Bacterial Antigen Kit includes sufficient reagents to perform
See also Precautions, section 6.
All components should be stored at 2 to 8°C under which condition they will
retain their activity until the expiry date of the kit.
Before use, bring all reagents to room temperature (18 - 30°C) and mix. Return
the unused reagents to the refrigerator after use.
instructions for use
disposable reaction Cards (2 packs)
disposable Mixing sticks (5 bundles)
disposable droppers (1 container)
Black rubber teat (1)
Strep B (pink cap)
H. influenzae b (pale blue cap)
S. pneumoniae (yellow cap)
N. meningitidis ACY W135 (grey cap)
N. meningitidis B/E. coli K1 (brown cap)
Five dropper bottles, one specific for each of the
groups above, containing 0.5% suspensions of
polystyrene latex particles in buffer containing
and/or 0.1% sodium azide as
the appropriate rabbit antibody, as labelled,
except for the N. meningitidis group B/E. coli K1
reagent, which is coated with murine monoclonal
5 dropper bottles (dark blue cap) containing
0.5% suspensions of polystyrene latex particles
in buffer containing 0.05% Bronidox
are coated with an appropriate preparation of
rabbit globulin or in the case of the N. meningitidis
group B/E. coli K1 latex, a murine monoclonal
antibody raised against Bordetella bronchiseptica.
The latex suspensions are provided ready for use
and should be stored at 2 to 8°C in an upright
position, until the expiry date of the kit. After
prolonged storage some aggregation or drying
of the latex may have occurred around the top of
the bottle. Under these circumstances the bottle
of latex should be shaken vigorously for a few
seconds until resuspension is complete. DO NOT
Two bottles (blue cap) containing freeze-dried
bacterial extracts containing antigens from
representative strains of each bacterial species
for which latex is provided. Contains 0.01%
bronopol before reconstitution and 0.004% when
Reconstitute using 3.6 ml of sterile distilled water.
After the addition of water allow the bottle to
stand for a few minutes and then swirl to mix.
Store reconstituted antigen at 2 to 8°C for up to
One dropper bottle (white cap) containing Glycine
saline buffer, pH 8.2, with 0.05% Bronidox
The reagents are for in vitro diagnostic use only.
For professional use only.
Please refer to the Safety Data Sheet (SDS) and product labelling for
information on potentially hazardous components.
Bacterial Antigen Kit
ZL26/R30859602 .....................30 Tests
Bacterial Antigen Kit provides a series of rapid latex tests
Haemophilus influenzae type b, Streptococcus pneumoniae (pneumococcus),
Neisseria meningitidis (meningococcus) groups A, B, C, Y or W135 and
Escherichia coli K1 present in cerebrospinal fluid (CSF) as a consequence of
infection. The kit can also be used to test other body fluids or blood culture
supernatants for most of these antigens and plate cultures for N. meningitidis
group B or Escherichia coli K1. (See Table 1 for indications supported by
NOTE: Tests performed directly on clinical specimens are intended for
screening purposes and should augment, not replace, culture procedures.
Results must be used in conjunction with other data; e.g. symptoms, results
of other tests, clinical impressions etc.
Meningitis has a wide variety of potential causes, either infectious or non-
infectious. If bacterial meningitis is not treated promptly and effectively, the
disease is likely to be fatal. Early identification of the infecting agent can be
of considerable value in providing the patient with appropriate and adequate
chemotherapy. Many bacterial species have been implicated in meningitis.
Streptococcus group B and E. coli K1 are two of the most common causes
of neonatal sepsis whilst in older age groups the commonest isolates are
H. influenzae type b, S. pneumoniae and N. meningitidis groups A, B, C, Y
and W135. These organisms carry specific polysaccharide surface antigens,
a quantity of which diffuses into culture media or body fluids such as CSF or
serum, and is excreted in the urine. The antigens can be detected by sensitive
immunological methods such as counterimmuno-electrophoresis and latex
reagents consist of polystyrene latex particles which
particles agglutinate in the presence of sufficient homologous antigen. The
Streptococcus and H. influenzae reagents are group B and type b specific
respectively, the S. pneumoniae reagent is sensitised with antibodies purified
from an omnivalent serum and the N. meningitidis polyvalent reagent reacts
with groups A, C, Y and W135 antigens. Meningococcus group B antigen is
more difficult to detect
as well as being structurally and immunologically
; both of these react with the N. meningitidis
In Vitro Diagnostic Medical Device
Contains sufficient for tests
Consult Instructions for Use
Key Code TSMX7713B
Europe +800 135 79 135
US 1 855 2360 190
CA 1 855 805 8539
ROW +31 20 794 7071
type b, S. pneumoniae and N. meningitidis ACY W135 contain 0.1%
sodium azide. Azides can react with copper and lead used in some
plumbing systems to form explosive salts. The quantities used in this kit
are small; nevertheless when disposing of azide-containing materials
they should be flushed away with large volumes of water.
