CN103940991B - Pig salmonella heat-stable toxin Rapid detection test strip - Google Patents

Abstract

The invention relates to a device for displaying a heat-resistant toxin detection reagent of Salmonella swine, in particular to a rapid detection test strip for the heat-resistant toxin of Salmonella swine. The test strip contains a support layer and a reaction reagent carrier adsorption layer. , the reaction reagent carrier adsorption layer is pasted on the support layer, followed by the fiber layer from the sample testing end, the gold-labeled monoclonal antibody or multi-antibody fiber layer of Salmonella porcine heat-resistant toxin, the cellulose film layer, and the water-absorbing material layer at the handle end; Swine Salmonella heat-resistant toxin paired monoclonal antibody or polyclonal antibody or monoclonal antibody solution printed on the fiber layer detection blot "<b>|</b>", "<b>/</b>" or "<b>\ </b>", use goat (rabbit) anti-mouse or pig IgG polyclonal antibody or use SPA solution to print control blots on the cellulose membrane layer "<b>｜</b>", "<b>//</b>" or "<b>\</b>". The detection test strip has strong specificity and high sensitivity, and the detection results are vivid, intuitive and accurate. It does not require equipment, professional testing personnel, low cost, simple and fast operation, which can greatly reduce labor intensity and shorten detection time. On-site detection can be carried out in farms, meat processing plants, entry-exit inspection and quarantine bureaus and other places, and it is easy to popularize and apply.

Description

Rapid test strip for detection of heat-resistant toxin of Salmonella swine

1. Technical field

The invention relates to a detection reagent display device for the heat-resistant toxin of Salmonella swine, in particular to a detection test strip capable of detecting the heat-resistant toxin of Salmonella swine.

2. Technical Background

Salmonella is an important zoonotic pathogen. In today's world, the food poisoning cases caused by it account for about 40% of food poisoning cases. There are often reports of human deaths due to Salmonella food poisoning. The main diseases caused by humans are typhoid fever , paratyphoid, gastroenteritis and sepsis. In recent years, the frequency of the disease is still on the rise, because human food poisoning mainly comes from livestock and poultry and their products. Therefore, rapid and accurate detection of Salmonella-positive infections among livestock and poultry has become a top priority.

Porcine salmonellosis mainly occurs in weaned piglets under 4 months of age. Adult pigs and suckling pigs are rarely affected. Bacteria can infect healthy pigs through the digestive tract through the feces of sick pigs or pigs with bacteria, polluted water sources and feed. Rats can also spread the disease. Salmonella is widely distributed and can be introduced into pigs from various routes. Many pigs can be eliminated or immunized by their own resistance, and some become carrier pigs. However, if the pig's resistance is generally reduced due to improper feeding and management, climate change or long-distance transportation, or the pathogen has passed through the pig's body several times, the virulence of the pig will increase, which can also cause the outbreak of the disease. Piglets aged 1 to 4 months are more susceptible. The immune system of pigs over half a year old has been gradually improved, and they seldom get sick after infection, but they carry this bacteria for a considerable period of time. Under the action of stress factors, especially when swine fever occurs, the concomitant and secondary infection of this disease often occurs. The disease can occur throughout the year, and it is more likely to occur in rainy and humid seasons. It is generally distributed or endemic in pigs. Stress factors such as polluted environment, humidity, crowded sheds, accumulation of feces, and untimely supply of feed and drinking water can easily promote the occurrence of this disease.

Clinically divided into acute (septic) type and chronic (necrotizing enteritis) type. The former is more common in piglets before and after weaning. Manifestations include body temperature rising to 41-42°C, lack of energy, loss of appetite, reluctance to move, dyspnea, diarrhea, vomiting, purplish spots or dark red spots on ears, chest, abdomen, and lower limbs. Mostly end in death. In the latter, diarrhea is usually the main symptom, and the feces are porridge-like, with off-white or yellow-green foul-smelling watery feces, sometimes mixed with blood and necrotic tissue fragments. Decreased appetite and increased thirst. Due to continuous diarrhea, he gradually became thinner and weaker, and finally died of exhaustion. When swine fever occurs, it is often concurrent or secondary to the disease.

