Self-Contained Biological Indicator With Integrated Activation Control (AC-SCBI)

Abstract

The invention relates to a self-contained biological indicator comprising a vial, an ampule arranged inside said vial, a growth medium for growing microorganisms, the growth medium being arranged inside the ampule and the growth medium having a first color, a biological indicator, a carrier for holding the biological indicator, wherein the biological indicator is arranged on the carrier, and at least one color change indicator having a second color, wherein the at least one color change indicator is arranged inside the vial but outside the ampoule, the growth medium does not contain any of the at least one color change indicator and the first color of the growth medium is changed by the second color of the at least one color change indicator when mixed with the at least one color change indicator.

Claims

1. A self-contained biological indicator (SCBI) comprising a vial, an ampule arranged inside said vial, the ampule containing a growth medium for growing microorganisms, a liquid of the growth medium containing a first color or is transparent, a biological indicator (BI) on a carrier, and at least one color change indicator (CCI) having a second color, wherein: the at least one CCI is arranged inside said vial but outside said ampule, the growth medium inside the ampule does not contain any of the at least one CCI and the first color of the growth medium is changed by the second color of the at least one CCI when the growth medium is mixed with the at least one CCI.

2. The SCBI according to claim 1, wherein the at least one CCI is arranged on the carrier together with the biological indicator.

3. The SCBI according to claim 1, wherein the at least one CCI is separately arranged inside the vial as at least one pearl or on at least one separate carrier so there is no contact to the biological indicator thereby preventing growth of microorganisms or a negative influence on the long-term stability of the biological indicator on the carrier.

4. The SCBI according to claim 3, wherein the at least one CCI is arranged on an inner surface of a wall of the vial and/or on an outer surface of a wall of the ampule.

5. The SCBI according claim 1, wherein the at least one CCI is inside a second ampule dissolved in a liquid which is placed in the vial together with the ampule of the growth medium.

6. The SCBI according to claim 1, wherein the at least one CCI changes its color due to an enzymatic reaction together with a chemical substance.

7. The SCBI according to claim 1, wherein the ampoule ampule is made from glass and/or the vial is made from a deformable plastic.

8. The SCBI according to claim 1, wherein the carrier is a carrier disc or a strip and/or the carrier is made from paper, stainless steel or glass fiber or any plastic material.

9. The SCBI according to claim 1, wherein the at least one CCI is not arranged inside said ampule or in any other ampule inside said vial.

10. The SCBI according to claim 1, wherein the at least one CCI is a pH-indicator.

11. The SCBI according to claim 1, wherein the at least one CCI is arranged at more than one location inside said vial but outside said ampule.

12. The SCBI according to claim 1, wherein the carrier is arranged inside said vial and outside said ampule.

13. The SCBI according to claim 1, wherein the SCBI is usable for testing sterility achieved by radiation or by gas sterilization.

14. The SCBI according to claim 1, wherein the second color of the at least one CCI changes to an indication color in a reaction to contact with at least one metabolic product from the biological indicator.

15. A method for testing sterility using an SCBI according to claim 1, the method comprising the chronological steps of A) Activating an ampule transferring a growth medium inside a vial; B) Bringing the growth medium in contact with a biological indicator and with at least one CCI, wherein a color of the growth medium is changed by the at least one color change indicator; C) Allowing microorganisms from the biological indicator to grow in the growth medium; and D) Observing by visual or photometric inspection if a change of color occurs which could be a result of a reaction of the at least one CCI with at least one metabolic product from the microorganism.

16. The method according to claim 15, wherein before method step C) is carried out, controlling if a change of the color of the growth medium occurred and only if the change of color is observed continuing with step C) and otherwise further opening the ampule or deforming the vial to allow mixing of the growth medium with the at least one CCI.

17. The SCBI according to claim 4, wherein the at least one CCI is arranged on an inner surface of a wall of the vial and/or on an outer surface of a wall of the ampule without being in contact with the biological indicator on the carrier.

18. The SCBI according to claim 6, wherein the at least one CCI changes its color due to an enzymatic reaction together with a chemical substance, wherein the color change, an optical density change, or a biofluorescence reaction with UV-light of the at least one CCI is detectable.

