FR3067110A1 - DEVICE AND METHOD FOR DETECTION AND IMAGING BIOCONTAMINANT ELEMENTS - Google Patents

Abstract

The invention relates to a device and a method for detecting and imaging biocontaminant elements (BC), comprising a matrix (M) of detector pixels having an active face (FA) on which a light (L) is incident, a light-transparent support (S) which covers the active face (FA) and illumination means (ME) which produce the light (L) incident on the active face (FA), visualization means (MV). The invention is characterized in that the incident light (L) is the light emitted by the biocontaminant elements (BC) and in that the device further comprises at least one filter (F), one polarizer (P) and an analyzer (A), said polarizer (P) and said analyzer (A) being positioned in a cross configuration to overcome the laser granularities in the images.

Description

® DEVICE AND METHOD FOR DETECTION AND IMAGING OF BIOCONTAMINANT ELEMENTS.

FR 3 067 110 - A1 (57) The invention relates to a device and a method for detecting and imaging biocontaminant elements (BC), comprising a matrix (M) of detector pixels having an active face (FA) on which a light (L) is incident, a support (S) transparent to the light which covers the active face (FA) and lighting means (ME) which produce the light (L) incident on the active face (FA), display means (MV). The invention is characterized in that the incident light (L) is the light emitted by the biocontaminant elements (BC) and in that the device also further comprises at least one filter (F), a polarizer (P) and an analyzer (A), said polarizer (P) and said analyzer (A) being positioned in a cross configuration to overcome laser granularities in the images.

DETECTION AND IMAGING DEVICE AND METHOD

BIOCONTAMINANT ELEMENTS

FIELD OF THE INVENTION

The present invention relates to a device and a method for detecting and imaging biocontaminant elements. The device according to the present invention more particularly comprises a matrix of detector pixels having an active face on which light is incident, a support transparent to light and which covers the active face, on which the biocontaminant elements are capable of being deposited, lighting means, which produce a beam of light which is incident on the active face, and display means suitable for viewing, in the form of still images or video images, a digital signal delivered by processing means.

PRIOR ART

Controlling biocontamination is a public health issue, both in terms of food safety and in health establishments or the pharmacopoeia. Similarly, in housing, in particular in collective housing (schools, catering, crèche, school, daycare, nursing home), compliance with hygiene rules must be guaranteed. It is therefore necessary to have means of monitoring air quality and the cleanliness of environments and surfaces.

In the field of clean and bio-clean rooms, there are optical counters for particulate monitoring (viable particle or not) as well as active samplers for monitoring biocontaminants (by impaction, filtration or bubbling) or passive by sedimentation (agars).

The air is generally contaminated by a diverse microbial flora which is often resistant and variable in time and space. To set up a global chain of cleanliness and hygiene control, it is necessary to be able to measure biocontaminants precisely and reactively. In addition, taking into account the kinetics of reproduction of these biocontaminants (for certain bacteria, every 20 to 40 minutes), it is necessary to be able to have means of in situ, reliable and rapid control of monitoring the growth of these biocontaminants.

For health establishments, the levels of bacteriological cleanliness are defined in standard NF S 90 351. The standard NF

S 90 351 recommends technical performance according to the risk zones.

In the pharmaceutical field, the Good Practice Guide for

Manufacturing (BPF) offers four levels of French and European also offer monitoring and microbiological classification of active production areas, in the case of the manufacture of sterile drugs.

The NF EN ISO 14698-1 standard describes two categories of air sampling devices applicable to controlled environments:

- passive samplers: sedimentation plates

- active samplers: by impaction, filtration and sparging.

All these sampling techniques are based on conventional methods of culture (or culture), i.e. the ability of microorganisms, deposited on a suitable agar culture medium, to give birth to visible colonies, depending on the environment. culture used and incubation conditions and

The incubation period is usually 2 to 7 days for bacteria and 7 to 7 days for yeasts and molds.

In practice, a first reading is made in the laboratory after 48 hours for bacteria and up to date for yeasts and molds. The incubation temperature is usually 30 to 35 ° C for bacteria and 20 to 25 ° C for yeasts and molds. Note the development of alternative methods (faster than conventional methods) with a shorter response level and a level of quality of results at least equivalent to that of conventional methods.

Among these alternative methods, let us retain flow cytometry, fluorescence of particles, intrinsic or after labeling with a fluorochrome.

