Muscle tail bacteriophage model for expressing bacterial infection process

Abstract

The invention relates to the technical field of teaching aids, in particular to a muscular tail bacteriophage model for expressing a bacterial infection process. The muscle tail phage model comprises a head, a neck and a tail which are connected in sequence, and the structural centers of the three fall on the central axis of the tail; the head comprises a capsid and a nucleic acid chamber nested in the capsid, a rotating shaft is arranged in the center of the nucleic acid chamber and perpendicular to the middle axis of the tail, and a nucleic acid silk thread is wound on the rotating shaft; the tail part comprises an upper tail sheath, a lower tail sheath and an inner tail tube fixed in the tail sheath through a limiting plate, and the central axis of the tail sheath coincides with the central axis of the inner tail tube; when the lower tail sheath retracts, the air pressure in the model is suddenly increased, at the moment, the high-pressure gas impacts the whole inner wall of the model, and the excitation head is separated from the lower tail sheath when impacted by the air pressure, so that the nucleic acid silk thread is drawn out to simulate the behavior that the tail sheath is contracted by muscle tail bacteriophage to inject nucleic acid into bacteria.

Description

Technical Field

[0001] The invention relates to the technical field of teaching tools, and in particular to a muscle tail phage model showing a bacterial infection process. Background Art

[0002] After the discovery of autophagosomes, people have obtained many remarkable results through research on them, such as proving that DNA is genetic material and using autophagosomes to successfully treat Pseudomonas aeruginosa infection in burn patients.

[0003] According to current research results, the morphological structure of phages can be divided into tailed, tailless and linear phages. Currently, more than 95% of the phages found in nature are tailed phages. According to the morphology of the phage tail observed by electron microscope, it can be further divided into the Mvovinidae with a long, straight, retractable tail, the Siphoviridae with a long, soft, non-contractile tail, and the Podoviridae with a short, thick, non-contractile tail.

[0004] In the current phage infection experiment teaching, in order to facilitate students' understanding, teachers usually use a combination of pictures, texts and models to conduct teaching. For this reason, relevant practitioners continue to optimize the phage teaching model so that students can understand its infection process:

[0005] For example, the patent with application number "201220311397.2" provides a phage model, in which the inventor uses a detailed and vivid model to show the structure and morphology of the long-tailed phage, showing the head, neck, neck ring, base plate, tail and other features of the phage, which is an excellent example.

[0006] Similar to the above example, the patent with application number "201210182982.1" also provides a phage model. Not only that, it also provides a model of bacteria (Escherichia coli) as the object of infection. The model further demonstrates the process of phage infecting Escherichia coli and injecting phage DNA molecules, which is also an excellent example.

[0007] In addition, the patent with application number "202010680777.2" goes a step further and uses circuit simulation to demonstrate the infection process of bacteriophage to enrich the teaching content.

[0008] When browsing the above excellent examples, the inventors found that the current phage models have reached a very high level of precision, and some models are very close to the physical appearance of phages, but most of the current phage models only focus on long-tailed phages and short-tailed phages, and there are relatively few muscle-tailed phage models. The reason is that during the infection process of muscle-tailed phages, their tail sheaths have the movement performance of "extending and injecting into the bacteria", and most of the current models are static models, which cannot show this process. Forcibly using static models will cause misunderstandings.

[0009] Based on the above considerations, the inventors attempted to design a model for the muscle-tailed phage, which has the most complex infection behavior. By designing a movable model structure, the inventors reproduced the behavior pattern of "extending the tail sheath and injecting nucleic acid" of the muscle-tailed phage when infecting bacteria, filling the gap in the current expression of the infection action of the muscle-tailed phage model. Summary of the invention

[0010] In order to solve the above problems, the present invention designs a muscle-tailed phage model that represents the bacterial infection process, aiming to dynamically demonstrate the behavior pattern of "extending the tail sheath and injecting nucleic acid" of the muscle-tailed phage when infecting bacteria through the model. The specific content is shown below.

