Schwan William R
Department of Microbiology, University of Wisconsin-La Crosse, 1725 State St., La Crosse, WI 54601, USA.
Microorganisms. 2022 Sep 21;10(10):1888. doi: 10.3390/microorganisms10101888.
is a major cause of skin/soft tissue infections and more serious infections in humans. The species usually requires the importation of proline to be able to survive. Previous work has shown that single mutations in genes that encode for proline transporters affect the ability of to survive in vitro and in vivo. To better understand proline transport in , double and triple gene mutant strains were created that targeted the , , and genes. Single gene mutants had some effect on proline transport, whereas double mutants exhibited significantly lower proline transport. An triple gene mutant displayed the lowest proline transport under low- and high-affinity conditions. To assess growth differences caused by the mutations, the same mutants were grown in brain heart infusion (BHI) broth and defined staphylococcal medium (DSM) with various concentrations of proline. The triple mutant did not grow in DSM with a low concentration of proline and grew poorly in both DSM with a high proline concentration and BHI broth. These results show that has multiple mechanisms to import proline into the cell and knocking out three of the main proline transporters significantly hinders growth.
是人类皮肤/软组织感染及更严重感染的主要病因。该菌种通常需要摄入脯氨酸才能存活。先前的研究表明，编码脯氨酸转运蛋白的基因发生单突变会影响其在体外和体内的存活能力。为了更好地了解该菌种中的脯氨酸转运，构建了靶向、和基因的双基因和三基因突变菌株。单基因突变对脯氨酸转运有一定影响，而双基因突变体的脯氨酸转运显著降低。在低亲和力和高亲和力条件下，三基因突变体的脯氨酸转运最低。为评估这些突变引起的生长差异，将相同的突变体在含有不同浓度脯氨酸的脑心浸液（BHI）肉汤和限定的葡萄球菌培养基（DSM）中培养。三基因突变体在低浓度脯氨酸的DSM中无法生长，在高浓度脯氨酸的DSM和BHI肉汤中生长均较差。这些结果表明，该菌种具有多种将脯氨酸导入细胞的机制，敲除三个主要的脯氨酸转运蛋白会显著阻碍其生长。
