JPS61267521A - Agent for controlling saprolegniasis and capsulated-pseudomonas disease of carp - Google Patents

Abstract

PURPOSE:To provide an agent for controlling saprolegniasis and capsulated pseudomonas disease of carp, having low toxicity for fish at a low cost, by using kasgamycin useful as an agent for controlling rice blast, or its salt as an active component. CONSTITUTION:The objective agent for controlling saprolegniasis and capsulated pseudomonas disease of carp can be produced by using kasugamycin or its salt as an active component. kasugamycin is extremely effective to capsulated pseudomonas disease caused by Pseudomonas and saprolegniasis caused by Saprolegnia. Furthermore, kasugamycin is a safe drug excreted relatively quickly from animal body and decomposable in natural environment. It has extremely low toxicity for fish and gives sufficient remedying effect without giving toxic effect to aquatic animal such as carp.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for controlling water mold and bacterial white cloud disease of carp, which is characterized by containing sugamycin or its salts (for example, hydrochloride, hereinafter referred to as kasugamycin) as an active ingredient. Regarding drugs.

Kasugamycin is an antibiotic produced by an actinomycete named Streptomyces kasugaensis (Japanese Patent Publication No. 6818/1983), and has a specific therapeutic effect on rice blast, so it is used for agricultural purposes. It is put into practical use as a disinfectant.

The present inventors screened various drugs for the purpose of developing drugs effective against water mold and bacterial white cloud disease occurring in carp. As a result, it has been found that kasugamycin is extremely effective against bacterial leucobia caused by carp, Tomonas bacterium, and water mold caused by Sabrolegnia. To provide a method for completely curing carp disease, bacterial leucoriasis, economically and without causing chemical damage to carp.

Since carp is an important protein resource, in recent years, fish farming methods have been gradually gaining popularity in conjunction with natural methods from the viewpoint of natural resource protection. however.

In the case of farmed fish, because a relatively large number of fish are kept in a limited habitat, they are susceptible to various diseases, so antibacterial agents including various antibiotics are used to treat these diseases. However, some of these are also used for human diseases, which is not necessarily desirable considering the possibility of another layer of resistant bacteria.

Kasugaisin is a drug developed as a rice blast control agent, and is currently widely used as a rice blast control agent. Its toxicity is extremely low, and no chronic toxicity is observed. Also, kasugamycin is released relatively quickly in the animal body. It has been confirmed that it is excreted by crabs and decomposed in the natural environment, making it an extremely safe drug.

Using the commonly used agar dilution method, we determined the minimum inhibitory concentration of kasugamycin against the water mold fungus that infects carp. The results are shown in Table 1.

Table 1 Carp water mold Note 1) 31.3 Note 1) Test bacteria
Note 2) Cultivation was carried out at 20°C for 48 hours.

Note 3) The medium composition is as follows.

Meat extract 0.5% Polypeptone 0.3% Agar bundle 1.2% pH 7.0 Furthermore, the half-lethal concentration of kasugamycin for aquatic animals is 100% for carp, waxfish, Japanese medaka, loach, tadpole, daphnia, and Daphnia daphnia. 11
000 pp or more, and has extremely low toxicity to fish.Therefore, even if a relatively high concentration of chemical treatment is performed, there is no worry that aquatic animals such as carp will be contaminated or die from wastewater containing the chemical, and it is safe for carp. It is possible to achieve the expected safety and sufficient therapeutic effect without causing any drug damage.

Kasugamycin can be used to treat carp diseases by bathing the carp in a solution of kasugamycin alone, or by dissolving it in a pond or other tank at a constant concentration. It can also be used in combination with other drugs such as furan drugs. Kasugamycin can also be mixed into feed and administered orally.

Next, Examples show that the drug of the present invention has an excellent therapeutic effect on carp diseases.

The therapeutic effect was calculated using the following formula.

Treatment survival score (tail) Test negative number (tail) (Example 1) Kasugamycin was placed in a tank containing 50 i fresh water (water temperature 22'C), and the concentration was 0.05% and 0.04.
%, 0.02% and 0.01%. Then, 16 carp infected with bacterial albinism were placed there and bathed in medicine for 24 hours. And fresh water (water temperature 22℃
) for 7 days, the therapeutic effect was investigated. The results are shown in Table 2.

Table 2 (Example 2) Fifteen carp infected with bacterial leukocoria were placed in a tank containing 50 ml of fresh water (water temperature: 22°C), and feed containing 2% kasugamycin was administered for 7 days. . In this case, the dose of sugamycin administered (the amount of active ingredient was 2 or less) was 0.2 g, OoIg and 0.05 g per 1 kg of fish weight. Then, after rearing in fresh water (water temperature: 22° C.) for another 7 days, the #IN effect was investigated. The result is the third
Shown in the table.

Table 3 (Example 3) Kasugamycin was added to a tank containing 50J1 of fresh water to a concentration of 0.01% gJ: and 0-o.

It was dissolved to a concentration of 5%. Then, 50 carp infected with water and disease were placed there and bathed in medicine for 24 hours. The animals were then returned to fresh water (water temperature: 22°C) and reared for 7 days, after which the therapeutic effects were investigated. The results are shown in Table 4.

Table 4 (Example 4) Twenty carp infected with water and disease were placed in a tank containing 50 ml of fresh water (water temperature: 22°C), and fed with feed containing 2% kasugamycin for 7 days. In this case, the dose of sugamycin administered is O, Ig, 0.1 g/kg of fish weight.
05g and 0.025g. After raising the animals in fresh water (water temperature: 22° C.) for an additional 7 days, the therapeutic effects were investigated. The results are shown in Table 5.

Table 5 (Example 5) Twenty carp infected with water mold were placed in a tank containing 501 fresh water (water temperature: 15°C), and feed containing 2% kasugamycin was administered for 7 days. In this case, the dosage of sugamycin was 0.2 g and O.1 g per kg of fish weight. And for another 7 days with fresh water (water temperature: 15
℃), and its therapeutic effect was investigated. The results are shown in Table 6.

Table 6

Claims (1)

[Claims] A control agent for water mold and bacterial white cloud disease of carp, characterized by containing kasugamycin or its salts as an active ingredient.