Aerococcus urinae is an emerging pathogen that causes urinary tract infections, bacteremia and infective endocarditis. The mechanisms through which A. urinae cause infection are largely unknown. The aims of this study were to describe the surface proteome of A. urinae and to analyse A. urinae genomes in search for genes encoding surface proteins. Two proteins, denoted Aerococcal surface protein (Asp) 1 and 2, were through the use of mass spectrometry based proteomics found to quantitatively dominate the aerococcal surface. The presence of these proteins on the surface was also shown using ELISA with serum from rabbits immunized with the recombinant Asp. These proteins had a signal sequence in the amino-terminal end and a cell wall-sorting region in the carboxy-terminal end, which contained an LPATG-motif, a hydrophobic domain and a positively charged tail. Twenty-three additional A. urinae genomes were sequenced using Illumina HiSeq technology. Six different variants of asp genes were found (denoted asp1-6). All isolates had either one or two of these asp-genes located in a conserved locus, designated Locus encoding Aerococcal Surface Proteins (LASP). The 25 genomes had in median 13 genes encoding LPXTG-proteins (range 6–24). For other Gram-positive bacteria, cell wall-anchored surface proteins with an LPXTG-motif play a key role for virulence. Thus, it will be of great interest to explore the function of the Asp proteins of A. urinae to establish a better understanding of the molecular mechanisms by which A. urinae cause disease.

尿球菌是一种新兴病原体，可引起尿路感染，菌血症和感染性心内膜炎。尿曲霉引起感染的机制在很大程度上尚不清楚。这项研究的目的是描述A.urinae的表面蛋白质组并分析A.urinae基因组中寻找编码表面蛋白的基因。通过使用基于质谱的蛋白质组学，发现两种蛋白质，分别称为航空球菌表面蛋白（Asp）1和2，可以定量地控制航空球菌表面。使用来自用重组Asp免疫的兔子的血清的ELISA也显示了这些蛋白质在表面上的存在。这些蛋白质在氨基末端具有信号序列，在羧基末端具有细胞壁分选区域，其中包含LPATG基序，疏水域和带正电荷的尾巴。使用Illumina HiSeq技术对另外23个尿曲霉基因组进行了测序。发现了6种不同的asp基因变体（表示为asp1-6）。所有分离物在保守的基因座中都具有一个或两个这些asp基因，这些基因被命名为编码气球菌表面蛋白（LASP）的基因座。这25个基因组中有13个编码LPXTG蛋白的基因（范围6–24）。对于其他革兰氏阳性细菌，具有LPXTG基序的细胞壁锚定表面蛋白在毒力中起关键作用。因此，探索尿壶菌的Asp蛋白的功能以建立对尿壶菌引起疾病的分子机制的更好理解将是非常有意义的。