Impact of Bicarbonate on PBP2a Production, Maturation, and Functionality in Methicillin-Resistant Staphylococcus aureus
Impact of Bicarbonate on PBP2a Production, Maturation, and Functionality in Methicillin-Resistant Staphylococcus aureus
复制标题
DOI：
10.1128/aac.02621-20
复制
发表时间：
2021-05-01
影响因子：
4.9
通讯作者：
Bayer, Arnold S.
中科院分区：
文献类型：
--
作者：
Ersoy, Selvi C.;Chambers, Henry F.;Bayer, Arnold S.
某些耐甲氧西林金黄色葡萄球菌（MRSA）菌株在体外、离体和体内存在NaHCO 3时表现出β-内酰胺敏感性（NaHCO 3-响应性MRSA）。在这里，我们研究了NaHCO 3对PBP 2a功能所需因素的影响。原型NaHCO 3响应性和非响应性MRSA菌株（如体外定义）评估NaHCO 3对PBP 2a生产成熟途径（mecA、blaZ、pbp 4、vraSR、prsA、sigB和floA）中涉及的基因表达、膜PBP 2a和PrsA蛋白含量以及膜类胡萝卜素含量的影响。在NaHCO 3反应性（与无反应性）MRSA中NaHCO 3暴露后，（i）mecA和blaZ，（ii）vraSR-prsA基因轴和（iii）pbp 4的表达显著降低。类胡萝卜素的生产减少，而floA的表达增加NaHCO 3暴露在所有MRSA菌株。这项工作强调了NaHCO 3对通过PBP 2a功能和成熟维持MRSA表型所需的基因编码因子干部的独特调节影响。
Certain methicillin-resistant Staphylococcus aureus (MRSA) strains exhibit beta-lactam susceptibility in vitro, ex vivo, and in vivo in the presence of NaHCO3 (NaHCO3-responsive MRSA). Here, we investigate the impact of NaHCO3 on factors required for PBP2a functionality. Prototype NaHCO3-responsive and -nonresponsive MRSA strains (as defined in vitro) were assessed for the impact of NaHCO3 on the expression of genes involved in PBP2a production-maturation pathways (mecA, blaZ, pbp4, vraSR, prsA, sigB, and floA), membrane PBP2a and PrsA protein content, and membrane carotenoid content. Following NaHCO3 exposure in NaHCO3-responsive (versus nonresponsive) MRSA, there was significantly reduced expression of (i) mecA and blaZ, (ii) the vraSR-prsA gene axis, and (iii) pbp4. Carotenoid production was reduced while floA expression was increased by NaHCO3 exposure in all MRSA strains. This work underscores the distinct regulatory impact of NaHCO3 on a cadre of genes encoding factors required for the maintenance of the MRSA phenotype through PBP2a functionality and maturation.