Department of Microbiology and Immunology, University of Nevada, Reno, School of Medicine, Reno, Nevada, USA.
Lao-Oxford-Mahosot Hospital Wellcome Trust Research Unit, Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao People's Democratic Republic.
Microbiol Spectr. 2022 Aug 31;10(4):e0076522. doi: 10.1128/spectrum.00765-22. Epub 2022 Aug 4.
Burkholderia pseudomallei is the causative agent of melioidosis, a life-threatening disease common in Southeast Asia and northern Australia. Melioidosis often presents with nonspecific symptoms and has a fatality rate of upwards of 70% when left untreated. The gold standard for diagnosis is culturing B. pseudomallei from patient samples. Bacterial culture, however, can take up to 7 days, and its sensitivity is poor, at roughly 60%. The successful administration of appropriate antibiotics is reliant on rapid and accurate diagnosis. Hence, there is a genuine need for new diagnostics for this deadly pathogen. The Active Melioidosis Detect (AMD) lateral flow immunoassay (LFI) detects the capsular polysaccharide (CPS) of B. pseudomallei. The assay is designed for use on various clinical samples, including serum and urine; however, there are limited data to support which clinical matrices are the best candidates for detecting CPS. In this study, concentrations of CPS in paired serum and urine samples from melioidosis patients were determined using a quantitative antigen capture enzyme-linked immunosorbent assay. In parallel, samples were tested with the AMD LFI, and the results of the two immunoassays were compared. Additionally, centrifugal concentration was performed on a subset of urine samples to determine if this method may improve detection when CPS levels are initially low or undetectable. The results indicate that while CPS levels varied within the two matrices, there tended to be higher concentrations in urine. The AMD LFI detected CPS in 40.5% of urine samples, compared to 6.5% of serum samples, suggesting that urine is a preferable matrix for point-of-care diagnostic assays. Melioidosis is very challenging to diagnose. There is a clear need for a point-of-care assay for the detection of B. pseudomallei antigen directly from patient samples. The Active Melioidosis Detect lateral flow immunoassay detects the capsular polysaccharide (CPS) of B. pseudomallei and is designed for use on various clinical samples, including serum and urine. However, there are limited data regarding which clinical matrix is preferable for the detection of CPS. This study addresses this question by examining quantitative CPS levels in paired serum and urine samples and relating them to clinical parameters. Additionally, centrifugal concentration was performed on a subset of urine samples to determine whether this might enable the detection of CPS in samples in which it was initially present at low or undetectable levels. These results provide valuable insights into the detection of CPS in patients with melioidosis and suggest potential ways forward in the diagnosis and treatment of this challenging disease.
类鼻疽伯克霍尔德菌是类鼻疽病的病原体，这是一种在东南亚和澳大利亚北部常见的危及生命的疾病。类鼻疽病常表现为非特异性症状，如果不治疗，其死亡率高达 70%以上。培养患者样本中的类鼻疽伯克霍尔德菌是诊断该病的金标准。然而，细菌培养可能需要长达 7 天的时间，而且其敏感性较差，约为 60%。只有快速、准确地诊断，才能成功地给予适当的抗生素治疗。因此，这种致命病原体确实需要新的诊断方法。主动类鼻疽检测（AMD）侧向流动免疫分析（LFI）检测类鼻疽伯克霍尔德菌的荚膜多糖（CPS）。该检测方法设计用于检测各种临床样本，包括血清和尿液；然而，支持哪种临床基质最适合检测 CPS 的数据有限。在这项研究中，使用定量抗原捕获酶联免疫吸附试验（ELISA）测定了类鼻疽病患者配对血清和尿液样本中的 CPS 浓度。同时，用 AMD LFI 检测了这些样本，并比较了两种免疫分析的结果。此外，对一部分尿液样本进行了离心浓缩，以确定当 CPS 水平最初较低或无法检测到时，该方法是否可以提高检测能力。结果表明，虽然两种基质中的 CPS 水平存在差异，但尿液中的浓度往往更高。AMD LFI 在 40.5%的尿液样本中检测到 CPS，而在 6.5%的血清样本中检测到 CPS，这表明尿液是用于即时诊断检测的理想基质。类鼻疽病的诊断极具挑战性。迫切需要一种能够直接从患者样本中检测类鼻疽伯克霍尔德菌抗原的即时检测方法。主动类鼻疽检测侧向流动免疫分析检测类鼻疽伯克霍尔德菌的荚膜多糖（CPS），设计用于检测各种临床样本，包括血清和尿液。然而，关于哪种临床基质最适合检测 CPS 的数据有限。本研究通过检查配对血清和尿液样本中的定量 CPS 水平，并将其与临床参数相关联，来解决这个问题。此外，对一部分尿液样本进行了离心浓缩，以确定这是否可以使最初低水平或无法检测到的 CPS 样本得以检测。这些结果为类鼻疽病患者的 CPS 检测提供了有价值的见解，并为这种具有挑战性的疾病的诊断和治疗提供了潜在的途径。
