The microbiological laboratory on the basis of “Institute of Preclinical Research” Ltd. was designed and equipped in accordance with the Sanitary and Epidemiological Regulations of SP 1.3.2322-08 “Safety of work with microorganisms of III-IV pathogenicity groups (hazards) and causative agents of parasitic diseases”.
License No. 47.01.05.001.Л.000001.04.18 of 20.04.2018 for carrying out activities in the field of the use of pathogens of human and animal infectious diseases (with the exception of the case if the indicated activity is carried out for medical purposes) and genetically engineered organisms III and IV the degree of potential danger in closed systems.
Microbiological laboratory works with microorganisms of III-IV pathogenicity groups, including gram-positive and gram-negative bacteria, dermatomycetes, yeast and mold fungi.
The laboratory identified three main activities:
– Determination of antimicrobial activity in vivo in small laboratory animals with experimental infection with various pathogenic agents.
– Determination of antimicrobial activity in vitro on test strains of microorganisms.
– Specialized services for nurseries and vivaria of laboratory animals (bacteriological monitoring of animal health and the environment).
Determination of the antimicrobial activity of the test samples under in vivo conditions
In the laboratory of microbiology, a zone for maintaining and working with small laboratory animals (mice, rats, guinea pigs, gerbils) was designed and equipped in individually ventilated cells that provide isolation of animals from the environment and protection of personnel.
Microbiological studies in animals make it possible to evaluate the therapeutic efficacy in the clinical way of using anti-bacterial and antifungal medicines, pro- and prebiotics, adsorbents, immunomodulators.
Experimental models: acute generalized infection in small animals; chronic septicopyemia (staphylococcal); pneumonia with generalization of infection; experimental pyelonephritis; Clostridial anaerobic infections, Helicobacter pylori and others.
Determination of antimicrobial activity in vitro on test strains of microorganisms
Determination of the antimicrobial activity of the test samples (chemical compounds, etc.) under in vitro conditions.
– Evaluation of the spectrum of action and the degree of anti-bacterial and antifungal activity in vitro antibacterial agents and antifungal drugs. Determination of the MIC (minimum inhibitory concentration), MBC (minimum bactericidal concentration), MPC (minimum fungicidal concentration) for reference strains and clinical isolates of Gram-positive and Gram-negative bacteria, dermatomycetes, yeast and mold fungi;
– Multidrug assessment;
– Speed of formation of resistance to new compounds;
– Study of targets and mechanisms of antibacterial action of compounds;
– Evaluation of the activity of reproducible drugs.
Bacteriological monitoring of the environment and animal health
Bacteriological monitoring of the environment includes monitoring efficiency of disinfection of premises and inventory, bacteriological evaluation of air and water quality.
Bacteriological monitoring of the health of laboratory animals is carried out in rinses, scrapings, cadaver, obtained from animals in accordance with international recommendations FELASA, 2014.
- Kryshen K.L., Muzhikyan A.A., Alyakrinskaya A.A., Kovaleva M.A., Makarova M.N., Makarov V.G. Intracutaneous injection of Staphylococcus aureus bacteria into the scapophoccular angle of the auricle as a model of acne in laboratory animals // International Veterinary Journal. – 2017, No. 1. – C. 84-91. [Full text is available in Russian].
- Borovkova К., Kryshen А., Kryshen К., Petrova А.V., Makarova М. Features of working with laboratory animals in microbiological laboratory. Laboratory Animals for Science. – 2019, №1. – С. 1-8. https://doi.org/10.29296/2618723X-2019-01-09 SUMMARY. Standardization of experimental conditions is the main criterion for obtaining qualitative results. For many decades, laboratory animals have been an integral part of biomedical research. The use of animals in pharmacological experiments is justified in particular when evaluating the antimicrobial activity of drugs and substances, since in vivo results may differ significantly from in vitro tests. In the modern scientific community, the design of experiments should comply with ethical principles. Particular attention is paid to the quality of animals. The laboratory should have a program for monitoring the health of animals; animals should be taken into the experiment with a known microbiological status. Animal welfare conditions are also important. In microbiological studies using pathogenic biological agents (PBA), the main criterion is to protect personnel and the environment from infected animals and their waste products. From this point of view, keeping animals in an individually ventilated system is optimal. Personnel with medical, veterinary, biological and other education and relevant specialization courses may be allowed to work with the PBA of the III-IV pathogenicity groups. Trained staff under the supervision of a veterinarian carries out animal manipulations. All procedures within the microbiological laboratory must be conducted in compliance with the requirements of biological safety. The choice of a model of an experiment on the infection of animals can be justified by conducting pilot studies. In this case, the researcher needs to take into account a number of features: the sensitivity of the animal, the route of infection, the tropism of microorganisms to certain tissues and systems, and, in fact, obtaining an experimental infectious process to clinical signs similar to humans. Thus, conducting experiments with infected animals requires a licensed microbiology laboratory equipped with the necessary equipment and materials, optimal animal welfare conditions, qualified and trained personnel, as well as scientific knowledge. Compliance with all the rules will allow to competently plan microbiological research with obtaining reliable quality results [Full text is available in Russian].
