Tjandra Kristel C, Ram-Mohan Nikhil, Abe Ryuichiro, Wang Tza-Huei, Yang Samuel
Department of Emergency Medicine, Stanford University School of Medicine, Palo Alto, California 94305, United States.
Departments of Mechanical Engineering and Biomedical Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, United States.
ACS Infect Dis. 2023 May 12;9(5):1160-1167. doi: 10.1021/acsinfecdis.3c00096. Epub 2023 Apr 28.
(NG) is an urgent threat to antimicrobial resistance (AMR) worldwide. NG has acquired rapid resistance to all previously recommended treatments, leaving ceftriaxone monotherapy as the first and last line of therapy for uncomplicated NG. The ability to rapidly determine susceptibility, which is currently nonexistent for NG, has been proposed as a strategy to preserve ceftriaxone by using alternative treatments. Herein, we used a DNA-intercalating dye in combination with NG-specific primers/probes to generate qPCR cycle threshold (Ct) values at different concentrations of 2 NG-relevant antimicrobials. Our proof-of-concept dual-antimicrobial logistic regression model based on the differential Ct measurements achieved an AUC of 0.93 with a categorical agreement for the susceptibility of 84.6%. When surveying the performance against each antimicrobial separately, the model predicted 90 and 75% susceptible and resistant strains, respectively, to ceftriaxone and 66.7 and 83.3% susceptible and resistant strains, respectively, to ciprofloxacin. We further validated the model against the individual replicates and determined the accuracy of the model in classifying susceptibility agnostic of the inoculum size. We demonstrated a novel PCR-based approach to determine phenotypic ciprofloxacin and ceftriaxone susceptibility information for NG with reasonable accuracy within 30 min, a significant improvement compared to the conventional method which could take multiple days.
淋病奈瑟菌（NG）是全球抗菌药物耐药性（AMR）的一个紧迫威胁。NG已对所有先前推荐的治疗方法迅速产生耐药性，使得头孢曲松单药治疗成为单纯性NG的一线也是最后一线治疗方法。快速确定药敏性的能力目前在NG中并不存在，有人提出通过使用替代治疗方法来保留头孢曲松，以此作为一种策略。在此，我们使用一种DNA嵌入染料与NG特异性引物/探针相结合，在2种与NG相关的抗菌药物的不同浓度下生成定量聚合酶链反应（qPCR）循环阈值（Ct）值。我们基于差异Ct测量的概念验证双抗菌药物逻辑回归模型的曲线下面积（AUC）为0.93，药敏性分类一致性为84.6%。当分别检测针对每种抗菌药物的性能时，该模型预测对头孢曲松敏感和耐药菌株分别为90%和75%，对环丙沙星敏感和耐药菌株分别为66.7%和83.3%。我们进一步针对单个重复样本验证了该模型，并确定了该模型在不考虑接种量的情况下对药敏性进行分类的准确性。我们展示了一种基于PCR的新方法，能够在30分钟内以合理的准确性确定NG对环丙沙星和头孢曲松的表型药敏性信息，与可能需要数天的传统方法相比有显著改进。