With regard to labeling based on an enzymatic reaction with the fluorochrome reagent, only viable microorganisms are made fluorescent. This technology combines filtration of the sample, direct labeling of viable microorganisms and cell counting by laser scanning cytometry and visualization using an automated epi-fluorescence microscope, in less than 3 hours.

To date, the monitoring of biocontamination processes is carried out using passive or active samplers.

Active samplers operate by sedimentation. Sedimentation is a simple method of collecting microorganisms by gravity on open Petri dishes containing agar culture media. The results are expressed per unit area for a given time. This method is required by Good Manufacturing Practices in the pharmaceutical industry for the manufacture of sterile medicines. This method does not allow a quantitative result of aerobiocontamination but rather serves to assess the risk of biocontamination of an exposed surface in this environment, from a number of viable particles sedimented on the box depending on the surface and exposure time.

Active samplers offer active collection of biocontaminants. The different methods of collecting biocontaminants collected in a certain volume drawn in air for a certain time (or biocollectors) are:

- the method by impaction on the culture medium which is the most widespread and which requires a short duration of sampling followed by a long duration of culture and microbiological analysis;

- the filtration method which allows longer samples (optimal over 8 hours) and the use of different methods of microbiological analysis after recovery of the filter membrane in liquid medium and successive dilutions of the sample (it is however advisable to make sure that the filtration conditions do not affect the viability of the microorganisms collected);

- the bubbling method in liquid medium which has the major advantage of avoiding the risk of drying of the sample, the microorganisms being transferred directly into liquid medium. This collection method is considered less stressful for biocontaminants and should therefore be preferred.

The prior art has the following drawbacks.

Passive samplers are control plates which are exposed under the same conditions as those in which the individual or object whose biocontamination is sought to be exposed is exposed.

These control plates are then removed, cleanly packaged and transported to an oven for incubation which will promote the growth of biocontaminants and allow a count visible to the eye but after a significant period of up to 72 hours. one week following the microorganisms and the culture media. It is a long and tedious process which, moreover, does not guarantee the quality of the result, insofar as some of the microorganisms present on the plates can die before arriving at the laboratory of biological analyzes, or even put in a state called "adverse", that is to say an almost lethargic state, without reproduction and therefore not detectable.

The results obtained with these active samplers are results of sedimented biocontamination expressed in CFU per unit area.

Active samplers, or biocollectors, have the same drawbacks as passive samplers with regard to their long response time linked to the incubation period.

note however that today there are active samplers which make it possible to overcome this drawback because they are coupled with rapid microbiology methods (Rapid

Microbiology Method or RMM).

Among these

RMM, methods which rely on autofluorescence detected by a CCD imaging system or

CMOS. An even more efficient method is the fluorescent labeling and laser excitation method which makes it possible to detect growing microcolonies. The biocontamination results obtained with these active samplers are airborne biocontamination data and are expressed in CFU per unit of volume sampled.

Consequently, there are at least two sources of error in the current count of microorganisms according to techniques of the prior art:

at the level of dynamic collection of shown a physical efficiency which varies between and according to the models of biocollectors, at the level of the culture itself because the same study shows that the biological efficiency of culture from a sample of

L. Pneumophila for example in a liquid medium can vary from to 5.

The device according to the invention does not have these drawbacks.

Furthermore, according to the prior art, a device for detecting and imaging biocontaminating elements is known, comprising a matrix of detector pixels having an active face on which light is incident, a support transparent to light and which covers the active face, support on which the biocontaminating elements are likely to be deposited, lighting means which produce the light which is incident on the active face, processing means capable of transforming the signal delivered by the matrix of detector pixels into digital signal, and display means able to display in the form of still images or video images the digital signal delivered by the processing means. These measures

is described 03/23/2010. in the patent document FR 2 964 980 published on However, the still images or video obtained by this

device have laser granularities, speckles and / or have a speckle, forming small spots. In the English language, these spots are called speckle.

SUMMARY OF THE INVENTION

The invention provides a device for detecting and imaging biocontaminant elements which does not have the aforementioned drawbacks of the devices of the prior art and which, in particular, presents images of improved quality by eliminating the speckle.

