阅读说明：本技术 管路类和容器类医疗器械无菌检测方法 (Method for detecting sterility of pipeline and container medical instruments ) 是由 张萌萌 栾园园 郝树彬 王文庆 黄经春 栾同青 于 2021-06-15 设计创作，主要内容包括：本发明属于医疗器械无菌检测领域,提供管路类和容器类医疗器械无菌检测方法,步骤为：为向管路类和容器类医疗器械内加入无菌培养基,振荡冲洗之后将培养基转移到无菌容器内进行培养并进行菌落检查,即培养基冲洗法；或者向管路类和容器类医疗器械内加入无菌培养基直接进行培养并进行菌落检查,即培养基灌装法。本发明的培养基冲洗法与薄膜过滤法相比,无需使用无营养成分的冲洗液冲洗,直接采用有营养成分的培养基冲洗,检出率更高,无需过滤操作,降低了假阳性的概率；培养基灌装法直接将培养基灌装入容器内腔进行培养,无需对产品进行洗脱,大大减少了假阴性的可能,提高了检出率。(The invention belongs to the field of medical instrument sterility test, and provides a method for testing the sterility of pipeline and container medical instruments, which comprises the following steps: adding a sterile culture medium into the pipeline medical instruments and the container medical instruments, transferring the culture medium into a sterile container for culture after shaking and washing, and carrying out bacterial colony inspection, namely a culture medium washing method; or adding a sterile culture medium into the pipeline medical instruments and the container medical instruments to directly culture and carry out bacterial colony inspection, namely a culture medium filling method. Compared with a membrane filtration method, the culture medium flushing method does not need flushing liquid without nutrient components, directly adopts the culture medium with nutrient components for flushing, has higher detectable rate, does not need filtration operation, and reduces the probability of false positive; the culture medium filling method directly fills the culture medium into the inner cavity of the container for culture without eluting the product, thereby greatly reducing the possibility of false negative and improving the detection rate.)

1. The method for detecting the sterility of the pipeline medical instruments and the container medical instruments is characterized by comprising the following steps of:

and (3) a culture medium washing method: adding a sterile culture medium into the pipeline medical instruments and the container medical instruments, after shaking and washing, transferring the culture medium into a sterile culture container for culture and carrying out colony inspection;

or, the culture medium filling method: and adding a sterile culture medium into the pipeline medical instruments and the container medical instruments to directly culture and perform bacterial colony inspection.

2. The method for sterility testing of tubing and container medical devices according to claim 1, wherein the container medical device is a blood bag and the tubing medical device is an infusion set.

3. The method for aseptically detecting a pipeline-type medical device according to claim 1, wherein the method for aseptically detecting the infusion device by a medium flushing method is to allow a sterile medium to flow through the lumen of the pipe at a constant speed, preferably at a flow rate of 10 mL/min.

4. The method for sterility testing of medical devices of the line type and the container type according to claim 1, wherein the sterile medium is trypticase soy peptone broth (TSB medium) or thioglycolate broth (FTM medium).

5. The method for aseptically testing medical devices of pipelines and vessels according to claim 1, wherein the culture conditions of the medium flushing method is 2 days in an incubator, the culture conditions of the medium filling method is 14 days in an incubator, the culture temperature of the TSB medium is 22.5 ℃, and the culture temperature of the FTM medium is 32.5 ℃.

6. The method for sterility testing of tubing and container medical devices according to claim 1, wherein the sterile culture container comprises a sterile test tube, a disposable sterile sampling cup and a sterile culture flask.

7. The sterility test method for medical devices such as pipelines and containers according to claim 1, wherein the colony inspection method of the medium flushing method is to monitor the growth status of microorganisms by detecting metabolites produced by the growth of the microorganisms, and comprises the following steps: and adding the washed culture medium into a culture flask containing the silica gel membrane and the pH indicator, and judging that the microorganism grows if the color of the pH indicator changes.

8. The method for detecting the sterility of medical instruments such as pipelines and containers according to claim 1, wherein the colony inspection method of the culture medium filling method is to determine the presence or absence of microorganisms by determining the turbidity of the culture medium in the cavity of the medical instrument, and if the culture medium is clear, the sterility is determined, and if the culture medium is turbid, the sterility is determined.

Technical Field

The invention belongs to the technical field of medical health, and particularly relates to a method for detecting the sterility of medical instruments such as pipelines and containers.