In accordance with the principles of Good Laboratory Practice it is
infectious and handled with all necessary precautions.
When handling radiometric blood culture medium, the basic rules of
a) Radioactive material should be stored in a designated area in an
b) Handling of radioactivity should take place in a designated area.
No mouth pipetting of radioactive material should be carried out.
The local Radiation Safety Officer should be consulted concerning
procedure after use, although the preferred method is to autoclave for
15 minutes at 121°C. Disposables should be autoclaved or incinerated.
Spillage of potentially infectious materials should be removed
immediately with absorbent paper tissue and the contaminated areas
swabbed with a standard bacterial disinfectant or 70% alcohol. Do
NOT use sodium hypochlorite. Materials used to clean spills, including
gloves, should be disposed of as biohazardous waste.
Do not pipette by mouth. Wear disposable gloves and eye protection
thoroughly when finished.
When used in accordance with the principles of Good Laboratory
stated in these Instructions for Use, the reagents supplied are not
considered to present a hazard to health.
Do not use the reagents beyond the stated expiry date.
Latex reagents should be brought to room temperature (18 to 30°C)
before use. Latex reagents which show signs of aggregation or
‘lumpiness’ before use may have been frozen and must not be used.
It is important when using dropper bottles that they are held vertically
wet an incorrect volume will form around the end and not at the tip;
if this occurs dry the nozzle before progressing.
6.10 The reagents provided with each kit are matched in performance and
should not be used in conjunction with reagents from a kit having a
different lot number.
6.11 Do not touch the reaction areas on the cards.
6.12 Mechanical rotators may be used in this assay. The following
characteristics have been found to be satisfactory:
Orbital rotators (also known as dimensional rotators) operating at 25
at 18 rpm with a rotating angle of 16 to 17.5 degrees.
6.13 Avoid microbial contamination of reagents as this may lead to
after collection as possible. If the fluid cannot be tested immediately
it may be stored overnight at 2 to 8°C, or for longer periods frozen at
–15 to –25°C. If bacteriological analyses are required on the sample,
these should be set up prior to performing the latex test, to avoid
contaminating the sample.
Blood cultures may be sampled and tested after 18 to 24 hours
incubation at 37°C and/or as soon as bacterial growth is observed.
Plate cultures (N. meningitidis B/E. coli K1 only). Isolated colonies
growing on enriched agar medium (e.g. blood, chocolate agar) may
be tested after overnight incubation at 37°C. A Gram stain should be
performed to assist with the interpretation of the latex test result.
REqUIRED MATERIALS PROVIDED
Kit Contents, section 5.
MATERIALS REqUIRED BUT NOT PROVIDED
Boiling water bath
Laboratory centrifuge or membrane filters (0.45 µm)
Rotator (optional – refer to Precautions, section 6)
PREPARATION OF CLINICAL SPECIMENS
Body fluid samples must be heated before testing by the Wellcogen
procedures are recommended:
a) For CSF and urine, heat the sample for 5 minutes in a boiling
water bath. Cool the sample to room temperature (18 to 30°C)
and clarify by centrifugation or membrane filtration (0.45 µm)
prior to testing. For maximum sensitivity urine samples may be
concentrated up to 25-fold in a Minicon
b) For serum, add 3 volumes 0.1 M disodium ethylenediaminetetra-
acetate (EDTA) pH 7.4 per 1 volume serum, heat the sample for 5
minutes in a boiling water bath, cool to room temperature (18 to 30°C)
and clarify as above. A suitable EDTA solution (10 ml) is available (Code
Blood cultures. Centrifuge a 1 to 2 ml sample to pellet the red blood
cells, for example at 1000 g for 5 to 10 minutes. Perform the latex test
on the supernatant.
If a non-specific reaction occurs with a blood culture supernatant (see
water bath for 5 minutes, cool to room temperature (18 to 30°C),
clarify by centrifugation and repeat the test.
the culture plate.
