JPH0378366B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a preventive/therapeutic agent for bacterial diseases of aquatic animals. In the seafood industry, D-(threo)-1-(p-
Substituted phenyl)-2-dihaloacetamide-1,
Antibiotics classified as 3-propanediols are already in use. Namely, this type of antibiotics include chloramphenicol and thiamphenicol, but due to the increasing incidence of drug-resistant bacteria to these substances, in recent years chloramphenicol and thiamphenicol have been used less frequently. However, it has become impossible to obtain satisfactory preventive and therapeutic effects. In particular, among fish diseases, Edwardsiella tarda, which is the causative agent of paracoro disease in eel, and Vibrio anguillarum, which is the causative agent of vibrio disease in sweetfish, have been known for a long time. In Pasteurella piscicida, the causative bacterium, drug resistance is not limited to the above-mentioned chloramphenicol and thiamphenicol, but also to tetracycline antibiotics (tetracycline, chlortetracycline, oxytetracycline, etc.) and sulfur drugs ( The reality is that countermeasures against these diseases are extremely difficult because antibacterial compounds commonly used as fisheries chemicals (sulfisozole, sulfamonomethoxine, sulfadimethoxine, sulfamerazine, etc.) are included. It is. The present inventors have conducted various studies on prophylactic and therapeutic agents that are effective in preventing and treating these diseases and have no side effects, and as a result, they have completed the present invention. That is, the present invention is based on the formula A preventive/therapeutic agent for bacterial diseases of aquatic animals containing a compound represented by the formula [wherein X represents a chlorine or fluorine atom and R represents a hydrogen atom or a glycyl] or a salt thereof. Examples of the compound represented by the above formula () include D-(threo)-1-(p-methylsulfonylphenyl)-2-dichloroacetamide-3-
Fluoro-1-propanol (hereinafter abbreviated as compound A), D-(threo)-1-(p-methylsulfonylphenyl)-2-difluoroacetamide-
3-fluoro-1-propanol (hereinafter referred to as compound B)
), D-(threo)-1-(p-methylsulfonylphenyl)-2-difluoroacetamide-3-fluoro-1-propanolglycinate (hereinafter abbreviated as compound C), and the like.
Compound A is particularly preferred. Among compounds (), compounds in which R is glycyl may be used as a salt with an acid, such as an organic acid (acetic acid, oxalic acid, trifluoroacetic acid, etc.) or an inorganic acid (hydrochloric acid, sulfuric acid, phosphoric acid, etc.). Among them, the hydrochloride salt is particularly preferred. Compound () is a known compound, and its physicochemical properties and manufacturing method are described in, for example, Japanese Patent Application Laid-Open No.
It is described in Publication No. 115855. The compound () is effective in preventing and treating bacterial diseases in aquatic animals such as fish and arthropod crustaceans. Examples include saltwater fish such as yellowtail, sea bream, and flounder, and examples of crustaceans include shrimp such as kuruma prawn and Japanese shrimp. In particular, the compound () has remarkable efficacy against bacterial diseases of fish. Specifically, the bacterial diseases include the above-mentioned parakoro disease of eel, nodular disease of yellowtail, vibrio disease of yellowtail, sea bream, flounder, rainbow trout, and prawns (causing bacteria: Vibrio anguillarum, etc.), and pseudomonas disease of yellowtail (causative bacteria: Vibrio anguillarum, etc.). Bacteria: Pseudomonas butida, etc.), Eel fin red disease (Causing bacteria: Aeromonas hydrophylla, etc.), Amago furrow disease (Causing bacteria: Aeromonas salmonicida, etc.), Eel and carp gill disease (Causing bacteria: Flexibacter, etc.) Columnaris), etc. As is clear from the experimental examples below, compound () has high antibacterial activity against a wide range of pathogenic bacteria of aquatic animals, including the drug-resistant bacteria that cause paracoloosis, vibrio disease, and nodular disease. When actually administered to fish, chloramphenicol has a preventive and therapeutic effect not only on infections with naturally resistant bacteria, but also surprisingly on infections with pathogenic bacteria that are susceptible to chloramphenicol and thianphenicol. I found that it was superior to that of 2000 and 30% of the population. In other words, the compound () has high antibacterial activity against a wide range of pathogenic bacteria in aquatic animals, and therefore, compared to previously known compounds, it can be used in small amounts to simultaneously cause bacterial diseases in many different types of aquatic animals. It has the characteristic of being effective in prevention and treatment. The preventive/therapeutic agent for bacterial diseases of aquatic animals of the present invention can be prepared by diluting the compound () or its salt with a solid or liquid carrier, a diluent or without diluting it into a powder, dust, granule, fine granule, etc. tablets, liquids,
It can be made as a syrup or by adding it to feed, either directly or once dispersed in a diluent. Any diluent may be used as long as it is physiologically harmless in itself, and it is more desirable to use a diluent that can be used as feed or a component of feed. Examples of solid carriers include minced fish, raw bait such as shrimp, fish meal, soybean meal, yeast, wheat flour,
Powdered or solid compound feeds containing vitamins, etc., as well as lactose, sucrose, glucose, starch, yeast, fishmeal, talc, acid clay, clay, etc. are included, and liquids include water, physiological saline, etc. , physiologically harmless organic solvents (such as propylene glycol), etc., and it is used as a solution with these or as a suspension with soybean oil. Other appropriate adjuvants such as emulsifiers, dispersants, suspending agents, wetting agents, thickening agents, gelling agents, and solubilizing agents may be added in appropriate amounts. When using these for the prevention and treatment of bacterial diseases in aquatic animals such as yellowtail, sweetfish, eel, trout, and prawns, the most practical method is to add them to feed and administer them orally. In some cases, it can also be administered as a bath or as an injection (intramuscular or intraperitoneal administration). For example, when administering the compound of the present invention orally, it is usually administered as a so-called premix solution, powder, fine granule, etc. using the above-mentioned carriers and diluents.
This can be added directly to the feed, or it can be used as a vitamin supplement or as an adhesive (spreading agent) additive such as guar gum, gluten, alpha starch, or fish oil to prevent the feed from dissipating in the water. It may be used by pre-mixing with or adding to the feed at the same time. That is, for example, in order to include the compound of the present invention in feed and orally administer it to aquatic animals, the compound () or its salt may be added directly or after making it into the above premix, commercially available mixed feed, fishmeal, adhesive, etc. Mix or knead with raw bait, etc., and finally add fishmeal (1 to 80% by weight) and adhesive (0.1% by weight).
It is preferable to feed marine products as a composition containing 0.01 to 2% of the compound of the present invention, including 20% of the compound of the present invention. In this case, the premix used may contain fish meal and an adhesive in advance. When producing the above-mentioned composition of the present invention, a meat crusher or a stirrer may be used if necessary to make the composition uniform and to improve the efficiency of feeding during administration. Next, the dosage of the drug of the present invention varies depending on the progress of the disease, the target aquatic animal, the type of disease, the purpose of administration, etc., but in general, the dose of the drug of the present invention is equivalent to 2 to 50 mg of the active ingredient of the present invention per 1 kg of body weight. The daily dose is orally administered for about 1 to 5 days, preferably 5 to 30 mg from the viewpoint of efficacy and administration, for 3 to 5 days, but as appropriate depending on the symptoms of the disease, etc. Needless to say, it can be increased or decreased. The safety of the aquatic medicine of the present invention for aquatic animals is extremely high. For example, compound A
Even when a large amount of 1,000 mg per 1 kg of fish body weight was fed for 7 days, no abnormalities such as side effects were observed, and it can be used with peace of mind in practice.In addition to its excellent preventive and therapeutic effects, it is useful in the industry. is extremely large. Although the present invention is specifically disclosed below as experimental examples and examples, the present invention is not limited thereto. Experimental Example 1 In vitro antibacterial activity test against fish pathogens: The minimum inhibitory concentration of the compound of the present invention against 26 strains of 5 representative pathogenic bacteria causing bacterial diseases of fish was determined by the agar plate dilution method. Examined. Chloramphenicol, thiamphenicol, oxytetracycline, and sulfisozole were used as control drugs. As shown in Table 1, the test results show that compounds A, B, and C of the present invention all have strong antibacterial properties against a wide range of fish-pathogenic bacteria, and even against fish-pathogenic bacteria that are resistant to other antibacterial agents. All showed susceptibility.