Autopsy: acute septicemia, with bleeding spots on the ears, abdomen, and inner skin of the limbs, bleeding spots in the serosa of various organs, larynx, bladder mucosa, and kidneys, enlarged spleen, blunt edges, and a characteristic blue color. The lymph nodes were swollen and bleeding, and the gastrointestinal mucosa showed catarrhal inflammation. The carcasses of dead pigs with chronic disease were emaciated, and the cecum and colonic mucosa were focally or diffusely thickened, covered with grayish-yellow caseous pseudomembrane, and ulcers were formed when the pseudomembrane was removed. The spleen is slightly enlarged, sometimes yellow-gray necrotic spots can be seen in the liver, and the lungs have chronic catarrhal inflammation with yellow caseous nodules.

In recent years, the occurrence frequency of the disease is on the rise, which has brought serious harm to the pig industry. Therefore, finding a simple, fast and specific detection method is undoubtedly of great significance in the diagnosis and epidemiological detection of Salmonella swine infection. At present, the commonly used detection methods for Salmonella and heat-resistant toxins are as follows:

(1) Isolation and culture of bacteria: Streak inoculation of disease material or enrichment culture solution on selective medium (S·S and bismuth sulfite agar) directly. Small, with neat and translucent edges, and some with black colonies in the center due to the production of hydrogen sulfide (H ₂ S), inoculate the suspicious colonies on the slant of trisaccharide-iron medium, and incubate at 37°C for 18-24 hours. Observe that the bottom layer of glucose produces acid or acid and gas, produces hydrogen sulfide and turns brown and black, and the lactose on the upper slope does not decompose and does not change color, then it can be preliminarily determined to be Salmonella.

(2) Microscopic examination: Take the tested materials (liver, spleen, kidney, and mesenteric lymph nodes) to make smears, dry them naturally, and use Gram staining for microscopic examination. If you see blunt round or oval at both ends, Gram-negative small bacilli that do not move, do not form spores and capsules, are preliminarily considered to be Salmonella.

(3) Immunofluorescence antibody test: Take a platinum ear of the tested sample that has been cultured by enrichment, make a thin smear, dry it, and fix it with a fixative (60 ml of ethanol, 30 ml of chloroform, and 10 ml of formaldehyde) Fix it for 5-10 minutes, then soak it with 95% ethanol and dry it. Then drop Salmonella fluorescent antibody on the specimen smear, put it in the wet box, take it out after 30 minutes at 37°C, wash away the excess fluorescent antibody with 0.01MPH9.0 phosphate buffer; then use the same phosphate buffer solution for 10 minutes, then rinsed with distilled water, dried, and then added dropwise with pH9.0 carbonate buffered glycerol, sealed with a cover slip, and examined under the microscope.

(4) Enzyme-linked immunosorbent assay: Enzyme-linked immunosorbent assay is to adsorb bacterial antigens or heat-resistant toxin antibodies on a solid-phase carrier, and perform immunoenzyme staining on the carrier. judgement result. The antigens on the lipopolysaccharide molecules on the surface of Salmonella, flagellar antigens and outer membrane protein antigens have played an important role in the diagnosis of Salmonella infection. The direct ELISA and sandwich ELISA methods established by using monoclonal antibodies of these bacterial proteins or heat-resistant toxins can effectively detect Salmonella and heat-resistant toxins.

(5) Polymerase chain reaction (PCR) technology: PCR technology has the advantages of high sensitivity and high specificity, and multiplex PCR method has been widely used in the identification and epidemiological investigation of Salmonella heat-resistant toxins and pathogenic bacteria.

The above-mentioned detection method requires professionals to operate in the laboratory, the operation is cumbersome, and the detection is time-consuming and labor-intensive; moreover, it requires expensive instruments and equipment, such as PCR instrument, microplate reader, etc. For non-professionals, the above-mentioned detection method is difficult to complete. Although the above methods are particularly sensitive, they cannot achieve on-site rapid detection or diagnosis. The present invention studies a simple, fast, real-time on-line detection test paper, which is of great significance for controlling food poisoning and eliminating the disease.

3. Contents of the invention

The purpose of the present invention is to overcome the shortcoming of detecting the heat-resistant toxin of Salmonella swine in the prior art, to provide a specific, sensitive, simple and fast method for detecting the heat-resistant toxin of Salmonella swine, and to develop a detection test for detecting the heat-resistant toxin of Salmonella swine note.