To this end, the first object of the invention is a device for detecting and imaging biocontaminant elements, comprising:

a matrix of detector pixels having an active face on which a light is incident, a support transparent to light which covers the active face, on which support, biocontaminating elements are likely to be deposited and to multiply, means of lighting which produce the light incident on the active face, display means capable of displaying, in the form of still images or video images, a digital signal delivered by processing means, characterized in that the light is re-emitted light by the biocontaminating elements and in that the device further comprises at least one filter, a polarizer and an analyzer, said polarizer and said analyzer being positioned in a cross configuration to overcome laser granularities in said images.

The second object is a method of detecting and imaging biocontaminant elements comprising the steps of:

supply of a device comprising a matrix (M) of detector pixels having an active face on which a light is incident, a transparent support to the light which covers the active face, on which support the biocontaminating elements are likely to deposit and multiply, lighting means which produce the light incident on the active face, display means capable of displaying, in the form of still images or video images, a digital signal delivered by processing means, and at less a filter, a polarizer and an analyzer, said polarizer and said analyzer being positioned in a cross configuration;

deposits and multiplication elements bio-contaminants on the support r lighting support wearing the items bio-contaminants by the means lighting r

filtration of the light re-emitted by the biocontaminating elements by the filter, and polarization and analysis of said filtered light;

acquisition of an image signal by the matrix of detector pixels;

processing of this signal acquired by the processing means and communication of the digital signal to the display means with a view to viewing fixed or video images representative of the biocontaminant elements.

Advantageously, the support comprises one or more growth media for biocontaminants; - The growth medium or media of the biocontaminants are nutrient media of said biocontaminants; - the growth medium or media of the biocontaminants comprise fluorescent chemical markers; the support comprises a mosaic of biocontaminant growth media, the characteristics of at least two of these growth media being different; - The device comprises a high optical density filter centered around the emission wavelength of the incident light beam, with a narrow pass band, between plus and minus 20 nm; the device comprises a high pass filter filtering the incident light beam; - The device comprises a heating system, and means for controlling the temperature of the nutrient medium (s); - The device further comprises an opaque slave cover; the lighting means are laser means; - the matrix and / or the support are mobile; the support is divided into a ίο mosaic of biocontaminant growth media, the characteristics of at least two of these growth media being different; - The device further comprises an opaque cover (C), and the opening and closing of this cover are synchronized with the detection phase; and the device also comprises a pump coupled to a flow meter, so as to actively take the air from the room, which is projected onto the surface of the support and the Colony-forming Units per m ³ of air taken are calculated, and the aerobiocontamination measured.

BRIEF DESCRIPTION OF THE FIGURES

The invention will be better understood on reading the following nonlimiting description, drawn up with reference to the appended drawings, in which:

Figure 1 is a schematic representation of the device according to the invention;

FIG. 2 schematically shows an embodiment of the device according to the invention, in which the collection medium forms a mosaic of specific agars, and in which the device comprises an optionally heating cover intended to facilitate incubation, over short periods of the order of an hour, and to optimize the detection and image of viable fluorescent particles; and FIGS. 3A and 3B are real images (FIG. 3A) and obtained by means of a device according to the invention (FIG. 3B) in the case of an example in which a very concentrated solution (10 hours of culture in liquid medium “LB” with stirring at 32 ° C.) of Bacillus subtilis whose membranes have been marked with the fluorescent marker referenced FM 1-43 specific for the plasma membrane of all living beings.

DETAILED DESCRIPTION OF THE INVENTION

Definitions are given below of terms used in the present description according to the invention.

Bio-contamination:

Contamination of a material, a device, an individual, a surface, a liquid, a gas or air by viable particles according to the standard

ISO 14698-1.

Biocontaminants have the following additional features compared to particulate or chemical contamination:

- their ability to reproduce very quickly,

- their ability to mutate, adapt to even the most severe conditions.

The main families of biocontaminants are:

- bacteria,

- viruses,

- yeasts, molds and fungi.

Bacteria:

Bacteria are microscopic single-celled living beings, reproducing by scissiparity and whose nucleus is not delimited by a membrane. Bacteria, like all other cells, need energy. L ΆΤΡ is the universal source of biochemical energy. LΆΤΡ is common to all forms of life, but the redox reactions involved in its synthesis are very varied depending on the organism and in particular in bacteria.

They can thus use a very wide variety of carbon and / or energy sources.