【table】

[Table] Experimental Example 2 Effect of oral administration on eels artificially infected with Edwardsiella tarda bacteria (1): Edwardsiella tarda strain E-12 used in Experimental Example 1 was incubated on Brain Heart Infusion (BHI) agar medium. Culture and suspend the cultured bacteria in physiological saline so that the light transmittance of the light wavelength of 540 millimicrons (mμ) is 60%.
Artificial infection was carried out by injecting it into the dorsal muscle of eel G.
At the same time as infection, 25 mg of Compound A of the present invention and 50 mg of chloramphenicol and oxytetracycline, both of which showed natural resistance in Experimental Example 1, were administered in capsules at a dosage of 50 mg per 1 kg of fish body weight. The patient was orally administered once. Observation is water temperature
As a result of testing under running water at 25° for 10 days, as shown in Table 2, Compound A of the present invention exhibited excellent effects even within the fish body.

[Table] Experimental Example 3 Effect of oral administration on eels artificially infected with Edwardsiella tarda bacteria (2): Edwardsiella tarda strain K-3 used in the antibacterial test in Experimental Example 1 was treated in exactly the same manner as shown in Experimental Example 2. 45 g of eel was infected, and at the same time as the infection, 6.3, 12.5 or 25 mg of the compound A of the present invention was administered, 6.3, 12.5 or 25 mg of chloramphenicol, which was confirmed to be susceptible in Experiment 1, was administered as a control drug, and thiamphenicol was administered. 50, 100 or 200 mg, each dose per 1 kg of fish body weight, was placed in a capsule and administered orally once, and observed for 10 days under the same conditions as Experimental Example 2. The results are shown in Table 3. As can be seen, Compound A caused fewer deaths than the control drug even at a lower dosage, and was found to be superior to the present invention.