The technical solution of the present invention is to provide a detection test strip for the heat-resistant toxin of Salmonella swis, the test strip contains a support layer and an adsorption layer, the support layer is a thin sheet layer that does not absorb water, the adsorption layer is attached to the support layer, and the adsorption layer From the test end, there are sample adsorption fiber layer, gold-labeled antibody fiber layer, cellulose film layer and water-absorbing material layer at the handle end. There are detection marks and control marks on the cellulose film layer; the gold-labeled antibody fiber layer is adsorbed with nano-scale Monoclonal antibody against Salmonella thermostable toxin labeled with gold particles, detection blot printed with paired monoclonal antibody against Salmonella thermostable toxin, control blot with goat or rabbit anti-mouse IgG polyclonal antibody; or gold-labeled antibody fiber layer The polyclonal antibody against Salmonella heat-resistant toxin is adsorbed with nano-scale gold particles, and the detection blot is prepared with anti-Salmonella heat-resistant toxin monoclonal antibody, and the control blot is prepared with Staphylococcus aureus protein A (SPA) or anti-pig IgG polyclonal antibody .

The preparation of paired monoclonal antibody against Salmonella heat-resistant toxin for detection blot is prepared by paired monoclonal antibody solution of Salmonella heat-resistant toxin; the preparation of polyclonal antibody against Salmonella heat-resistant toxin for detection blot is the polyclonal antibody of Salmonella heat-resistant toxin preparation.

The support layer is made of non-absorbent rigid plastic sheet or cardboard strip; the sample adsorption fiber layer at the test end is made of glass wool; the gold-labeled antibody fiber layer is made of glass wool and gold-labeled antibody, and the gold-labeled antibody can be Monoclonal or polyclonal antibodies.

The cellulose membrane layer is made of nitrocellulose membrane, or pure cellulose membrane, or carboxylated cellulose membrane, or polyvinylidene fluoride PVDF cellulose membrane.

The absorbent material layer is made of absorbent paper.

The test blot and the control blot are linear or oblique, and the cellulose film layer contains a detection blot and a control blot, and the arrangement of the detection blot and the control blot is " | | ", " // ", " \\ "Any one of.

There is a protective layer on the adsorption layer of the test strip, and the protective layer is attached to the adsorption layer. The sample adsorption fiber layer, the gold label antibody fiber layer and the water-absorbing material layer are covered with a protective film at the test end. The sample adsorption fiber layer at the test end is A sample marking line is printed on the protective film corresponding to the junction of the gold-labeled antibody fiber layer, and the marking line is about 0.5 cm away from the side of the sample adsorption fiber layer at the test end.

According to needs, select one of the above-mentioned arrangement forms of the gold-labeled antibody fiber layer, detection blot and control blot.

Positive beneficial effect of the present invention:

1. Strong detection specificity and high sensitivity: the detection test strip of the present invention is made on the basis of nano-scale gold particles labeling high-affinity specific monoclonal antibodies or specific polyclonal antibodies. There is no covalent bond between the molecules, and the two are combined through the van der Waals force between opposite charges. Gold particles do not affect the specificity and binding force of monoclonal antibodies or polyclonal antibodies, and have a high labeling rate. The detection test strip of the invention has high specificity and sensitivity, and can detect heat-resistant toxin of nanogram level Salmonella.

2. Easy and fast operation: when using the test strip of the present invention, there is no need to attach any other instruments and reagents, just insert the test end into the sample liquid to be tested for about 30 seconds, and then the test can be determined within 1-5 minutes Test results.

3. The test result is intuitive and accurate: the test strip of the present invention uses whether the test strip shows a brown-red test line and a control line as the basis for judging positive and negative results, that is, only a brown-red control line is displayed at the mark of the control line on the cellulose membrane C, and there is no brown-red band displayed at the test line imprint, indicating that the detected Salmonella heat-resistant toxin is negative; a brown-red control line C is displayed at the control line imprint of the cellulose membrane, and a brown-red control line is displayed at the test imprint. The brown-red band T indicates that the detected Salmonella heat-resistant toxin is a positive result. Regardless of positive or negative results, the control line C should be displayed. When the control line C is not displayed, it means that the test strip is invalid.

