Antagonistic properties of bacteria found in sugar beet leaf silage against pathogens naturally occurring in the mouth of cattle

摘要

The aim of the study was to present antibacterial properties of bacteria found in sugar beet silage against Shigella. The experiment involved bullocks, from which the pathogenic bacteria were isolated, and microorganisms obtained from silage (without additives), lit was found that pathogenic bacteria are inhibited by bacteria present in the silage. Experimental subjects included 10 bullocks (crosses of Limousine with Black and White Lowland (BWL) of 700 kg mean body weight. Silage was prepared from sugar beet leaves contaminated with soil. Pliant material was ensiled in 6 PCV containers (barrels) of 200 dm(3) in volume closed with a cover allowing the release of gaseous products. The ensiling process lasted 120 days. Samples for chemical and microbiological analyses were collected from three barrel depths (15, 30 and 45 cm) and were subsequently pooled to make a representative sample of 0.9 kg weight. The basic composition of the silage was determined in accordance with AOAC.The strain antagonistic to Shigella was identified by the molecular method: after isolating bacterial DNA, a PCR reaction was performed. The PCR analysis and the DNA sequence analysis showed that the organism which naturally occurs in sugar beet leaf silage and exhibits antagonistic properties to Shigella bacteria was Bacillus subtilis. Shigella spp., a pathogenic microorganism that is of particular concern to humans, was found in the mouth of cattle.