Chen Xiaoli, Cao Sijia, Ni Yan, Chen Xinyi, Qiu Yu, Zhang Mingjing, Fu Jianguo, Zheng Lijuan, Tang Zimin, Ye Huiming
Department of Laboratory Medicine, Fujian Key Clinical Specialty of Laboratory Medicine, Department of Gynecology and Obstetrics, Women and Children's Hospital, School of Medicine, Xiamen University, Xiamen, China.
Department of Obstetrics, Department of Gynecology and Obstetrics, Women and Children's Hospital, School of Medicine, Xiamen University, Xiamen, China.
BMC Pregnancy Childbirth. 2025 Apr 12;25(1):439. doi: 10.1186/s12884-025-07544-w.
Group B streptococcus (GBS) is a major cause of perinatal infectious morbidity and mortality. Although intrapartum antibiotic prophylaxis (IAP) administration for ≥ 4 h is effective in preventing neonatal early-onset GBS diseases, the conventional culture-based approach to identify GBS often takes 24-72 h. This study aimed to find a strategy to improve the efficacy of GBS screening.
We developed a fluorescence immunochromatographic test (FICT) strip to detect GBS within 15 min. The detection limit, analytical sensitivity, cross-reactivity and performance of the strip were evaluated. The performance of the strip on vaginal-rectal swabs with or without enrichment culture was compared with real-time quantitative polymerase chain reaction (qPCR) and colloidal gold immunochromatography (GIC) assay with conventional enrichment culture method as the reference method.
The detection limit of the strip ranges from 10 CFU/mL to 10 CFU/mL. Additionally, the strip has detected all of the positives from 48 h enrichment cultures (175/175). and 30 GBS strains representing different serotypes at cell density of 10 CFU/mL yielded positive results. Cross-reactivity test indicated no false-positive results. The sensitivity on direct samples was 34.48%, while 4 h enrichment in LIM broth prior to FICT has greatly increased the sensitivity to 90.91% with the specificity being 95.35%.
The improved procedure based on the FICT for GBS detection from short-term LIM broth cultures was expected to guide IAP administration in obstetrical emergencies.
B族链球菌（GBS）是围产期感染性发病和死亡的主要原因。尽管产时抗生素预防（IAP）给药≥4小时可有效预防新生儿早发型GBS疾病，但传统的基于培养的GBS鉴定方法通常需要24 - 72小时。本研究旨在寻找一种提高GBS筛查效率的策略。
我们开发了一种荧光免疫层析测试（FICT）试纸条，可在15分钟内检测GBS。评估了试纸条的检测限、分析灵敏度、交叉反应性和性能。将该试纸条在有无富集培养的阴道 - 直肠拭子上的性能与实时定量聚合酶链反应（qPCR）和胶体金免疫层析（GIC）测定法进行比较，以传统富集培养方法作为参考方法。
试纸条的检测限为10 CFU/mL至10 CFU/mL。此外，该试纸条检测出了48小时富集培养物中的所有阳性样本（共175/175例）。30株代表不同血清型的GBS菌株在细胞密度为10 CFU/mL时产生了阳性结果。交叉反应性测试表明无假阳性结果。直接样本检测的灵敏度为34.48%，而在FICT之前在LIM肉汤中进行4小时富集可将灵敏度大幅提高至90.91%，特异性为95.35%。
基于FICT从短期LIM肉汤培养物中检测GBS的改进方法有望指导产科急诊中的IAP给药。
