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Clostridium difficile:Clostridium difficile:
Laboratory Laboratory InvestigationsInvestigations
Tony Tony KormanKorman
National Clostridium difficile WorkshopNational Clostridium difficile Workshop
20 August 201020 August 2010
Introduction to Laboratory testing Tony Introduction to Laboratory testing Tony KormanKorman
ANZ Clostridium difficile Laboratory Survey ANZ Clostridium difficile Laboratory Survey Results and Recommendations for Testing and Results and Recommendations for Testing and Laboratory Practice John FergusonLaboratory Practice John Ferguson
ASID Guidelines for Management of C. ASID Guidelines for Management of C. difficile infection Allen Chengdifficile infection Allen Cheng
C. difficile: C. difficile: Diagnosis Diagnosis
Laboratory Laboratory Investigations Investigations
C. difficile detectionC. difficile detection
C. difficile toxin detectionC. difficile toxin detection
Laboratory Laboratory Investigations Investigations
C. difficile detectionC. difficile detection
CultureCulture
Antigen detectionAntigen detection
C. difficile culture C. difficile culture Limited clinical value!Limited clinical value!
Several days for resultsSeveral days for results
No differentiation b/w No differentiation b/w toxigenictoxigenic & & nonnon--toxigenictoxigenic
Antimicrobial susceptibilityAntimicrobial susceptibility
Molecular typing, epidemiologyMolecular typing, epidemiology
C. difficile GDH C. difficile GDH antigen antigen
<2 hours<2 hours
>90% sensitivity>90% sensitivity
screening testscreening test
\\
Laboratory Laboratory Investigations Investigations C. difficile toxin detectionC. difficile toxin detection
ToxigenicToxigenic cultureculture
Cell Cell cytotoxicitycytotoxicity neutralisatonneutralisaton assay assay (CCNA)(CCNA)
Enzyme Immunoassay (EIA)Enzyme Immunoassay (EIA)
ImmunochromatographicImmunochromatographic testtest
PCRPCR
Cell Cell cytotoxicitycytotoxicityneutralisatonneutralisaton assayassay
““Gold standardGold standard””
Specific (99Specific (99--100%)100%)
Cell culture expertiseCell culture expertise
2424--48 hours48 hours
Cell Cell cytotoxicitycytotoxicityneutralisatonneutralisaton assayassay
““Gold standardGold standard””
Specific (99Specific (99--100%)100%)
Cell culture expertiseCell culture expertise
2424--48 hours48 hours
Enzyme Immunoassay Enzyme Immunoassay (EIA)(EIA)
SpecificSpecific
4 hours4 hours
No cell culture expertiseNo cell culture expertise
Sensitivity 60Sensitivity 60--90%90%
ImmunochromatographiImmunochromatographicc Tests (ICT)Tests (ICT)
SpecificSpecific
<1 hour<1 hour
No expertise requiredNo expertise required
Sensitivity 50Sensitivity 50--65%65%
Polymerase Chain Polymerase Chain Reaction (PCR)Reaction (PCR)
<2 hours<2 hours
SpecificSpecific
SensitiveSensitive
CostCost
BD BD GeneOhmGeneOhm
Up to 6 specimens per runUp to 6 specimens per run
GeneXpertGeneXpert
result <1 hourresult <1 hour
18 18 bpbp deletiondeletion
GeneXpertGeneXpert