WO2010089659A2

WO2010089659A2 - Medical device to verify the presence of microorganisms or bacteria in a sample of an organ or a biological tissue, diagnostic apparatus comprising said medical device and relative method

Info

Publication number: WO2010089659A2
Application number: PCT/IB2010/000228
Authority: WO
Inventors: Paolo Galiano
Original assignee: Alifax Holding Spa
Priority date: 2009-02-06
Filing date: 2010-02-05
Publication date: 2010-08-12
Also published as: ITUD20090027A1; WO2010089659A3

Abstract

Medical device (10) to verify the presence of microorganisms or bacteria in a sample (32) of an organ or biological tissue inside a container element (28), which is made of material transparent to the electromagnetic radiations that are emitted toward it along a path (P) and has at least an aperture (30) through which said sample (32) is inserted. Liquid culture means (34) are provided inside the container element (28) which are suitable to promote the growth of microorganisms or bacteria possibly present in the sample (32). The medical device (10) comprises a closing element (12) able to be located in correspondence with the aperture (30) and a support element (16) of the oblong type, which extends from the closing element (32) and is able to be introduced inside the container element (28). The support element (16) has an end portion (20) able to be associated stably with the sample (32) so as to keep the sample (32) suspended and at least partly immersed in the liquid culture means (34) inside the container element (28).

Description

"MEDICAL DEVICE TO VERIFY THE PRESENCE OF MICROORGANISMS OR BACTERIA IN A SAMPLE OF AN ORGAN OR A BIOLOGICAL TISSUE, DIAGNOSTIC APPARATUS COMPRISING SAID MEDICAL DEVICE AND RELATIVE METHOD"

FIELD OF THE INVENTION

The present invention concerns a medical device to verify the presence of microorganisms or bacteria in a sample of an organ or biological tissue, a diagnostic apparatus comprising said medical device and the relative method. In particular, but not only, the present invention is used to carry out preliminary analyses before operations to transplant an organ or biological tissue, to verify the presence of microorganisms or bacteria in the sample, which could be harmful for the recipient.

BACKGROUND OF THE INVENTION It is known that operations to transplant organs and/or tissues, such as the cornea, entail preliminary procedures to verify whether or not the organ or tissue in question is infected or not.

In particular, manual culture procedures are known, based on tubes of tryptose, into which a sample of organ or tissue is inoculated; these procedures, however, are very long-lasting, typically about 4 - 6 days, which makes them disadvantageous in terms of time and cost. The technique based on the deflection of a beam of light (light-scattering) is also known, due to the presence of corpuscular elements (bacteria, fungi or other microorganisms) more or less aggregated and/or forming colonies inside a liquid culture solution, in order to quantify, classify and possibly identify bacteria in a biological sample mixed with the liquid culture medium.

The light-scattering technology, usually achieved by means of an apparatus provided with emitter/receiver means of electro-magnetic radiations, is particularly sensitive and therefore suitable to perform quick measurements of the diffused light due to bodies in suspension in the culture broth, such as for example the bacteria and other microorganisms, even when the concentration of the suspension is extremely limited.

For example, the patent application UD2008A000190, in the name of the present Applicant, and the patent application EP-A-565994 describe, for different applications, a method to quantify, classify and possibly identify bacteria in a biological sample, based on the light-scattering technology.

However, said technology based on light-scattering normally suffers from the presence of corpuscular elements or other obstacles to the transmission of analysis radiation in the culture broth.

The document DE-C-508597 is also known, which describes a container for a culture medium suitable for growing bacteria. The container provides a stopper with a short suspension hook facing toward the inside of the container. In document DE-C-508597, a suturing thread is also freely hung from the suspension hook; in turn, an organ part, immersed in a culture medium, is suspended from the suturing thread. One disadvantage of this known solution is that it does not allow to dispose the organ sample in a fixed and stable position in the container, since the sample is affected by the fact that the suturing thread, which is not only flexible because of its very nature, but also is suspended freely from the suspension hook and can therefore oscillate laterally and/or vertically. Consequently, when it is used in an optical analysis system based on light- scattering, the solution shown in DE-C-508597 would also not guarantee the absence of movements of the organ sample immersed in the culture medium and therefore the absence of unforeseeable impediments and obstacles to the transmission of the analysis radiation into the culture broth.