4. Reduced detection cost: using the detection test strip of the present invention does not require other instruments and reagents, which saves the cost of instruments, equipment and additional reagents; non-professionals can also detect online in real time at any time, without paying expert diagnostic inspection fees and related expenses, It can greatly reduce the input of detection cost and reduce the detection cost.

5. Wide range of use: the detection test strip of the present invention is easy to operate, that is, "fool-style" operation, and it is convenient to carry and store, and can meet the needs of different units and personnel at different levels, including professional testing, customs quarantine, health and epidemic prevention, and quality monitoring. , animal product processing, intensive breeding to individual breeding, etc., have broad market prospects and social benefits.

4. Description of drawings:

Fig. 1 is a schematic diagram of the side view structure of a detection test strip for Salmonella porcine heat-resistant toxin

Fig. 2 is a top view structure schematic diagram of a detection test strip of Salmonella porcine heat-resistant toxin

5. Specific implementation methods:

The following examples are only for further illustrating the present invention, and do not limit the content of the present invention. The preparation of test strips for the detection of heat-resistant toxin of Salmonella in pigs requires the preparation of monoclonal and polyclonal antibodies against the heat-resistant toxin of Salmonella, which are used to prepare the detection blot and gold-labeled antibody fiber layer; at the same time, it is necessary to prepare goat or rabbit anti-mouse IgG Antibodies, goat or rabbit anti-pig IgG, were used to prepare control blots.

1. Preparation of sheep (rabbit) anti-mouse or anti-pig IgG antibody:

Extract the IgG in mouse or pig serum by saturated ammonium sulfate method, take 1 part of serum and 2 parts of PBS solution (pH7.2) and mix well, add an equal volume of saturated ammonium sulfate solution and mix well, put it in a refrigerator at 4°C for 2 hours, Centrifuge at 4°C, 10000r/min for 15min, discard the supernatant; dissolve the precipitate with an appropriate amount of PBS solution (pH7.2), add saturated ammonium sulfate solution to a final concentration of 33%, put it in a refrigerator at 4°C for 2h, and store it at 4°C, Centrifuge at 10000r/min for 15min, discard the supernatant, dissolve the precipitate with a small amount of PBS solution (pH7.2), put it in a refrigerator at 4°C and dialyze overnight with PBS solution (pH7.2), change the solution 2-3 times, and Centrifuge at 10,000 r/min for 15 min, collect the supernatant, and measure the protein concentration with an ultraviolet spectrophotometer. Inject 50μg-100μg (IgG)/kg body weight subcutaneously or intramuscularly into antibody-negative healthy sheep or rabbits for 3-4 times. After 20 days of the last immunization, blood is collected from the vein, and the serum antibody titer is above 1:2000 by ELISA. Blood collection or carotid artery bloodletting, collecting hyperimmune serum, extracting sheep (rabbit) anti-mouse or pig IgG with saturated ammonium sulfate method (the extraction method is the same as the above-mentioned extraction of mouse serum IgG, and will not be repeated), for A control blot of a test strip of the invention was prepared.

2. Preparation of Salmonella heat-resistant toxin monoclonal antibody (Mi):

Each mouse was immunized with 50μg-100μg of Salmonella heat-stable toxin antigen for three times, with an interval of 15-30 days between each time; 3-4 days after the third booster immunization, the immunized mice were bled from the eyes and killed by pulling the neck for 75 days. Soak in % alcohol for 5-10 minutes, aseptically take the spleen, cut it into pieces, filter through a 100-mesh nylon mesh, and centrifuge at 1000r/min for 10 minutes to collect spleen cells; mix 1×10 ⁸ spleen cells with 2-5×10 ⁷ NS0 Mix the myeloma cells, centrifuge at 1000r/min for 10min, discard the supernatant, place the centrifuge tube containing the precipitated cells in water at 37°C, and slowly add 0.7-1ml of 40%-50%PEG4000 (pH8.5-9.0) for 1min. Then slowly add 15ml of serum-free 1640 medium to terminate the effect of PEG, bathe in water at 37°C for 5-10min, centrifuge at 1000r/min for 10min, discard the supernatant, resuspend the cell pellet in HAT selection medium, and add