Background

Medical instruments directly or indirectly act on human bodies, and the extremely high degree of hygiene of the medical instruments is of great significance for ensuring medical effects and patient health, so that the medical instruments need to be sterilized before being introduced into the market or used, and particularly, aseptic examination needs to be carried out on large-batch disposable medical instruments so as to reduce the risk of infection to human bodies in the subsequent use process. Sterility testing refers to a method of testing whether drugs, dressings, sutures, sterile instruments, and other items suitable for pharmacopoeia requiring sterility testing are sterile. Currently, the aseptic test method for the medical instrument finished product commonly adopted in the medical instrument industry mainly comprises a membrane filtration method and a direct inoculation method.

The membrane filtration method needs to elute microorganisms on a product and collect eluent for membrane filtration, and on one hand, false positive is caused by the fact that the steps are more, the operation is more complicated and exogenous pollution is easy to introduce; on the other hand, more importantly, the technology may not be capable of eluting all microorganisms on the product, so that the eluent cannot completely represent the microorganism level of the product, thereby increasing the possibility of false negative and ensuring the detection rate.

The direct inoculation method needs to directly put the sample or representative parts thereof into a culture medium for culture, and is not suitable for medical equipment products only requiring sterile inner cavities; in addition, for a test article with an elongated tubular shape, the test article is difficult to cut open and cut, so that the culture medium contacts the tube cavity, the probability of false negative is increased, and the application of the test article in the sterile detection of the medical instrument with the cavity is limited.

Disclosure of Invention

The invention provides a method for detecting the sterility of pipeline and container medical instruments, aiming at solving the technical problems of false positive, false negative and complex operation in the sterility test of the pipeline and container medical instruments in the prior art.

In order to achieve the purpose, the invention adopts the following technical scheme:

the method for detecting the sterility of the pipeline medical instruments and the container medical instruments is characterized by comprising the following steps of:

and (3) a culture medium washing method: adding a sterile culture medium into the pipeline medical instruments and the container medical instruments, after shaking and washing, transferring the culture medium into a sterile container for culture and carrying out colony inspection;

or, the culture medium filling method: adding a sterile culture medium into the pipeline medical instruments and the container medical instruments for direct culture and bacterial colony inspection;

preferably, the pipeline medical instrument is further preferably an infusion apparatus, and the container medical instrument is further preferably a blood bag;

preferably, the sterile medium is trypticase soytone broth (TSB medium) or thioglycolate fluid medium (FTM medium);

preferably, the shaking method for adding the sterile culture medium into the blood bag is manual shaking for 2 min;

preferably, the flushing method of the infusion apparatus is to make the sterile culture medium flow through the inner cavity of the tube at a constant speed, and the flow rate is about 10 mL/min.

Preferably, the transfer is performed by introducing the rinse solution directly into the sterile culture vessel.

Preferably, the sterile culture container comprises a sterile test tube, a disposable sterile sampling cup and a sterile culture bottle;

preferably, the culture conditions of the medium flushing method are 2 days of culture in a culture instrument, the culture conditions of the medium filling method are 14 days of culture in an incubator, the culture temperature of the TSB medium is 22.5 ℃, and the culture temperature of the FTM medium is 32.5 ℃.

Preferably, the colony inspection method is to monitor the growth condition of the microorganisms by detecting metabolites generated by the growth of the microorganisms, and specifically comprises the steps of adding the culture medium after flushing the medical instruments into a culture flask with a silica gel membrane and a pH indicator, and judging that the culture medium contains the microorganisms if the color of the pH indicator changes after culturing for 2 days.

The blake bottle includes bottle lid and transparent bottle through threaded connection, the bottom of transparent bottle is provided with the silica gel membrane circle, the cross section of silica gel membrane circle is semi-closed shape, the silica gel membrane circle with form confined annular region at the bottom of the bottle of transparent bottle be provided with the pH indicator in the annular region, the silica gel membrane circle is for allowing CO indicator₂Permeable polymeric semipermeable membrane, metabolite CO produced by microbial growth in culture medium₂Permeable silica gel membrane at the bottom of the culture flask, CO₂Generation of H by dissolution ionization⁺， H⁺The color change of the pH indicator in the closed space of the silica gel membrane ring can be realized.

One or more technical solutions provided by the embodiments of the present invention have at least the following technical effects:

(1) the operation method is simple, does not need filtration operation, does not need a bacteria collecting instrument and a membrane filter, reduces the test operation cost, reduces the possibility of introducing exogenous bacteria, and reduces the probability of false positive;

(2) compared with a membrane filtration method, the culture medium flushing method does not need flushing liquid without nutrient components, directly adopts culture medium with nutrient components for flushing, and has higher detectable rate.