[0011] The muscle-tail phage model designed by the present invention comprises a head, a neck and a tail connected in sequence, and the central axes of the three coincide with each other;

[0012] The head includes a capsid and a nucleic acid chamber nested inside the capsid, a rotating shaft is arranged at the center of the nucleic acid chamber perpendicular to the central axis of the tail, and a nucleic acid thread is wound around the rotating shaft;

[0013] The tail portion includes a tail sheath and a tail plate connected up and down, the tail sheath includes an upper tail sheath and a lower tail sheath, and an inner tail tube fixed inside the upper tail sheath through a limiting plate, and the central axes of the upper tail sheath and the inner tail tube coincide;

[0014] Two snap-on ball protrusions are symmetrically arranged on the outer wall of the inner tail pipe away from the neck;

[0015] The lower tail sheath is a hollow structure with a limiting groove at one end and a limiting ring at the other end;

[0016] When the limiting groove is connected to the limiting plate, the lower tail sheath can be sleeved in the gap between the upper tail sheath and the inner tail tube, and the upper tail sheath and the lower tail sheath can maintain linear sliding;

[0017] One end of the upper tail sheath away from the lower tail sheath passes through the neck and communicates with the nucleic acid chamber;

[0018] The tail plate is connected to the lower end of the lower tail sheath, and a limiting through groove adapted to the clamping ball convex is provided on the inner wall of the tail plate, and three pairs of spikes are vertically arranged on the side of the tail plate away from the lower tail sheath;

[0019] The spike is composed of a fixed tube and a movable spike elastically sleeved in the fixed tube; the spike includes a pair of trigger spikes corresponding to the positions of the limit slots, the movable spikes of the trigger spikes penetrate the fixed tube and extend into the limit slots, and when the movable spikes of the trigger spikes extend into the limit slots, the locking state of the clamping ball protrusion and the limit slots can be released;

[0020] A neck ring is arranged on the neck perpendicular to the central axis, and a tension spring is arranged between the neck ring and the tail plate and is sleeved on the outside of the tail sheath, with the central axis coinciding with the tail sheath.

[0021] Description: The function of the stretch spring is the same as the contractile tissue on the tail sheath of the myo-tail phage, both of which play the role of contracting the tail sheath and ejecting the inner tail tube.

[0022] Furthermore, a push lock plate is provided on one side of the capsid adjacent to the connection point between the rotating shaft and the nucleic acid chamber, and the push lock plate includes a rotating plate rotatably connected to the capsid, a lock buckle with a locking track, and an elastic locking rod with a sliding head arranged in the capsid; when the elastic locking rod is located at different positions on the locking track, the push lock plate on the capsid can be closed and opened.

[0023] Note: The present invention uses a "lock-type" locking structure instead of other locking structures such as magnetic attraction in order to improve the overall structural strength and air tightness of the model when subjected to high internal pressure, and to prevent the airflow from pushing open the pressing lock plate and affecting the excitation of the nucleic acid thread; the working principle of the pressing lock plate is as follows:

[0024] The locking track is composed of an entry track, a recessed track and an exit track connected in sequence, and the travel end of the exit track intersects with the entry track, and the exit track is higher than the entry track at the intersection, and the drop forms a limit platform;

[0025] When the lock buckle is pressed to insert it into the shell, the sliding head of the elastic lock rod slides into the entry track (due to the existence of the limit platform, the sliding head will not mistakenly enter the exit track during the entry stage). As the pressure continues, the sliding head is stuck in the connection between the entry track and the recessed track. At this time, the pressure is released, and the natural rebound causes the sliding head to fall into the recessed part of the recessed track, completing the locking;

[0026] After the push-lock plate is locked, applying pressure on the push-lock plate again will force the sliding head to rise and enter the side of the recessed track with a larger entry angle, and stop at the connection between the recessed track and the exit track. At this time, the pressure is released, and the natural rebound will cause the sliding head to fall into the exit track, completing the unlocking.

