Probiotic Bacilli Inhibit Biofilm Formation Without Killing Planktonic Cells.

Salmonellosis is a foodborne infection caused by Domestic poultry species are one of the main reservoirs of , which causes the foodborne infection salmonellosis, and are responsible for many cases of animal-to-human transmission. Keeping backyard chickens is now a growing trend, increasing the frequency of direct contact with the flock and, by consequence, the incidence of infections. KATMIRA1933 and B-1895 are probiotic bacilli that produce the bacteriocins subtilosin A and subtilin, respectively. The antimicrobial activity of the two strains was determined against the reference strain ATCC 10420. The cell-free supernatant of KATMIRA1933 inhibited biofilm formation by subsp. serovar Hadar, subsp. serovar Enteritidis phage type 4, and subsp. serovar Thompson by 51.1, 48.3, and 56.9%, respectively. The cell-free supernatant of B-1895 inhibited the biofilm formation of these strains by 30.4, 28.6, and 35.5%, respectively. These findings suggest that the bacillus strains may have the potential to be used as probiotics and antibiotic alternatives for the control of in poultry. The number of planktonic cells was unaffected by treatment with the cell-free supernatant. A co-culture of the strains with either bacilli showed no signs of growth inhibition, suggesting that it might have been quorum sensing that is affected by the two strains.