Method for constructing urinary tract infection rabbit model

Abstract

The invention discloses a method for constructing a urinary tract infection domestic rabbit model, which comprises the following steps of: on the basis of catheter guidance, placing a ureteral catheter into a bladder through a urethra to manufacture a barrier-free artificial channel, then placing a spiral epidural catheter into the bladder through a ureteral catheter channel, and finally, placing the spiral epidural catheter into the bladder through the ureteral catheter channel. After Escherichia coli is injected through a ureteral catheter, a urethral orifice is quickly ligated with a silk thread, and the urethra is reopened after 2 hours. According to the invention, the condition of complicated urinary tract infection caused by common clinical calculi, foreign matter retention (stent tubes, ureters and the like) and the like can be simulated; compared with a ureter semi-ligation model, the method is relatively simple to operate, low in infection rate and high in repeatability; compared with a bladder direct injection bacterial model without laparotomy, the model has the advantages of typical pathological process and high and stable urinary tract infection success rate.

Description

Technical Field

[0001] The present invention relates to the technical field of constructing a rabbit model of urinary tract infection, and specifically relates to a method for constructing a rabbit model of urinary tract infection. Background Art

[0002] During the treatment process in urology, catheter-associated urinary tract infection (CAUTI) is a relatively common complication in patients using catheters. Its clinical incidence is relatively high, and it is one of the most common infections. Relevant studies have confirmed that the formation of bacterial biofilms is the main cause of catheter-associated urinary tract infections. When planktonic bacteria adhere to and aggregate on inert implants, such as the surface of catheters, they secrete various extracellular substances to form a bio-aggregation state with a hydrophobic structure. After the body invades the implant, the inert surface of the catheter provides a platform for the adhesion and aggregation of planktonic bacteria. The planktonic bacteria on the catheter surface, urethral and body tissue secretions jointly aggregate to form a bacterial biofilm centered on the catheter biomaterial. The main ways for bacteria to form biofilms in catheters are: through the extra-luminal route. When the catheter is inserted into the urinary system and retrogradely ascends, the microorganisms at the urethral orifice ascend and reproduce and infect along with the catheter. In patients using urine drainage bags, bacteria mainly reproduce in the lumen and cause infections.

[0003] In the prior art, it is proposed to establish a urinary tract infection model by implanting biomaterials into the bladder of rabbits through experimental means to elaborate on the relationship between uropathogenic Escherichia coli and host inflammatory responses, and to reveal the molecular biological mechanism of "down-regulating the expression level of flhDC of uropathogenic Escherichia coli → reducing the formation of bacterial biofilms on the surface of silicone rubber materials → reducing the virulence and immune escape ability of bacteria → reducing the inflammatory response of urinary tract infection", so as to provide important experimental basis for studying early diagnostic screening indicators and potential intervention or treatment targets for silicone catheter implantation-related urinary tract infection diseases in clinical diagnosis and treatment.

[0004] Currently, the traditional animal model of urinary tract infection is still a method of making a rabbit model of urinary tract infection by "semi-ligating" one side of the ureter, injecting bacteria into the bladder and clamping the urethral orifice at the same time. There are also relevant researchers who directly inject Escherichia coli into the bladder through an incision in the lower abdomen and clamp the urethral orifice to establish a urinary tract infection model. These operation methods are not only time-consuming, but also easily increase the infection rate of rabbits, and even cause septicemia and death of animals, with a low success rate of model establishment. In recent years, some scholars have successfully prepared an acute pyelonephritis model by directly injecting Escherichia coli into the bladder through the urethra without laparotomy. Although this method reduces the infection rate caused by laparotomy, the persistence and success rate of the established model are still relatively low. Based on this, the present invention explores a method of inserting a silicone catheter into the bladder through the urethra and injecting Escherichia coli to establish a rabbit model of urinary tract infection, so as to establish a rabbit model of urinary tract infection with a high success rate and stability. Summary of the Invention

[0005] To this end, the present invention provides a method for constructing a rabbit model of urinary tract infection to solve the problems that the traditional animal model construction method for urinary tract infection is prone to increase the infection rate of rabbits and the success rate of model establishment is low.

[0006] To achieve the above object, the present invention provides the following technical solution: A method for constructing a rabbit model of urinary tract infection, the method comprising:

[0007] S1, Rabbit preparation: The experimental rabbits are deprived of water, anesthetized by intraperitoneal injection, and the vulva is disinfected and covered with a sterile drape after disinfection.