Although their name derives from the Greek baktêria, "stick", bacteria have variable forms:

spherical (cocci, from the Greek kôkkos, grain or micrococci),

- stick (bacilli pl. baccili from Latin baculus, stick),

- or spiral (spirochetes).

The size of bacteria varies from

0.02 micrometer for nanobacteria to 0.75 millimeter for Thiomargari ta namibiensis, visible to the naked eye

Most, however, are between 0.5 and 100pm.

The bacteria reproduce asexually, by scissiparity (a simple cell division). The genetic material is first duplicated, then the bacteria lengthens, contracts in its middle and divides, forming two daughter cells identical to the mother cell.

Thus, the offspring of a bacterial cell is a clone of genetically identical cells, called a colony. The bacteria are then counted in terms of Colony-forming Units (CFU). Some bacteria divide every 20 to 40 min. Under favorable conditions, at the rate of a division every 30 min, a single cell will have produced, in just fifteen hours, a colony visible to the naked eye.

one billion daughter cells

On the other hand, under poor conditions, certain species produce spores, dormant forms of the cell, capable of withstanding extreme conditions of temperature or drought. The rate of spontaneous bacteria mutations is very high, especially when placed in an unfavorable environment.

Yeast:

A yeast is a unicellular fungus (certain yeasts are however able to display a pseudo-pluricellular aspect by the formation, for example, of pseudomycelium) capable of causing fermentation of organic animal or vegetable matter. Yeasts are used to make wine, beer, spirits, industrial alcohols, bread and antibiotics.

These microorganisms, of variable shape depending on the species (spherical, ovoid, bottled, triangular) but generally oval, around 6 to 10 microns and up to 50 micrometers, multiply by budding or by scissiparity. They are often able to perform sporulation either for the purpose of dormancy in an unfavorable environment, or for the purpose of dispersal.

Microorganisms:

Microorganisms are microbiological entities, cellular or not, capable of reproducing or transferring genetic material.

Molds:

Molds are multicellular organisms. They are filamentous microscopic fungi from the kingdom of fungi. There are thousands of different varieties. A given species of microscopic fungus can generate several types of mycotoxins, and the same mycotoxin can be produced by several species of mold. These are molecules of low molecular weight (<1000 d), most often thermostable in non-aqueous medium. Hardly degradable, they can remain in foodstuffs even after the elimination of molds.

Sedimentation plate:

A sedimentation plate is a suitable receptacle, for example a Petri dish, of appropriate size, containing an appropriate, sterile culture medium, which is left open for a defined period in order to allow the deposit of viable airborne particles (standard NF EN ISO 14698-

1) ·

Viable unit (UV):

A viable unit is made up of one or more viable particles which are counted as a single unit. When there are viable units on an agar medium, it is customary to call them "Colony Forming Units" (UFC). A PDU can consist of one or more UV (standard NF EN ISO 14698-1).

Classification of microorganisms:

In the currently accessible standards of the 14644 and 14698 series, there is no classification of biocontamination, neither in volume nor in surface. However, the ISO 14698-1 standard recommends measures aimed at counting viable units per dm ² and per hour to assess the kinetics of contamination.

The invention relates to a device for sampling, early detection and imaging of growing microorganisms. This device is shown in Figure 1. This device generally constitutes a passive sampling device. However, in certain embodiments, this device is an active sampling device.

In general, the device according to the invention comprises:

a matrix M of detector pixels having an active face FA on which a light L is incident, a support S transparent to light which covers the active face FA, on which support S, biocontaminants BC are likely to be deposited and to be multiply, lighting means ME which produce the light L incident on the active face FA, display means MV able to display, in the form of still images or video images, a digital signal SMT delivered by means of MT treatment, characterized in that the light L is the light re-emitted by the biocontaminant elements BC and in that the device also comprises at least one filter F, a polarizer P and an analyzer A, said polarizer P and said analyzer A being positioned in cross configuration to overcome laser granularities in said images.

The invention proposes a new concept of so-called active sedimentation and growth plates, because they alone allow almost real-time monitoring of sedimented airborne biocontamination or surface biocontamination. The device according to the invention generally does not modify the aeraulics of the room to collect viable particles. These particles are naturally deposited on the nutritive collection medium. However, in certain embodiments, a pump is added to the device according to the invention, and coupled to a flow meter, so as to actively take air from the room, which is then projected onto the surface of the support, allowing a calculation of the Colony-forming Units per m ³ of air taken, for the measurement of aerobiocontamination.

