Каumenov N.S., senior lecturer

A. Baitursynov Kostanai State University

Dissemination of listeria in soil, water and plant

The causative agent of listeriosis has expressed resistance to adverse factors able to vegetate in the soil, growing media and organisms of flora and fauna [1].

In the abiotic environment is intense multiplication of listeria, the concentration of which can reach up to 181-491 thous/g listeria can be stored indefinitely in the soil and growing media - 2 - 12 years. The ability of listeria to multiply in the soil and plant substrates and their wide distribution in these environments suggests that the soil and plant substrates are their ecological niche, natural habitat [2].

Widespread listeria in the environment greatly complicates the identification of the main source of infection in the study of the epidemiology and epizootiology of diseases. Listeria significantly frequent in the environment, in connection with this aim was to identify listeria in soil, water, feed and plant products [3].

In order to detect the presence of listeries has been studied in soil, water, feed and plant products. As objects of study were selected 67 samples 20 samples of soil: soil potato fields KH "Gardener" -15 samples, the soil of vegetable stores ( Gardener, Sadchikovka ) -5 samples were selected 15 samples of water from open reservoirs and lakes ( surface and bottom water samples ) - r. Tobol -2 sample reservoirs. ( Karatomar ) -3 samples , Lake District Uzunkol ( Uzunkol ) -5 trial and lake ( Burliy ) Karabalykskiy district - 5 samples, mixed feed - 15 samples were selected farms Fedorovsk , Kostanai areas ( livestock farms, poultry farms ), vegetable products: ( Root crops ) beets - 7 samples, carrots - 5 samples, potatoes - 5 samples were taken in Kostanai region, in private enterprises engaged in receiving, processing and storage of feed products in retail outlets Kostanai.

Samples were taken in the spring in areas Kostanai area outlets Kostanai, enterprises (F Gardener, LLS Sadchikovka), as well as animal husbandry. The studies were conducted in the laboratory of the department Veterinary Sanitation of A.Baitursynov KSU.

As a result, soil investigation, it was found that the bacteriological study of 20 soil samples were allocated there is a culture of listeria in three soil samples, respectively, of these 2 trials with potato fields and in one soil sample with a vegetable store, for a total of (15%).

In the study of water in open reservoirs p. Tobol listeria were not detected in water. Karatomar 1 sample was positive in the water of Lake Uzunkol listeria are found, and samples o.Burli listeria isolated in one sample, for a total of (13.3%).

Of the 10 samples tested combined feed from storage rooms and livestock farms using bacteriological crops not found listeria, were detected from 5 samples of feed residues of poultry farms in one sample.

Results of the study sample swabs root crops (beets, carrots, potatoes) bacteriologically listeria were detected in one sample of 5 samples of carrots. The number of positive samples in all feed was (6.25%).

Thus, studies have shown a listeria contamination of soil, water, feed grain and a variety of plant foods. Consequently the soil, water can serve as the source of listeriosis in livestock, in turn, feed grain may also serve as a nutritional transmission route, the presence of listeria in vegetable products may during watering, the presence of soil particles, as well as during storage.

All listeria isolates were studied by conventional diagnostic methods that allowed them to describe the morphological, cultural, biological and biochemical properties.

For the experiment, we used the following culture medium: 0.004% MPA with nalidixic acid, MPB, MPBH broth enrichment, Palcam-agar, Oxford-agar, Fraser broth, bacteriophages type L 4A and L 2A, and 5% hydrogen peroxide.

Sampling and preparation for bacteriological analysis was performed according to GOST 26668-85, 26669-85, GOST 1721-85, GOST 1722-85, GOST 7176-85, GOST 12220-96, GOST 13496.0-80, guidelines. Research methods for listeria food. MUK № 8.05002.04. Soil sampling was carried out according to conventional methods. For detection of listeria in water samples were taken from each of 10 ml. Of forage and root crops 25 g slurry prepared by adding to the rigging of sterile saline. All test samples previously for 2-3 months were "cold enrichment" and kept at 4⁰С.