[0027] Furthermore, a knob is provided at the axial intersection of the side surface of the shell and the rotating shaft, and the knob is fixedly connected to the rotating shaft.

[0028] Note: The operator can manually adjust the rotation axis through the knob to retract and release the nucleic acid thread, which is convenient for resetting the model after teaching demonstration.

[0029] Furthermore, a torsion spring is provided at the rotation connection between the rotation shaft and the nucleic acid chamber.

[0030] Note: The torsion spring is another way to recover and reset the nucleic acid thread, which gives the model the ability to automatically recover the stimulated nucleic acid thread.

[0031] Furthermore, one end of the nucleic acid thread is wound around the rotating shaft, and the other end is connected to an excitation head, and a limiting cone is provided at the end of the excitation head.

[0032] Note: The gap between the upper tail sheath and the inner tail tube, the nucleic acid chamber, and the inner cavity of the lower tail sheath are an interconnected whole. When the lower tail sheath retracts, the air pressure inside the model will increase sharply. At this time, the high-pressure gas will impact the entire inner wall of the model, and the part blocked by the excitation head will become a structural weak point. When impacted by the air pressure, the excitation head will detach from the lower tail sheath and further pull out the nucleic acid thread, simulating the nucleic acid injection behavior of the muscle-tailed phage.

[0033] Furthermore, a metal spring sheet is arranged in the limiting through groove, and the metal spring sheet separates the trigger protrusion and the clamping ball protrusion on both sides thereof.

[0034] Note: The metal shrapnel has two functions: one is to act as a "lubricant" between the trigger protrusion and the catch ball protrusion to prevent contact between the two and reduce jamming; the other is that the metal shrapnel itself is elastic and can assist the trigger protrusion to push the catch ball protrusion out of the limiting slot.

[0035] Furthermore, a compression spring is provided at the joint between the clamping ball protrusion and the inner tail pipe.

[0036] Description: The compression spring enables the catch ball to pop out automatically.

[0037] Furthermore, the maximum cross-sections through the center of the neck ring and the tail plate are both hexagonal and equal in size; three pairs of magnetic grooves are evenly spaced on the side of the tail plate, and the magnetic grooves bind the tail wire with a magnetic ball at the root through magnetic force.

[0038] Note: The shapes of the neck ring and tail plate simulate the appearance of the neck ring and tail plate of the bacteriophage itself; and the cooperation between the magnetic groove and the magnetic ball can easily simulate the movement state of the bacteriophage tail filament.

[0039] Furthermore, the length of the upper limit groove of the lower tail sheath is 1 / 2 of the length of the lower tail sheath.

[0040] Description: A notable feature of the muscle-tailed phage is its retractable tail sheath. Studies have shown that under electron microscopy, the contraction rate of the tail sheath of the muscle-tailed phage is about 55%, causing the rigid tail tube inside to separate and extend; therefore, the retractability of the lower tail sheath in the present invention is set at 50%.

[0041] Furthermore, there are three limiting grooves, and the angle between the three limiting grooves is 120°.

[0042] Note: The distribution form and quantity limitation of the limit grooves are mainly to improve the stability when the upper tail sheath and the lower tail sheath slide quickly against each other.

[0043] Compared with the existing phage model, the beneficial effects of the present invention are:

[0044] The muscle-tailed phage model designed in the present invention is based on the analysis of the movement of the tail sheath and inner tube of the phage. Through structural design, the behavior of the muscle-tailed phage "extending the tail sheath to inject nucleic acid" when infecting bacteria is demonstrated in the form of a dynamic demonstration on the teaching model. Compared with previous static models, it is more vivid and easier for students to understand.