96-well culture plate (100 μl ~ 200 μl/well), cultured in a 5% CO ₂ incubator at 37°C. After culturing for 7-10 days, coat 96-well ELISA plates with 5 μg-10 μg/ml of purified pathogen-specific antigens, detect hybridoma culture supernatants by enzyme-linked immunosorbent assay (ELISA), and pick strong positive cell clones ( OD ₄₅₀ ≥ 0.5) were cloned by the limiting dilution method three times in a row to obtain a positive hybridoma cell line with a chromosome number of 92-98. The monoclonal antibody secreted by it can specifically recognize the heat-resistant toxin of Salmonella, and is not related to other The toxin cross-reacts with an affinity constant of 10 ^{9 ~ 10} , the subtype of the light chain is к or λ, and the subtype of the heavy chain is IgG ₁ , IgG _2a , IgG _2b , IgG ₃ ; the paired monoclonal antibodies obtained are used for gold production Single-antibody glass wool or detection blot.

3. Preparation of gold standard monoclonal antibody glass wool:

Preparation of nano-scale gold particles by sodium citrate reduction method: add 2-4 ml of 0.5-2% trisodium citrate solution to 50-100 ml of boiling 0.01-0.05% chloroauric acid aqueous solution to obtain nano-scale gold particles with a diameter of about 15 nm. gold particles. Adjust the pH of the gold particle solution with 0.1mol/L K ₂ CO ₃ to 8.5-9.5, and add the monoclonal antibody to be labeled into the gold sol with a pH of 8.5-9.5 at a labeling ratio of 1:1000-1300, and label for 10 minutes Finally, add 20% PEG10000 to a final concentration of 0.05%, centrifuge at 4°C, 1500-3000r/min for 20min, remove unbound gold particles, centrifuge at 4°C, 15000r/min for 1h, discard the supernatant, and obtain the gold-labeled antibody mixture Afterwards, use propylene dextran S-400 column chromatography to separate and purify the gold-labeled antibody to obtain the gold-labeled antibody. Adsorb the gold-labeled antibody diluted 1:100-500 in refined glass wool, and dry it under vacuum at 4°C to prepare gold-labeled monoclonal antibody glass wool.

4. Preparation of Salmonella heat-resistant toxin polyclonal antibody (Ci):

Preparation of Polyclonal Antibody to Salmonella Thermostable Toxin (Ci). Antibody-negative healthy pigs were immunized multiple times with Salmonella heat-stable toxin antigen. 20 days after the last immunization, blood was collected from the vein, and the serum antibody titer was determined to be above 1:2000 by ELISA. Blood was collected from the heart or carotid artery, and the hyperimmune serum was collected. The IgG antibody in the serum was extracted by the saturated ammonium sulfate method (the method is the same as that of mouse serum The extraction of IgG was the same and will not be repeated).

The preparation method of gold-labeled polyclonal antibody and gold-labeled polyclonal antibody glass wool is the same as that of gold-labeled monoclonal antibody glass wool, and will not be repeated here. For details, see content 3 in the detailed description.

5. The detection principle of the test strip of the present invention

When the testing end of the test strip of the present invention is inserted into the sample solution to be tested, the solution to be tested will drive the heat-resistant toxin of Salmonella to enter the gold-labeled antibody fiber layer through a siphon, and together with the gold-labeled antibody (Mi or Ci) therein will flow along the nitric acid The cellulose membrane diffuses toward the handle end, and finally penetrates into the water-absorbing material layer of the handle end. During the diffusion process, the gold-labeled antibody can combine with the corresponding Salmonella heat-resistant toxin to be detected, and the Salmonella heat-resistant toxin combined with the gold-labeled antibody can be detected on the cellulose membrane. When the paired monoclonal antibody or polyclonal antibody of the blot is intercepted, when the sample solution contains the heat-resistant toxin of Salmonella, a brown-red detection line will appear; goat or rabbit anti-mouse or anti-pig IgG can be combined with the corresponding gold-labeled monoclonal antibody Or multiple antibody combination, a brown-red control line appears. When the sample liquid to be tested does not contain the heat-resistant toxin of Salmonella, the test strip only shows a brown-red control line; when there is no control line on the cellulose film, it indicates that the test strip has failed.

