Correlation of acetate catabolism and growth yield in Staphylococcus aureus:: Implications for host-pathogen interactions
Correlation of acetate catabolism and growth yield in Staphylococcus aureus:: Implications for host-pathogen interactions
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DOI：
10.1128/iai.71.8.4724-4732.2003
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发表时间：
2003-08-01
影响因子：
3.1
通讯作者：
Musser, JM
中科院分区：
文献类型：
--
作者：
Somerville, GA;Sayd-Salim, B;Musser, JM
最近，我们报道了典型的金黄色葡萄球菌菌株RN 6390（NCTC 8325的衍生物）相对于不同的S.金黄色葡萄球菌分离株，导致菌株RN 6390具有受损的三羧酸（TCA）循环介导的乙酸催化酶的假设。RN 6390培养上清液的分析证实，乙酸被不完全分解代谢，这表明S.金黄色。为了验证这一假设，我们研究了S。金黄色葡萄球菌菌株，其基因组序列是公开可获得的。所有菌株都分解代谢葡萄糖并将乙酸盐排泄到培养基中。然而，菌株NCTC 8325和N315未能分解代谢乙酸在postexponential生长阶段，导致显着较低的生长产量相对于分解代谢乙酸的菌株。菌株NCTC 8325和RN 6390在rsbU中含有11-bp缺失，rsbU是编码由sigB编码的替代sigma因子sigma（B）的正调节子的基因。含有野生型rsbU基因的RN 6390的同基因衍生菌株具有显著增加的乙酸催化剂，表明sigma（B）是乙酸催化剂所需的。总之，这些数据表明，自然发生的突变可以改变S。这是一个令人惊讶的发现，因为TCA循环功能已被证明涉及几种病原生物的毒力、存活和持久性。此外，这些突变降低了S.金黄色葡萄球菌通过减少置于后续世代中的后代的数量来抑制生长，这表明在某些情况下，降低的生长产率是有利的。
Recently, we reported that the prototypical Staphylococcus aureus strain RN6390 (a derivative of NCTC 8325) had significantly reduced aconitase activity relative to a diverse group of S. aureus isolates, leading to the hypothesis that strain RN6390 has impaired tricarboxylic acid (TCA) cycle-mediated acetate catabolism. Analysis of the culture supernatant from RN6390 confirmed that acetate was incompletely catabolized, suggesting that the ability to catabolize acetate can be lost by S. aureus. To test this hypothesis, we examined the carbon catabolism of the S. aureus strains whose genome sequences are publicly available. All strains catabollized glucose and excreted acetate into the culture medium. However, strains NCTC 8325 and N315 failed to catabolize acetate during the postexponential growth phase, resulting in significantly lower growth yields relative to strains that catabolized acetate. Strains NCTC 8325 and RN6390 contained an 11-bp deletion in rsbU, the gene encoding a positive regulator of the alternative sigma factor sigma(B) encoded by sigB. An isogenic derivative strain of RN6390 containing the wild-type rsbU gene had significantly increased acetate catabolism, demonstrating that sigma(B) is required for acetate catabolism. Taken together, the data suggest that naturally occurring mutations can alter the ability of S. aureus to catabolize acetate, a surprising discovery, as TCA cycle function has been demonstrated to be involved in the virulence, survival, and persistence of several pathogenic organisms. Additionally, these mutations decrease the fitness of S. aureus by reducing the number of progeny placed into subsequent generations, suggesting that in certain situations a decreased growth yield is advantageous.