remel Xpect Clostridium difficile Toxin A/B Manual Del Usuario

ENGLISH
Clostridium difficile
Toxin A/B
INTENDED USE
®
Remel Xpect Clostridium difficile Toxin A/B test kit is a rapid in vitro
immunochromatographic test for the direct, qualitative detection of
Clostridium difficile Toxin A and/or B in human fecal specimens from
patients suspected of having Clostridium difficile-associated disease
(CDAD). The test is intended for use as an aid in diagnosis of CDAD.
The test can also be used for confirmation of toxigenic C. difficile from
Brain Heart Infusion (BHI) broth culture.
SUMMARY AND EXPLANATION
C. difficile was first described in 1935, but it was not until 1977 that
links were made between the organism and disease. C. difficile is a
toxin-producing, spore-forming anaerobic gram-positive bacillus. The
clinical presentation of C. difficile infection includes, in increasing
order of severity, asymptomatic carriers, antibiotic-associated colitis,
pseudomembranous colitis (PMC), and fulminant colitis.
of the normal microbial flora in the colon, usually caused by antibiotic
therapy, allows overgrowth of C. difficile. Symptoms of antibiotic-
associated colitis usually begin four to ten days after antibiotic
treatment has begun.
Most pathogenic strains of C. difficile produce two toxins, Toxin A
(enterotoxin) and Toxin B (cytotoxin), which are the main virulence
factors for the organism. There appears to be a cascade of events,
which result in the expression of the activity of these toxins. Toxin A
is mildly cytopathic but induces large fluid shifts and mucosal
inflammation. Toxin B is intensely cytopathic but its role in the
disease process is not clearly understood. Variant strains which are
Toxin A-negative, Toxin B-positive are known to exist, are fully
pathogenic, and capable of producing the full spectrum of disease.
The prevalence of these variant strains varies widely by institution
2-7
and geographic location.
C. difficile-associated disease (CDAD) primarily occurs in hospitalized
8,9
patients. Individuals with CDAD shed spores in the stool, which can
survive for as long as five months in the environment. Clinical and
pathological features of CDAD are not easily distinguished from those
of other gastrointestinal diseases, including ulcerative colitis, chronic
inflammatory bowel disease, and Crohn's disease.
toxigenic C. difficile is a potentially life-threatening disease process;
however, when properly treated, patient mortality rates are low.
Thus, rapid diagnosis, allowing clinicians to initiate appropriate
therapy and implement adequate measures to control nosocomial
spread, is important.
PRINCIPLE
®
The Xpect Clostridium difficile Toxin A/B test is a qualitative
immunochromatographic assay that detects C. difficile Toxin A and
Toxin B in stool specimens or cultures of toxigenic C. difficile. In
performing the test, a specimen is first diluted with Specimen Diluent
to help solubilize the toxins. A portion of the diluted sample is then
mixed with a volume of Conjugate 1 containing antibodies to Toxin A
and Toxin B coupled to colored microparticles, plus a volume of
Conjugate 2 containing biotinylated antibodies to Toxin A and Toxin
B. A volume of this mixture is transferred to a test device having
immobilized streptavidin as a test line and goat anti-immunoglobulin
antibody as a control line. Immunocomplexes of toxin and conjugated
antibodies form a visible band as they flow across the test line.
Excess colored particle conjugates form a visible band at the control
line to document that the test is functioning properly.
STORAGE
Store test devices in sealed foil pouches at 2-30C (room temperature or
refrigerated). Store all kit reagent bottles and vials at 2-8C. Do not
freeze or overheat. Allow components to equilibrate to room
temperature before use. Mix bottled reagents gently prior to use.
Return the unused reagents to the refrigerator after use.
PRECAUTIONS
1. For In Vitro Diagnostic Use.
2. Standard precautions should be taken against the dangers of
biological hazards by properly sterilizing specimens, containers,
and test devices after use. Consult appropriate references when
necessary.
3. Directions should be read and followed carefully.
4. Reagents are provided at the necessary working strength and
are to be dispensed directly from the dropper bottles. Do not
dilute reagents.
5. Do not interchange reagents between kits of different lots.
6. Do not use reagents beyond the printed expiration dates.
7. Microbial contamination of reagents may decrease the accuracy
of the assay.
SPECIMEN COLLECTION, STORAGE, AND TRANSPORT
Specimens should be collected in clean, airtight, leak-proof containers.

Fresh, untreated stool specimens should be stored at 2-8°C and
tested within 72 hours of collection. If fresh specimens cannot
be tested within 72 hours, they should be frozen at -20°C or
below in a non-defrosting freezer and tested within 2 months of
collection. Avoid multiple freeze-thaw cycles.
1 
A reduction Fresh specimens diluted in the Sample Diluent provided in the
kit can be stored refrigerated for up to 24 hours prior to testing.

Stool specimens collected in modified Cary Blair Transport
Medium with indicator (or equivalent) may be stored refrigerated
(2-8C) or stored at room temperature (20-25C) and should be
tested within 5 days of collection.

Stool specimens that have been concentrated or collected in
Formalin, SAF, or PVA are not suitable for use with this test.
REAGENTS AND MATERIALS SUPPLIED
1. Test Devices (20 / 40): Each foil pouch contains one single-use
test device with desiccant; membrane is striped with capture
reagents
2. Conjugate 1 (3.6 ml x 1) / (3.6 ml x 2): Blue-black microparticles
coated with mouse anti-Toxin A and rabbit anti-Toxin B with
0.05% ProClin
3. Conjugate 2 (3.0 ml x 1) / (3.0 ml x 2): Biotinylated goat anti-
Toxin A and rabbit anti-Toxin B with 0.03% ProClin
<0.1% sodium azide
4. Specimen Diluent (12.0 ml x 1) / (12.0 ml x 2): Buffered
Infection with
solution with 0.05% ProClin
5. Positive Control (2.0 ml x 1) / (2.0 ml x 2): Culture supernatant
containing C. difficile Toxin A and B with 0.05% ProClin
6. Negative Control (2.0 ml x 1) / (2.0 ml x 2): Buffered solution
with 0.05% ProClin
7. Disposable Transfer Pipettes (40 / 80): Pipettes with marked
graduations at 0.1 ml increments
8. Dilution Tubes (40 / 80): Tubes for specimen preparation with
marked 0.5 ml volume
9. Wooden Applicator Sticks (20 / 40)
10. Instructions For Use (IFU)
MATERIALS REQUIRED BUT NOT SUPPLIED
(1) Stool specimen collection container(s), and (2) Timer.
Optional materials not provided:
(1) Specimen transport media, (2) BHI Broth, and (3) Test tube rack.
PROCEDURE
1. Allow kit components and stool specimens to equilibrate to room
temperature before use.
2. Mix stool specimens thoroughly prior to testing (regardless of
consistency).
3. Remove the test device from the foil pouch when ready to
perform the test and place it on a flat surface.
4. Label the device (and dilution tubes) with patient or control
identification.
10
®
300 and <0.1% sodium azide
®
300 and <0.1% sodium azide
®
and <0.1% sodium azide
20 / 40 Tests
®
300 and
®
300