It is recommended that the section on Precautions, section 6, is read carefully
before performing the test.
Body fluid samples and Blood culture supernatants:
NOTE: If there is only a limited volume of test sample available, it should be
used with the Test Latexes first and if a positive result is obtained the sample
should be tested with the appropriate Control Latex. If sufficient sample
is available, it should be tested against both the Test and Control Latexes
Process the sample as described under
Shake the latex reagents.
Place 1 drop of each test Latex or Control Latex
into a separate circle on a Reaction Card. Ensure
that the dropper bottles are held vertically to dispense
an accurate drop. (See Precautions, section 6).
Using a Disposable Dropper, dispense 1 drop
(approximately 40 µl) of test sample next to each
drop of latex.
Mix the contents of each circle with a Mixing Stick
and spread to cover the complete area of the circle.
Use a separate stick for each circle and discard it for
safe disposal after use.
for 3 minutes, holding the card at normal reading
distance (25 to 35 cm) from the eyes. Do not use a
magnifying lens. Mechanical rotation (3 minutes) may
be used (See Precautions, section 6). The patterns
obtained are clear cut and can be recognised under all
normal lighting conditions.
Discard the used Reaction Card for safe disposal.
from the same source as the specimen should be used as a negative control.
Note: testing uninoculated media is important as false-positives can occur
with some formulations of blood culture media.
a) Previously assayed positive and negative samples, aliquoted and
stored at –15 to –25°C or below, may be used as positive and negative
controls respectively, if desired. The Positive Control can also be used
in place of the test sample.
b) For colony identification tests (Wellcogen
N. meningitidis B/E. coli K1
be confirmed using fresh, overnight cultures of reference strains
of bacteria, following the method described in test Procedure.
Suitable reference strains are:
ATCC 13090 – N. meningitidis group B (positive reactivity)
ATCC 23503 – E. coli type K1 (positive reactivity)
ATCC 13077 – N. meningitidis group A (negative reactivity)
ATCC 13090 and ATCC 23503 should give agglutination with the
Test Latex and no significant agglutination in the Control Latex,
ATCC 13077 should give no significant agglutination with either the
Test or Control Latex.
READING OF RESULTS
within 3 minutes (20 seconds for colony testing) of mixing the latex with the
test sample, showing clearly visible clumping of the latex particles (Figure 1).
The speed of appearance and quality of agglutination depend on the strength
of the antigen, varying from large clumps which appear within a few seconds of
mixing, to small clumps which develop rather slowly. In culture identification,
most positive reactions will be almost instantaneous.
In a negative reaction the latex does not agglutinate and the milky appearance
remains substantially unchanged throughout the test (Figure 2). Note,
however, that faint traces of granularity may be detected in negative patterns,
depending on the visual acuity of the operator. In culture identification, some
strains may cause a “stringy” aggregation of the latex with a milky background;
this should be interpreted as a negative reaction.
NOTE: The latex particles used in the Wellcogen
N. meningitidis B/E. coli K1
other reagents, and give a finer agglutination.
INTERPRETATION OF RESULTS
Clear agglutination of a single Test Latex accompanied by negative reactions
with all other Test Latex reagents and the Control Latex indicates the presence
and identity of a bacterial antigen in the test sample. As a general rule a
positive result with Wellcogen
N. meningitidis B/E. coli K1 against a neonatal
group B is more likely.
Negative reactions with all the Test Latex reagents indicates the absence of a
detectable level of the bacterial antigens in the test fluid – it does not eliminate
the possibility of an infection caused by these organisms, and if symptoms
persist it may be desirable to perform the test on subsequent or alternative
specimens, or after concentration of the urine specimen.
With a culture, lack of agglutination in Wellcogen
N. meningitidis B/E. coli K1
N. meningitidis B/E. coli K1 only):
For each culture to be tested place 1 drop of
test Latex in one circle on a Reaction Card and 1
drop of Control Latex in a separate circle.
NOTE: it is essential to use the Control Latex for
suspected E. coli cultures.