(3) The culture medium filling method directly fills the culture medium into the inner cavity of the container for culture without eluting the product, thereby greatly reducing the possibility of false negative and improving the detection rate.

(4) The colony inspection method of the culture medium flushing method is to monitor the growth condition of the microorganism by detecting metabolites generated by the growth of the microorganism, namely to utilize CO generated by the microorganism₂The method can judge whether microorganisms exist in the culture medium according to the principle that the pH indicator in the culture bottle changes in color, reduces the subjectivity of the traditional visual inspection, and shortens the inspection period.

Drawings

Fig. 1 is a comparison graph of test bacteria detection rates (TSB medium) of infusion set products under different sterility test methods (detection rate comparison of different sterility test methods (TSB medium) of different gradients of infusion set).

FIG. 2 shows the detection rate comparison (FTM medium) of different gradient sterility test methods for infusion set.

FIG. 3 shows the detection rate comparison (TSB medium) of different sterile test methods for different gradients of blood bags.

FIG. 4 is a comparison graph of the test bacteria detection rate of blood bag products under different sterility test methods (FTM medium) (comparison of detection rates of blood bag products under different gradient sterility test methods (FTM medium)).

Detailed Description

The present invention is further illustrated by, but not limited to, the following examples.

It should be noted that the experimental methods described in the following examples are all conventional methods unless otherwise specified; the reagents, materials and equipment are commercially available, unless otherwise specified.

Example 1

The sterility test method for the pipeline medical apparatus and instruments adopts a culture medium flushing method to carry out sterility test on an infusion apparatus, and comprises the following steps:

(1) the puncture needle of the transfusion system (model: A0.55 × 19RW LB) is inserted into the mouth of a liquid medium containing tryptone soy peptone or thioglycollate liquid medium bottle, the medium is made to flow through the inner cavity of the tube, the flow rate is about 10mL/min, and 100mL of flushing liquid is collected in a sterile culture bottle.

In order to calculate the detectable rate, the infusion apparatus in the step is subjected to artificial pollution treatment in advance, and the method comprises the following specific operations:

a. preparation of test bacterial suspensions

Using a pipette to obtain a solution with a concentration of 1.9X 10 in 0.1mL⁸0.1mL of ATCC9372 suspension was added to 9.9mL of 40% ethanol solution to prepare a 1.9X 10 suspension⁶0.1mL of bacterial suspension, and sequentially diluting the bacterial suspension in a gradient manner to 1.9X 10⁴/0.1mL、1.9×10²0.1mL, at a concentration of 1.9X 10²/0.1marking mL of the bacterial suspension as A, adding 5mL of the bacterial suspension A into 5mL of 40% alcohol solution to obtain bacterial suspension 1/2A (gradient 1), and sequentially diluting in a gradient manner to obtain bacterial suspension 1/4A (gradient 2), bacterial suspension 1/8A (gradient 3) and bacterial suspension 1/16A (gradient 4).

The bacterial suspension 100 μ L from gradient 1 to gradient 4 was counted separately, and two plates were selected for each gradient for counting, the results are shown in table 1.

b. Preparation of artificially contaminated sample

And (b) inoculating 0.1mL of ATCC9372 bacterial suspension from the gradient 1 to the gradient 4 prepared in the step a into a sterile infusion set, shaking the infusion set to enable the bacterial suspension to be distributed in a pipeline of the infusion set as uniformly as possible, and then placing the infusion set into a drying oven to dry for 4 hours at 55 ℃, wherein 30 infectious infusion sets are prepared by each inoculation gradient.

(2) Culturing the sterile culture flask containing the flushing solution in a culture instrument for 2 days, wherein the culture temperature of the TSB culture medium is 22.5 ℃, and the culture condition of the FTM culture medium is 32.5 ℃. The culture bottle comprises a bottle cap and a transparent bottle body which are connected through threads, a silica gel membrane ring is arranged at the bottom of the transparent bottle body, the cross section of the silica gel membrane ring is in an inverted L shape, a closed annular area is formed by the silica gel membrane ring, the bottom of the transparent bottle body and the wall of the transparent bottle body, a pH indicator is arranged in the annular area, and the silica gel membrane ring is a ring allowing CO₂Permeable polymeric semipermeable membrane, metabolite CO produced by microbial growth in culture medium₂Permeable silica gel membrane at the bottom of the culture flask, CO₂Generation of H by dissolution ionization⁺， H⁺The color of the pH indicator in the closed space of the silica gel membrane ring can be changed, and if the color of the pH indicator is changed, the incubator reports positive.