Then carefully prepared samples were placed in medium and enrichment broth and incubated at Fraser 37⁰C for 24-48 hours. After incubation of the tubes using a bacteriological loop in Petri dishes seeded on an agar medium: MPA with 0.004% nalidixic acid , Palcam- agar , Oxford- agar . Further crops were sent in an incubator at 37⁰C for 24-48 hours. At the end of incubation , the agar surface was carried out with the selection of the most typical listeria colonies and subcultured them MPB 1% glucose broth enrichment and sent in an incubator at 37⁰C for 24 hours. Then the obtained culture was investigated by conventional methods.

Listeria culture were subjected to culture-morphological, biological and biochemical studies.

Typical for all crops was a rod-shaped form. All cultures in smears Gram stained positively, while they looked in the form of short rods with rounded ends, ranging randomly: singly, in pairs and as small chains. The broth 12 hour culture of listeria obtained at room temperature (18-20⁰C), had a well-defined mobility. In old cultures (over 1 month) listeria had filamentous forms.

The cultures grown pretty good at MPB broth enrichment broth Fraser, MPA, Palcam-agar, Oxford-agar and other nutrient media. When cultured on the growth of listeria MPB characterized haze, after shaking were clearly visible more waves. At 37⁰C for 48-72 hours on a bottom of the tube precipitate appeared, the supernatant became transparent. With a uniform shaking slimy precipitate raised and looks like a "pigtail" hard enough breaks in uniform turbidity.

In enrichment broth and Fraser broth at 30⁰C in 1-2 days there was a significant growth of listeria, resulting in plant painted a dark brown color.

On MPA on a day there are small, isolated, round, transparent, resembling dew colony. Most subsistence crops have smooth edges and a smooth surface.

After 2-3 days, they increased in size, the upper part of the colonies was rounded, had a rough surface with a shiny grayish-bluish tinge.

On Palcam-agar 24-48 hours of incubation at 37⁰C colonies were the size of 0.5-1.0 mm, round form with gray-greenish tint and a dark halo around. On Oxford-agar colony 24-48 hours had a dark brown color, size 0.5-1.0 mm with a black rim around.

After 2 days, these colonies increased to 2.0-2.5 mm, getting black colony center immersed in agar.

Biochemical properties: Selected cultures experience carbohydrates 0.3 % MPA indicator using Andrade: arabinose, glucose, fructose, lactose, maltose, mannitol, rhamnose, sorbitol, raffinose, xylose, sucrose, dulcitol, and salicin. Within 48 hours, the crops were incubated at 37⁰C. The resulting strains were digested with an acid without gas: glucose, fructose, rhamnose, was observed after 3 days of fermentation of maltose and salicin. All strains have not changed environment with dulcitol, arabinose, xylose and raffinose. Four strains were digested sucrose and only 2 strains reacted positively with mannitol. According to a study of freshly listeria strains have various biochemical properties.

All the isolates did not produce indole, ammonia and hydrogen sulfide, but showed catalase activity. Wherein hydrogen peroxide is cleaved to form gas bubbles.

In the study of cultural sensitivity to bacteriophages (L2A, L4A) 4 strains of listeria showed belonging to serogroup 1 and 3 strains - to 2 serogroup.

Pathogenic properties: In order to determine the pathogenic properties of the isolated strains was performed conjunctival test in guinea pigs. At 5 strains conjunctival test was positive in two strains obtained from water and soil, conjunctival test was negative.

Thus, Listeria isolated from different environmental media (soil, water, plant material) had typical cultural- morphological, biochemical and pathogenic properties.

From this it follows that the investigated objects, one way or another can be a factor of transmission, which creates prerequisites for careful monitoring of environmental objects, raw materials of animal and vegetable origin and mandatory compliance with preventive measures.

Literature:

1. Rakhmanov A.G., Prigogine V.K. Handbook of Infectious Diseases // Section. Listeriosis. - St. Petersburg, 1999. - P.172-174.

2. Gershun V.I. Listeriosis agricultural animal. Alma-Ata: Kynar, 1981.-94c.

3. Tartakovsky I.S. Listeria: the role of infectious disease in humans and laboratory diagnostics / / Clin. Microbiology. antimicrobial. Chemotherapy. - 2000. - № 2 (2.) - P.20-30.