Take a Mixing Stick and pick up some of the culture
by touching it with the flat end of the stick. As a guide,
an amount of growth roughly equivalent to 1 large
colony should be picked.
by rubbing with the flat end of the stick. Rub
thoroughly, but not so vigorously as to damage the
surface of the card. Spread the latex to cover as much
of the circle as possible. Discard the Mixing Stick for
Using a separate stick, emulsify a similar sample of
culture in the Control Latex.
for 20 seconds holding the card at normal reading
distance (25 to 35 cm) from the eyes. Do not use a
magnifying lens. The patterns obtained are clear cut
and can be easily recognised under all normal
The following procedures should be carried out initially with each shipment of
test kits and with each run of test samples. In practice, a run may be defined
as a testing period of up to 24 hours. Any departure from the expected results
indicates there may be a problem with the reagents, which must be resolved
before further use with clinical samples.
dropped onto the test card and if there is evidence of clumping before addition
of the test sample, the suspension must not be used. After prolonged storage
some aggregation or drying may have occurred around the top of the bottle.
If this is observed, the bottle should be shaken vigorously for a few seconds
until resuspension is complete.
POSITIVE CONTROL PROCEDURE
Control to a reaction circle in which the test sample has not agglutinated the
Test Latex after 3 minutes rotation.
Use a Disposable Dropper to add 1 drop of Positive
Control to the circle containing Test Latex and
Mix using a Mixing Stick and discard it for safe
Rock the card manually or by a rotator for a further
3 minutes. After this time, definite agglutination
should be visible in the Test Latex.
NEGATIVE CONTROL PROCEDURE
Control Latexes (or Test Latex only where no Control Latex has been used),
this constitutes a valid negative control for the reagents and no further
testing is necessary.
If a test sample gives agglutination with the Test Latex and no agglutination
with the Control Latex then the Test Latex should be tested either with the
Negative Control or uninoculated blood culture medium, as appropriate
Place one drop of Test Latex in one circle on a
Dispense one drop of Negative Control or
uninoculated blood culture medium next to the Test
Rock the card manually or by a rotator for a further
3 minutes. After this time, there should be no
significant agglutination in the Test Latex.
For tests with body fluid samples, the Negative Control provided with the
kit should be used.
Agglutination of more than one Test Latex reagent or corresponding Test and
Control Latexes indicates a non-specific reaction. In most cases, non-specific
reactions with body fluids may be eliminated by heating and clarifying the
(see Preparation of Clinical specimens, section 8). If a non-specific
water bath for 5 minutes, cool to room temperature (18 to 30°C), clarify by
centrifugation and repeat the test.
11.1 for infant body fluids (Group B strep only) – False negative test results
may occur with specimens containing levels of antigen below the limits
of detection of this device. Negative results should be followed up
with selective broth culture. A positive result indicates the presence of
Group B streptococcal antigen; the result does not necessarily indicate
the presence of viable organisms.
11.2 for infant body fluids (Group B strep only) – Use of this device should
not substitute for microbiological culture. Performance of this device
for predicting Group B streptococcal disease from tests of infant urine
has not been established.
11.3 Group B streptococcus infections occur primarily in neonates. Positive
results obtained with body fluid samples from patients older than six
months should be interpreted with caution. Positive results obtained
with blood culture supernatants from patients of any age may be
11.4 A positive result in the test depends on the presence of a detectable
level of antigen in the body fluid or blood culture medium.
11.5 Limited clinical data are available for the detection of antigen in urine
or serum using Wellcogen
N. meningitidis B/E. coli K1 (Table 6). No
N. meningitidis ACY W135 (Table 5). However, antigen
possess common antigens and, as with any immunological test system,
the possibility of cross reactions occurring in the latex test can not be
Samples containing a detectable level of group B streptococcal antigen, H.
influenzae type b antigen, S. pneumoniae capsular antigen, N. meningitidis
A, C, Y, W135 antigens, or N. meningitidis B / E. coli K1 antigen will give an
agglutination reaction with the appropriate Test Latex.
13.1 Body fluids and Blood Cultures
Clinical studies were carried out in 15 centres using body fluid
Both traditional and radiometric cultural techniques were used in
the blood culture studies. Stored body fluid samples were not heat
treated as described under Preparation of Clinical specimens, section
after heating by this procedure.
The sensitivity of each latex in the kit was established from tests on
there was other evidence of infection (clinical diagnosis plus other
antigen test positive).
Tables 2 to 6 show the numbers of each type of specimen tested
results obtained. The sensitivity of each latex in detecting bacterial
antigen in CSF was 67% (12/18) for Wellcogen
Strep B, 97% (87/90)
H. influenzae b, 88% (45/51) for Wellcogen
S. pneumoniae, 71% (29/41) for Wellcogen
N. meningitidis ACY
W135 and 65% (11/17) for Wellcogen
N. meningitidis B/E. coli K1.
The specificity of each of the Wellcogen
reagents was evaluated using
body fluid (fresh and frozen) and blood culture samples from patients
with bacterial or aseptic meningitis and other unrelated conditions.
