DETERMINATION OF THE SECURITY CRITERION IN THE CONTENT OF CONVENTIONAL ANIMALS BY THE IMPROVED HORIZONTAL METHOD OF LISTERIA MONOCYTOGENES DETECTION

It is particularly important for market operators — such as producers of meat from slaughtered animals, wholesale bases, agroindustrial markets, supermarkets, etc. — to determine one of the safety criteria, the presence of Listeria monocytogenes during the production of meat raw materials, its transportation, storage and marketing. The absence of this pathogenic microorganism indicates the proper sanitary and hygienic status of the business entities, the observance of personal hygiene for the production and circulation of beef, pork, mutton, goat meat. The conducted researches have revealed that the colonies of Listeria monocytogenes were detected in 24±2 hours and were small in size (1.5–2.0 mm), gray-green or olive-green, sometimes with black halo; in 46±2 hours — green with a flask center and black halo . These colonies were detected in the following samples of slaughter meat: in 2 samples of beef, 3 samples of pork and 1 sample of goat meat sold in the agroindustrial markets, in 2 samples of pork and 1 sample of beef sold in supermarkets. In beef, pork, mutton during production at facilities and storage at wholesale bases, as well as in mutton and goat meat realized on the agromarkets and in supermarkets, the characteristic colonies of Listeria monocytogenes were not detected. The improved horizontal detection method of Listeria monocytogenes is economical in terms of using nutrient media, it is simple to implement, and its results provide specific qualitative indices of the color and size of Listeria monocytogenes colonies, this method can be used in combination with other methods for determining the safety of slaughter animals. The reliability of the developed improved horizontal method for detecting Listeria monocytogenes in slaughtered animals was 99.8 %. The improved horizontal method for detecting Listeria monocytogenes in slaughter meat can be applied throughout the food chain for defining safety criteria for the production of safe meat, its transportation, storage and sale in production laboratories of meat processing plants, and enterprises for the implementation and storage of meat of slaughtered animals (in shops, supermarkets, wholesale bases, refrigerators, etc.), as well as in state laboratories of veterinary medicine and their departments.

Commission Regulation No. 2073/2005 establishes that food business operators should develop a sample collection program and microbiological studies for this trial. The program must be a part of the implementation procedures, developed on the basis of proper hygienic practices and HACCP system principles. The frequency of sample collection should be based on the analysis of risks, should keep in scale with the food business's character and size and also should take into account other factors such as raw materials properties, finished product, manufacturing process, etc. [1,4].
It is particularly important for market operators -producers of meat from slaughtered animals, wholesale bases, agroindustrial markets, supermarkets, etc. -to determine one of the safety criteria, the presence of Listeria monocytogenes for the production of meat raw materials, its transportation, storage and marketing. The absence of this pathogenic microorganism indicates the proper sanitary and hygienic status of the business entities, the observance of personal hygiene for the production and circulation of beef, pork, lamb, goat meat [5,10,11].

Materials and methods
As the materials for researches samples of muscle tissue (the longest muscle of the back) of beef, pork, lamb and goat meat were used in the amount of 230, which were selected on meat production facilities, wholesale bases during storage and agromarkets and supermarkets during realization in the Kyiv region. Bacteriological studies were conducted to detect and identify Listeria monocytogenes with the advanced horizontal method developed using selective enriched media such as Fresher and PALKAM-agar [3].

