RU212279U1 - Bacteriological loop - Google Patents

Abstract

The utility model relates to microbiology, namely to laboratory instruments for cultivating and studying the mobility of microorganisms in semi-liquid nutrient media. SUBSTANCE: bacteriological loop for sowing microbial cultures in a test tube contains a handle on one side and a removable working element on the other side in the form of a metal rod with an eyelet at its end, fixed in the handle with a coupling. The working element near the sleeve is additionally provided with a cylindrical cap with the possibility of installing it on the upper end of the test tube, and the diameter of the cylindrical cap exceeds the outer diameter of the test tube.

Description

The utility model relates to microbiology, namely to laboratory instruments for cultivating and studying the mobility of microorganisms in semi-liquid nutrient media. The most effective use of a bacteriological loop is when inoculating microbial cultures by injection into test tubes with a semi-liquid nutrient medium.

It is necessary to determine the mobility when identifying isolated cultures of Listeria according to GOST 32031-2012, cultures of Campylobacter according to GOST ISO 10272-1-2013, as well as other microorganisms. The mobility of cultures is determined by sowing with an injection into the center of a column of a special semi-liquid medium. Incubate under optimal conditions and evaluate the result of growth visually. For example, Listeria are mobile at 22°C and form a characteristic “folded umbrella” turbidity zone around the injection line. Campylobacter in special semi-liquid media (SZhN and others) grow in the form of a gray-blue disk 1-4 mm wide under the surface of the medium. Thus, the correct technique for seeding a bacterial culture in the center of a column of semi-liquid medium is very important in laboratory practice.

A bacteriological loop is known, which is a handle on one side and a removable working element of robiology and immunology / T.S. Kostenko, E.I. Skarshevskaya, S.S. Gitelson. - M.: Agropromizdat, 1989. - S. 23. - [1]).

A bacteriological loop is also known, containing a handle on one side and a working element in the form of a metal rod with a closed loop (eyelet) at its end. It is used when transferring microbial cultures from one test tube to another. Sowing by injection is done using a bacteriological loop, which is injected into a column of semi-liquid nutrient medium (Workshop on veterinary microbiology and immunology / V.N. Kislenko. - M: Kolos, 2005. - S. 29-31. - [2]).

The disadvantage of the known bacteriological loops is that the manipulation of the transfer of microbial cultures from one test tube to another requires the concentration of efforts of laboratory workers and their concentration to introduce the working element of the bacteriological loop strictly in the center of the nutrient medium column. Performing such precise work, the laboratory worker needs to keep the brush in a tense state. Concentration and performance of actions aimed at a given point of the working element of the bacteriological loop entails additional time spent on the manipulation.

In this case, the displacement of the loop away from the center of the cross section of the test tube and, accordingly, from the center of the semi-liquid nutrient medium is not ruled out. The zone of unintentional introduction of the pathogen culture into unplanned areas of the semi-liquid nutrient medium increases. Subsequently, this can distort the characteristic features of the growth of various microorganisms, which reduces the possibility of a visual assessment of the results of determining the mobility.

In addition, the concentration of researchers is necessary when determining the depth of sowing by pricking microbial cultures into a semi-liquid nutrient medium, namely, as is generally accepted, at 2/3 of the height of the medium column. It is often difficult for a laboratory worker to balance the efforts when introducing a bacteriological loop deep into a semi-liquid nutrient medium. Such a manipulation, being repeated, cannot be routinely performed on all samples, which can also distort the research results. As a rule, such results are not taken into account and the work is performed again. The latter often cannot be duplicated under experimental conditions when studying bacterial motility.

A bacteriological loop is known (patent No. 2520327), containing a handle on one side and a removable working element on the other hand in the form of a metal rod with an eyelet at its end, fixed in the handle with a coupling, the working element near the coupling is additionally equipped with metal stops located perpendicular to the working element, at the same time, metal guides are fixed at the ends of the metal limiters, which are located along the metal rod with an eye and at a distance from it equal to the outer radius of the test tube cross section. This bacteriological loop is chosen as a prototype.

The disadvantage of the prototype is the complexity of the design, due to the presence of four metal limiters.

The technical result of the proposed bacteriological loop is to simplify the design and inoculation of microbial cultures in the center of a semi-liquid nutrient medium and at the same depth in all samples.

