JP2003093042A - Halo picture-taking device and method for taking halo picture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a halo picture-taking device capable of taking the picture of the halo at an early period after the culturing clearly, and a method for taking the picture of the same. SOLUTION: The device for taking the halo picture is provided by arranging a laboratory dish 30 filled with an agar medium for detecting bacteria from a specimen between a camera 12 and a transmitting light source 20 of light having a white color and uniform flat surface form, capable of adjusting the position of the transmitting light source so as to make the distance between the transmitting light source and the laboratory dish as a prescribed distance, arranging a first shading plate 34 at the substantially same height to that of the dish for shielding positions other than the laboratory dish so as not to irradiate the positions other than the laboratory dish with light from the transmitting light source and also arranging a second shielding plate 36 in the proximity of the transmitting light source for shielding an area other than the area which is larger by each prescribed size in an outer direction than the projection area of the laboratory dish viewed from the camera at the transmitting light source.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a halo photographing device and a halo photographing method. More specifically, the present invention relates to an apparatus and method for photographing a halo of a colony of bacteria (in particular, Listeria, Bacillus cereus, Staphylococcus aureus, etc.) formed on an agar medium. Here, a colony is a colony formed on an agar medium as a result of the division and growth of bacteria, and a halo (HALO) is a cloudy zone formed around a colony of bacteria. .

[0002]

2. Description of the Related Art Foods are obliged to determine the presence or absence of contamination indicator bacteria and food poisoning bacteria by a bacterial test in accordance with official regulations. Such a method of bacteria inspection is stipulated as an official law and inspection guide in the “Food Sanitation Law” and the “Food Sanitation Inspection Guideline / Microbial Edition” under the supervision of the Ministry of Health, Labor and Welfare. In the inspection by the official method and the inspection guideline, it is a rule to judge the contamination indicator bacteria and food poisoning bacteria by a qualitative or quantitative test after applying a sample on an agar medium filled in a petri dish and culturing for a certain period of time.

On the other hand, in typical food poisoning bacteria such as Listeria monocytogenes, Bacillus cereus, and Staphylococcus aureus, it is known that a halo is formed around a colony, and a specific agar medium corresponding to each bacterium is known. It is known that the halo formation is specific to each bacterium when used with. Therefore, the discrimination of halo has an important meaning in determining the presence or absence of these halo-forming food poisoning bacteria.

[0004]

However, since the halo is extremely thin in the initial stage of culture, it is difficult to visually distinguish the halo early by the conventional apparatus and method. Therefore, an object of the present invention is to provide a halo photographing device and a photographing method for photographing a halo clearly and at an early stage after culturing, and to construct a system capable of determining a result of a bacterial test at an early stage.

[0005]

According to the halo photographing apparatus of the present invention, a petri dish filled with agar medium for detecting bacteria from a specimen is a camera and a transmission light source having a white and uniform plane shape. The position of the transmission light source can be adjusted so that the distance between the transmission light source and the petri dish is a predetermined distance, and other than the petri dish so that the light from the transmission light source does not hit any place other than the petri dish. The first shielding plate for shielding the portion of the petri dish is arranged at substantially the same height as the petri dish, except for the area that is larger than the projected area of the transmissive light source as seen from the camera of the petri dish by a predetermined size. The second shielding plate that shields the area of 1 is disposed in the vicinity of the transmissive light source.

The halo photographing device according to claim 2 of the present application is
3. The device according to claim 1, wherein a third shielding plate that shields a region of the transmission light source that is larger than the projection region of the petri dish viewed from the camera by a predetermined size and is smaller than the shielding region of the second shielding plate. However, it is characterized in that it is arranged close to the transmitted light source.

The halo photographing device according to claim 3 of the present application is
The apparatus according to claim 1, wherein the predetermined distance between the transmissive light source and the petri dish is 5 to 15 cm.

The halo photographing device according to claim 4 of the present application is
The apparatus according to claim 3, wherein the predetermined distance between the transmissive light source and the petri dish is 10 cm.

The halo photographing device according to claim 5 of the present application is
The device according to any one of claims 1 to 4, wherein:
The predetermined size of the shielding plate is 0 to 3 cm.

The halo photographing device according to claim 6 of the present application is
The apparatus according to claim 5, wherein the predetermined size of the second shield plate is 1 cm.

The halo photographing device according to claim 7 of the present application is
The device according to any one of claims 1 to 6, wherein:
The predetermined size of the shielding plate is 0 to 1 cm.

The halo photographing method according to claim 8 of the present application is
The first step of arranging the culture dish with the specimen inoculated between the camera and the transmission light source having a white and uniform planar shape, and the position of the transmission light source so that the distance between the transmission light source and the dish is a predetermined distance. The second step of adjusting the, and the third step of shielding the light from the transmission light source to the portion other than the petri dish so that it does not hit the portion other than the petri dish, and the projection area seen from the camera of the petri dish in the transmission light source. A fourth step of shielding an area other than an area large by a predetermined size outward, and illuminating a petri dish with a transmissive light source to photograph the image.
And a fifth step of obtaining an image of.

