Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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This application is a division of application Serial
No. 233,326, filed August 12, 1975.
The present invention is concerned with an analytical
device and more particularly with a method for the rapid detec-
tion of microorganisms from an isolating medium, that is to say
the enabling of a diagnosis by a process of elimination in the
case of a search for a particular microbe.
It is known in the art that reactions of bacteria in
a liquid nutritive medium can take place in test tubes, with the
liquid medium necessary for the growth of bacteria having been
freshly prepared just prior to the reaction. Furthermore, cer-
tain reactions, such as bacterial reactions in a urea-indole
medium, denature the reaction medium, which eliminates the
possibility of conducting other reactions in the same medium
at a later time. These reactions, have the further disadvantage
of occurring very slowly. The reading of a reaction in a urea-
indole medium for example is only possible after about four
hours. Other reactions are achieved by immersing reactive test
strips in the test tubes. This procedure presents the incon-
venience because it necessitates a dense medium and equally be-
cause it denatures the reaction medium, which as mentioned above
prevents the medium from being utilized further.
The present invention substantially alleviates the
aforementioned problems by providing an analytical device in-
cluding a test strip which enables the obtaining of rapid re-
sults and enables the bacteria being tested to effect the ultimate
reactions in liquid media. The present invention is also con-
cerned with a process for determining a microorganism such as a
bacterium and a novel cover for glass ampoules.
In one embodiment of this invention an analytical
device is provided which comprises in combination.
(a) a tube adapted to receive a portion of a nutri-
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tive liquid medium containing an unknown bacterium and having
means for sealing-off said tube, and
(b) a test strip comprising:
(1) at least one liquid-reactive surface in-
tended to be immersed in said liquid medium, said surface con-
taining in a dry state some nutritive elements complementary to
the nutritive elements in the liquid medium and a reagent which
reacts with said bacterium, said reagent being incapable of in-
hibiting growth of said bacterium and being non-toxic to said
bacterium, and
(2) at least one vapor-reactive surface not in-
tended to be immersed in the liquid medium when said liquid-
reactive surface is immersed in the liquid medium, said surface
containing in a dry state a reagent which may be toxic to said
specimen and reacts on contact with vapors or gases emitted by
the liquid medium due to the presence of the bacterium therein.
Thus the analytical device is the combination of a
tube which has means for obturation or sealing off of the tube
and contains at least a portion of a nutritive liquid medium
permitting the growth of an unknown microorganism such as a
bacterium, and a test strip which has at least two reactive
regions, one of which is situated in close proximity to the
end of the strip, and is intended to be immersed in the liquid
contained in the tube and contains, in its dry state, some
nutritive elements complementary to the liquid medium enclosed
in the tube and at least one reagent which permits spontaneous
reactions with the bacterium in the liquid medium. The reagent
must be non-toxic to the bacterium and not capable of inhibiting
their growth. The strip also contains at least one other surface
situated on the strip which is not to be immersed in the liquid
medium and contains, in its dry state, a reagent or reagents
which are toxic to the bacterium and react on contact with vapors
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emitted by the liquid medium in the presence of the bacterium.
The reactions take place in a tube placed in an
incubator at about 37C. According to the nature of the bacteria
present, a reaction in the liquid stage can occur and is visually
indicated by a change of color. Furthermore, the liquid medium
releases some volatile products which can initiate some reactions
with the toxic reagents contained in a dry state in the areas
of the strips not immersed. These reactions are also indicated
visually by changes in color of these reactive regions. It is
of interest to note that such reactions do not completely denature
the liquid medium contained in the tube thus permitting new reac-
tions to be conducted using the same medium at a later time.
The analytical device is used to detect the presence
of bacteria and as a screen for preliminary identifying a class
or classes of bacteria. If the screen gives positive results,
that is a visual change in color corresponding to a positive
reaction between the test strip and the bacteria, the investiga-
tion can be extended to a more elaborate testing procedure for a
more accurate determination of the bacteria as, for example, by
using the twenty-test or fifty-test strip method as outlined in
Canadian Patent ~o. 1,024,869, issued January 24, 1978.
Another advantage of this device is that it can be
stored for a relatively long period of time. Furthermore, the
tube can contain chemical products in a liquid form which cannot
be dehydrated or decomposed while the active surfaces of the strip
contain chemical products complementary to those of the liquid
medium, preserved perfectly when dry but poorly or not at all
when in the liquid medium.
Other advantages include the rapid rate of analysis,
on the order of two hours, and the easy preparation of the com-
ponents for use.
Advantageously the tube contains, in addition to a
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portion of a nutritive liquid medium permitting the growth of
bacteria, at least one reactive product which enables spontaneous
reactions with the bacteria to occur in the liquid medium and yet
is non-toxic with respect to these bacteria and does not inhibit
their growth.