[0008] S2, Bladder foreign body indwelling: First, use a small curved forceps to vertically lift the rabbit urethra along the horizontal plane, lubricate a common epidural catheter, slowly insert it into the urethra, rotate it left and right with resistance and move forward 1-2 cm, enter the bladder, and press the lower abdomen of the rabbit to see clear urine flowing out; Vertically extract the urethra, lubricate the ureteral catheter with the blind end cut off, insert it into the urethra along the epidural catheter for 1-2 cm. At this time, there is great resistance, and then rotate it left and right and move forward to 2-3 cm, pull out the epidural catheter, and press the abdomen to see urine flowing out from the ureteral catheter; Insert the self-made spiral epidural catheter into the bladder by spiraling 1-2 turns along the lumen of the ureteral catheter and then push it into the bladder with a zebra guide wire. See clear urine flowing out from the lumen of the ureteral catheter, and the indwelling of the foreign body is successful.

[0009] S3, Inject Escherichia coli: Slowly inject Escherichia coli bacterial solution into the bladder through the ureteral catheter, quickly ligate the urethral orifice, release it after a period of time, resume normal diet, and observe for a certain number of days.

[0010] Further, step S1 specifically includes:

[0011] The experimental rabbits are deprived of water for 24 hours, anesthetized by intraperitoneal injection with 1% pentobarbital at 8 mg / kg, and then the vulva is disinfected with 75% ethanol and covered with a sterile drape.

[0012] Further, in step S2, it specifically includes:

[0013] The method for making the self-made spiral catheter is: Use a disposable epidural anesthesia catheter with an outer diameter of 0.6 mm - 1.0 mm, spiral it around a cotton swab stick or a ureteral stent catheter and fix it, and perform plastic shaping after high-temperature and high-pressure treatment. The spiral section is placed in the bladder and coiled in the bladder to play a fixing role and is not easily detached from the urethra.

[0014] Further, in step S2, it specifically includes:

[0015] The ureteral catheter uses an F4 ureteral catheter.

[0016] Further, in step S3, it specifically includes:

[0017] Slowly inject 0.5 mL of Escherichia coli bacterial solution at a concentration of 15×108 CFU / mL into the bladder, quickly ligate the urethral orifice, and release it after 2 h.

[0018] Furthermore, the method specifically further includes:

[0019] Randomly divide the experimental rabbits into a blank group, a non-foreign body group, and a foreign body group using a random number table method;

[0020] For the blank group: There is no indwelling bladder foreign body and no Escherichia coli injection. Only inject an equal amount of sterile isotonic saline into the bladder, and divide it into two groups to observe for 7 d and 14 d respectively;

[0021] For the non-foreign body group: There is no indwelling bladder foreign body, but inject an equal amount of Escherichia coli bacterial solution into the bladder, and divide it into two groups to observe for 7 d and 14 d respectively.

[0022] The present invention proposes a method for constructing a rabbit model of urinary tract infection. Based on catheter guidance, a ureteral catheter is inserted into the bladder through the urethra to create an unobstructed artificial channel, and then a spiral epidural catheter is inserted into the bladder through the ureteral catheter channel. Finally, after injecting Escherichia coli through the ureteral catheter, quickly ligate the urethral orifice with silk thread, and reopen the urethra after 2 h. The present invention can simulate the situation of complex urinary tract infection caused by common clinical reasons such as stones and foreign body retention (stent tubes, urethral catheters, etc.). Compared with the ureteral semi-ligation model, this method is relatively simple in operation, has a low infection rate, and strong repeatability; compared with the model of directly injecting bacteria into the bladder without laparotomy, this model has a typical pathological process, a high success rate of urinary tract infection, and stability. Description of the Drawings

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only exemplary, and for those of ordinary skill in the art, without creative efforts, other implementation drawings can be obtained according to the provided drawings.

[0024] The structures, ratios, sizes, etc. illustrated in this specification are only used to cooperate with the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they do not have technical essence. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention.

[0025] Figure 1Flowchart of a method for constructing a rabbit model of urinary tract infection provided by an embodiment of the present invention;

[0026] Figure 2 Schematic diagram of a self-made spiral catheter in a method for constructing a rabbit model of urinary tract infection provided by an embodiment of the present invention. Detailed implementation manners

[0027] The following specific embodiments illustrate the implementation manners of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0028] The first embodiment of the present invention provides a method for constructing a rabbit model of urinary tract infection. The following is combined with Figure 1 for illustration.