(3) The positive condition of the incubator is observed, and the results are shown in tables 2 and 3.

Positive control:

taking 4 sterile infusion sets respectively, and adding ATCC9372 into a TSB culture medium or an FTM culture medium in the step (1) without artificial pollution to ensure that the gradient concentration is the same as the gradient 1 to the gradient 4, wherein other steps are the same as the steps (1) to (3), and the results are shown in tables 2 and 3.

Negative control:

taking 4 sterile infusion sets respectively, carrying out no artificial pollution, and carrying out the same steps as the steps (1) to (3), wherein the results are shown in tables 2 and 3.

Example 2

The aseptic detection method of the container medical apparatus adopts a culture medium flushing method to carry out aseptic detection on the blood bag, and comprises the following steps:

(1) adding 100mL of TSB culture medium or FTM culture medium into the disposable plastic blood bag by using a disposable sterile syringe, and manually shaking for 2 min;

in order to calculate the detection rate, the blood bag in the step is subjected to artificial pollution treatment in advance, and the method comprises the following specific operations:

a. preparation of test bacterial suspensions

Using a pipette to obtain a solution with a concentration of 1.9X 10 in 0.1mL⁸0.1mL of ATCC9372 suspension was added to 9.9mL of 40% ethanol solution to prepare a 1.9X 10 suspension⁶0.1mL of bacterial suspension, and sequentially diluting the bacterial suspension in a gradient manner to 1.9X 10⁴/0.1mL、1.9×10²0.1mL, at a concentration of 1.9X 10²Marking the bacterial suspension A (gradient 1 ') in/0.1 mL, adding 5mL of the bacterial suspension A into 5mL of 40% alcohol solution to obtain a bacterial suspension 1/2A (gradient 2'), and sequentially carrying out gradient dilution to obtain a bacterial suspension 1/4A (gradient 3 '), a bacterial suspension 1/8A (gradient 4') and a bacterial suspension 1/16A.

100 μ L of each of the bacterial suspensions from gradient 1 'to gradient 4' was counted, and two plates were selected for each gradient for counting, and the results are shown in Table 4.

b. Preparation of artificially contaminated sample

And (b) inoculating 0.1mL of ATCC9372 bacterial suspension from the gradient 1 'to the gradient 4' prepared in the step a into a sterile blood bag, shaking the blood bag to distribute the bacterial suspension in the blood bag as uniformly as possible, and then placing the blood bag into a drying oven to dry for 4 hours at 55 ℃, wherein 30 infected blood bags are prepared by each inoculation gradient.

(2) The sterile flask containing the rinse was incubated in the incubator for 2 days at 22.5 ℃ for TSB medium and 32.5 ℃ for FTM medium, as in example 1.

(3) The positive condition of the incubator is observed, and the results are shown in tables 5 and 6.

Positive control:

4 sterile blood bags were each taken without artificial contamination, and in step (1), ATCC9372 was added to the TSB medium or FTM medium so that the gradient concentration was from gradient 1 'to gradient 4', and the other steps were the same as those from step (1) to step (3), and the results are shown in tables 5 and 6.

Negative control:

4 sterile blood bags were taken each without artificial contamination, and the other steps were the same as the steps (1) to (3), and the results are shown in tables 5 and 6.

Example 3

The sterility test method for the pipeline medical instruments adopts a culture medium filling method to carry out sterility test on the infusion apparatus, and comprises the following steps:

(1) the puncture needle of the infusion apparatus with the same type as the infusion apparatus in the embodiment 1 is punctured into the bottle mouth of the bottled TSB culture medium or FTM culture medium, so that the flushing fluid flows into and fills the inner cavity of the infusion tube, the end of the puncture needle is covered with a protective cap, and the other end of the puncture needle is clamped by a clamping piece to avoid the outflow of the culture medium.

In order to calculate the detectable rate, the infusion set in the step is subjected to artificial pollution treatment in advance, and the specific operation is the same as that in the embodiment 1.

(2) The infusion set containing the culture medium is placed in an incubator for 14 days, the culture temperature of the TSB culture medium is 22.5 ℃, and the culture temperature of the FTM culture medium is 32.5 ℃.

(3) Visually observing the turbidity of the culture medium in the step (2), and if the culture medium is clear, performing aseptic growth; if the mixture is turbid, bacteria grow, and the results are shown in tables 2 and 3.

