DETERMINATION OF ANTAGONISTIC ACTIVITY OF ISOLATED STRAINS E.COLI

Introduction

The approach to the development of probiotics should be based on the study of many parameters, including the first comprehensive assessment of the properties of microorganisms - probionts. These characteristics include the antagonistic activity, the ability to adhere and colonize the intestinal mucosa, a certain level of resistance to hydrochloric acid and bile, and certainly apatogennity [1, p. 3-7].

Determination of the spectrum of antagonistic activity of E.coli strains isolated in relation to the opportunistic microorganisms and selected strains of E.coli, having high antagonistic properties and ability to produce bacteriocine. To have an effective medicines against antagonistic conditionally - pathogenic microflora it are needed a strains with high enough stable biological properties that promote good survival in the animal [2, p. 782-786].

One of the most valuable properties of probiotic microorganisms is their antagonistic activity against pathogenic conditionally - pathogenic microorganisms [3, p. 23].

Materials and Methods

In the result of breeding we have selected five strains of Escherichia (E. coli 42, E. coli 64, E. coli 39, E. coli 34, E. coli 16), which were used in experiments to study their antagonistic properties.

Determination of the antigenic structure was conducted with the common "0" - and if monovalent agglutinating serum.

The presence of the adhesive antigen examined in agglutination on glass agglutinating anti-adhesive number - at the beginning of the complex serum and if a positive response - with monovalent serum.

Fermentation of carbohydrates was determined on the indicator SLA with Andrede^,s indicators with various sugars and polyols.

The antagonistic activity of E. coli was studied on solid nutrient media. The degree of antagonistic activity of strains studied for each testifying organisms by the width of the zone of growth inhibition of the latter: up to 10 mm is the average, more than 20 mm - high, the lack of growth inhibition zone - the zero-sum activity.

As the testifying cultures were taken cultures, isolated from sick animals in the farms of the Almaty region, having pathogenic properties, belonging to the genus Salmonella (S. abortus ovis, S. typhymurium), Klebsiella (K. pneumoniae - 2 strains), Streptococcus (Str . pneumoniae - 2 strains) and Escherichia (E. coli - 2 strains).

The results of research

On the MPA observed steady growth with a bluish tinge, formed round, smooth, translucent colonies. On Endo media in Petri dishes strains grew as red colored colonies.

Bacteria have good mobility. The optimum of temperature for growth is 37 – 38⁰ C, pH is 7.0-7.2. During the microscopic investigation we can be seen randomly placed sticks. Plated on MPS medium are marked clouding even to form on the bottom of the tube can be easily broken cake.

Determining the antigenic structure showed that all strains of the above serum agglutinated in four crosses, indicating the usefulness of their antigenic properties and has: E. coli 42 - 0111; E. coli 39 - 142; E. coli 34 - 078.

As a result of the presence of the adhesive antigen founded that a strain of E. coli 42 showed a positive agglutination reaction - with the serum of K88, the strain E. coli 39 to serum with K99, E. coli 34 in association F 41 + K99.

Reaction with the formation of acid and gas was observed in media containing glucose, lactose, sucrose, maltose, mannitol, sorbitol and dultsitom.

The study of the biological properties of the test strains showed that all strains on MPA formed S - shape and no showed hemolytic activity. The antagonistic activity of E. coli are shown in Table 1.

The studies have shown that significant variation in the level of antagonistic activity of different strains of Escherichia suppressed in the spectrum of microorganisms. The highest antagonistic activity has strains of E. coli 39 and E. coli 34 that inhibited the growth of all samples in the test culture experience.

Conclusions

The test strains of Escherichia has typical morphological, tinctorial, cultural - biochemical and antigenic properties characteristic of the genus of Escherichia.

The strains E. coli 39, E. coli 34 also showed high antagonistic activity against virulent cultures of E. coli.

References:

1. Subbotin V.V., Sidorov M.A. Prevention of gastrointestinal diseases of newborn animals with signs and symptoms of diarrhea / / Veterinary Medicine. - 2001. - № 4. Pp. 3-7.

2. Brinton C.C. Mon-fragellar appen dages of bacteria / / Nature. - 1988. - V.183. - P. 782-786

3. Chervinets Y. Antagonistic strains of lactobacilli, are promising for designing new probiotic medicines. [Text]: The dissertation on candidate of medical sciences: 2006 / Yu.V. Chervinets. - Moscow, 2006. C.23.

Scientific manager:

Doctor of Veterinary Sciences, Professor B.K. Biyashev