THE EFFECT OF LACTOBACILLUS-SALIVARIUS AD MINISTRATION ON COLIFORMS AND ENTEROCOCCI IN THE CROP AND CECA OF CHICKEN BROILERS

A rifampicin-resistant Lactobacillus salivarius 51R was isolated from chicken caeca and administered orally to newly hatched broiler chicken s. The resistance to rifampicin enabled us to differentiate the admini stered organism from indigenous strains. First day after inoculation, L. salivarius 51R dominated among lactobacilli in the crop and caeca o f inoculated chickens and its counts were slightly over 7 log c.f.u. p er 1 g of digesta even after 10 days. L. salivarius significantly (P < 0.01) lowered counts of enterococci and coliforms in the crop during the whole experimental period (10 days). Effects of L. salivarius admi nistration on caecal counts other than lactobacilli were generally sma ll. The influence of Lactobacillus strain used to species composition of enterococci and coliforms were also observed. 105 strains of entero cocci and 96 strains of coliforms isolated from the crop and caeca of both control and experimental groups were characterized using identifi cation sets and computer program. Regarding, enterococci, 63% was iden tified to the species level, 31% to the genus level, and 6% was not id entified. Regarding coliforms, 48% was reported to the species level, 25% to the genus level, and 26% was not identified. The most prevalent species among the enterococci was E. faecalis and among the coliforms E. coli. 24 h after the administration of L. salivarius 51R there was significantly higher (P < 0.05) occurrence of E. faecalis (57% out of ail enterococcal isolates) in experimental group than those in the co ntrol group (31% out of all enterococcal isolates). The perspectives i n the control of pathogens in young chickens via probiotics was discus sed.