Positive control

Taking 4 sterile infusion sets respectively, adding ATCC9372 into a TSB culture medium or an FTM culture medium in the step (1) without artificial pollution, enabling the gradient concentration to be the same as that from the gradient 1 to the gradient 4, and observing and recording the growth condition of bacterial colonies in the same steps as those from the step (1) to the step (3), wherein the results are shown in tables 2 and 3.

Negative control

Taking 4 sterile infusion sets respectively, carrying out no artificial pollution, and carrying out the same steps as the steps (1) to (3) on other steps, wherein the results are shown in tables 2 and 3.

Example 4

The sterile detection method for the container medical instruments adopts a culture medium filling method to carry out sterile detection on blood bags, and comprises the following steps:

(1) adding 100mL of TSB culture medium or FTM culture medium into the disposable sterile plastic blood bag by using a disposable sterile syringe;

in order to calculate the detectable rate, the blood bag in this step is previously subjected to artificial contamination treatment, and the specific operation is the same as that in example 2.

(2) The blood bags containing the culture medium were placed in an incubator for 14 days, the culture temperature of the TSB medium was 22.5 ℃ and the culture temperature of the FTM medium was 32.5 ℃.

(3) Visually observing the turbidity of the culture medium in the step (2), and judging aseptic growth if the culture medium is clear; if the bacteria appeared turbid, the bacteria were judged to grow, and the results are shown in tables 5 and 6.

Positive control

Taking 4 sterile blood bags respectively, not carrying out artificial pollution, adding ATCC9372 into a TSB culture medium or an FTM culture medium in the step (1) to ensure that the gradient concentration is from 1 'to 4', and observing and recording the growth condition of colonies in the same steps from the step (1) to the step (3), wherein the results are shown in tables 5 and 6.

Negative control:

4 sterile blood bags were taken each without artificial contamination, and the other steps were the same as the steps (1) to (3), and the results are shown in tables 5 and 6.

Comparative example 1

The method for performing sterility test on the infusion set by using the membrane filtration method comprises the following steps:

(1) according to the requirements of a pharmacopeia method and a GB/T14233.2-2005 method, a puncture needle part of an infusion apparatus is punctured into the mouth of a 0.9% sodium chloride injection, flushing liquid flows through an inner cavity of a tube, the flow rate is about 10mL/min, 100mL of flushing liquid is collected in a sterile sampling cup, and the infusion apparatus in the step is prepared according to the artificial pollution sample in the embodiment 1;

(2) filtering the washing solution through a membrane filter by using a bacteria collector, adding 100mL of TSB culture medium into the filter after the filtration is finished, and culturing for 14 days at 22.5 ℃, or adding 100mL of FTM culture medium and culturing for 14 days at 32.5 ℃;

(3) visually observing the turbidity of the culture medium in the step (2), and if the culture medium is clear, performing aseptic growth; if the mixture is turbid, bacteria grow, and the results are shown in tables 2 and 3.

Positive control:

taking 4 sterile infusion sets, adding ATCC9372 into 0.9% sodium chloride injection in the step (1) without artificial pollution, enabling the gradient concentration to be the same as that of the solution in the gradient 1 to 4, observing the growth condition of bacterial colonies and recording the growth condition of the bacterial colonies in the same steps as the steps (1) to (3), wherein the results are shown in tables 2 and 3.

Negative control:

taking 4 sterile infusion sets, carrying out no artificial pollution, and carrying out the same steps as the steps (1) to (3) on other steps, wherein the results are shown in tables 2 and 3.

Comparative example 2

A method for sterility testing of blood bags using membrane filtration comprising the steps of:

(1) according to the requirements of the pharmacopoeia method and the GB/T14233.2-2005 method, 100mL of 0.9% sterile sodium chloride solution is injected into a blood bag by using a disposable syringe, and the blood bag in the step is prepared by referring to the artificially contaminated sample in the example 4 and manually shaking for 2 min;

(2) filtering the washing solution through a membrane filter by using a bacteria collector, adding 100mL of LTSB culture medium into the filter after the filtration is finished, and culturing for 14 days at 22.5 ℃, or adding 100mL of FTM culture medium and culturing for 14 days at 32.5 ℃;

(3) visually observing the turbidity of the culture medium in the step (2), and if the culture medium is clear, performing aseptic growth; if the mixture became turbid, the bacteria grew, and the results are shown in tables 5 and 6.

