Antigenemia immunoassay for point of care dianostic melioidosis

类鼻疽实验室诊断现状目前，多部位培养是金 实验室诊断标准。文化需要有经验的人员，需要3-4天。级别 菌血症很低(~I cfu/ml)。一种诊断类鼻疽病的临床点免疫分析方法可以大大 影响患者预后，因为高比例的急性败血症患者在24-48小时内死亡 入院时，用于经验治疗败血症的抗生素对假鼻疽杆菌无效。 由于急性脓毒症的早期阶段没有抗体，抗体检测的价值有限 流行地区背景抗体水平较高(6)。已有多项研究报道了用聚合酶链式反应检测B。 但已报道的检测下限往往高于活细菌的范围 人类疾病期间的血液计数(118)。 类鼻疽免疫诊断的潜在抗原靶点胞外检测 多糖已经成功地治疗了多种细菌感染。假鼻疽杆菌有三种候选抗原：胞外多糖(EPS)、壳多糖(CPS)和脂多糖(LPS)。EPS是一种重复的四糖的未支化聚合物：[-3)-p-D-Galp2Ac-(i-4)-a-D-Galp-(i-3)-p-D-Galp-(i-5)-|3-Kdo-(2-](115)。CP是一种未支化的[-3)-2-O-acetyl-6-deoxy-p-D-mannoheptopyranose-(均聚物 I-](120)。脂多糖是一种无支化的双糖重复单元的聚合物，具有基本的 结构：[-3-)-|3-D-glucopyranose-(i-3)-6-deoxy-a-L-talopyranose-(i-](120)。类鼻疽患者会产生针对EPS、CPS和内毒素的抗体，这表明这些抗原是在体内产生的。到目前为止，还没有假鼻疽蛋白被确定为抗原靶向诊断类鼻疽病的候选蛋白。建议的InMAD过程有可能识别在体内脱落的假鼻疽抗原，并可能作为一个快速广泛的发现平台，以应对许多微生物威胁。

Status of laboratory diagnosis of melioidosis Currently, culture from multiple body sites is the gold standard for laboratory diagnosis. Culture requires experienced personnel and takes 3-4 days. Levels of bacteremia are very low (~ i CFU/ml). A point-of-care immunoassay for diagnosis of melioidosis could greatly impact patient outcome because a high percentage of patients with acute septicemia die within 24-48 h of admission, and the antibiotics used for empiric treatment of septicemia are not effective for B. pseudomallei. Assays for antibody have limited value due to an absence of antibody in the early stages of acute sepsis and a high level of background antibodies in endemic regions (6). Several studies reported PCR for detection of B. pseudomallei, but the reported lower limit of detection tends to fall above the range for the viable bacteria count in blood during human disease (118). Potential antigen targets for immunodiagnosis of melioidosis Detection of extracellular polysaccharides has been successful for a variety of bacterial infections. There are three candidate antigens for B. pseudomallei: the exopolysaccharide (EPS), the capsular polysaccharide (CPS), and the lipopolysaccharide (LPS). EPS is an unbranched polymer of a repeating tetrasaccharide: [-3)-p-D-Galp2Ac-(i-4)-a-D-Galp-(i-3)-p-D-Galp-(i-5)-|3-Kdo-(2-] (115). CPS is an unbranched homopolymer of [-3)-2-O-acetyl-6-deoxy-p-D-mannoheptopyranose-( i-] (120). LPS is an unbranched polymer of disaccharide repeating units having the basic structure: [-3-)-|3-D-glucopyranose-(i-3)-6-deoxy-a-L-talopyranose-(i-] (120). Melioidosis patients make antibodies to EPS, CPS and LPS, indicating that these antigens are produced in vivo. To date, no B. pseudomallei proteins have been identified as candidates for antigen-targeted diagnosis of melioidosis. The proposed InMAD process has the potential to identify B. pseudomallei antigens shed in vivo and may serve as a rapid broad discovery platform for many microbial threats.