Coxiella burnetii utilizes both glutamate and glucose during infection with glucose uptake mediated by multiple transporters
Coxiella burnetii utilizes both glutamate and glucose during infection with glucose uptake mediated by multiple transporters
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DOI：
10.1042/bcj20190504
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发表时间：
2019-10-15
影响因子：
4.1
通讯作者：
Newton, Hayley J.
中科院分区：
文献类型：
--
作者：
Kuba, Miku;Neha, Nitika;Newton, Hayley J.
贝氏柯克斯体是一种革兰氏阴性细菌，可引起Q热，这是一种具有急性和慢性表现的复杂且危及生命的感染。C.贝氏菌侵入多种宿主细胞类型，并在来源于宿主细胞溶酶体的独特液泡内复制。为了了解C.贝氏菌在该细胞内生态位内存活，我们已经研究了细胞内和无菌培养细菌的碳代谢。这两种细菌种群被证明同化外源性[C-13]葡萄糖或[C-13]谷氨酸，伴随着糖酵解和异生中间体的标记，并在TCA循环。值得注意的是，这两个人口显示代谢途径的配置文件，反映其繁殖环境中的营养物质的可用性。C.通过转座子诱变，贝氏葡萄糖转运蛋白CBU 0265导致[C-13]葡萄糖利用率显著降低，但没有消除葡萄糖利用，表明C. Burnetii表达额外的己糖转运蛋白，其可能能够补偿CBU 0265的损失。这得到了人细胞的细胞内感染的支持，并且昆虫模型中的体内研究显示CBU 0265的缺失对细胞内复制或毒力没有影响。使用这种诱变和[C-13]葡萄糖标记方法，我们鉴定了第二种葡萄糖转运蛋白CBU 0347，其破坏也显示C-13标记掺入显著降低，但不影响细胞内复制或毒力。这些分析表明，C.贝氏菌可以在体内使用多种碳源，并且表现出比预期更大的代谢灵活性。
Coxiella burnetii is a Gram-negative bacterium which causes Q fever, a complex and life-threatening infection with both acute and chronic presentations. C. burnetii invades a variety of host cell types and replicates within a unique vacuole derived from the host cell lysosome. In order to understand how C. burnetii survives within this intracellular niche, we have investigated the carbon metabolism of both intracellular and axenically cultivated bacteria. Both bacterial populations were shown to assimilate exogenous [C-13]glucose or [C-13]glutamate, with concomitant labeling of intermediates in glycolysis and gluconeogenesis, and in the TCA cycle. Significantly, the two populations displayed metabolic pathway profiles reflective of the nutrient availabilities within their propagated environments. Disruption of the C. burnetii glucose transporter, CBU0265, by transposon mutagenesis led to a significant decrease in [C-13]glucose utilization but did not abolish glucose usage, suggesting that C. burnetii express additional hexose transporters which may be able to compensate for the loss of CBU0265. This was supported by intracellular infection of human cells and in vivo studies in the insect model showing loss of CBU0265 had no impact on intracellular replication or virulence. Using this mutagenesis and [C-13]glucose labeling approach, we identified a second glucose transporter, CBU0347, the disruption of which also showed significant decreases in C-13-label incorporation but did not impact intracellular replication or virulence. Together, these analyses indicate that C. burnetii may use multiple carbon sources in vivo and exhibits greater metabolic flexibility than expected.