Tufts University School of Medicine, Boston, Massachusetts, USA.
Department of Microbiology and Immunology, University of South Alabama, Frederick P. Whiddon College of Medicine, Mobile, Alabama, USA.
Appl Environ Microbiol. 2024 Nov 20;90(11):e0156724. doi: 10.1128/aem.01567-24. Epub 2024 Oct 30.
Between 2% and 15% of pregnant women unknowingly experience asymptomatic bacteriuria (ASB), defined as ≥10 CFU per milliliter of urine in the absence of symptoms. ASB increases the risk of adverse pregnancy outcomes including pyelonephritis, preterm labor, and low-birth weight infants. While pregnant women in the United States are routinely screened for ASB, those in developing countries with limited resources and funding lack an accurate mechanism for ASB screening. Aquagenx water quality test kits detect , the most common causative agent of ASB, and total coliform bacteria in drinking water via colorimetric and fluorescent indicators. We found that the Aquagenx system is compatible with human urine and then proceeded to develop an ASB screening protocol using disposable inoculating loops. Our protocol diagnosed artificial ASB samples (10 CFU/mL ) with a false positive (FP) rate of 33% ( = 18) and ASB (10 CFU/mL ) with a false negative (FN) rate of 5.6% ( = 18). Clinical sample testing with our protocol revealed a FP rate of 0% in ASB samples ( = 28) and a FN rate of 0% in ASB samples caused by coliforms ( = 13). Aquagenx did not detect ASB in nine clinical samples with non-coliform etiological agents due to the limitations of the technology. However, with very high accuracy for detection of and other causative agents that collectively account for 90.1% of ASB cases, these kits could be used as a diagnostic ASB screening tool in developing countries in which there is currently no alternative to urine culture.IMPORTANCEAsymptomatic bacteriuria (ASB) affects 2%-15% of pregnant women and can result in adverse maternal and fetal outcomes if left undetected and untreated. In the United States and other developed nations, pregnant women are regularly screened for ASB via urine culture. However, in low-resource countries where bacterial culture is not available, dipstick testing is used. Although accurate in cases of symptomatic bacteriuria, dipstick detection is ineffective for detecting ASB. Here, we made use of an existing water quality field test for ASB urine screening, which would be readily deployable in low-resource settings. We optimized a dilution protocol for sampling patient urine within the detection limits of the Aquagenx kit technology. Overall, we were able to detect ASB samples with Gram-negative pathogens that collectively account for 90% of all ASB cases. Utilization of this repurposed technology for proactive medical screening may help prevent adverse pregnancy and birth outcomes due to ASB.
在 2%至 15%的孕妇中，存在无症状菌尿（ASB）而不自知，ASB 定义为每毫升尿液中≥10 个 CFU，但无相关症状。ASB 会增加不良妊娠结局的风险，包括肾盂肾炎、早产和低出生体重儿。虽然美国的孕妇会常规筛查 ASB，但在资源和资金有限的发展中国家，缺乏用于 ASB 筛查的准确机制。Aquagenx 水质测试套件通过比色和荧光指示剂检测最常见的 ASB 病原体——大肠埃希菌和饮用水中的总大肠菌群。我们发现 Aquagenx 系统与人类尿液兼容，然后使用一次性接种环开发了 ASB 筛查方案。我们的方案以 33%的假阳性率（=18）诊断人工 ASB 样本（10 CFU/mL），以 5.6%的假阴性率（=18）诊断 ASB 样本（10 CFU/mL）。使用我们的方案对临床样本进行测试显示，在 ASB 样本中假阳性率为 0%（=28），在由大肠埃希菌引起的 ASB 样本中假阴性率为 0%（=13）。由于技术限制，Aquagenx 在 9 个非大肠埃希菌病因的临床样本中未检测到 ASB。然而，该试剂盒对 和其他共同导致 90.1%ASB 病例的病原体的检测具有非常高的准确性，因此可作为目前无法进行尿液培养的发展中国家诊断 ASB 的筛查工具。
无症状菌尿（ASB）影响 2%-15%的孕妇，如果未被发现和治疗，可能会导致母婴不良结局。在美国和其他发达国家，孕妇会通过尿液培养定期筛查 ASB。然而，在资源匮乏的国家，由于无法进行细菌培养，会使用尿试纸条检测。虽然在有症状菌尿的情况下，尿试纸条检测准确，但对于检测 ASB 无效。在这里，我们利用现有的水质现场检测技术进行 ASB 尿液筛查，这将易于在资源匮乏的环境中部署。我们优化了一种在 Aquagenx 试剂盒技术检测限内采样患者尿液的稀释方案。总的来说，我们能够检测到占所有 ASB 病例 90%的革兰氏阴性病原体的 ASB 样本。这种经过重新利用的技术用于主动医疗筛查，可能有助于预防 ASB 引起的不良妊娠和分娩结局。
