通用PCR法在痰标本真菌检测中的临床应用价值分析

目的:探讨通用PCR法在痰标本真菌检测中的临床应用价值。方法:选择2015年9月至2017年9月本院收治的免疫力低下患者178例作为研究资料,各收集痰标本2份,其中一份用于PCR扩增,另一份经培养后若观察到真菌或可疑菌落,则提取后在此进行PCR扩增测序。比较3种方法对真菌的检出情况、真菌阳性率,与组织病理学结果进行比较,分析3种方法的诊断效能。结果:178份痰标本经平板培养可观察到107份真菌生长,其余71份未见真菌生长。挑取真菌及可疑菌落行PCR结果显示阳性、阴性分别115、63份。对痰标本直接PCR结果显示,阳性、阴性分别124、54份。PCR扩增产物测序结果显示大多是白色念珠菌感染,仅3份是曲霉菌感染。内对照扩增验证结果显示有1份阴性标本存在扩增抑制现象。3种方法的真菌阳性率:直接PCR法痰培养后PCR法痰培养,但组间无显著差异(P0.05)。3种方法诊断效能总体趋势:直接PCR法痰培养后PCR法痰培养,其中直接PCR法与痰培养后PCR法的特异度、准确度均显著高于痰培养法(P0.05),直接PCR法的敏感度显著高于痰培养法(P0.05)。结论:通用PCR法在痰标本真菌检测中的临床应用价值较高,直接PCR具有操作简单、快速等优势。

Clinical Application of General PCR Method in Fungal Detection of Sputum Specimens

ABSTRACT Objective: To explore the clinical value of general PCR method for the detection of fungi in sputum specimens. Methods: From September 2015 to September 2017, 178 cases of immunocompromised patients in our hospital were selected as the research data, 2 sputum specimens were collected in each patients, one of which was used for PCR amplification, after cultivation, if observed or suspected fungal colonies, another one was extracted after PCR amplification and sequencing. The fungal detection rates and fungal positive rates of three methods were compared. Compared with the histopathological results, the diagnostic efficacy of three methods was analyzed. Results: In 178 sputum samples by plate culture, 107 cases were observed in fungal growth, the remaining 71 copies showed no fungal growth. Sputum culture positive fungal or suspected colonies were detected by PCR analysis, 115 samples were positive, 63 cases were negative, sputum direct PCR showed that 124 cases were positive, 54 cases were negative. PCR amplification products were compared among 3 copies of Aspergillus infection, the infection of Candida albicans. The amplification inhibition was found in 1 negative specimen by internal control amplification. The general trend of fungal positive rate among the three methods showed that direct PCR method > post-culture PCR method > culture method, but there was no significant difference between the groups (P>0.05). The overall trend of the diagnostic efficacy of the three methods showed direct PCR > post-culture PCR > sputum culture. The specificity and accuracy of the direct PCR method and the post-cultivation PCR method were significantly higher than that of the limulus culture method (P<0.05). The sensitivity of the direct PCR method was significantly higher than that of the axillary culture method (P<0.05). Conclusion: The general PCR method was of high clinical value in the fungal detection of sputum specimens, and the direct PCR had the advantages of simple and rapid operation, and it was worth being popularizd.