[Table] Experimental Example 4 Effect of oral administration on artificially infected yellowtails with Vibrio anguillarum bacteria: The Vibrio anguillarum 012B strain whose antibacterial activity was examined in Experimental Example 1 was cultured on BHI agar medium, and the cultured bacteria was added to physiological saline for 560 min. Artificial infection was carried out by injecting 0.5 ml of the suspension of the bacterial suspension so that the light transmittance of millimicron light wavelength was 15% into the abdominal cavity of a yellowtail weighing 1100 g. Simultaneously with the infection, Compound A of the present invention was administered by force orally in the form of a capsule at a dose of 5 or 10 mg per 1 kg of fish body weight. Compound A with chloramphenicol and oxytetracycline as control drugs.
The effects were compared by giving the same amount. After infection, the animals were observed for 5 days in a circulating water tank at a water temperature of 25°. The results are shown in Table 4. Although Compound A was not necessarily superior to the control drug in terms of antibacterial activity in vitro, as confirmed in Experimental Example 1,
The number of fish deaths was lower than that of the control drug, indicating that it is highly effective when administered to fish.

[Table] Experimental Example 5 Effect of oral administration on Wakin artificially infected with Vibrio anguillarum bacterium 0.1 ml of the bacterial solution used in Experimental Example 4 was injected intramuscularly into Wakin weighing approximately 30 g to cause artificial infection. Simultaneously with the infection, compounds A, B, and C of the present invention were administered orally once by force using a metal probe in the form of a paste at doses of 1.25 mg and 2.5 mg per 1 kg of fish body weight. As control drugs, chloramphenicol and thiamphenicol were given in the same amount or more than the compound (2) and their effects were compared. After infection, place in a running water tank with a water temperature of 25°6.
Observed for days. As shown in Table 5, the results showed that compounds A, B, and C were all more effective than the control drug.

[Table] Example 1 1 part by weight of the compound A of the present invention and 19 parts by weight of lactose were thoroughly mixed to obtain a powder of the drug of the present invention. This 800
After mixing well with 10 kg of a commercially available vitamin supplement for fish farming containing vitamins, fish meal (40% by weight), soybean powder, liver powder, adhesive (5% by weight of guar gum), etc., raw sardine feed (300 kg) was mixed. ), mince it with a meat crusher, mix it evenly with a stirrer, and then dose it to yellowtail (fried yellowtail) weighing about 1 ton. By repeating this daily dose for 4 days, the purpose as a preventive and therapeutic agent for yellowtail tubercle disease can be achieved. Example 2 5 parts by weight of the compound B of the present invention, 94 parts by weight of propylene glycol, and 1 part by weight of a surfactant HCO-50 (manufactured by Nikko Chemical Co., Ltd.) were mixed to obtain a liquid preparation of the drug of the present invention. Add 30ml of this commercially available feed oil (fish oil) to 150ml.
ml, sprinkle it evenly on 3 kg of a commercially available solid compound feed whose main composition is fishmeal (70% by weight) to absorb it, and administer it to ayu fish weighing 100 kg. By repeating this once a day for 3 days, it is possible to achieve the purpose as a preventive and therapeutic agent for Vibrio disease in sweetfish. Example 3 1 part by weight of the compound C of the present invention, 7.3 parts by weight of lactose,
Mix 1.5 parts by weight of corn starch and 0.2 parts by weight of hydroxypropyl cellulose using a pony mixer.
After granulating with a granulator, power mill (16 mesh ~
Fine granules of the drug of the present invention were obtained by crushing with a 30-mesh wire mesh screen). Add 100g of this to fishmeal (75% by weight) and adhesive (alpha starch by weight).
By adding the mixture to 10kg of a commercially available eel culture compound feed consisting of 18%) and administering it to eels weighing approximately 500kg for 5 days, it is possible to achieve its purpose as a preventive and therapeutic agent for paracoloarosis. can. Example 4 A combination consisting of nutritional ingredients of 68% fish meal, 5% soybean flour, 2% brewer's yeast, 2% liver powder, 2% vitamin premixes, 1% mineral premixes, and 20% alpha-ized potato starch as an adhesive. Feed 50
Kg and 1 Kg of the powder of Example 1 are thoroughly mixed until uniform, and then 65 Kg of water and 1.5 Kg of fish oil are added and kneaded. The feed containing the active ingredient thus obtained is fed once a day for 4 days to a pond of about 2 tons of eels infested with fin blight.

Claims (1)

[Claims] 1 formula A prophylactic/therapeutic agent for bacterial diseases of aquatic animals, which contains a compound represented by the formula [wherein X represents a chlorine or fluorine atom and R represents a hydrogen atom or a glycyl] or a salt thereof.