South Sector Microbiology, Alberta Precision Laboratories, Calgary, AB, Canada; Alberta Public Health Laboratory, Alberta Precision Laboratories, Calgary, AB, Canada; Department of Pathology and Laboratory Medicine, University of Calgary, Calgary, AB, Canada.
Alberta Public Health Laboratory, Alberta Precision Laboratories, Calgary, AB, Canada; Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB, Canada.
Int J Infect Dis. 2022 Jan;114:195-201. doi: 10.1016/j.ijid.2021.10.035. Epub 2021 Oct 24.
Many laboratories use culture-independent diagnostic tests for bacterial gastroenteritis (i.e. real-time polymerase chain reaction, RT-PCR) instead of culture because of better sensitivity, automation, and faster turnaround times. To address some gaps in initial evaluations and lack of intraassay comparisons for many commercial RT-PCRs, this study compared the ability of four commercially available RT-PCR tests (Ridagene, Fast Track Diagnostics, BD Max, and Prodesse Progastro) to detect five major bacterial enteric pathogens: Campylobacter, Salmonella, Shiga-toxin producing Escherichia coli (STEC), Shigella, and Yersinia.
Clinical stool specimens and contrived samples comprising commonly circulating species, serotypes, biovars, and/or toxin subtypes were used for the comparison.
Concordance rates for RT-PCR and culture using culture-positive and culture-negative clinical stools were >90% for Campylobacter (97.5-100%), Salmonella (97.5-100%), Shigella (100%), and STEC (90-100%). However, the agreement between RT-PCR and culture for Y. enteroccolitica ranged from 70-90%. For the contrived sample set, stx was detected by one of four assays. Of note, no assay could detect Yersinia non-enterocolitica and Campylobacter upsaliensis.
Depending on the prevalence of certain stx sub-types, Yersinia species, and Campylobacter species in a laboratory's jurisdiction, without further improvement in culture-independent tests, culture methods remain critical for the detection of these pathogens.
由于具有更好的灵敏度、自动化程度和更快的周转时间，许多实验室使用非培养的诊断性检测方法（例如实时聚合酶链反应，RT-PCR）代替培养方法来检测细菌性肠胃炎。为了弥补初始评估中的一些空白，以及许多商业 RT-PCR 缺乏内标比较，本研究比较了四种市售 RT-PCR 检测方法（Ridagene、Fast Track Diagnostics、BD Max 和 Prodesse Progastro）检测五种主要肠道病原菌的能力：弯曲菌、沙门氏菌、产志贺毒素大肠埃希菌（STEC）、志贺菌和耶尔森菌。
使用临床粪便标本和包含常见循环种属、血清型、生物型和/或毒素亚型的人工样本进行比较。
使用培养阳性和培养阴性的临床粪便标本进行 RT-PCR 和培养的一致性率 >90%，用于弯曲菌（97.5-100%）、沙门氏菌（97.5-100%）、志贺菌（100%）和 STEC（90-100%）。然而，耶尔森菌的 RT-PCR 与培养的一致性率为 70-90%。对于人工样本集，stx 被四种检测方法中的一种检测到。值得注意的是，没有一种检测方法能够检测非肠炎耶尔森菌和弯曲菌 upsaliensis。
根据实验室管辖范围内某些 stx 亚型、耶尔森菌种和弯曲菌种的流行情况，如果不进一步改进非培养检测方法，培养方法仍然是检测这些病原体的关键。