The test strip of the invention comprises a primary
sheet of material such as a plastic material having a plurality
of openings equal to the number of surfaces, a weave of the same
material placed over the openings and a sheet of flat covering
material, the woven material being arranged between the two
aforementioned sheets and the three parts sealed together by a
heat-sealing process.
The reagents are deposited on the weave of material
adjacent to the openings as a solution which is allowed to
evaporate to remove solvent therefrom and to leave the surface
impregnated with the reagents.
In still another embodiment of this invention a
flexible cap for a glass container having a narrow sealed neck
such as a heat-sealed ampoule or vial is provided which performs
the dual function of-(a) permitting opening of the container by
breaking of the narrow sealed neck through pressure exerted on
the flexible cap in the vicinity of the narrow neck and (b)
enclosing the opened container to protect and seal the contents
thereofO
In accordance with one aspect of the present invention,
there is provided a hollow flexible cap having an open interior
portion for receiving the narrow sealed end portion of an
elongated unitary glass container, the cap being adapted to per-
form the dual function of opening the container when the sealed
end portion of the container is received with the cap by break-
ing the narrow sealed end portion of a unitary glass container
and for closing the container after opening thereof, the cap
being tapered away from the ~ ng therein and being capable
107~44
of engaging and breaking the sealed end portion from the container
to open the same in response to the external pressure applied
to the tapered portion of the cap when the cap receives the
sealed end portion of the container and in which the cap has
an open cylindrical body portion and a closed end portion dis-
posed opposite the opening in the body portion, the end portion
being substantially planar and extending at an oblique angle
with respect to the longitudinal axis of the body portion, the
angle of the end portion causing force directed thereto to be
transmitted at an angle to the longitudinal axis of the glass
container and to break the narrow sealed end.
The invention will be more completely described with
reference to the following drawings and description.
FIGURE 1 is a front view of the test strip.
FIGURE 2 is a side view of the test strip.
FIGURE 3 is a view of the tube before utilization.
FIG~RE 4 is a view of the tube and the test strip
in the course of testing.
Referring to Figures 1 and 2, the test strip 2 con-
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tains at least two reactive surfaces 3 and 4. The reactive sur-
face 3 contains in its dry state some nutritive elements and
some products which allow spontaneous reactions with the bacteria
in the liquid medium, these products being non-toxic for the
bacteria and not inhibiting their growth. The reactive surface
4 contains products in a dry state which upon reacting when in
contact with gases emitted by the liquid medium in the presence
of certain bacteria are toxic.
Figure 3 shows a tube 5 which before utilization is
sealed. The upper part of the tube 6 may be cut off to permit
the introduction of reagents, the cap 7 having been designed to
seal this tube after introduction of reagents. Tube 5 can con-
tain 1 ml of culture medium and some agents complementary to the
agents contained on the reactive region 3 which region can be
immersed in the culture medium. The cover is made of a flexible
material such as a resin plastic material and fits slidably
over the upper part of the tube 6. The cover also serves to
break the upper part of the tube before use by pressing the
angled portion of the cover against the upper portion of the
tube using, for example, I'thumb pressure`'. In this manner the
tube can be opened safely without directly touching the glass
with the hand. The broken portion of the tube is then removed,
the test strip 2 is placed in the tube and the tube is resealed
with the cover 7.
The strip 2 consists of a primary sheet of material 8
having two perforations 9 and 10 corresponding to the reactive
regions 3 and 4, respectively, a woven or textured tissue or
mesh 12 placed over the perforations 9 and 10 and the top por-
tion of the strip so that the upper end portion of the strip
serves as a gripping area for the test strip, and a flat cover
sheet 13 of plastic material covering the primary sheet with the
woven material over the perforations being exposed between sheets
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8 and 13. The sheets can be made of plastic materials such as
polyvinyl chloride, polyamide or other synthetic polymer. The
three parts are assembled by joining or welding at high frequency
in the case of polyvinyl chloride or by a heat proeess, by im-
pulses, or by ultrasonic vibrations, for the ease where the
materials are made from polyamides or other polymers.
In practice, the upper portion 6 of the tube 5 is
broken off, then a suspension of the specimen-to be analyzed
is made. Then the strip 2 is introduced into tube 5 so that
only region 3 is immersed, region 4 being located just above
the liquid. The tube is covered by cap 7 and placed in an ineu-
bator at 37C for two hours.
The result of the reactions is indicated by eventual
ehanges in the eolor of the liquid and/or the reaetive regions.
Thus, for example, the eulture medium ean inelude as a reagent
"ONPG`' ( -galactosidose) whieh turns yellow for a positive
reaetion, while the region 3 may contain "TDA" (tryptophane)
whieh turns maroon on reaetion, and region 4 may contain l'IND"
or "INDOLE" (Kovacs reagent) which turns to violet on reaction.
The test strip 5 can contain a plurality of operational
or reaetive regions 3 and a plurality of operations or reaetive
regions 4 in aecordanee with the invention.
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