[0029] In this embodiment, the experimental rabbits are divided into a blank group, a no-foreign-body group, and a foreign-body group by the random number table method;

[0030] For the blank group: No bladder foreign body is indwelled, and no Escherichia coli injection is performed. Only an equal amount of sterile isotonic saline is injected into the bladder, and it is divided into two groups to be observed for 7 days and 14 days respectively;

[0031] For the no-foreign-body group: No bladder foreign body is indwelled, but an equal amount of Escherichia coli bacterial solution is injected into the bladder, and it is divided into two groups to be observed for 7 days and 14 days respectively.

[0032] The specific construction process is as follows:

[0033] Step S1, Rabbit preparation: The experimental rabbits are deprived of water, intraperitoneally injected with anesthetic, and the vulva is disinfected and covered with a sterile drape after disinfection.

[0034] In this embodiment, the experimental rabbits are deprived of water for 24 hours, intraperitoneally injected with 1% pentobarbital at 8 mg / kg for anesthesia, and then the vulva is disinfected with 75% ethanol and covered with a sterile drape.

[0035] Step S2, Bladder foreign body indwelling (foreign body group): ① First, use a small curved clamp to vertically lift the rabbit's urethra along the horizontal plane, lubricate a common epidural catheter, and slowly insert it into the urethra. Rotate it left and right with resistance and advance 1 - 2 cm to enter the bladder. Press the lower abdomen of the rabbit to see clear urine flowing out; ② Vertically extract the urethra, lubricate the ureteral catheter with the blind end cut off, insert it into the urethra along the epidural catheter for 1 - 2 cm. At this time, there is great resistance, then rotate it left and right and advance to 2 - 3 cm, pull out the epidural catheter, and press the abdomen to see urine flowing out from the ureteral catheter; ③ Insert the self-made spiral epidural catheter into the bladder by spiraling 1 - 2 turns (about 1 cm) along the lumen of the ureteral catheter and then push it into the bladder with a zebra guide wire. See clear urine flowing out from the lumen of the ureteral catheter, and the indwelling of the foreign body is successful.

[0036] In this embodiment, in step S2, the method for making the self-made spiral catheter is as follows: Use a disposable epidural anesthesia catheter with an outer diameter of 0.6 mm - 1.0 mm, spiral it around a cotton swab stick or a ureteral stent catheter and fix it, and then perform plastic shaping under high temperature and high pressure. After the spiral section is placed in the bladder, it coils in the bladder to play a fixing role and is not easily detached from the urethra. The self-made spiral catheter is as Figure 2 shown.

[0037] In this embodiment, in step S2, the ureteral catheter used is an F4 ureteral catheter.

[0038] Step S3, Inject Escherichia coli: Slowly inject Escherichia coli bacterial solution into the bladder through the ureteral catheter, quickly ligate the urethral orifice, release it after a period of time, resume normal diet, and observe for a certain number of days.

[0039] Specifically, in this embodiment, slowly inject 0.5 mL of Escherichia coli bacterial solution at 15×108 CFU / mL into the bladder, quickly ligate the urethral orifice, and release it after 2 h.

[0040] For the foreign body and non-foreign body groups, slowly inject 0.5 mL of Escherichia coli bacterial solution at 15×108 CFU / mL into the bladder through the catheter, and the blank group injects an equal amount of sterile isotonic saline; ligate the urethral orifice and release it after 2 h, and resume normal diet.

[0041] Animals that can be used for the urinary tract infection model include mice, rabbits, dogs, pigs, etc. Among them, rabbits are convenient to operate. Bacteria can be injected or foreign bodies can be placed from the urethra or directly into the abdominal cavity. Due to the anatomic characteristics of the urinary tract, spontaneous ureterovesical reflux of urine is likely to occur. The method of clamping the urethral orifice while injecting bacteria is used to create increased hydrostatic pressure in the bladder mechanically to cause retrograde infection. Therefore, it is more suitable for the preparation of the urinary tract infection animal model.