19. The SCBI according to claim 7, wherein the ampule is made from a translucent deformable plastic.

20. The SCBI according claim 9, wherein the at least one CCI is arranged without any container inside said vial.

21. The SCSI according to claim 13, wherein the SCSI is usable for testing sterility achieved by UV radiation and gamma radiation, or by ethylene oxide sterilization, formaldehyde sterilization (LTSF), and steam.

Description

BRIEF DISCUSSION OF THE FIGURES

[0059] FIG. 1 shows a standard SCBI according to the state of the art with a pH-indicator or other CCI inside a glass ampoule together with a growth medium;

[0060] FIG. 2 shows an SCBI according to a first embodiment according to the present invention having a CCI outside a glass ampoule on a carrier with BI;

[0061] FIG. 3 shows an SCBI according to a second embodiment according to the present invention having a color change indicator arranged as a pearl at the bottom area of the plastic vial;

[0062] FIG. 4 shows an SCBI according to a third embodiment according to the present invention having a CCI arranged at the surface inside the SCBI plastic vial;

[0063] FIG. 5 shows an SCBI according to a fourth embodiment according to the present invention having a CCI arranged at the outside glass ampoule surface;

[0064] FIG. 6 shows an SCBI according to a fifth embodiment according to the present invention having a CCI arranged in a second glass ampoule below or above the glass ampoule containing the growth medium;

[0065] FIG. 7 shows an SCBI according to a sixth embodiment according to the present invention having a CCI arranged on a piece of paper inside the plastic vial, outside of the glass ampoule.

[0066] FIG. 8 shows an exemplary sequence diagram for a method according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0067] FIG. 2 shows an SCBI 1 according to the present invention. The SCSI 1 comprises a growth medium 9 which is contained inside an ampoule 4. The growth medium 9 can be colorless, transparent or of a white appearance. The ampoule 4 can be translucent. The ampoule 4 is contained in a vial 5. The ampoule 4 can be made of glass or another manually breakable material. The vial 5 can be made of a plastic which is deformable, preferably from an elastically deformable plastic. The vial 5 can be deformable such as to allow breaking of the ampoule 4 inside the vial 5. The vial 5 is translucent to allow visual control of the color of its ingot.

[0068] A biological indicator 3 (BI) can be arranged on a carrier inside the vial 5 but outside the ampoule 4 so that no physical contact between the BI 3 and the growth medium 9 can occur. The vial 5 can be closed to the outside by means of a cap 7. The cap 7 can comprise filter 6 being permeable for gases but being impermeable for microorganisms and a passage 8 for allowing a gas exchange through cap 7.

[0069] According to the present invention, at least one CCI 10 is arranged inside the vial 5 but outside the ampoule 4. The CCI 10 is arranged on the carrier. Alternatively, the CCI could also be located on a separate carrier apart from the carrier for the BI 3.

[0070] FIG. 3 shows a second embodiment of an SCBI 1 according to the present invention. The SCBI 1 comprises a growth medium 9 which is contained inside an ampoule 4. The growth medium 9 can be colorless, transparent or of a white appearance. The ampoule 4 can be translucent. The ampoule 4 is contained in a vial 5. The ampoule 4 can be made of glass or another manually breakable material. The vial 5 can be made of a plastic which is deformable, preferably from an elastically deformable plastic. The vial 5 can be deformable such as to allow breaking of the ampoule 4 inside the vial 5. The vial 5 is translucent to allow visual control of the color of its ingot.

[0071] A biological indicator 3 (BI) can be arranged on a carrier inside the vial 5 but outside the ampoule 4 so that no physical contact between the BI 3 and the growth medium 9 can occur. The vial 5 can be closed to the outside by means of a cap 7. The cap 7 can comprise filter 6 being permeable for gases but being impermeable for microorganisms and a passage 8 for allowing a gas exchange through cap 7.

[0072] According to the present invention, at least one CCI 11 is arranged inside the vial 5 but outside the ampoule 4. The CCI 11 is formed as at least one pearl inside the vial 5 but outside the ampoule 4. Alternatively, the CCI could also be located on a separate carrier apart from the carrier for the BI 3.

