Overview of current detection methods and microRNA potential in Clostridioides difficile infection screening

Table 1 Summary of Clostridioides difficile diagnostic tests

Test	Abbreviation	Sensitivity	Specificity	Turn-around time	Target substance
Culture-based
Cell cytotoxicity neutralisation assay	CCTN	High	High	< 24 h	Toxins
Toxigenic culture	TC	High	Low1	> 3 d	C. difficile vegetative cells or spores
DNA-based
Nucleic acid amplification test2	NAAT	High	Low/moderate	< 4 h	Toxin genes
Protein-based
Glutamate dehydrogenase	GDH-EIA	High	Low1	< 2 h	C. difficile antigens
Toxin A and B enzyme immunoassays	EIA	Low	Moderate	< 2 h	Toxins

¹Nucleic acid amplification test, mainly using the PCR technique.

²Must be combined with a toxin test.

C. difficile: Clostridioides difficile; TC: Toxigenic culture; NAAT: Nucleic acid amplification test; CCTN: Cell cytotoxicity neutralisation assay; GDH: Glutamate dehydrogenase; EIA: Enzyme immunoassay.

Table 2 Selected Food and Drug Administration-approved molecular assays

Assay name	Developer	Target	Method	Sensitivity/specificity (%)
AmpliVue C. difficile assay[70]	Quidel	tcdA	Isothermal nucleic acid amplification	93.6/94.1
ARIES C. difficile assay[71,72]	Luminex	tcdA and tcdB	qRT-PCR	90-98/92-98
ARTUS C. difficile QS-RGQ MDX Kit[73]	QIAGEN, GMBH	tcdA and tcdB (+ tcdBv)	qRT-PCR	100/90-100
BD Diagnostics BD MAX C. diff assay[71,74-77]	GeneOhm Sciences	tcdB	TaqMan probe-based qRT-PCR	86-98/89-100
BD GeneOhm C. diff assay[78-82]	BD Diagnostics/GeneOhm Sciences	tcdB	Beacon probe-based PCR	91-95/96-100
Cobas C. diff Nucleic Acid Test For Use On The Cobas Liat System[83,84]	Roche	tcdB	TaqMan probe-based qRT-PCR	93/99
GenePOC C. diff[85]	GenePOC	tcdB of toxigenic C	TaqMan probe-based qRT-PCR	81/97
ICEPlex C. diff Kit1[86]	PrimeraDx	tcdB	qRT-PCR + capillary electrophoresis-based detection	90/97
Illumigene C. diff DNA Amplification assay[77]	Meridian Bioscience	tcdA	Loop-mediated isothermal DNA amplification	82-100/94-100
IMDx C. difficile for Abbott m2000[76,77]	Intelligent Medical Devices	tcdA and tcdB (+ tcdBv)	Probe-based qRT-PCR	62-84/94-99
Portrait Toxigenic C. difficile assay[87,88]	Great Basin Scientific	tcdB	Primer-mediated helicase-dependent amplification + chip-based detection	98.2/92.8
ProGastro Cd assay[81,89]	Prodesse	tcdB	Probe-based qRT-PCR	77-100/94-99
Quidel Molecular Direct C. difficile assay[70,90]	Quidel	tcdA and tcdB	TaqMan probe-based qRT-PCR	82-96/97-100
Simplexa C. difficile Universal Direct assay[70,91]	Focus Diagnostics	tcdB	qRT-PCR + bifunctional fluorescent primer-probes	87-98/99-100
Solana C. difficile assay1[92]	Quidel	tcdA	Helicase-dependent amplification	93/99
Verigene C. difficile Nucleic acid Test[91,93,94]	Nanosphere	tcdA, tcdB, cdt and tcdCΔ117	PCR + nanoparticle-based array	94-96/96-98
X/Pert C. difficile/Epi[71,77,95,96]	Cepheid	tcdA, tcdB, cdt and tcdCΔ117	TaqMan probe-based qRT-PCR	90-100/93-99

¹The sensitivity and specificity were provided by the manufacturer.

tcdCΔ117: The tcdC deletion nt 117; tcdBv: tcdB variant; cdt: Binary toxin; C. difficile or C. diff: Clostridioides difficile; qRT: Quantitative real-time.

Table 3 Major immunochromatographic membrane assays

Methods/assays	Target(s)	Developer	Cell cytotoxicity assay		Toxigenic culture
			Sen, %	Spe, %	Sen, %	Spe, %
Microwell enzyme immunoassay (enzyme-linked immunosorbent assay)
GA C. diff Antigen[97]	Toxin A + B	The Binding Site	76.8	90.0	68.8	91.4
Premier toxin A+B[97-106]	Toxin A + B	Meridian Bioscience	58-99	94-100	40-86	91-100
Ridascreen toxin A/B[97,107,108]	Toxin A + B	Ridascreen	57-67	95-97	52-60	96-98
ProSpecT toxin A/B[97,109]	Toxin A + B	Remel/Oxoid (Thermo Scientific)	90-91	93-97	82	93
Techlab C. diff Chek-60 (GDH)[53,97,110]	GDH	Techlab	92.0-93.5	94.0-98.0	88.0-93.0	94.0-97.0
TechLab toxin A/B II[81,97,100,109-111]	Toxin A + B	TechLab	72-91	87-100	58-85	96-99
Membrane enzyme immunoassay
ImmunoCard toxins A/B[41,97,109,112,113]	Toxin A + B	Meridian Bioscience	85-96	97-99	41-69	93-99
Quick Chek Complete[40,105,112,114-117]	Toxin A + B	TechLab	50-73	100	29-79	89-100
Remel X/pect C. diff toxin A/B[97,113,118]	Toxin A + B	Remel	44-83	99-100	48-69	95-99
Tox A/B Quick Check[97,115,119-121]	Toxin A + B	TechLab	61-84	99	40-74	94-100
Chemiluminescence immunoassay
Liaison C. difficile toxins A and B[122,123]	Toxin A + B	DiaSorin	88	95	69-88	95-99
Enzyme-linked fluorescent assay
Vidas toxin A and B[97,116,123-128]	Toxin A + B	Vidas	53-98	99-100	44-80	95-99
Vidas GDH[40,129]	GDH	Vidas	97	87	56	100

Sen: Sensitivity; Sep: Specificity; GDH: Glutamate dehydrogenase; C. difficile or C. diff: Clostridioides difficile.