Bacteriocin-producing Bacillus pumilus strains as a tool to control enteric clostridial diseases

DAILOFF, G.; REDONDO, L.; SAUKA, D.; FERNÁNDEZ MIYAKAWA, M.

Buenos Aires

Otro; Reunión Conjunta de Sociedades de Biociencias; 2017

SAIC, SAIB, SAI, SAA, SAB, SAFE, SAFIS, SAH y SAP

Bacillus spp. are Gram-positive, rod-shaped, aerobic or facultative anaerobicbacteria. In stressful conditions form central endospores resistant to hightemperatures and common chemical disinfectants. Several strains of Bacillus spp. have been used as probioticsfor the control of pathogens, in part due to their ability to producebacteriocins. Bacteriocins are defined as biologically active peptides withbactericidal properties. The objective of the present study was to isolate andcharacterize bacteriocin-producing Bacillusspp. strains with activity against avian Clostridiumperfringens strains to control necrotic enteritis in broilers. Bacillus spp. were isolated fromcommercial poultry litter samples after ethanolic shock. Six isolates wereidentified as Bacillus species basedon standardized methods including observation of cell morphology Gram-staining,catalase activity, 50 CH API test and 16S rRNA gene sequence analysis.Inhibition tests were repeated against several C. perfringens poultry strains and some strains of Bacillus identified as B. pumilus were able to inhibit 100% ofthe challenged strains. The bacteriocin title and percentage of sporulation ofthe B. pumilus strains were furtherstudied. With a title of bacteriocin and a percentage of sporulation from 16,0.05%; 1, 1.07%; 32, 0.29%; 4, 1.81%; 64, 0.18%; 2, 0.29% to INTA201401,INTA201402, INTA201403, INTA201404, INTA201405, INTA201406 respectively. Furthermore,in vitro assays were performed usingCaco-2 cell line to study the adhesion of B.pumilus strains with a reference strain ATCC 13124. Adhesive properties ofselected B. pumilus strains to higherpercentage of adherence (20% INTA201402, 38.83% INTA201405) with respect to theother Bacillus strains and C. perfringens (5% ATCC 13124). Inconclusion, bacteriocins from several strains of B. pumilus as well as bacteria cells could be used as a biotechnologicaltool for the control of necrotic enteritis in chickens.