[0073] FIG. 4 shows a third embodiment of an SCBI 1 according to the present invention. The SCBI 1 comprises a growth medium 9 which is contained inside an ampoule 4. The growth medium 9 can be colorless, transparent or of a white appearance. The ampoule 4 can be translucent. The ampoule 4 is contained in a vial 5. The ampoule 4 can be made of glass or another manually breakable material. The vial 5 can be made of a plastic which is deformable, preferably from an elastically deformable plastic. The vial 5 can be deformable such as to allow breaking of the ampoule 4 inside the vial 5. The vial 5 is translucent to allow visual control of the color of its ingot.

[0074] A biological indicator 3 (BI) can be arranged on a carrier inside the vial 5 but outside the ampoule 4 so that no physical contact between the BI 3 and the growth medium 9 can occur. The vial 5 can be closed to the outside by means of a cap 7. The cap 7 can comprise filter 6 being permeable for gases but being impermeable for microorganisms and a passage 8 for allowing a gas exchange through cap 7.

[0075] According to the present invention, at least one CCI 12 is arranged inside the vial 5 but outside the ampoule 4. The CCI 12 is arranged on the inner side of a wall of the vial 5. Alternatively, the CCI could also be located on a separate carrier apart from the carrier for the BI 3.

[0076] FIG. 5 shows a fourth embodiment of an SCBI 1 according to the present invention. The SCBI 1 comprises a growth medium 9 which is contained inside an ampoule 4. The growth medium 9 can be colorless, transparent or of a white appearance. The ampoule 4 can be translucent. The ampoule 4 is contained in a vial 5. The ampoule 4 can be made of glass or another manually breakable material. The vial 5 can be made of a plastic which is deformable, preferably from an elastically deformable plastic. The vial 5 can be deformable such as to allow breaking of the ampoule 4 inside the vial 5. The vial 5 is translucent to allow visual control of the color of its ingot.

[0077] A biological indicator 3 (BI) can be arranged on a carrier inside the vial 5 but outside the ampoule 4 so that no physical contact between the BI 93 and the growth medium 9 can occur. The vial 5 can be closed to the outside by means of a cap 7. The cap 7 can comprise filter 6 being permeable for gases but being impermeable for microorganisms and a passage 8 for allowing a gas exchange through cap 7.

[0078] According to the present invention, at least one CCI 13 is arranged inside the vial 5 but outside the ampoule 4. The CCI 13 is arranged on the outer side of a wall of the ampoule 4. Alternatively, the CCI could also be located on a separate carrier apart from the carrier for the BI 3.

[0079] FIG. 6 shows a fifth embodiment of an SCBI 1 according to the present invention. The SCBI 1 comprises a growth medium 9 which is contained inside an ampoule 4. The growth medium 9 can be colorless, transparent or of a white appearance. The ampoule 4 can be translucent. The ampoule 4 is contained in a vial 5. The ampoule 4 can be made of glass or another manually breakable material. The vial 5 can be made of a plastic which is deformable, preferably from an elastically deformable plastic. The vial 5 can be deformable such as to allow breaking of the ampoule 4 inside the vial 5. The vial 5 is translucent to allow visual control of the color of its ingot.

[0080] A biological indicator 3 (BI) can be arranged on a carrier inside the vial 5 but outside the ampoule 4 so that no physical contact between the BI 3 and the growth medium 9 can occur. The vial 5 can be closed to the outside by means of a cap 7. The cap 7 can comprise filter 6 being permeable for gases but being impermeable for microorganisms and a passage 8 for allowing a gas exchange through cap 7.

[0081] According to the present invention, at least one CCI 14 is arranged inside the vial 5 but outside the ampoule 4. The CCI 14 is arranged in a second ampoule 16, which is arranged inside the vial 5. Alternatively, the CCI could also be located on a separate carrier apart from the carrier for the BI 3.