The halo photographing method according to claim 9 of the present application is
The method according to claim 8, wherein a sixth step of shielding a region that is larger than the projection region of the transmission light source seen from the camera by the camera and has a predetermined size and a region smaller than the shielding region in the fourth stage, The seventh step of obtaining a second image by illuminating the petri dish with a transmissive light source and photographing the petri dish is further provided.

A halo photographing method according to a tenth aspect of the present invention is characterized in that, in the method of the eighth or ninth aspect, the predetermined distance between the transmission light source and the dish is 5 to 15 cm.

According to an eleventh aspect of the present invention, in the halo photographing method according to the tenth aspect, the predetermined distance between the transmissive light source and the petri dish is 10 cm.

A halo photographing method according to claim 12 of the present application is the method according to any one of claims 8 to 11, wherein the predetermined distance in the fourth step is 0 to 3c.
It is characterized by being m.

The halo photographing method according to claim 13 of the present application is the method according to claim 11, wherein the predetermined distance in the fourth step is 1 cm.

The halo photographing method according to claim 14 of the present application is the method according to any one of claims 8 to 13, characterized in that the predetermined distance in the sixth step is 0 to 1 cm.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a halo photographing apparatus according to a preferred embodiment of the present invention will be described with reference to the drawings. A halo imaging apparatus according to a preferred embodiment of the present invention, generally designated by reference numeral 10 in FIG. 1, comprises a camera 12. The camera 12 is typically a CC
Although the D type is used, cameras of other types may be used. The camera 12 is attached to a vertical pole 16 fixed to a base 14 via an arm 18, as shown in FIG.

The halo imager 10 also includes a transmissive light source 20. The transmitted light source 20, as shown in FIG.
A support 24 is attached to the vertical pole 22 fixed to the base 14.
It is mounted so that it can be raised and lowered via. That is, the support tool 24 supporting the transmitted light source 20 is
The motor 28 is configured to move in the vertical direction along the rail 26 attached to the. Since such lifting means itself is publicly known, detailed description thereof will be omitted.

The transmissive light source 20 is a white and uniform plane light source, and is preferably formed of a white light emitting diode adjusted to have a uniform brightness.

The halo imaging device 10 further includes a petri dish 30 filled with agar medium for detecting bacteria in a specimen. The petri dish 30 having a circular plane shape is attached to the vertical pole 16 via an arm 32.
According to experiments conducted by the present inventor, the distance between the transmissive light source 20 and the dish 30 is preferably 5 cm to 15 cm, and most preferably 10 cm. The distance between the transmission light source 20 and the petri dish 30 is appropriately adjusted by using the above-mentioned lifting means.

The hello photographing device 10 further includes a petri dish 30.
First shield plate 34 mounted at approximately the same height as
Is equipped with. The first shielding plate 34 has an opening 34 a having a plane shape substantially the same as the plane shape of the petri dish 30, so that light from the transmissive light source 20 does not reach the camera 12 from a place other than the petri dish 30. Help to. By providing the first shielding plate 34, the dish 3
Diffuse reflection of light that hits the side wall of 0 is prevented.

The halo photographing device 10 further includes a transmission light source 20.
The second shield plate 36 is provided immediately below the second shield plate 36.
The second shield plate 36 has an opening 36a having a size described later.
And serves to adjust the amount of light of the transmissive light source 20.

The opening 36a of the second shielding plate 36 is preferably sized so as to minimize the unevenness of the brightness in the image of the dish 30. As a result of various experiments, the present inventor found an opening 36a having an optimum size for photographing the halo. Assuming that the distance between the camera 12 and the dish 30 is L1, the distance between the dish 30 and the transmissive light source 20 is L2, and the diameter of the dish 30 is D, as shown in FIG.
The diameter E of the projected area viewed from the camera 12 is E = D ×
It is expressed by (L1 + L2) / (L1), and the size of the opening 36a is E + 2X. According to the experiments by the present inventor, X
Is preferably 0 to 3 cm, most preferably 1c
It turned out to be m.

As shown in FIG. 3, the halo photographing device 10 further includes a third shielding plate 38 mounted immediately below the transmissive light source 20. The third shield plate 38 has a diameter E + 2Y which is slightly larger than the diameter E of the projection area of the petri dish 30 as viewed from the camera 12 (see FIG. 4). According to experiments conducted by the present inventor, Y is preferably 0 to 1
cm. The third shielding plate 38 serves to prevent the dish 30 from being directly illuminated. The third shield plate 38 must be smaller than the opening 36a of the second shield plate 36.

The halo photographing device 1 configured as described above
A method of photographing a halo by using 0 will be described. First, the dish 30 is filled with an agar medium, and a sample is smeared, followed by culturing for a certain time. Next, the distance L2 between the petri dish 30 and the transmissive light source 20 is set to 5 to 15 cm, and the first shield plate 34 and the second shield plate 36 are arranged and photographed to obtain a first image (first image). Then, the entire petri dish is represented brightly, and the halo is represented relatively darkly). Then
In addition to the above-described state, a second image is obtained by photographing with the third shielding plate 38 arranged (in the second image, the entire petri dish is dark and the halo is relatively bright). .

