RU2339700C1 - Method for biological assay version for determination of specific accessory of micobacteria - Google Patents

Abstract

FIELD: medicine, veterinary science.

SUBSTANCE: invention concerns area of veterinary science and can be used at differential diagnostics of the tuberculosis caused by micobacteria of the bird's kind. The method of biological assay version for determination of a specific accessory of micobacteria provides intravenous introduction of suspension of micobacteria in number of 1 UN to quails in mass 120-125 g at the age of 41 days. The invention provides reduction of terms of version of the diagnosis on the bird's tuberculosis and the best informativity at determination of a kind of the originator by results of pathoanatomical researches of the fallen animals. The way is approved in laboratory on working out of measures of control over tuberculosis of agricultural animals by GNU IEVS and DV SO of the Russian Academy of Agrarian Sciences during 2004-2006.

EFFECT: reduction of terms of version of the diagnosis on the bird's tuberculosis and provision of the best informativity at determination of a kind of the originator by results of pathoanatomical researches of the dead animals.

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Description

The invention relates to the field of veterinary medicine, in particular to methods of veterinary diagnosis of tuberculosis of agricultural animals, can be used in the differential diagnosis of tuberculosis caused by avian mycobacteria.

A known method of staging a biological sample, in which to determine the species of cultures of the pathogen, according to the pathogenic properties for laboratory animals, infect rabbits intravenously with a suspension of mycobacteria in a dose of 1 mg of bacterial mass in 1 ml of physiological solution. Bovine mycobacteria cause generalized tuberculosis in rabbits, and human mycobacteria cause single foci in the lungs and rarely in the kidneys, more often there are no lesions. Avian mycobacteria cause sepsis in rabbits, characterized by a sharp increase in the spleen and death of animals within 10-30 days.

The disadvantage of this method is the difficulty of differentiating cultures of avian mycobacteria, since some highly pathogenic M. avium strains are capable of causing changes in the internal organs of rabbits, identified by pathological studies as specific for M. bovis (Manual for the diagnosis of animal tuberculosis. - M., 2002. - P.35-40; Bushmeleva P.V. Features of the course of bird tuberculosis in rabbits./P.V. Bushmeleva, V.N.Afonyushkin // The latest trends in the development of agricultural science in the works of young scientists: Tr. II International .. Scientific and practical conference mol scientists (April 20-21, 2006, pos Krasnoobsk..) / Sib RAAS Dep-set -....., Novosibirsk, 2006, S.482-487).

The closest to the essence of the proposed solution is a method of staging a biological sample to determine the species of mycobacteria, where for infection they take chickens at least 150 days old, with a live weight of at least 1.8 kg. A suspension for infection of birds is prepared according to the optical standard of turbidity of the BCG vaccine (Laboratory diagnosis of tuberculosis: Recommendations / VNIIBTZH; Comp. Khaikin B.Ya., Kolychev N.M., Boganets N.S., Karimova L.M. - Omsk, 1988. - S.25-28).

The disadvantage of this method is the age (150 days) at which chickens reach the weight of an adult bird (1.8 kg) and a large dosage of mycobacteria culture for a characteristic pathological anatomical picture, which lengthens the diagnosis of avian tuberculosis.

The task of the invention is to reduce the time of diagnosis for avian tuberculosis and to work out the optimal dose of mycobacteria culture for infection of quail, as well as determining the age for infection.

The problem is solved in that in the method of setting a biological sample to determine the species of mycobacteria, including intravenous administration to birds of a suspension of mycobacteria, according to the invention, a suspension of mycobacteria is administered in the amount of 1 unit of quail weighing 120-125 g at the age of 41 days.

The choice of quail as a biological model for determining the species of mycobacteria was due to the following factors. First of all, quails differ from chickens in smaller body sizes. In Russia, the most common Japanese quail of the Moscow population. These quails have a body weight of 120-125 g. Quail content does not require significant areas. The precocity of this bird is three and a half times higher than that of chicken eggs. At 10 days, young growth changes the feather, at 25 - feathers, at 30 - becomes an adult, and at 40-45 days begins to rush. One of the characteristics of quail is the highest body temperature among farm birds. The natural resistance of quail to infectious diseases allows them to be maintained without resorting to vaccination (Quail Content / Auth. - comp. SP Bondarenko. - M .: ACT Publishing House LLC; Stalker Donetsk, 2002. - 95 p. ) With age, the natural resistance of animals and birds to tuberculosis infection increases. When using the same dose of mycobacterial culture, old animals and poultry are sick longer than young ones (Tuberculosis Guide. / Ed. By Einis V.L., Strukova A.I. // T.1. M., "Medgiz" , 1959. - S.187-188). The proposed method of staging a biological sample involves the use of quails that differ in live weight (adult quail weight 120-125 g) and age (41 days).

The proposed solution will reduce the diagnosis of avian tuberculosis due to the age and timing of death of quail since infection. In addition, the proposed method achieves an accurate determination of the type of pathogen according to the results of pathological studies of dead birds.

The method was carried out as follows.