The technical result is achieved due to the fact that the bacteriological loop for sowing microbial cultures in a test tube contains a handle on one side and a removable working element on the other side in the form of a metal rod with an eyelet at its end, fixed in the handle with a coupling. The working element near the sleeve is additionally provided with a cylindrical cap with the possibility of installing it on the upper end of the test tube, and the diameter of the cylindrical cap exceeds the outer diameter of the test tube.

The essence of the proposed bacteriological loop is shown in Fig. 1, which shows a general view.

The bacteriological loop contains a handle 1, a removable working element in the form of a metal rod 2 with an eyelet 3 at its end, fixed in the handle 1 by a coupling 4. At the same time, the working element is provided with a cylindrical cover 5 installed outside the test tube.

The bacteriological loop is used as follows. In the left hand, take a test tube with a microbial culture and a test tube for subculture with a semi-liquid nutrient medium.

Both test tubes are held in one hand in an inclined state at a distance of 30-50 cm from the burner. The bacteriological loop is held by the handle 1 with the right hand. Before taking a microbial culture, the working element of the bacteriological loop is carefully burned on a burner flame, that is, it is flambéed. Without letting go of the test tubes, carefully open them near the flame with the free fingers (little and ring fingers) of the right hand. At the same time, their corks are pressed with the little finger of the right hand to the palm, and after removing them from the test tubes, they are held in the hand.

For reseeding the microbial culture, a flambéed metal rod 2 with an eyelet 3 of the bacteriological loop is inserted into the lumen of the test tube without bringing it to the surface of the medium with the microbial culture, and cooled.

Then the culture is touched with a bacteriological loop and captured. The culture lingers in his ear 3.

For reseeding into the next test tube, a metal rod 2 with an eyelet 3 of a bacteriological loop is directed into a test tube with a semi-liquid nutrient medium. The advancement of the metal rod 2 with the eyelet 3 of the bacteriological loop inside the test tube is continued until it stops at the limiters 5. This ensures the introduction of microbial cultures deep into the semi-liquid nutrient medium to a predetermined depth - 2/3 of the height of its column.

Microbes remain on the path of the working element of the bacteriological loop deep into the semi-liquid nutrient medium, they can grow by injection. That is, the microbial culture is sown by injection into a test tube with a semi-liquid nutrient medium in a column. Then the bacteriological loop is taken out of the test tube. Both tubes are stoppered and placed in a rack.

After using the bacteriological loop, it is sterilized both assembled and disassembled. In the latter case, the coupling 4 is unscrewed and the working element in the form of a metal rod 2 with an eye 3 is released from the handle 1.

The collapsible design of the bacteriological loop is also provided for replacing its worn-out elements. So, for example, flaming the working element of the bacteriological loop can lead to wear (burning out) of the metal rod 2, eyelet 3.

In repeated tests of the proposed bacteriological loop, not only its unimpeded passage deep into the semi-liquid nutrient medium was revealed, but also the penetration of the abalone 3 with microbial cultures into this nutrient medium to a standard predetermined depth - 2/3 of the height of its column, which is facilitated by the cylindrical cover 5.

The device of the bacteriological loop allows the researcher to work equally confidently with both the right and left hand.

The use of the proposed bacteriological loop allows you to:

increase the controllability and convenience of the laboratory instrument;

observe the technique of sowing and studying the mobility of microbial cultures strictly in the center of a semi-liquid nutrient medium and at the same depth - 2/3 of the height of its column;

reduce the time for manipulation;

reduce the intensity of the researcher's work mode;

observe the technique of cultivating microorganisms;

improve the readability and accuracy of laboratory test results;

Eliminate the need for re-testing.

When using the proposed bacteriological loop, a decrease in labor intensity was noted when working with this laboratory instrument. In this case, the sowing of microbial cultures was carried out strictly in the center of the semi-liquid nutrient medium, as well as at the same depth in all samples.

Claims (1)

Bacteriological loop for sowing microbial cultures in a test tube, containing a handle on one side and a removable working element on the other side in the form of a metal rod with an eyelet at its end, fixed in the handle with a coupling, characterized in that the working element near the coupling is additionally equipped with a cylindrical cover with the possibility installing it on the upper end of the tube, and the diameter of the cylindrical cap exceeds the outer diameter of the tube.

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