Positive control:

taking 4 sterile blood bags respectively, not carrying out artificial pollution, adding ATCC9372 into 0.9% sodium chloride injection in the step (1), enabling the gradient concentration to be the same as the gradient from 1 'to 4', and observing and recording the growth condition of bacterial colonies in the same steps from the step (1) to the step (3), wherein the results are shown in tables 5 and 6.

Negative control:

4 sterile blood bags were taken each without artificial contamination, and the other steps were the same as the steps (1) to (3), and the results are shown in tables 5 and 6.

Three different test methods are used for carrying out aseptic test operation on a sample of a contaminated blood bag and a sample of a contaminated infusion apparatus, then detection rate results of tables 2 and 3, detection rate results of tables 5 and detection rate results of tables 6 are plotted, the results are shown in figures 1-4, meanwhile, the infusion apparatus and the blood bag are subjected to chi-square test under the conditions of different culture media, different artificial contaminated bacterial colony gradients and different detection methods, and the results are shown in table 7.

TABLE 1 Flat plate count results for different gradient bacterial suspensions used for artificially contaminated infusion set products

TABLE 2 microbiological examination rates (TSB Medium) of infusion set products at different gradients and different sterility tests

Note: "-" indicates sterile growth; "+" indicates the presence of bacteria.

TABLE 3 microbial detection Rate of infusion set products at different gradients and different sterility test methods (FTM Medium)

Note: "-" indicates sterile growth; "+" indicates the presence of bacteria.

TABLE 4 plate count results for different gradient bacterial suspensions for artificially contaminated blood bag products

TABLE 5 microbial detection Rate (TSB Medium) of blood bag products at different gradients and different sterility test methods

Note: "-" indicates sterile growth; "+" indicates the presence of bacteria.

TABLE 6 microbial detection Rate (FTM Medium) of blood bag products at different gradients and different sterility test methods

Note: "-" indicates sterile growth; "+" indicates the presence of bacteria.

TABLE 7 chi fang test results of infusion set, blood bag in different culture media for three detection methods

As can be seen from table 7, there is a significant difference between the two higher dilutions of the media rinse method and the membrane filtration method for the infusion set products (gradient 3, gradient 4), and the difference between the methods is more significant with increasing dilution gradient; there is a significant difference between the two higher dilutions of media wash and membrane filtration of blood bag products (gradient 3 ', gradient 4'), and the difference between the methods is more significant with increasing dilution gradient; the culture medium filling method and the membrane filtration method of the infusion apparatus have obvious difference (p is less than 0.05); the culture medium filling method of the blood bag and the membrane filtration method have obvious difference (p is less than 0.05).

According to the detection and inspection results, the membrane filtration method needs to elute microorganisms on the product and collect eluent for filtration, and because the steps are more, the operation is complicated, and false positive caused by pollution is easily introduced; more importantly, the technology can not elute all microorganisms on the product, so that the eluent can not completely represent the microorganism level of the product, thereby improving the possibility of false negative and greatly reducing the detection rate.

The culture medium filling method directly fills the culture medium into the inner cavity for culture without eluting the product, so that all microorganisms on the product are checked. The culture medium filling method has obvious advantages, but due to the limitation of the transparency of product materials, the observation of the turbidity of the culture medium can be influenced, so that the culture medium filling method is not suitable for all cavity type medical instruments; there are also many problems in the operation process of the infusion apparatus culture medium filling method, which are as follows: firstly, the culture medium is easy to cause air bubbles due to narrow and long tube cavities in the process of flowing through the inner cavities of the infusion set, so that the culture medium cannot completely fill the inner cavities of the tubes. Secondly, the time node that the culture medium just fills the inner cavity of the tube is not controlled well, the culture medium is easy to flow out due to untimely closing of the flow regulator, and the flowing culture medium can carry bacteria. Both cases increase the probability of false negatives. Therefore, the medium filling method is not suitable for performing the sterility inspection on the medium filling method, and the medium filling method is more suitable for the sterility inspection of the container type medical apparatus with the transparent cavity.

The culture medium flushing method adopts a culture medium to replace a flushing liquid without nutrient components to flush the inner cavity of the container, and then directly cultures the culture medium. The operation steps of membrane filtration are reduced, the operation is simpler, and false positive caused by pollution is not easy to introduce. And the flushing liquid with nutrient components is used, so that the culture medium with rich nutrient substances is more beneficial to the enrichment of bacteria in the same elution mode because the bacteria have tropism, and the elution effect is obviously better than other eluents. In conclusion, the culture medium flushing method is more suitable for the sterility test of pipeline medical instruments.