Document CH-A-341914 is also known, which shows a container having a closing element that has a spring element insertable inside the container. The spring element has two end beaks that normally act elastically on the internal walls of the container in order to maintain the closed condition. The closed condition is easily reversible, by pressing the closing element so as to distance the ends of the spring element from the wall.

Purpose of the present invention is therefore to achieve a medical device to verify the presence of microorganisms or bacteria in a sample of an organ or biological tissue, a diagnostic apparatus comprising said medical device and a relative method, which allow rapid, reliable analysis at a reduced cost.

The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other puφoses and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.

In accordance with the above purposes, a medical device according to the present invention is used to verify the presence of microorganisms or bacteria in a sample of an organ or biological tissue located inside a container element.

The container element is made of material transparent to the electro-magnetic radiations which are emitted toward it along a determinate path, in order to actuate a detection based on light-scattering technology, typically by means of an apparatus provided with emission/reception means of electro-magnetic radiations. The container element has at least an aperture through which the sample is inserted. Liquid culture means, for example the liquid culture medium tryptose, are provided inside the container element, which are suitable to promote the growth of microorganisms or bacteria possibly present in the sample.

The medical device according to the present invention comprises a closing element able to be located in correspondence with the aperture of said container element and a rigid support element of the oblong type, which is rigidly constrained to said closing element and extends from said closing element so as to be able to be inserted, during use, inside the container element.

The support element has, in a single piece, an end portion able to be associated stably to said sample so as to keep the sample suspended, at least partly immersed, in a predefined position in the liquid culture means present inside the container element, at a desired level with respect to the bottom of the container element.

The size of the support element, in relation to the height of the container element and the position of the emission/reception means of the electro-magnetic radiation, is such that the sample of organ or tissue under examination does not interfere with the path of the electro-magnetic radiations.

With the present invention, therefore, the verification of the microorganisms and bacteria is considerably quicker than in the state of the art, since it is based on the light-scattering technology, and at the same time it gives considerable reliability and accuracy, since the sample of organ or tissue is maintained suspended in the test tube, still and stable in its suspended position, and does not interfere with the electro-magnetic radiations that pass through the liquid culture means in which the bacterial growth takes place, in practice thus cancelling the factors of sensitivity to foreign bodies that are typical of the light-scattering technology.

Advantageously, the above-mentioned end portion is a hook portion, so as to prevent the sample from accidentally falling into the test tube. According to another characteristic of the present invention, a diagnostic apparatus, based on the light-scattering technology, to verify the presence of microorganisms or bacteria in a sample of organ or biological tissue comprises:

- emitter means able to emit electro-magnetic radiations along a determinate path inside a container element made of material transparent to electro-magnetic radiations, said container element having an aperture through which said sample is inserted, liquid culture means being provided inside said container element which are suitable to promote the growth of possible microorganisms or bacteria possibly present in the sample;

- sensor means able to detect the electro-magnetic radiations coming from the container element and to transmit coordinated signals;

- processing means of the electronic type able to process the signals transmitted by said sensor means in order to verify the presence of microorganisms or bacteria.

The apparatus according to the present invention also comprises a medical device comprising a closing element able to be located in correspondence with the aperture of the container element and a rigid support element of the oblong type, which is rigidly constrained to said closing element and extends, during use, from said closing element toward the inside of the container element. The support element has, in a single body, an end portion able to be stably associated with said sample so as to maintain said sample suspended, stable and at least partly immersed, in a predefined position in the liquid culture means present inside the container element.

Advantageously, the longitudinal size of said support element, in relation to the height of said container element and the position of both said emitter means and of said sensor means of said electro-magnetic radiations, is such that the position of the sample suspended at said end portion does not interfere with the path of said electro-magnetic radiations. A method to verify the presence of microorganisms or bacteria in a sample of organ or biological tissue also comes within the spirit of the present invention, comprising:

- a first step in which, based on the light-scattering technology, electro-magnetic radiations are emitted along a determinate path inside a container element made of material transparent to electro-magnetic radiations, said container element having an aperture through which said sample is inserted, liquid culture means being provided inside said container element which are suitable to promote the growth of microorganisms or bacteria possibly present in the sample;

- a second step in which, again based on the light-scattering technology, the electro-magnetic radiations coming out of the container element are detected and coordinated signals are transmitted;

- a third step in which the signals transmitted are processed to verify the presence of microorganisms or bacteria.