[0045] The aim is to dynamically demonstrate through a model the behavior pattern of the muscle-tailed phage "extending the tail sheath to inject nucleic acid" when infecting bacteria. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is the appearance of the muscle tail phage model;

[0047] Figure 2 This is an exploded view of the structure of the muscle-tailed phage model;

[0048] Figure 3 yes Figure 1 A partial enlarged view of the middle A;

[0049] Figure 4 yes Figure 1 A partial enlarged view of point B in the middle;

[0050] Figure 5 yes Figure 3 A partial enlarged view of point C in the middle.

[0051] In the figure:

[0052] 1-head, 11-capsid, 111-pressing lock plate, 1111-rotating plate, 1112-locking buckle, 1113-locking track, 11131-entering track, 11132-recessed track, 11133-exiting track, 11134-limiting platform, 1114-elastic locking rod, 1115-sliding head, 112-knob, 12-nucleic acid chamber, 13-rotating shaft, 131-torsion spring, 14-nucleic acid thread, 141-excitation head, 1411-limiting cone;

[0053] 2-neck, 21-neck ring;

[0054] 3-tail, 31-tail sheath, 311-upper tail sheath, 3111-limiting plate, 312-lower tail sheath, 3121-limiting groove, 3122-limiting ring, 313-inner tail tube, 3131-clamping ball convex, 3132-compression spring, 32-tail plate, 321-limiting through groove, 322-metal shrapnel, 333-magnetic groove, 33-tail wire, 331-magnetic ball, 34-spike, 341-fixed tube, 342-movable spike, 343-trigger spike;

[0055] 4- Extension spring. DETAILED DESCRIPTION

[0056] In order to further illustrate the method adopted by the present invention and the effect achieved, the technical solution of the present invention will be clearly and completely described in combination with experiments below.

[0057] Example 1: This example describes a myotail phage model that demonstrates the bacterial infection process.

[0058] The muscle-tail phage model designed by the present invention comprises a head 1, a neck 2 and a tail 3 which are connected in sequence, and the central axes of the three coincide with each other;

[0059] The head 1 includes a capsid 11 and a nucleic acid chamber 12 nested inside the capsid 11. A rotating shaft 13 is arranged at the center of the nucleic acid chamber 12 perpendicular to the central axis of the tail 3. A nucleic acid thread 14 is wound around the rotating shaft 13.

[0060] The tail portion 3 includes a tail sheath 31 and a tail plate 32 connected in an upper and lower manner, the tail sheath 31 includes an upper tail sheath 311 and a lower tail sheath 312, and an inner tail tube 313 fixed inside the upper tail sheath 311 through a limiting plate 3111, and the central axes of the upper tail sheath 311 and the inner tail tube 313 coincide with each other;

[0061] Two snap-on ball protrusions 3131 are symmetrically arranged on the outer wall of the inner tail pipe 313 away from the neck 2;

[0062] The lower tail sheath 312 is a hollow structure with a limiting groove 3121 at one end and a limiting ring 3122 at the other end;

[0063] When the limiting groove 3121 is connected to the limiting plate 3111, the lower tail sheath 312 can be sleeved in the gap between the upper tail sheath 311 and the inner tail tube 313, and the upper tail sheath 311 and the lower tail sheath 312 can maintain linear sliding;

[0064] One end of the upper tail sheath 311 away from the lower tail sheath 312 passes through the neck 2 and communicates with the nucleic acid chamber 12;

[0065] The tail plate 32 is connected to the lower end of the lower tail sheath 312. The inner wall of the tail plate 32 is provided with a limiting groove 321 adapted to the clamping ball protrusion 3131. The side of the tail plate 32 away from the lower tail sheath 312 is vertically provided with three pairs of spikes 34.