The organisms isolated from the infected samples were H. influenzae b,
Staphylococcus aureus, Enterobacter aerogenes, Klebsiella
pneumoniae, Mycobacterium tuberculosis, Proteus mirabilis,
Staphylococcus epidermidis, alpha-haemolytic streptococcus, beta-
haemolytic streptococcus group A, Klebsiella oxytoca, Pseudomonas,
Streptococcus sanguis, Toxoplasma gondii and a coliform bacterium.
The specificity of all five Wellcogen
latexes in tests on CSF was greater
than 98%. Details of the number of samples tested and the specificity
of each Wellcogen
with each type of specimen are given in tables 2
13.2 Plate Cultures (N. meningitidis B/E. coli K1).
N. meningitidis and E. coli cultures grown on an enriched agar medium
group B and E. coli K1 cultures were correctly identified. There were no
cross-reactions with other groups of N. meningitidis or other E. coli K
antigens (Table 7). A high proportion of the E. coli cultures with other
K antigens which were tested gave non-specific reactions (Table 7).
specimens which have been evaluated with
Strep. B H. influenzae b S. pneumoniae N. meningitidis
Data available to support this application.
Limited data available.
No data available.
other antigen test).
Bacteria other than Strep. B/no growth.
E. coli isolated.
P. mirabilis isolated.
Staph. epidermidis; beta-haemolytic strep. group A; E. coli + Enterococcus;
Staph. epidermidis + Enterococcus isolated.
results of clinical studies on Wellcogen
h. influenzae b
No. tested No. positive No. tested No. positive
90 87 375
21 20 21 0
10 10 236 0
One additional CSF sample gave a non-specific reaction.
One sample aseptic; E. coli isolated from other sample.
Two additional blood culture supernatants gave non-specific reactions.
One sample aseptic. Other samples grew: Staph. aureus; E. coli + Staph.
51 45 483
6 6 13 0
105 46 320
One additional CSF gave a non-specific reaction.
Enterobacter aerogenes; coliform bacterium.
Three additional urine samples gave non-specific reactions.
Pseudomonas; Strep. sanguis; Staph. epidermidis + Enterococcus; Strep.
29 423 2
Includes 8 group A, 25 group C and 1 group Y (the remainder were not
K. aerogenes; E. coli.
Five additional urine samples gave non-specific reactions.
Strep. sanguis; Staph. epidermidis + Enterococcus.
N. meningitidis B
E. coli K1
6 4 128 0
Samples stored frozen. All other samples tested fresh.
Aerobic and anaerobic cultures (beta-haemolytic strep A) for same patient;
N. meningitidis group C
N. meningitidis group 29E
N. meningitidis group W135
N. meningitidis group X
N. meningitidis group Y
N. meningitidis group Z
E. coli K1
E. coli – other antigens
Cultures identified by slide agglutination.
An additional 10 cultures gave non-specific reactions.
Polyribitol-phosphate: an antigen of four gram-positive bacteria cross-reactive
J. Immunol., 112, 649.
Commercial latex agglutination for detection of group B streptococcal antigen
J. Pediatr., 102, 393.
Surface polysaccharide of Moraxella non-liquefaciens identical to Neisseria
NIPH Annals, 6, 65.
Bacterial antigen detection in body fluids: methods for rapid antigen concentration
J. Clin. Microbiol., 11, 380.
Countercurrent immunoelectrophoresis of urine as well as of CSF and blood for
J. Pediatr., 89, 773.
Latex agglutination in diagnosis of bacterial infections, with special reference to
Amer. J. Clin. Path., 68, 284.
Immunochemical similarity between polysaccharide antigens of Escherichia coli
J. Immunol., 110, 262.
Immunochemical relations between pneumococcal group 19 and Klebsiella
J. Immunol., 127, 1619.
Enteric bacteria cross-reactive with Neisseria meningitidis groups A and C and
Infect. Immun., 6, 651.
Rapid bacteriological diagnosis of pyogenic meningitis by latex agglutination.
is the registered trade name of Cognis UK Ltd.
is a trade mark of the Millipore Corporation.
Remel Europe Ltd
Clipper Boulevard West, Crossways
Dartford, Kent, DA2 6PT
IFU X7713B, Revised July 2014
For technical assistance please contact your local distributor.