According to the present invention, at least during the first and second step the sample is maintained suspended and at least partly immersed in a predefined stable position in the liquid culture means present inside the container element.

In advantageous forms of embodiment, the method provides to maintain the sample suspended in a stable position at a desired level such as not to interfere at least with the path of said electro-magnetic radiations. In particular, the sample is kept suspended at a desired level such as not to interfere at least with the path of said electro-magnetic radiations. BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of a preferential form of embodiment, given as a non-restrictive example with reference to the attached drawings wherein:

- fig. 1 is a schematic representation of a medical device according to the present invention;

- fig. 2 is a schematic representation of a diagnostic apparatus comprising a medical device according to the present invention;

- fig. 3 is a schematic representation of a variant of the medical device according to the present invention;

- fig. 4 is a schematic representation of a part of the variant of the medical device in fig. 3.

DETAILED DESCRIPTION OF A PREFERENTIAL FORM OF

EMBODIMENT

With reference to the attached drawings, a medical device 10 according to the present invention is used to attach and keep suspended a sample 32 of an organ, such as a cornea, kneecap or other human tissues for transplant, inside a container element or test tube 28, for the purposes of a diagnostic analysis to verify the presence of bacteria or microorganisms in general possibly present in the sample 32.

Typically the test tube 28 is cylindrical and oblong (length about 45 mm, diameter about 14 mm), made of material transparent to electro-magnetic radiations, glass or more generally plastic.

The device 10 comprises a closing element or stopper 12, made of rubber, to close an aperture 30 of the test tube 28, for example by pressure or screwing.

A rigid support element 16, oblong in shape, is rigidly constrained to the stopper 12 and extends longitudinally to be inserted inside the test tube 28. The support element 16 is used to attach the sample 32 and keep it suspended inside the test tube 28.

Consequently, since the support element 16 is rigid and is constrained rigidly and stably to the stopper 12 above, the reliability of the diagnostic analysis is guaranteed, since the sample 32 that is attached and suspended in the test tube 28 is in turn in a desired fixed and stable position, and cannot oscillate laterally or vertically.

Furthermore, the extension in length of the support element 16 is suitably chosen in correlation with the sizes of the test tube 28, so as to locate the sample 32 in a desired and predefined position, functional for the good outcome of the diagnostic analysis to be carried out.

In particular embodiments, a connection body 24 extends from the stopper 12, at the end of which connection body 24 a sealing element 26 is provided to seal the test tube 28. From the connection body 24 a central body 14 protrudes, oblong and conical in shape, which during normal use is located completely inside the test tube 28. The support element 16 is attached rigidly and stably to the central body 14. Typically, the support element 16 is made of metal, or rigid plastic, and is formed by a rectilinear segment 18, partly incorporated inside the central body 14 and partly protruding from the lower end of the central body 14. At a lower end of the rectilinear segment 18 of the support element 16, which protrudes externally from the central body 14, a hook portion 20 is provided, by means of which to attach the sample 32 and keep it suspended. The hook portion 20 is substantially U-shaped, that is, with a curved segment that extends from the end of the support element 16 and then develops, with the pointed terminal segment, again in a direction substantially parallel to the support element 16, but in the opposite direction. The shape of the support element 16 can substantially be compared to that of a fish hook. The shape of the hook portion 20, which substantially supports the sample 32 and constrains it stably, with the curved segment and the pointed terminal segment, allows the sample 32 to be gripped securely, preventing it from slipping downward, for example due to the force of gravity. The extension in length of the support element 16 is such as to guarantee that, when the device 10 is introduced inside the test tube 28 with the sample 32 attached to the hook portion 20, the sample 32 is at a desired level Ll from the bottom 31 of the test tube 28.

At an upper end of the rectilinear segment 18 a stop portion 22 is provided, also incorporated in the central body 14, and is shaped for example curved, to function as an element to retain the support element 16 in the central body 14.