[0066] The spike 34 is composed of a fixed tube 341 and a movable spike 342 elastically sleeved in the fixed tube 341; the spike 34 includes a pair of trigger spikes 343 corresponding to the positions of the limiting slots 321, and the movable spikes 342 of the trigger spike 343 penetrate the fixed tube 341 and extend into the limiting slots 321, and when the movable spikes 342 of the trigger spike 343 extend into the limiting slots 321, the locking state between the clamping ball protrusion 3131 and the limiting slots 321 can be released;

[0067] The neck 2 is provided with a neck ring 21 perpendicular to the central axis, and a tension spring 4 is provided between the neck ring 21 and the tail plate 32 and is sleeved outside the tail sheath 31 and has its central axis coincident with the tail sheath 31 .

[0068] Specifically, a pressing lock plate 111 is provided on one side of the capsid 11 adjacent to the connection point between the rotating shaft 13 and the nucleic acid chamber 12. The pressing lock plate 111 includes a rotating plate 1111 rotatably connected to the capsid 11, a lock buckle 1112 with a locking track 1113, and an elastic locking rod 1114 with a sliding head 1115 arranged in the capsid 11; when the elastic locking rod 1114 is located at different positions on the locking track 1113, the pressing lock plate 111 can be closed and opened on the capsid 11.

[0069] Specifically, a knob 112 is provided at a position where the side surface of the shell 11 intersects the axial direction of the rotating shaft 13 , and the knob 112 is fixedly connected to the rotating shaft 13 .

[0070] Specifically, one end of the nucleic acid thread 14 is wound around the rotating shaft 13 , and the other end is connected to an excitation head 141 . A limiting cone 1411 is provided at the end of the excitation head 141 .

[0071] Specifically, a metal spring piece 322 is disposed in the limiting through groove 321 , and the metal spring piece 322 separates the trigger protrusion 343 and the locking ball protrusion 3131 on both sides thereof.

[0072] Specifically, a compression spring 3132 is provided at the joint between the clamping ball protrusion 3131 and the inner tail pipe 313 .

[0073] Specifically, the maximum cross-sections through the center of the neck ring 21 and the tail plate 32 are both hexagonal and equal in size; three pairs of magnetic grooves 333 are evenly spaced on the side of the tail plate 32, and the magnetic grooves 333 bind the tail wire 33 with the magnetic ball 331 at the root through magnetic force.

[0074] Specifically, the length of the upper limit groove 3121 on the lower tail sheath 312 is 1 / 2 of the length of the lower tail sheath 312 .

[0075] Specifically, there are three limiting grooves 3121 , and the angle between the three limiting grooves 3121 is 120°.

[0076] Example 2: The recording scheme of this example is based on the content of Example 1. Except for the following differences, the rest of the content is the same as Example 1:

[0077] A torsion spring 131 is provided at the rotation connection between the rotation axis 13 of the myotail phage model and the nucleic acid chamber 12 .

[0078] The torsion spring 131 is another way to recover and reset the nucleic acid thread, which gives the model the ability to automatically recover the nucleic acid thread and facilitates the operator to reset the model.

[0079] Application example: The description of this experimental example is based on the scheme described in Example 1, and is intended to illustrate the use method and working principle of the present invention.

[0080] The method for using the muscle tail phage model designed by the present invention is as follows:

[0081] When teaching, the teacher first pushes the lower tail sheath 312 of the muscle-tail phage model toward the upper tail sheath 311 until the sound of the snap-in ball protrusion 3131 snapping into the fiber slot 3121 is heard, completing the model debugging; then the teacher holds the muscle-tail phage model to show the students the appearance and main structure of the muscle-tail phage: the head 11, the neck 2, the neck ring 21, the tail 3, the tail sheath 31, the inner tail tube 313, the tail plate 32, the tail filament 33 and the spike 34;

[0082] After students have a preliminary understanding of the structure of the muscle-tailed phage, show them the behavior of the muscle-tailed phage infecting bacteria:

[0083] The angle of the muscle-tail phage model is adjusted so that the tail filaments are close to the bacterial model (simulating the behavior of the muscle-tail phage attaching to bacteria). Furthermore, the spikes 34 of the muscle-tail phage model are attached to the surface of the bacterial model and the model is pressed (simulating the muscle-tail phage being fixed on the bacterial surface through the spikes 34).

