RU2420249C2 - Method of determining anthelmintic resistance in fasciola of ruminants - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to field of veterinary. Method lies in obtaining fasciola eggs from liver of culled animals during their slaughter. Obtained eggs are washed in distilled water, centrifuged and counted. After that, prepared are mother liquor and series of dilutions of anthelmintic from closantel group, into which suspension of fasciola eggs is placed and cultivated for 10-15 days at temperature 27-28°C to obtain miracidia. Anthelmintic resistance in fasciola is estimated by miracidia viability in solutions with various anthelmintic concentration.

EFFECT: method makes it possible to eliminate unnecessary costs for treatment of fascioliasis.

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Description

The invention relates to veterinary medicine, namely to the detection of anthelmintic resistance in ruminant fasciolas.

A known method for detecting anthelmintic resistance in strongilata of the digestive tract of ruminants [1]. The essence of the method.

However, the disadvantage of using this method is that it does not take into account the anthelmintic resistance of fasciol, and fascioliasis causes significant damage to agriculture due to a decrease in milk yield, weight gain and liver utilization. It is known that in Russia, on average, 8–9% of cattle slaughtered are affected by fascioli [2].

The aim of the invention is the detection of anthelmintic resistance in fasciol and in the case of low effectiveness of the drugs used to treat helminthiasis, replacing them with a similar spectrum of action.

The essence of the proposed method lies in the fact that the method for detecting anthelmintic resistance in fasciol, including methods for detecting anthelmintic resistance in strongilata of the digestive tract, characterized by the level of resistance of fasciol in different concentrations of the mother liquor of the clozantel group of drugs (rolenol), and the solution concentration is 5000 μg / ml , which is 25-1500 times higher, while the eggs of fasciol are taken from the liver of culled animals during slaughter.

The inventive method is as follows:

1. Fasciol eggs are taken from the liver of culled animals during slaughter (for example, cows) in parallel from two farms, Golden Niva and Kolos, Kursk Region.

2. The resulting eggs are washed 3-4 times in distilled water, centrifuged, counted.

3. In work with fascioloids, tests are used for the development and release of miracidia from fasciol eggs into a solution of rolenol of different concentrations and their death in solution is taken into account.

4. Prepare a mother liquor of an anthelmintic, for example, rolenol, at a concentration of 5000 μg / ml, and from it a series of dilutions are prepared with a concentration of: 500; fifty; 5; 0.5; 0.05 and 0.005 μg / ml.

5. The test is placed in Petri dishes with a volume of 5 ml.

6. In each of the 6 cups make 3.5 ml of a solution of rolenol in the indicated concentrations, in the seventh cup - an equal volume of distilled water (control).

7. 0.5 ml of a fasciol egg suspension containing at least 100 eggs is added to all cups.

8. Fasciol eggs are cultured in an incubator in anthelmintic solutions for 10-15 days at a temperature of 27-28 ° C.

9. Every 3-4 days in cups, under the binocular magnifier and a microscope, the development and yield of miracidia is examined. In this case, the number of eggs with an open lid and mobile and immobile miracidia in eggs and solution are taken into account.

10. When viewing and evaluating the development of eggs, fasciol comes from an epizootic situation. At the Zolotaya Niva farm, they are taken into account as rerenol-resistant, and in the Kolos farm, they are taken into account as rollenol-sensitive.

Table 1 The results of the action of rolenol on the rolenol-sensitive and resistant strains in the test of the exit of larvae from fasciolus eggs No. p / p Concentration of rolenol μg / ml Rolenol-feels. strain Rolenol-resistant strain Miracidia developed and emerged from eggs,% Miracidia died during development in eggs,% Miracidia developed and emerged from eggs,% Miracidia died during development in eggs,% one 5000 0 one hundred 0 one hundred 2 500 0 one hundred 26 74 3 fifty 32 68 43 57 four 5 54 46 70 thirty 5 0.5 65 35 88 12 6 0.05 78 22 90 10 7 The control 95 5 96 four

It can be seen from the above data that, at a concentration of 50 μg / ml of rolenol, the viability of miracidia in the eggs of the fasciol-resistant strain ranged from 43-57% (an average of 50%). Therefore, LC50 (lethal concentration for 50% fasciol) was equal to 50 μg / ml.

In the sensitive fasciol strain, approximately the same viability of miracidia (46-54%) was observed at a concentration of rolenol of 5 μg / ml, i.e. LC50 was 5 μg / ml, and resistance was 10 times lower.

To confirm the results obtained, the cows of both farms (n-180 and 150) in December 2005 were dewormed with rolenol individually subcutaneously, according to the instructions at a dose of 5 mg / kg by ADV.

The treatment result was evaluated by individual double helminthovoscopic examinations of animals before treatment and 40 days after. The calculation of the effectiveness of treatment in each household was performed as a critical test. The results of the experiment are shown in table 2.

table 2 The effectiveness of the use of rolenol in cows invaded by sensitive and resistant strains of fasciol Name of the farm Before treatment After treatment Treatment effectiveness EI AI EI AI EE IE Rolenol-resistant fasciol strain Golden Niva one hundred 63,2 33.3 twenty 66.7 68,4 Rolenol-sensitive strain of fasciol "Ear" one hundred 70.8 twenty 11.5 88 83.8 Control group of animals one hundred 68,2 one hundred 68.7 - - Note: EI - Extensinvasion AI - Intensinvasion EE - Extensibility IE - Intensity Efficiency

The table shows that the effectiveness of rolenol in the test for reducing the number of eggs, the “critical test” was 68.4% in the farm with a resistant strain, and with a sensitive strain of 83.8%, i.e. 15% higher.

From this it follows that at the Zolotaya Niva farm there is a habituation of fasciol to rorenol (as well as to other drugs of the clozantel group) and with the next deworming it is necessary to change the group of drugs.

The proposed method for detecting anthelmintic resistance in ruminant fasciola allows, in case of low effectiveness of the drugs used to treat helminthiasis, to replace this drug with a similar spectrum of action, but from a different chemical group.

Thus, the use of the proposed method for detecting anthelmintic resistance in ruminant fasciols due to the techniques and parameters specified in the image formula is economically feasible and eliminates unjustified treatment costs.

Used Books

1. Theory and practice of controlling parasitic diseases / Materials of reports of a scientific conference. Issue II. M., Printing house of the Russian Agricultural Academy, 2006. - S. 122.

2. Guidelines for the detection of anthelmintic resistance in strongilata of the digestive tract of ruminants. M., Printing house VASKHNIL, 1991. - S.3-18.

Claims (1)

A method for detecting anthelmintic resistance in ruminant fasciolas, characterized in that fasciolus eggs are obtained from the liver of culled animals when they are slaughtered, washed in distilled water, centrifuged and counted, then a mother liquor and a series of dilutions of the anthelmintic from the clozantel group are placed into which the suspension is placed Fasciol eggs and cultivated for 10-15 days at a temperature of 27-28 ° C to obtain miracidia, and the anthelmintic resistance of fasciol is evaluated by the viability of miracidia in solutions with azlichnoy concentration anthelmintics.