The support S forms a collection surface by sedimentation of the microorganisms, covered with an agar G with optimized optical properties and preferably incorporating fluorescent markers. These markers mark viable particles such as plasma membranes, nucleic acids or specific enzyme reactions. Their use increases the contrast of growing biocontaminants on the nutrient medium. The support S is transparent to light. It covers the active face FA of lighting and detection. It is treated to allow the development of viable particles likely to deposit there. In addition, the nutritive window-medium diopter is treated so as to reduce the signal losses emitted by the viable particles. An additional originality of the invention is associated with the possibility of using disposable removable blades covered with a specific culture medium or not, in place of the collecting porthole. These slides can be heated in situ to optimize the growth conditions and allow visualization of the growth of CFUs, or even biofilms in real time. Finally, a heating system controls the temperature of the transparent support in order to promote the optimized growth of the viable particles collected, and a system for controlling the hygrometry of the nutritive medium which determines the lifetime of the nutritive medium before change.

A cover device C or opaque cover is placed on the collection surface to prevent, during growth, the dissemination of the bacteria in development in the clean environment and optimizing the detection conditions. Synchronous servo-control allows the opaque cover to be placed on the collection surface before the automatic detection of viable particles deposited on the collection surface begins.

The opening and closing of the cover are therefore synchronized with the detection phase to improve the signal / noise ratio. Furthermore, the cover itself is optionally heated, in order to facilitate

Incubating the biocontaminants over a short period of time, thereby improving detection. The cover is optionally equipped with at least one suction nozzle, said at least one suction nozzle being connected to a pump, for example with variable flow rate and controlled by a flow meter allowing air aspirations at flow rates notably below 100

L / min. The inlet of the sucked air at the level of said at least one nozzle is carried out on the external part of the cover, and the outlet of the sucked air is located opposite the agar collecting the biocontaminant elements, directly below the CCD or CMOS matrix.

The lighting means ME produce the monochromatic light which is incident on the active face. These means comprise for example a light-emitting diode, a laser diode or a laser.

The matrix M of detector pixels is arranged directly below the transparent support. It has an active face on which a light is incident. The matrix of detector pixels is for example a matrix of CCD sensors or a matrix of CMOS sensors. The exposure times of the sensor are advantageously relatively long, between 10 and 100 ms.

The imaging means, comprising the detector and the matrix M, and / or the support S, can be moved in a plane, along XY axes, or in space, along XYZ axes.

Filter F includes a high pass filter which cuts the incident beam. The device also comprises an additional filter, centered around the emission wavelength, with a fine passband, for example of the order of +/- 10 to 20 nm.

The crossed polarizer P and the analyzer A makes it possible to dispense with the possible “speckle” of the lighting means ME, in particular when it is a laser light source.

The processing means MT are able to transform the signal delivered by the matrix M of detector pixels into a digital signal SMT. They include means capable of counting the biocontaminant elements per unit area and / or per time unit, and means making it possible to visualize the morphology of the growing biocontaminant elements.

The visualization means MV are able to visualize in the form of still images or video images the digital signal SMT delivered by the processing means in order to follow the growth of the viable particles over long periods, in particular of the order of day, a week or more. These means make it possible to follow the evolution of the size of a particle over time.

The device

The invention may allow classification of certain biocontaminants.

These biocontaminants are the GRAM + bacteria and

GRAM. A marker, which could be used for this classification, is a mixture of iodide hexidium and SYTO ™ from ThermoFisher ™. However, said GRAM + bacteria and

GRAM- can also be the subject of an a posteriori identification. Such a posteriori identification can also be used for a classification of other biocontaminant elements, such as yeasts, molds or fungi. It can be done, for example, by direct observation of the biocontaminant elements, after sufficiently long growth. It would also give morphological information on biocontaminant elements (eg hulls, bacilli, etc.).

To this end, and as shown in FIG. 2, the device advantageously has a “mosaic” culture medium G. In the example in FIG. 2, this is a mosaic of 4 different agars specific for different viable particles. The culture medium can be a medium capable of promoting the growth of a large number of different biocontaminant elements or a specific culture medium which promotes a particular type of biocontaminant. Each part of the culture medium is then specific for the contaminants to be detected either because it incorporates - or not - fluorescent markers or growth inhibitors or a nutrient medium specific for such or such contaminant.