[0084] When the spike 34 is compressed, the active spike 342 of the trigger spike 343 rises and enters the limiting groove 321, squeezing the metal spring 322 in the limiting groove 321, thereby causing the locking ball protrusion 3131 to be out of the locked state. Under the action of the tension spring 4, the head 1 quickly retracts into the lower tail sheath 312. At this time, the lower tail sheath 312 squeezes the entire inner cavity of the model, increasing the internal air pressure. The high-pressure gas impacts the entire inner wall of the model, and the part blocked by the excitation head 141 becomes a structural weak point. When impacted by the air pressure, the excitation head 141 will break away from the lower tail sheath 312, further extracting the nucleic acid thread 14 in the head 1, simulating the nucleic acid injection behavior of the muscle-tailed bacteriophage.

[0085] When the demonstration is over, the teacher applies pressure to the push lock plate 111 to make it pop open, and twists the knob 112 to recycle the stimulated nucleic acid thread 14, and finally rearranges the stimulation head 141 at the end of the nucleic acid thread 14 in the inner tail tube 313 to reset the model.

[0086] The working principle of the pressing lock plate 111 is as follows:

[0087] The locking track 1113 on the lock buckle 1112 is composed of an entry track 11131, a recessed track 11132 and an exit track 11133 connected in sequence, and the travel end of the exit track 11133 intersects with the entry track 11131, and the exit track 11133 is higher than the entry track 11131 at the intersection, and the drop forms a limit platform 11134;

[0088] When the lock buckle 1112 is pressed to insert it into the shell 11, the sliding head 1115 of the elastic locking rod 1114 slides into the entry track 11131 (due to the existence of the limit platform 11134, the sliding head 1115 will not mistakenly enter the exit track 11133 during the entry stage). As the pressure continues, the sliding head 1115 is stuck in the connection between the entry track 11131 and the recessed track 11132. At this time, the pressure is released, and the natural rebound causes the sliding head 1115 to fall into the recessed part of the recessed track 11132, completing the locking.

[0089] After the lock plate 111 is locked, applying pressure to the lock plate 111 again will force the sliding head 1115 to rise and enter the side of the recessed track 11132 with a larger entry angle, and stop at the connection between the recessed track 11132 and the exit track 11133. At this time, the pressure is released, and the natural rebound will cause the sliding head 1115 to fall into the exit track 11133, completing the unlocking.

Claims

1. A muscle-tailed phage model showing the bacterial infection process, comprising a head (1), a neck (2) and a tail (3) connected in sequence, and the central axes of the three coincide, characterized in that: The head (1) is a capsid (11) and a nucleic acid chamber (12) nested inside the capsid (11); a rotating shaft (13) is arranged at the center of the nucleic acid chamber (12) perpendicular to the central axis of the tail (3); a nucleic acid thread (14) is wound around the rotating shaft (13); The tail portion (3) comprises a tail sheath (31) and a tail plate (32) connected in an upper and lower manner, the tail sheath (31) comprises an upper tail sheath (311) and a lower tail sheath (312), and an inner tail tube (313) fixed inside the upper tail sheath (311) through a limiting plate (3111), and the central axes of the upper tail sheath (311) and the inner tail tube (313) coincide with each other; Two locking ball protrusions (3131) are symmetrically arranged on the outer wall of the inner tail pipe (313) away from the neck (2); The lower tail sheath (312) is a hollow structure and has a limiting groove (3121) at one end and a limiting ring (3122) at the other end; When the limiting groove (3121) is butted against the limiting plate (3111), the lower tail sheath (312) can be sleeved in the gap between the upper tail sheath (311) and the inner tail tube (313), and the upper tail sheath (311) and the lower tail sheath (312) can maintain linear sliding; One end of the upper tail sheath (311) away from the lower tail sheath (312) passes through the neck (2) and is connected to the nucleic acid chamber (12); The tail plate (32) is connected to the lower end of the lower tail sheath (312), the inner wall of the tail plate (32) is provided with a limiting through groove (321) adapted to the clamping ball protrusion (3131), and three pairs of spikes (34) are vertically arranged on one side of the tail plate (32) away from the lower tail sheath (312); The spike (34) is composed of a fixed tube (341) and a movable spike (342) elastically sleeved in the fixed tube (341); the spike (34) includes a pair of trigger spikes (343) corresponding to the positions of the limiting through groove (321); the movable spikes (342) of the trigger spike (343) penetrate the fixed tube (341) and extend into the limiting through groove (321); and when the movable spikes (342) of the trigger spike (343) extend into the limiting through groove (321), the locking state between the clamping ball protrusion (3131) and the limiting through groove (321) can be released; The neck (2) is provided with a neck ring (21) perpendicular to the central axis, and a tension spring (4) is provided between the neck ring (21) and the tail plate (32), which is sleeved outside the tail sheath (31) and whose central axis coincides with the tail sheath (31).