Figs. 3 and 4 show a variant of the device according to the present invention, indicated for convenience by the reference number 110, where equal parts have equal reference numbers. The device 110 comprises, attached above the stopper 12, a gripper element or knob 52, typically made of rubber, in the specific solution ball shaped. The knob 52 is advantageous because, considering the sizes of the test tube 28, in some circumstances it could be difficult to maneuver both the device 110 and the test tube 18. Consequently, the knob 52 is shaped and has sizes such as to allow the device 110 and the test tube 28, when connected to the device 110, to be gripped and maneuvered easily.

The device 110 provides that a cylindrical body 64, connecting with the stopper 12 below, extends from the lower part of the knob 52.

In this case (fig. 4), the cylindrical body 64 is housed in a mating cavity 65 made through the stopper 12 and the bodies 14 and 24.

The cylindrical body 64 of the device 110 in turn has inside it an internal cavity 62 in which a screw 55 is inserted, provided with a head 56, resting on the bottom of the cavity 65, and a pin 60 with a thread 58 that protrudes upward, to be screwed into the internal cavity 62 and to achieve the overall attachment of the stopper 12 and knob 52.

In the test tube 28 a liquid culture means, for example tryptose 34, is typically present, or is introduced as needed, able to promote the growth of the microorganisms or bacteria possibly present in the sample 32. The use of tryptose is advantageous for the nutritional requirements of the microorganisms or bacteria and so as to be a parallelism with the methods known in the state of the art.

In some embodiments, a magnetic bar or anchor 29 is also immersed in the test tube 28, in order to continuously stir and mix the tryptose during the analysis.

Once the sample 32 has been attached to the hook portion 20, the device 10,

110 is inserted into the test tube 28 and closed by the stopper 12. The sample 32 is thus disposed in a desired and predetermined position, immersed in the liquid culture means 34 inside the test tube 28. In particular, it is possible to position the sample 32 at a desired level Ll with respect to the bottom 31 of the test tube 28.

From this moment the proliferation and growth of the bacteria possibly begins, and is investigated and analyzed by a diagnostic apparatus 40 based on the light- scattering technology, such as for example in the patent application UD2008A000190, in the name of the present Applicant, and in the patent application EP-A-565994, both incorporated here in their entirety, as a reference. The test tube 28 is positioned in a suitable housing of the apparatus 40, of a known type in its essential elements, to detect the presence of bacteria contained in the sample 32 based on light-scattering technology. In this case, the apparatus 40 comprises, in an integrated structure (fig. 2), an emitter 42 of electro-magnetic radiations, coherent and collimated light (laser), and a first 44 and second 46 reception sensor, disposed respectively at 90° and 150° with respect to the emitter 42; the first 44 and second 46 sensors are able to receive and detect, advantageously with a periodic cadence, the light which, emitted by the emitter, passes through the test tube 28 inside which the tryptose is stirred by the magnetic bar 29. It should be noted that in fig. 2, for convenience of representation, the proportions of the components of the apparatus 40 and the test tube 28 with the device 10 may not correspond to the real proportions. The emitter 42 emits the electro-magnetic radiation along a path P that is on a level L2 with respect to the bottom 31 of the test tube 28, lower than the level Ll at which the sample 32 is kept by the support element 16. In fact, the extension of the support element 16 including the hook 20 is such as to determine the positioning of the sample 32 at said desired level Ll . The level Ll is suitably chosen based on the level L2 at which the path P of the electro-magnetic radiation emitted develops, so as to satisfy said reciprocal positioning condition of level Ll and level L2.

Thanks to the fact that the sample 32 is kept suspended stably and rigidly, without any oscillations, in the liquid culture means based on tryptose 34, by means of the hook portion 20 of the support element 16 on level Ll, higher than level L2, it does not interfere with the path P of the light emitted by the emitter 42, and thus allows a reliable and accurate measurement, without any possible interference from external bodies. Advantageously, the size of the support element, in relation to the height of the test tube 28 and the position of the emitter 42 of said electro-magnetic radiations and the sensors 44, 46, is such that the suspended sample 32 does not interfere with the path P of said electro-magnetic radiations.

The data, expressed respectively as signals S 1 and S2, collected by the first 44 and second 46 sensor are sent to a control unit 50 by a conditioning device 48, which amplifies, filters and processes the data collected.