For staging a biological sample used 41 day quails. A culture suspension of the highly virulent M. avium strain (piece 78, NIVI of the Non-chernozem zone of the Russian Federation) with typical species properties was prepared according to the optical turbidity standard - 1 U of microbial bodies / ml, as follows. The bacterial mass obtained on solid media (egg, potato) was ground with a pestle in a mortar with a small amount of saline, and then poured into a test tube. The suspension was prepared according to the optical turbidity standard to a concentration of 10 PIECES (1 mg of dry BCJ vaccine in 1 ml of physiological saline or 0.8 × 10 ⁹ microbial bodies / ml, respectively). The required concentration of mycobacteria culture was obtained by dilution method.

The resulting suspension was infected with 6 quails (group I), 41 days old and weighing 120-125 g. The suspension was injected into the axillary vein. As a control for infection, 6 chickens were used (group II), with a live weight of at least 1.8 kg, 150 days old. Each group of birds was administered a dose. For quail, the dose of culture of mycobacteria was 1 unit, and for chickens 10 units. The object of the study was fallen quail and hens.

The results of the timing of the death of animals and pathological studies of dead birds are presented in table 1.

Table 1 Option Bird view Dose, UNIT Deadlines after infection (days) Pathological changes I quail one 24-54 (group average 35) Dystrophy of the liver and spleen, miliary tuberculosis of the liver and spleen, kidneys are enlarged with hemorrhages II hens 10 17-82 (41) Dystrophy of the liver and spleen, in the liver of the TV * foci 2-4 mm in size, kidneys are enlarged

From table 1 it is seen that in comparison with the prototype, the application of the proposed method allows 7 days earlier to establish a diagnosis of avian tuberculosis.

To confirm the received data, the following example is given.

Example 1

In order to calculate the optimal dose administered to the quail culture of mycobacteria, the following studies were carried out. Suspensions were prepared from M.avium culture (pcs. 78, NIVI of the Non-chernozem zone of the Russian Federation) according to the optical turbidity standard in doses of 10; 1 and 0.1 DB. Quails, 36 animals, 41 and 150 days old, were divided into six groups of 6 each and were infected simultaneously with the control group. As a control, a suspension of a culture of avian mycobacteria at a dose of 10 PIECES was administered to 6 chickens (group VII).

Experience outline

Group I - 6 quail 41 days old (dose 0.1 units); Group II - 6 quail 150 days old (dose 0.1 units); Group III - 6 quail 41 days old (dose 1 unit); Group IV - 6 quail 150 days old (dose 1 unit); V group - 6 quails 41 days old (dose 10 units); Group VI - 6 quails of 150 days of age (dose 10 units); VII group - 6 chickens of 150 days of age (dose of 10 PIECES);

The results of studies on the calculation of the optimal dose for infection of quail with the culture of avian mycobacteria and the age of the birds are presented in table 2.

table 2 Option Dose, UNIT Age of birds, days Deadlines after infection, days Pathological changes one 2 3 four 5 I 0.1 41 28-86 (group average 46) Dystrophy of the liver and spleen, miliary tuberculosis of the liver and spleen, kidneys are enlarged with hemorrhages II 150 24-75 (51) Dystrophy of the liver and spleen, single TB ^* foci on the liver and spleen, kidneys are enlarged with hemorrhages III 41 24-54 (35) Dystrophy of the liver and spleen, miliary tuberculosis of the liver and spleen, kidneys are enlarged with hemorrhages IV one 150 24-60 (40) Dystrophy of the liver and spleen, single TV foci on the liver, kidneys are enlarged with hemorrhages V 41 19-47 (31) Dystrophy of the liver and spleen, kidneys are enlarged with hemorrhages VI 10 150 21-55 (34) Dystrophy of the liver and spleen, kidneys are enlarged with hemorrhages VII 150 17-82 (41) Dystrophy of the liver and spleen, in the liver of the TV ^* foci 2-4 mm in size, kidneys are enlarged Note - TV * - tuberculosis

The results obtained indicate that the timing of death of birds of group III is 6 days earlier than group IV and 7 days - control, respectively. Quail from groups V and VI died earlier, but without visible changes characteristic of tuberculosis.

Thus, the tests showed that the most informative result in terms and terms for confirming avian tuberculosis was obtained by intravenous administration of 41-day quail culture of mycobacteria at a dose of 1 unit. The results obtained indicate that replacing chickens with a live weight of at least 1.8 kilograms and older than 150 days with quails - 120-125 g reduces the time of death of animals by an average of 7 days. In addition, the use of quails of 41 days of age for staging a biological sample in a pathoanatomical study provides a more accurate pathoanatomical picture for establishing a diagnosis of avian tuberculosis. The use of quails of 150 days old (more adult) age for the identification of avian tuberculosis mycobacteria is impractical, as the timing of diagnosis increases (Table 2).

The proposed method allows to reduce the time of death of infected birds, which makes it possible to accelerate the time of diagnosis for avian tuberculosis. In addition, the proposed method is most informative in determining the type of pathogen according to the results of pathological studies of dead birds.

The proposed method was tested in the laboratory for the development of measures to combat tuberculosis of agricultural animals GNU IEVS and FE SB of the Russian Academy of Agricultural Sciences during 2004-2006

Claims (1)

A method of staging a biological sample to determine the species of mycobacteria, including intravenous administration to birds of a suspension of mycobacteria, characterized in that the suspension of mycobacteria is administered in an amount of 1 unit of quail weighing 120-125 g at the age of 41 days.