bioassey in microbiology

From Big Medical Encyclopedia

BIOASSEY in microbiology — the general name of the methods of a research based on infection of laboratory animals or introduction by it biol, drugs; it is applied to diagnosis of infectious diseases, identification of pathogenic microorganisms and control of the studied material.

Depending on research objectives, a species of laboratory animals and the studied microorganism at B.'s statement items use various methods of application (hypodermic, enteral, intravenous, intraperitoneal etc.). At diagnosis of infectious diseases infect with pathological material susceptible animals in whose organism the pathogenic microorganism selectively breeds and can be allocated in pure form. E.g., for detection of a pneumococcus in the material contaminated by foreign microorganisms (phlegm) infect intraperitoneally white mice and in 5 — 6 hours allocate the activator from blood of animals at crops for mediums or find it in smears from a spleen.

For allocation of culture of a plague bacillus use Guinea pigs (preferably) or white mice who are infected subcutaneously or intraperitoneally. If material is strongly contaminated, apply a cutaneous method of infection. The plague bacillus is found in smears from bodies, blood and at crops on mediums.

At diagnosis of a tularemia infect with the studied material subcutaneously, less often nakozhno, white mice or Guinea pigs. After death of animals find the activator in smears from bodies and at crops on special mediums.

The bp is an important diagnostic method of tuberculosis. Guinea pigs are infected, entering material under skin of a groin or intraperitoneally. In the presence in material of tubercular bacteria at Guinea pigs generalized tuberculosis develops.

The bp is applied also to detection in the studied material of some bacterial exotoxins (botulinic, tetanic).

At infection of males of a Guinea pig with rickettsiae of a rat sapropyra their specific periorchitis is developed.

For diagnosis of smallpox infect with material from the patient a rabbit (in the scarified cornea). In positive cases the variolezny keratitis develops. By method of an immunofluorescence in cuts of a cornea it is possible to find Gvarniyeri's little bodies and a viral antigen.

For diagnosis of rage to a rabbit enter intratserebralno a suspension of brain fabric. The animal perishes from a paralytic form of rage.

At diagnosis of the diseases caused by Koksaki's viruses, infect with the studied material mice suckers. The diagnosis is established on a histologic picture of damage of muscles of a trunk and extremities and by means of a neutralization test of a virus by specific serum.

Bps apply to control of various biological drugs (vaccines, serums) on harmlessness (Guinea pigs), toxicity (white mice), pyrogenicity (rabbits), immunological activity (mice, rabbits). In these researches an important role is played by a look, a floor, weight of laboratory animals, a method and frequency rate of immunization, a total dose of the entered substance.

See also Bacteriological techniques .

Bibliography: The guide to clinical laboratory trials, under the editorship of E. A. Kost and JI. G. Smirnova, M., 1964; The Guide to microbiological diagnosis of infectious diseases, under the editorship of K. I. Matveev, M., 1973.

S. S. Belokrysenko.