The biological samples, with the presence of microorganisms or bacteria duplicating in the tryptose liquid culture means 34 in the test tube 28, when hit by the radiation from the emitter 42, emit signals of diffused light, collected by the sensors 44 and 46, which the control unit 50 processes so as to supply, starting from about 45 minutes after the beginning of incubation, specific curves that express the trend of bacterial growth over time.

From the signals, respectively Sl and S2, supplied by the two sensors 44 and 46, we obtain two growth curves of the bacterium possibly present, having respective slopes and a reciprocal divarication that allow to verify the presence of the bacterium.

The signal obtained from the second sensor 46 with an angle of 150° defines a first curve relating to the presence of microorganisms or bacteria and consequent measurement of the bacterial load over time.

Moreover, the signals obtained from the first sensor 44 with an angle of 90° are more characterized by the morphology of the bacteria and define a second curve.

Typically, once the bacterial presence has been detected, the sample of organ or tissue is discarded as unsuitable.

It is clear that modifications and/or additions of parts may be made to the medical device 10, 110 as described heretofore, without departing from the field and scope of the present invention. It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of medical device, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

Claims

1. Diagnostic apparatus for verifying the presence of microorganisms or bacteria in a sample (32) of an organ or biological tissue comprising:

- emitter means (42) able to emit electromagnetic radiations along a determinate path (P) inside a container element (28) made of material transparent to electromagnetic radiations, said container element (28) having at least an aperture (30) through which said sample (32) is inserted, liquid culture means (34) being provided inside said container element (28) which are suitable to promote the growth of microorganisms or bacteria possibly present in the sample (32); - sensor means (44, 46) able to detect the electromagnetic radiations exiting from the container element (28) and to transmit coordinated signals (Sl, S2);

- electronic type processing means (50) able to process the signals (Sl, S2) transmitted by said sensor means (44, 46) so as to verify the presence of microorganisms or bacteria, characterized in that it comprises a medical device (10, 110) comprising a closing element (12) able to be located in correspondence with the aperture (30) of the container element (28) and a rigid support element (16) of the oblong type, which is rigidly constrained to said closing element (32) and extends from said closing element (32) toward the inside of the container element (28), said support element (16) having, in a single body, an end portion (20) able to be stably associated with said sample (32) so as to keep said sample (32) suspended and at least partly immersed in a predefined stable position in the liquid culture means (34) present inside the container element (28).

2. Apparatus as in claim 1, characterized in that the size of said support element (16), compared with the height of said container element (28) and the position of said emitter means (42) and said sensor means (44, 46) of said electromagnetic radiations, is such that the position of the sample (32) suspended at said end portion (20) does not interfere with the path (P) of said electromagnetic radiations.

3. Apparatus as in claim 1 or 2, characterized in that said end portion is a hook portion (20).

4. Apparatus as in any claim from 1 to 3, characterized in that said medical device (110) comprises a gripper element (52) attached to the closing element (12) on the opposite side with respect to the support element (16).

5. Method for verifying the presence of microorganisms or bacteria in a sample

(32) of an organ or biological tissue comprising:

- a first step in which, by means of emitter means (42), electromagnetic radiations are emitted along a determinate path (P) inside a container element (28) made of material transparent to electromagnetic radiations, said container element (28) having at least an aperture (30) through which said sample (32) is inserted, liquid culture means (34) being provided inside said container element (28) which are suitable to promote the growth of microorganisms or bacteria possibly present in the sample (32);

- a second step in which, by means of sensor means (44, 46), the electromagnetic radiations exiting from the container element (28) are detected and coordinated signals (Sl, S2) are transmitted;

- a third step in which, by means of electronic type processing means (50), the signals (Sl, S2) transmitted by said sensor means (44, 46) are processed so as to verify the presence of microorganisms or bacteria, characterized in that, at least during the first and second step, the sample (32) is kept suspended and at least partly immersed in a predefined stable position in the liquid culture means (34) inside the container element (28).

6. Method as in claim 5, characterized in that it provides to keep the sample (32) suspended in a stable position at a desired level (Ll) such that it does not interfere at least with the path (P) of said electro-magnetic radiations.