According to still

The invention, another additional characteristic of the MT treatment means comprises means capable of visualizing the morphology of the biocontaminant elements.

The invention also relates to a system for detecting and imaging biocontaminant elements, characterized in that it comprises a set of devices for detecting and imaging microorganisms according to the invention, the pixel arrays of detector devices detection and imaging being networked.

For the implementation of the method of detection and imaging of biocontaminant elements according to the invention, a device as described above is provided. The opaque cover is open, and said elements are naturally deposited on the agar carried by the support, by sedimentation, or else, actively, if said cover is provided with nozzles connected to a suction pump coupled to a flow meter. These biocontaminants multiply on the support. For viewing these elements, the cover is closed and the transparent support carrying said elements is lit from below by the lighting means. The light produced by these lighting means is re-emitted by the biocontaminating elements. It is filtered, then crosses the crossed assembly formed by the polarizer and the analyzer, before processing, which eliminates the speckles in the images. An image signal is acquired by the matrix of detector pixels and this acquired signal is processed by the processing means, then sent to the display means for the display of still or video images representative of the biocontaminant elements.

Ultimately, the device and the method according to the invention constitute a simple and easily transportable means which makes it possible to monitor, in situ and continuously, or even in a network, the microorganisms liable to develop into biofilms on the surfaces.

A list of advantages of the device and of the method according to the invention is mentioned below:

- control viable sedimented particles in environments with biological risks,

- allow continuous monitoring over long periods of viable particles in a controlled environment or other environment, even outside,

- provide in real time the evolution of viable surface particles deposited on the surfaces of a room or several rooms at the same time,

- do not modify the ventilation of the room by dynamic sampling,

- provide objective evidence of the presence of these viable particles with photo taking and video monitoring of their evolution (traceability guaranteed),

- follow the growth kinetics of the colony forming units from a viable unit,

- alert as soon as possible of the presence of these viable particles by detecting the first moments of growth, in times of the order of the hour,

- deduce a kinetics of biocontamination depending on the operating conditions of the rooms, the number of operators, visitors, temperature, filtration rate, etc. thanks to the static sampling method representative of the exposure situation of the drugs, patients or food to be protected,

- allow the frequency of surface cleaning to be optimized by real-time monitoring of surface biocontamination,

- allow a real saving of time compared to the passive witness plates of the prior art,

- improve the reliability of the results by avoiding any transfer of the collection plates from the sampling point to the analysis point,

- differentiate viable units from dead units or units in an adverse state by video or regular monitoring of their growth,

- differentiate viable units from dead units or those in an adverse state by UV laser lighting and a culture medium incorporating fluorochromes,

- allow the specific development of a particular micro-organism using selective culture media,

- Carry out inexpensive biocontaminant analysis methods compared to the prior art laboratory analysis methods.

The invention finds applications in all industries (pharmaceutical and agrifood industry, but also in space, micromechanics, optics, nanotechnologies), and in healthcare establishments and in the fight against bioterrorism.

To date, mastering biocontamination involves short-term samples, via passive or active samplers. Then, these samples must follow a long culture process at a temperature and for periods of up to seven days.

The means of visualizing the deposit of microorganisms in near real time proposed by the invention is an advantageous substitute for these samplers, especially since it is very close in concept to the reference method based on passive exposure of agars at risk points for biocontamination of the installation. It makes it possible to instantly signal that alert or action levels have been reached in a particular area.