- Khaibunasova L.R, Borovkova К.E., Salmova J.V. Lung bacterial infections. Animal models. Laboratory Animals for Science. – 2020, №2. https://doi.org/10.29296/2618723X-2020-02-06 Abstract. Pneumonia is the leading cause of morbidity and mortality worldwide, especially among children and the elderly people. Nosocomial pneumonia in a hospital setting is one of the most serious infectious complications often caused by opportunistic pathogens. There is an urgent need for improved treatment and prevention of pneumonia. Therefore, animal models have been developed to better understand the pathogenesis of the disease, testing new drugs and vaccines. This review summarizes scientific studies about animal models of bacterial pneumonia as well as the main causative agents of the disease, routes of infectious agents administration and estimated parameters. Various microorganisms such as Streptococcus pneumoniae, Legionella pneumophila, Haemophilus influenzae, Neisseria meningitidis, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Acinetobacter baumannii, Klebsiella pneumoniae are considered in this review as a causative agents of bacterial pneumonia. The most popular microorganism used for modeling pneumonia is Streptococcus pneumoniae. According to data presented in scientific articles, mice, rats, rabbits, pigs and primates are used as a test system for modeling bacterial pneumonia. Mice are the most suitable animals for bacterial pneumonia studies. This type of animal is easy to handle and allows to use the sufficient number of animals for results evaluation. The main assessed parameters in pneumonia studies are data about clinical signs, survival, bacteremia, the number of bacteria in the lungs, pathological and histological characteristics, quantitative assessment of antibody titers, markers of inflammation etc. Depending on the purpose of the study methods of bacterial inoculum administration are differ. An intravenous and intraperitoneal route of administration is used to assess virulence, an intratracheal route of administration is used to study the effectiveness of new antibiotics, and an inoculum is administered intramuscularly to animals when developing new vaccines for bacterial pneumonia the choice of animals, the type of microorganism, the method of infection and the estimated parameters depends on the tasks and research objectives [Full text is available in Russian].
- Gushchin Y.A., Kryshen A.A.Testing of an infective inflammation model of the gastrointestinal tract, associated with helicobacter pylori, in laboratory gerbils. Laboratory Animals for Science. – 2020, №3. https://doi.org/10.29296/2618723X-2020-03-08 Abstract. Peptic ulcer of the stomach and duodenum is a chronic recurrent disease that occurs with alternating periods of recrudescence and remission. The main manifestation of this disease is the formation of a defect in the wall of the stomach and duodenum. One of the main factors in the occurrence of peptic ulcer disease is infection with Helicobacter pylori (H. pylori). These are microaerophilic, non-spore-forming, gram-negative, curved rod-shaped or coccoid bacteria. They play an important role in enhancing the aggressive properties of gastric contents and weakening of gastric and duodenal mucosal defense. The high frequency of chronic Helicobacter gastritis causes a high incidence of cancer. Therefore, the development of a model of Helicobacter-induced gastroduodenal diseases in vivo to search for alternative therapy for H. pylori infection is currently relevant. Thus, the aim of the study was to develop a model of infectious (associated Helicobacter pylori) inflammation of the gastrointestinal tract. Assessment of the developed pathology was carried out by determining microscopic changes in the tissues of the gastrointestinal tract. 30 Mature male laboratory gerbils were used as a test system. Positive control animals were infected with a suspension of fresh H. pylori culture at a concentration of 2×109 CFU / ml in a volume of 0.5 ml with intragastric administration twice, once a day, for 2 days. Sterile trypton soy broth (a medium for H. pylori cultivation) was gavaged to negative control animals according to a similar scheme. The morphological analysis was based on the international classification of chronic gastritis (the Sydney system and its Houston modification). As a result of the study, laboratory gerbils had a pathology of the gastric mucosa by the 24th week of the experiment. After 8 weeks, the infected animals registered initial manifestations of catarrhal gastritis. By the end of the 16th week of the experiment, in addition to increasing gastritis, bacteria corresponding to H. pylori in their morphological forms were identified. By the end of the study, there was an inflammatory component in the gastric mucosa, atrophy of the glands, and erosive and ulcerative lesions of the mucous membrane. Bacterial forms corresponding to H. pylori was identified with a specific staining in the mucous membrane of the stomach. Pathological changes were observed mainly in the antral part of the stomach. The chosen system for assessing the severity of the pathology proved to be sufficient and objective, allowing us to fully analyze the development of pathology. However, the use of this strain of H. pylori did not lead to the formation of ulcerative and metaplastic changes when observed at 24 weeks of pathology development, which was expected based on the literature data. Also, during this period of time, it was not possible to achieve the development of duodenite. It is likely that the used strain of bacteria did not have sufficient virulence, which should be taken into account in future studies [Full text is available in Russian].