First and second obtained as described above
Image is processed as follows. An image in which the absolute value of the difference between the density values of the same coordinate pixels of the first image and the second image is used as the pixel value is created, and this is referred to as the third image. Similarly, an image in which the absolute value of the difference between the density values of the same coordinate pixels of the reverse image of the first image and the second image is the pixel value is created, and this is referred to as the fourth image. By performing image processing in this way, the halo is clearly represented.

The present invention is not limited to the above-described embodiments of the invention, and various modifications can be made within the scope of the invention described in the claims, and they are also within the scope of the invention. Needless to say, it is included in.

For example, although the petri dish 30 is shown as having a circular planar shape in the above-described embodiments, a petri dish having a rectangular planar shape may be used. Further, in the above-described embodiment, the distance L2 between the light source 20 and the dish 30 is configured to be mechanically adjustable, but the distance L2 may be manually adjusted.

[0031]

According to the present invention, with the conventional apparatus and method, it is possible to obtain a clear image of the halo, which was difficult to be visually discriminated in the early stage after the culture. The presence and number of food poisoning bacteria to be formed can be accurately determined.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a halo photographing device according to a preferred embodiment of the present invention.

FIG. 2 is a diagram showing dimensions of a shielding plate in FIG.

FIG. 3 is a diagram showing a state in which a third shielding plate is arranged in FIG.

FIG. 4 is a diagram showing dimensions of a shielding plate in FIG.

[Explanation of symbols]

10 Hello Imager 12 cameras 14 base 16 and 22 vertical poles 20 Transmitted light source 30 Petri dishes 34 First Shielding Plate 36 Second shielding plate 38 Third Shielding Plate

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Mihoko Hirata             2-39 North, Nango-dori, Shiraishi-ku, Sapporo-shi, Hokkaido               Plumnet Co., Ltd. (72) Inventor Samurai Koichi             12-1, Kita-jo Nishi, Kita-ku, Sapporo-shi, Hokkaido             Hokkaido Institute of Public Health F term (reference) 4B029 AA07 AA21 BB02 CC03 CC07                       FA01 FA11                 4B063 QA01 QQ06 QR69 QS40 QX01

Claims (14)

[Claims] 1. An apparatus for photographing a halo formed around a bacterial colony, wherein a petri dish filled with agar medium for detecting bacteria in a sample has a camera and a transmitted light source having a uniform white planar shape. The position of the transmission light source can be adjusted so that the distance between the transmission light source and the petri dish is a predetermined distance, and the dish from the transmission light source does not hit any place other than the petri dish. The first shielding plate that shields all other areas is located at substantially the same height as the petri dish, and each area is larger than the projected area of the transmitted light source as seen from the camera by the prescribed size. A device, wherein a second shielding plate that shields a region other than the above is arranged in proximity to the transmissive light source. 2. A third shield plate for shielding an area each having a predetermined size larger than a projection area of the transmission light source seen from the camera of the petri dish and smaller than the shield area of the second shield plate, The device according to claim 1, wherein the device is arranged in proximity to a light source. 3. The device according to claim 1, wherein the predetermined distance between the transmitted light source and the dish is 5 to 15 cm. 4. The apparatus according to claim 3, wherein the predetermined distance between the transmitted light source and the dish is 10 cm. 5. The predetermined size of the second shield plate is
Device according to any one of claims 1 to 4, characterized in that it is between 0 and 3 cm. 6. The predetermined size of the second shield plate is
Device according to claim 5, characterized in that it is 1 cm. 7. The predetermined size of the third shielding plate is
Device according to any one of claims 1 to 6, characterized in that it is between 0 and 1 cm. 8. A method for photographing a halo of a bacterial colony, comprising a first step of arranging a culture dish inoculated with a sample between a camera and a transmitted light source having a white and uniform planar shape, The second step of adjusting the position of the transmissive light source so that the distance between the transmissive light source and the petri dish is a predetermined distance, and the step of shielding the non-dishes part so that the light from the transmissive light source does not hit the parts other than the petri dish. The third step, and the fourth step of shielding the area other than the area that is larger than the projection area seen from the camera of the petri dish in the transmitted light source by a predetermined size, and illuminating the petri dish with the transmissive light source to take a picture, And a fifth step of obtaining one image. 9. A sixth step of shielding a region which is larger than a projection region of the petri dish viewed from the camera in the transmissive light source by a predetermined dimension and is smaller than the shielding region in the fourth stage, and the transmissive light source. The method according to claim 8, further comprising a seventh step of illuminating and photographing the petri dish to obtain a second image. 10. The method according to claim 8, wherein the predetermined distance between the transmitted light source and the dish is 5 to 15 cm. 11. The method according to claim 10, wherein the predetermined distance between the transmission light source and the dish is 10 cm. 12. The method according to claim 8, wherein the predetermined dimension in the fourth step is 0 to 3 cm.
The method according to any one of 1. 13. The method of claim 12, wherein the predetermined dimension in the fourth step is 1 cm. 14. The method according to claim 8, wherein the predetermined dimension in the sixth step is 0 to 1 cm.
The method according to any one of 1.