6. The detection operation method of the detection test strip of the present invention

(1) Treatment of test samples: take diseased pig diseased tissue or commercially available fresh meat, add normal saline at a ratio of 1 to 5 and cut it into pieces with scissors. After ~5 dilutions, it is the sample to be tested.

(2) Detection operation: insert the sample end of the test strip of the present invention into the sample liquid to be tested, the insertion depth does not exceed the marking line 9, take out the test strip after about 30 seconds, place it horizontally for about 1 to 5 minutes, and observe the result at the same time .

(3) Judgment of results: If only one brown-red control line C is displayed on the cellulose membrane of the test strip, it means that the test result is negative, indicating that there is no Salmonella heat-resistant toxin in the tested sample; if the test strip A control line C appears on the cellulose membrane on the test blot, and a test line appears on the test blot, indicating that the test result is positive, that is, the sample to be tested contains Salmonella heat-resistant toxin; if there is no control line C on the cellulose film, it indicates that the test result is positive. The note has expired.

Embodiment one: detection test strip of salmonella porcine heat-resistant toxin

See Figure 1 and Figure 2. In the figure 1 is the support layer, which is made of hard plastic thin strips, 2 is the sample adsorption fiber layer at the test end, which is made of glass wool, and 3 is the gold-labeled antibody fiber layer, which is adsorbed with nano-scale The glass wool of the monoclonal antibody of the anti-Salmonella heat-resistant toxin of gold particle label, prepare its gold standard monoclonal antibody glass wool according to the preparation method described in the above-mentioned specific embodiment 3, 4 is cellulose membrane layer, adopts nitrocellulose membrane 5 is the water-absorbing material layer, which is made of water-absorbing paper, and the layers numbered 2, 3, 4, and 5 are pasted on the hard plastic sheet strip 1 from the left end test end to the right, and the junctions between them cross and overlap each other . On the nitrocellulose membrane layer 4, 6 is the detection blot T printed with the anti-Salmonella heat-resistant toxin paired monoclonal antibody solution, 7 is the control blot C printed with the goat or rabbit anti-mouse IgG solution, the detection blot and the control The imprint is linear or slanted, and the combined form formed by the arrangement of the two imprinted strips is any one of " | | ", " // ", " \\ ". 8-1 is the white protective film covering the sample adsorption fiber layer 2 and the gold-labeled antibody fiber layer 3 at the test end, and the position corresponding to the protective film 8-1 at the junction of 2 and 3 is biased to the side of the sample adsorption fiber layer 2 by 0.5 The marking line 9 is printed at cm, and the right end of 9 is printed with arrows and max words, and the water-absorbing material layer 5 (handle end) is covered with a protective film 8-2 of other colors (such as yellow).

The preparation and detection operation steps of the sample solution to be tested are the same as the detection operation method in Embodiment 6, and will not be repeated here.

Embodiment two: the detection test strip of salmonella swine heat-resistant toxin is basically the same as embodiment one, the difference is:

The gold-labeled antibody fiber layer 3 is made of glass wool adsorbed with gold particle-labeled anti-Salmonella heat-resistant toxin polyclonal antibody, and its gold-labeled polyclonal antibody glass wool is prepared according to the preparation method described in the above-mentioned specific embodiment 3; On the nitrocellulose membrane layer 4, 6 is the detection blot T printed with the monoclonal antibody solution against the heat-resistant toxin of Salmonella, and 7 is the control blot C printed with the goat or rabbit anti-pig IgG solution, and the two blots are arranged The formed combination form is any one of " | | ", " // ", " ＼＼ ". Others including test sample preparation, operation method and result judgment are the same as the operation method in Embodiment 6 and will not be repeated.