2. A myotail phage model showing the bacterial infection process as claimed in claim 1, characterized in that: A pressing lock plate (111) is arranged on one side of the capsid (11) adjacent to the connection point between the rotating shaft (13) and the nucleic acid chamber (12), and the pressing lock plate (111) comprises a rotating plate (1111) rotatably connected to the capsid (11), a lock buckle (1112) with a locking track (1113), and an elastic locking rod (1114) with a sliding head (1115) arranged in the capsid (11); when the elastic locking rod (1114) is located at different positions on the locking track (1113), the pressing lock plate (111) on the capsid (11) can be closed and opened.

3. A myotail phage model showing the bacterial infection process as claimed in claim 1, characterized in that: A knob (112) is provided at a position where the side surface of the shell (11) intersects with the axial direction of the rotating shaft (13), and the knob (112) is fixedly connected to the rotating shaft (13).

4. A myotail phage model showing the bacterial infection process as claimed in claim 1, characterized in that: A torsion spring (131) is provided at the rotation connection between the rotating shaft (13) and the nucleic acid chamber (12).

5. A myotail phage model showing the bacterial infection process as claimed in claim 1, characterized in that: One end of the nucleic acid thread (14) is wound around the rotating shaft (13), and the other end is connected to an excitation head (141), and a limiting cone (1411) is provided at the end of the excitation head (141).

6. A myotail phage model showing the bacterial infection process as claimed in claim 1, characterized in that: A metal spring sheet (322) is arranged in the limiting through groove (321), and the metal spring sheet (322) separates the trigger protrusion (343) and the locking ball protrusion (3131) on both sides thereof.

7. A myotail phage model for demonstrating bacterial infection process as claimed in claim 1, characterized in that: A compression spring (3132) is provided at the joint between the snap-fit ​​ball protrusion (3131) and the inner tail pipe (313).

8. A myotail phage model for demonstrating bacterial infection process as claimed in claim 1, characterized in that: The maximum cross-sections through the center of the neck ring (21) and the tail plate (32) are both hexagonal and equal in size; three pairs of magnetic grooves (333) are arranged at equal intervals on the side of the tail plate (32), and the magnetic grooves (333) bind the tail wire (33) with the magnetic ball (331) at the root through magnetic force.

9. A myotail phage model for demonstrating bacterial infection process as claimed in claim 1, characterized in that: The length of the upper limit groove (3121) of the lower tail sheath (312) is 1 / 2 of the length of the lower tail sheath (312).

10. A myotail phage model for demonstrating bacterial infection process as claimed in claim 1, characterized in that: The number of the limiting grooves (3121) is three, and the angle between the three limiting grooves (3121) is 120°.

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