[0042] This model simulates the situation of complicated urinary tract infection caused by common clinical factors such as stones and foreign body retention (stent tubes, ureteral catheters, etc.). On the basis of catheter guidance, the ureteral catheter is inserted into the bladder through the urethra to create an unobstructed artificial channel. Then, the spiral epidural catheter is inserted into the bladder through the ureteral catheter channel. Finally, Escherichia coli is injected through the ureteral catheter, and then the urethral orifice is quickly ligated with silk thread. The urethra is reopened 2 hours later. At the end of the experiment, the spiral catheter can remain in the bladder without being discharged.

[0043] The results showed that urine and kidney bacterial cultures, kidney weight index, blood picture, and kidney and bladder pathology were consistent with acute pyelonephritis. Some models had a tendency to transform into chronic pyelonephritis, indicating successful model establishment.

[0044] Compared with the ureteral semi-ligation model, this method has relatively simple operation, low infection rate, and strong repeatability. Compared with the model of directly injecting bacteria into the bladder without laparotomy, this model has a typical pathological process, high success rate and stability of urinary tract infection.

[0045] Although the present invention has been described in detail with general descriptions and specific embodiments above, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A method for constructing a rabbit model of urinary tract infection, characterized in that, The method includes: S1. Rabbit preparation: The experimental rabbits are deprived of water, anesthetized by intraperitoneal injection, and the vulva is disinfected and covered with a sterile drape after disinfection. S2. Bladder foreign body indwelling: First, use a small curved forceps to vertically lift the rabbit's urethra along the horizontal plane, lubricate a common epidural catheter, slowly insert it into the urethra, rotate it left and right with resistance and advance 1 - 2 cm, enter the bladder, and press the lower abdomen of the rabbit to see clear urine flowing out; vertically lift the urethra, lubricate the ureteral catheter with the blind end cut off, insert it into the urethra along the epidural catheter for 1 - 2 cm. At this time, there is great resistance, then rotate it left and right and advance to 2 - 3 cm, pull out the epidural catheter, and press the abdomen to see urine flowing out from the ureteral catheter; insert the self-made spiral epidural catheter into the ureteral catheter lumen in a spiral for 1 - 2 turns and then push it into the bladder with a zebra guide wire. See clear urine flowing out from the ureteral catheter lumen, and the indwelling of the foreign body is successful. S3. Inject Escherichia coli: Slowly inject Escherichia coli bacterial solution into the bladder through the ureteral catheter, quickly ligate the urethral orifice, and release it after a period of time, then resume normal diet and observe for a certain number of days.

2. The construction method of a rabbit model of urinary tract infection according to claim 1, characterized in that, Step S1 specifically includes: The experimental rabbits are deprived of water for 24 h, anesthetized by intraperitoneal injection with 1% pentobarbital at 8 mg / kg, and then the vulva is disinfected with 75% ethanol and covered with a sterile drape.

3. The method for constructing a rabbit model of urinary tract infection according to claim 1, characterized in that, In step S2, it specifically includes: The method for making the self-made spiral catheter is: Use a disposable epidural anesthesia catheter with an outer diameter of 0.6 mm - 1.0 mm, coil it spirally around a cotton swab stick or a ureteral stent catheter, and perform plastic shaping after high-temperature and high-pressure treatment. The spiral section is placed in the bladder and coils in the bladder to play a fixing role and is not easily detached from the urethra.

4. The method for constructing a rabbit model of urinary tract infection according to claim 1, characterized in that, In step S2, it specifically includes: The ureteral catheter used is an F4 ureteral catheter.

5. The construction method of a rabbit model of urinary tract infection according to claim 1, characterized in that, In step S3, it specifically includes: Slowly inject 0.5 mL of Escherichia coli bacterial solution at 15×108 CFU / mL into the bladder, quickly ligate the urethral orifice, and release it after 2 h.

6. The method for constructing a rabbit model of urinary tract infection according to claim 1, characterized in that, The method specifically further includes: The experimental rabbits are divided into a blank group, a no-foreign-body group, and a foreign-body group by the random number table method; For the blank group: There is no indwelling of bladder foreign body and no injection of Escherichia coli. Only inject an equal amount of sterile isotonic saline into the bladder, and divide it into two groups to observe for 7 d and 14 d respectively; For the no-foreign-body group: There is no indwelling of bladder foreign body, but inject an equal amount of Escherichia coli bacterial solution into the bladder, and divide it into two groups to observe for 7 d and 14 d respectively.

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