Truenat MTB Plus assay (TruPlus), a chip-based portable machine, was compared with GeneXpert Ultra (GxUltra) for diagnosing drug-resistant OATB.
115 synovial fluid and pus specimens [22 culture-positive confirmed, 58 culture-negative clinically-suspected, 35 non-TB controls] processed between 2017 and 2023 were subjected to TruPlus, GxUltra and multiplex-PCR for diagnosing OATB. They were further screened for rifampicin resistance using TruRif chip. The performance was evaluated against composite reference standard, phenotypic drug susceptibility testing and rpoB gene sequencing.
TruPlus, GxUltra and MPCR detected 77.5 %, 71.25 %, and 83.75 %, cases of OATB, respectively. TruPlus detected five additional cases missed by GxUltra. The performance of TruPlus was comparable to GxUltra (p = 0.074) and to MPCR (p = 0.074), while performance of GxUltra was significantly inferior to MPCR (p = 0.004). The overall agreement with reference standard was substantial for TruPlus and MPCR and moderate for GxUltra. Both TruRif and GxUltra reported 4 cases as rifampicin resistant.
TruPlus along with TruRif offers better sensitivity than GxUltra. Its compact and portable platform allows wider application in peripheral settings, thus making it a pragmatic solution for diagnosing OATB and its drug resistance.
目的:TruenatMTBPlus检测(TruPlus),基于芯片的便携式机器,与GeneXpertUltra(GxUltra)进行了比较,用于诊断耐药OATB。
方法:115个滑液和脓液标本[22个培养阳性证实,58个临床怀疑培养阴性,2017年至2023年期间处理的35例非结核病对照]接受了TruPlus,GxUltra和多重PCR诊断OATB。使用TruRif芯片进一步筛选他们的利福平抗性。根据复合参考标准品评估性能,表型药敏试验和rpoB基因测序。
结果:TruPlus,GxUltra和MPCR检出77.5%,71.25%,83.75%,OATB的案例,分别。TruPlus检测到GxUltra错过了另外五个案例。TruPlus的性能与GxUltra(p=0.074)和MPCR(p=0.074)相当,而GxUltra的性能明显劣于MPCR(p=0.004)。与参考标准的总体一致性对于TruPlus和MPCR是实质性的,对于GxUltra是中等的。TruRif和GxUltra均报告4例利福平耐药。
结论:TruPlus和TruRif比GxUltra具有更好的灵敏度。其紧凑和便携的平台允许在外围设置更广泛的应用,从而使其成为诊断OATB及其耐药性的实用解决方案。