[0082] FIG. 7 shows a sixth embodiment of an SCBI 1 according to the present invention. The SCBI 1 comprises a growth medium 9 which is contained inside an ampoule 4. The growth medium 9 can be colorless, transparent or of a white appearance. The ampoule 4 can be translucent. The ampoule 4 is contained in a vial 5. The ampoule 4 can be made of glass or another manually breakable material. The vial 5 can be made of a plastic which is deformable, preferably from an elastically deformable plastic. The vial 5 can be deformable such as to allow breaking of the ampoule 4 inside the vial 5. The vial 5 is translucent to allow visual control of the color of its ingot.

[0083] A biological indicator 3 (BI) can be arranged on a carrier inside the vial 5 but outside the ampoule 4 so that no physical contact between the BI 3 and the growth medium 9 can occur. The vial 5 can be closed to the outside by means of a cap 7. The cap 7 can comprise filter 6 being permeable for gases but being impermeable for microorganisms and a passage 8 for allowing a gas exchange through cap 7.

[0084] According to the present invention, at least one CCI 15 is arranged inside the vial 5 but outside the ampoule 4. The CCI 15 is arranged on a paper, which is arranged inside the vial 5. Alternatively, the CCI could also be located on a separate carrier apart from the carrier for the BI 3.

[0085] FIG. 8 shows a method according to the present invention for using an SCBI as an exemplary sequence diagram on the right hand side. On the left hand side of FIG. 8 a method according to the state of the art is shown as a comparison. The method is discussed using an SCBI according to FIG. 2. After having used the SCBI 1 for a sterilizing cycle of any kind (gas sterilization or radiation sterilization), the ampoule 4 is broken inside the vial 5 of the SCBI 1 by deforming the vial 5. The liquid or pasty growth medium 9 flows from the broken ampoule 4 and mixes with the CCI 10 on the carrier and with the BI 3. Thereby, the at least one CCI 10 changes the color of the growth medium 9. By checking the color change of the growth medium 9 it can be checked if the growth medium 9 has been mixed with the at least one CCI 10 and with the BI 3. If not, the ampoule 4 has not been broken open and this can be taken care of.

[0086] If yes, the microorganisms of the BI 3 can grow in the growth medium 9 by processing it for a certain time at an adequate temperature suitable for growth of the microorganisms of the BI 3. Due to metabolic processes of the microorganisms, acid and/or other metabolic products are produced by the growing microorganisms. This acid or the other metabolic products result in a chemical reaction with the at least one CCI 10 which leads to a change in color. Thus, it can be checked if living BIs have been present by checking the color of the ingot of the so processed SCBI 1.

[0087] To prevent the possible user mistake of not bringing the SCBI 1 in the correct working condition, the invention separates the CCI 10-15 (like a pH-indicator) from the growth medium 9 but leaves it inside the vial 5. The growth medium 9 will preferably remain clear transparent without any color inside the growth medium 9 in this case. If the incubation is carried out without activation, that means without having destroyed the ampoule 4, the growth medium 9 will remain colorless indicating that the activation step had not been carried out before incubation. After the SCBI 1 is activated by cracking the ampoule 4, the CCI 10-15 (pH-indicator) outside the growth medium 9 but inside the vial 5 is getting dissolved in the liquid growth medium 9 changing the color of the solution, for example purple indicating activation. During incubation when no further color change occurs, the sterilization process was successful, opposite a color change, for example to yellow, signals an unsuccessful sterilization process.

[0088] The features of the invention disclosed in the above description, the claims, figures, and exemplary embodiments can be essential both individually and in any combination for implementing the various embodiments of the invention.

LIST OF REFERENCE NUMBERS

[0089] 1 Self-contained biological indicator (SCBI) [0090] 2 Mixture of growth medium with pH-indicator [0091] 3 Biological indicator (BI) [0092] 4 Ampoule [0093] 5 Vial [0094] 6 Filter [0095] 7 Cap [0096] 8 Passage [0097] 9 Growth medium [0098] 10 Color change indicator (CCI) on the carrier [0099] 11 Pearl of color change indicator [0100] 12 Color change indicator on the vial [0101] 13 Color change indicator on the ampoule [0102] 14 Color change indicator in separate ampoule [0103] 15 Color change indicator on paper [0104] 16 Second ampoule