Claims (7)

1. A detection test strip for detecting the heat-resistant toxin of Salmonella swine, the test strip contains a support layer and an adsorption layer, the support layer is a non-absorbent sheet layer, the adsorption layer is attached to the support layer, and the adsorption layer is sequentially from the test end It is the sample adsorption fiber layer, the gold-labeled antibody fiber layer, the cellulose film layer and the water-absorbing material layer at the handle end. On the cellulose film layer, there are detection blots and control blots, which are characterized in that the gold-labeled antibody fiber layer is adsorbed with nano-scale gold. Particle-labeled monoclonal antibody against Salmonella swine heat-stable toxin, detection blot printed with paired monoclonal or polyclonal antibody against Salmonella swine heat-stable toxin, control blot with goat or rabbit anti-mouse IgG polyclonal antibody or golden yellow Staphylococcus A protein printing; or the gold-labeled antibody fiber layer is adsorbed with nano-scale gold particle-labeled anti-Salmonella swine heat-resistant toxin polyclonal antibody, the detection blot is prepared with anti-Salmonella swine heat-resistant toxin monoclonal antibody, and the control blot is prepared with gold Preparation of Staphylococcus aureus protein A or anti-pig IgG polyclonal antibody; Wherein, the preparation method of the anti-Salmonella porcine heat-resistant toxin monoclonal antibody is as follows: Immunize Balb/c mice with 50μg-100μg of Salmonella heat-resistant toxin antigen three times, each time at an interval of 15-30 days; 3-4 days after the third booster immunization, the immunized mice were bled from the eyes, pulled to death, and killed with 75% alcohol Soak for 5-10 minutes, take the spleen under aseptic conditions, cut it into pieces, filter it through a 100-mesh nylon mesh, centrifuge at 1000r/min for 10 minutes, and collect the spleen cells; mix 1×10 ⁸ spleen cells with 2-5×10 ⁷ NS0 Mix the myeloma cells, centrifuge at 1000r/min for 10min, discard the supernatant, place the centrifuge tube containing the precipitated cells in water at 37°C, and slowly add 0.7-1ml of 40%-50% PEG4000 for 1min, the pH of the PEG4000 is 8.5-9.0 , then slowly add 15ml of serum-free 1640 medium to terminate the effect of PEG, bathe in 37°C water for 5-10min, centrifuge at 1000r/min for 10min, discard the supernatant, resuspend the cell pellet in HAT selection medium, and add to 96-well culture Plate, 100μl-200μl/well, cultured in a 5% CO ₂ incubator at 37°C; after 7-10 days of culture, coat a 96-well microtiter plate with 5μg-10μg/ml of purified pathogen-specific antigen, and use enzyme-linked Immunosorbent assay was used to detect the culture supernatant of hybridomas, and strong positive cell clones with OD ₄₅₀ ≥ 0.5 were picked and cloned by limiting dilution for three consecutive times to obtain positive hybridoma cell lines with chromosome numbers of 92-98 and secreted The monoclonal antibody can specifically recognize the heat-resistant toxin of Salmonella without cross-reaction with other toxins, the affinity constant reaches 10 ^{9 ~ 10} , the subtype of the light chain is к or λ, and the subtype of the heavy chain is IgG ₁ , IgG _2a , IgG _2b or _IgG3 . 2. The test strip according to claim 1, characterized in that the paired monoclonal antibody against Salmonella porcine heat-resistant toxin is used for detection imprinting, that is, prepared with the paired monoclonal antibody solution against Salmonella porcine heat-resistant toxin. 3. test strip according to claim 1 is characterized in that support layer is made of non-absorbent hard plastic sheet or hard paper strip; test end sample adsorption fiber layer is made of glass wool; gold standard antibody fiber The layer is made of glass wool and gold-labeled antibodies, which are monoclonal or polyclonal antibodies. 4. The test strip according to claim 1, characterized in that the cellulose film layer is made of nitrocellulose film or pure cellulose film or carboxylated cellulose film. 5. The test strip according to claim 1, characterized in that the water-absorbing material layer is made of water-absorbing paper. 6. The test strip according to claim 1, characterized in that the detection imprint and the contrast imprint are linear or oblique, and the cellulose film layer contains a detection imprint and a contrast imprint, and the detection imprint and the contrast imprint Arrangement form is any of "||", "//", "\\". 7. test strip according to claim 1, it is characterized in that on test end sample adsorption fiber layer, gold label antibody fiber layer and water-absorbing material layer, be covered with protective film, at test end sample adsorption fiber layer and gold label antibody A sample marking line is printed on the protective film corresponding to the junction of the fiber layers, and the marking line is about 0.5 cm away from the side of the sample adsorption fiber layer at the test end.