Example of implementation

A device according to the invention was produced using a Petri dish comprising a TSA culture medium incorporating a fluorescent marker referenced FM 1-43 from Thermofisher ™. A drop of very concentrated solution (10 hours of culture in an LB liquid medium with stirring at 32 ° C.) of Bacillus subtilis was placed in this box, the objective of the experiment not being to be representative of the mode of deposit but to show the proper functioning of the opto-mechanical device. In this example, a 447 nm monochromatic incident laser source was used with a crossed polarizer and analyzer. These tests show that the crossed polarizer / analyzer configuration eliminates the speckle of the laser source. A filter alone would not be enough to get rid of the speckle. A high-pass filter cutting the re-emitted and imaged light signals at 500 nm (OD 6) was used. An additional filter, centered around the emission wavelength of the FM marker 1-43, here centered at 600nm, with a passband of +/- 16 nm was used to analyze only the light emitted by the bacillus subtilis. The exposure times were between 10 and 100 ms and 8 and 20 images were acquired. In the configuration of this example, with the objective implemented, one pixel of the image corresponds to 18 pm. The sensor itself has pixels of 6.45 µm sides, which can be optimized, given the quality of the cameras available today. The mounting of the optimized device with opaque cover of the Petri dish corresponds to the optimized configuration in terms of contrast of the bacteria on the agar. The photograph in Figure 3A corresponds to the actual image. The photograph in FIG. 3B is the fluorescence image obtained by means of a device according to the invention, under the specific conditions implemented in this

Claims (15)

1. Device for detecting and imaging biocontaminant elements (BC), comprising: a matrix (M) of detector pixels having an active face (FA) on which a light (L) is incident, a support (S) transparent to light which covers the active face (FA), on which support (S) biocontaminating elements (BC) are liable to deposit and multiply, lighting means (ME) which produce the light (L) incident on the active face (FA), display means (MV) capable of displaying, in the form of still images or video images, a digital signal (SMT) delivered by processing means (MT) characterized in that the incident light (L) is the light emitted by the biocontaminant elements (BC) and in that the device further comprises at least one filter (F), and one analyzer (A), said and said analyzer (A) being positioned in cross configuration to overcome laser granularities in said images. 2. Device according to claim 1, characterized in that the support (S) comprises one or more growth media for biocontaminants. 3. Device according to claim 2, characterized in that the growth medium or media of the biocontaminants are nutrient media of said biocontaminants. 4. Device according to one of claims 2 or 3, characterized in that the growth medium or media of the biocontaminants comprise fluorescent chemical markers. 5. Device according to one of claims 2 to 4, characterized in that the support (S) comprises a mosaic of biocontaminant growth media, the characteristics of at least two of these growth media being different. 6. Device according to one of the preceding claims, characterized in that it comprises a high optical density filter centered around the emission wavelength of the incident light beam, with a narrow passband, between more and less 20 nm. 7. Device according to one of the preceding claims, characterized in that it comprises a high pass filter filtering the incident light beam. 8. Device according to one of the preceding claims, characterized in that it comprises a heating system, and means for controlling the temperature of the nutrient medium or media. 9. Device according to one of the preceding claims, characterized in that it further comprises an opaque slave cover. 10. Device according to one of the preceding claims, characterized in that the lighting means are laser means. 11. Device according to one of the preceding claims, characterized in that the matrix (M) and / or the support (S) are mobile. 12. Method for detecting and imaging biocontaminant elements (BC) comprising the steps of: supply of a device comprising a matrix (M) of detector pixels having an active face (FA) on which a light (L) is incident, a support (S) transparent to light which covers the active face (FA), on which support (S) the biocontaminant elements (BC) are liable to be deposited and to multiply, lighting means (ME) which produce the light (L) incident on the active face (FA), display means ( MV) able to visualize, in the form of still images or video images, a digital signal (SMT) delivered by processing means (MT), and at least one filter, a polarizer and an analyzer, said polarizer and said analyzer being positioned in cross configuration; removal and multiplication of biocontaminants (BC) on the support lighting of support (S) bearing the elements bio-contaminants (BC) by the means lighting (ME); filtration of light re-emitted by the elements bio-contaminants (BC) by the filter, and polarization and analysis of said filtered light; acquisition of a image signal by the pixel matrix detectors; treatment of this signal acquired by the means of digital signal processing and communication (SMT) to the display means (MV) for the display of still or video images representative of the biocontaminant elements (BC). 13. Method according to claim 12, characterized in that support (S) is divided into a mosaic of biocontaminant growth media, the characteristics of at least two of these growth media being different. 14. Method according to one of claims 12 or 13, characterized in that the device further comprises an opaque cover (C), and in that the opening and closing of this cover are synchronized with the phase 10 detection. 15. Method according to one of the preceding claims, characterized in that the device further comprises a pump coupled to a flow meter, so as to take 15 actively the air of the room, which is projected on the surface of the support (S) and in that the Colony-forming Units per m ³ of sampled air are calculated, and the aerobiocontamination measured.