gene spxA1a . The deletion of spxA1a from a CC3 strain resulted in increased susceptibility to RJ and its antimicrobial component 10‐hydroxy‐2‐decenoic acid. Moreover, the mutant became susceptible to low‐pH and oxidative stress, which may be encountered in brood foods. Differentially expressed gene analysis using wild‐type and spxA1a mutants revealed that 45 protein‐coding genes were commonly upregulated in spxA1a ‐positive strains. Many upregulated genes were located in a prophage region, and some highly upregulated genes were annotated as universal/general stress proteins, oxidoreductase/reductase, chaperons and superoxide dismutase. These results suggest that SpxA1a is a key regulator to control the tolerance status of M . plutonius against stress in honey bee colonies.

中文翻译：

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转录调节剂SpxA1a控制蜜蜂病原体Melissococcus plutonius对蜂王浆的抗菌活性的抵抗力。

蜂王浆（RJ）是蜜蜂的繁殖食品，具有很强的抗菌活性。欧洲蜜蜂的产臭蜂的病原体Melissococcus plutonius对这种抗菌活性具有抗药性，并且可以口服感染幼虫。在M的三个遗传上不同的组中（CC3，CC12和CC13）。在plutonius中，CC3菌株表现出最强的RJ抗性。在这项研究中，为了鉴定涉及RJ抗性的基因，我们通过UV诱变从高度RJ抗性的CC3菌株中生成了RJ易感衍生物。衍生物的基因组序列分析显示，在假定的调节基因spxA1a中存在移码突变。spxA1a的缺失CC3菌株产生的RJ对RJ及其抗菌成分10-羟基-2-癸烯酸的敏感性增加。而且，突变体变得容易受到低pH值和氧化应激的影响，而这在育雏食品中可能会遇到。使用野生型和spxA1a突变体的差异表达基因分析表明，在spxA1a阳性菌株中，通常有45个蛋白质编码基因上调。许多上调的基因位于原噬菌体区域，一些高度上调的基因被注释为通用/一般应激蛋白，氧化还原酶/还原酶，伴侣蛋白和超氧化物歧化酶。这些结果表明，SpxA1a是控制M的耐受状态的关键调节剂。冥王星 抵抗蜜蜂群体的压力。