Results and discussion
The microorganism may be in raw food, such as fresh meat -beef, pork, mutton and goat meat. EU Member States are required to apply the microbiological criteria highlighted in Commission Regulation (EC) No 2073/2005. In this document, pathogens are directly related to the type of food product. There are specific requirements for the microbiological criteria for food safety, which can be used only in domestic marketing Ukraine. However, these criteria can not be used in terms of exporting the food products to the EU market. Therefore, the purpose of our research is to develop a bacteriological research method in meat (beef, pork, mutton and meat of goat).
The European Commission and the Council (EC) No. 852/2004 on the hygiene of foodstuffs, which includes the Community legislation on microbiological criteria; The principles of the development and application of the criteria and proposals for further measures were developed in the EU countries [2,7].
The above microbiological criteria indicate the acceptability of food products and processes for their production. The use of proper hygienic practices (GHP) and the analysis of hazardous factors and critical control points (based on the HACCP system), and the application of the structured preventive approach that provides the proper and its production process. Represented in Regulations 852/2004 on the General Sanitary Regulations and Regulations No. 853/2004 on the approval of specific hygiene rules for foodstuffs of animal origin [12].
Widespread distribution and increase in comparison with most other microorganisms, the ability to grow or survive in a cooled environment makes Listeria monocytogenes a significant risk factor for the production of meat from slaughtered animals, when stored at wholesale bases, as well as for marketing in agro-markets and supermarkets. Therefore, we have developed an improved horizontal method for detecting Listeria monocytogenes in the meat of slaughter animals.
To develop an improved horizontal method for detecting Listeria monocytogenes in meat of slaughtered animals, an experimental suspension was used which was prepared in a ratio of 1:5 (sam-ples of meat and meat products in the amount of 10-11 g and 50-55 cm 3 of primary selective enriched medium -half broiler Freser), followed by incubation of the resulting suspension for 21-23 hours at a temperature of 31±1 °C and subsequent secondary enrichment: after initial enrichment, the resulting culture in the amount of 0.05-0.06 cm 3 is transferred to a test tube containing 5-6 cm 3 of secondary enriched medium (broiler broth), then incubate the medium with crops for 46-48 hours at 37 °C, and subsequently seed from primary (5-6 cm 3 ) and secondary (2.5-3 cm 3 ) enriched cultures on PALKAM-agar selective medium to obtain clearly separated Listeria monocytogenes colonies for 24±2 hours at 37±1 °C in the form of small gray-green or olive-green colonies, with a diameter of 1.5-2 mm, sometimes with a black halo, after 48 hours -in the form of green colonies with a diameter of 1.5-2.0 mm with a burning center and black they halo around. Individual colonies were selected for confirmation of the Listeria genus and transplanted into MPA with 1 % glucose and tryptone soy bean agar with yeast extract (TSVEA) and cultivated at 37 °C. for 24-48 hours. The corresponding morphologically cultural and biochem-ical tests were identified and confirmed, namely: mannose fermentation, rhomniosis, β-hemolysis; hydrolysis of lecithin with coal. The results of the test of the developed advanced horizontal detection method for Listeria monocytogenes in the meat of slaughter animals are presented in table.
The conducted researches revealed that the colonies of Listeria monocytogenes detected in 24±2 hours were small in size (1.5-2.0 mm), gray-green or olive-green, sometimes with black halo; in 46±2 hours -green with a flask center and black halo in the following samples of slaughter meat: in 2 samples of beef, in 3 samples of pork and in 1 samples of goat meat sold in the agroindustrial markets and in 2 samples of pork and in 1 samples of beef sold in supermarkets. In the beef, pork, mutton for production at facilities and storage at wholesale bases, as well as in mutton and goat, realized on the agromarkets and in supermarkets, the characteristic colonies of Listeria monocytogenes were not found [8].
The improved horizontal detection method of Listeria monocytogenes is economical in terms of using nutrient media, simple to implement, and its results provide specific qualitative indices of the color and size of Listeria monocytogenes colonies and can be used in combination with other methods for determining the safety of slaughter animals.

Conclusion
The reliability of the developed improved horizontal method for detecting Listeria monocytogenes in slaughtered animals was 99.8 %. The improved horizontal method for detecting Listeria monocytogenes in slaughter meat can be applied throughout the food chain for defining safety criteria for the production of safe meat, its transportation, storage and sale in production laboratories of meat processing plants, and enterprises for the implementation and storage of meat of slaughtered animals (in shops, supermarkets, wholesale bases, refrigerators, etc.), as well as in state laboratories of veterinary medicine and their departments.
Perspectives of the future investigations. In further scientific studies it is necessary to establish the content of the total number of microorganisms in the meat of slaughter animals for their treatment; also, to study qualitative indices of beef, pork, mutton, goat meat which Listeria monocytogenes was detected in; to establish a traceability system for inspection of the sanitary condition and the quality of disinfection of veterinary supervision facilities at meat production facilities for slaughtered animals, wholesale bases, agroindustrial markets, supermarkets.