Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona, USA.
PLoS Negl Trop Dis. 2012 Jan;6(1):e1453. doi: 10.1371/journal.pntd.0001453. Epub 2012 Jan 3.
Lipopolysaccharide (LPS) is one of the most important virulence and antigenic components of Burkholderia pseudomallei, the causative agent of melioidosis. LPS diversity in B. pseudomallei has been described as typical, atypical or rough, based upon banding patterns on SDS-PAGE. Here, we studied the genetic and molecular basis of these phenotypic differences. Bioinformatics was used to determine the diversity of genes known or predicted to be involved in biosynthesis of the O-antigenic moiety of LPS in B. pseudomallei and its near-relative species. Multiplex-PCR assays were developed to target diversity of the O-antigen biosynthesis gene patterns or LPS genotypes in B. pseudomallei populations. We found that the typical LPS genotype (LPS genotype A) was highly prevalent in strains from Thailand and other countries in Southeast Asia, whereas the atypical LPS genotype (LPS genotype B) was most often detected in Australian strains (~13.8%). In addition, we report a novel LPS ladder pattern, a derivative of the atypical LPS phenotype, associated with an uncommon O-antigen biosynthesis gene cluster that is found in only a small B. pseudomallei sub-population. This new LPS group was designated as genotype B2. We also report natural mutations in the O-antigen biosynthesis genes that potentially cause the rough LPS phenotype. We postulate that the diversity of LPS may correlate with differential immunopathogenicity and virulence among B. pseudomallei strains.
脂多糖 (LPS) 是伯克霍尔德氏菌的一种重要毒力和抗原成分，也是导致类鼻疽病的病原体。根据 SDS-PAGE 上的条带模式，将 Burkholderia pseudomallei 中的 LPS 多样性描述为典型、非典型或粗糙。在这里，我们研究了这些表型差异的遗传和分子基础。生物信息学用于确定与 LPS O-抗原部分生物合成相关的已知或预测基因的多样性，这些基因在 Burkholderia pseudomallei 及其近缘种中。开发了多重 PCR 检测方法，以针对 Burkholderia pseudomallei 群体中 O-抗原生物合成基因模式或 LPS 基因型的多样性进行检测。我们发现，典型 LPS 基因型 (LPS 基因型 A) 在来自泰国和东南亚其他国家的菌株中高度流行，而非典型 LPS 基因型 (LPS 基因型 B) 则最常检测到在澳大利亚菌株中 (~13.8%)。此外，我们报告了一种新的 LPS 梯状模式，这是一种非典型 LPS 表型的衍生物，与一种罕见的 O-抗原生物合成基因簇相关，该基因簇仅存在于一小部分 Burkholderia pseudomallei 亚群中。这个新的 LPS 组被指定为基因型 B2。我们还报告了 O-抗原生物合成基因的自然突变，这些突变可能导致粗糙 LPS 表型。我们推测，LPS 的多样性可能与 Burkholderia pseudomallei 菌株之间的差异免疫病理和毒力相关。
