Discrimination of probiotic Lactobacillus strains for poultry by repetitive sequenced‐based PCR fingerprinting

BACKGROUND: Four repetitive element sequence‐based polymerase chain reaction (rep‐PCR) methods, namely repetitive extragenic palindromic PCR (REP‐PCR), enterobacterial repetitive intergenic consensus PCR (ERIC‐PCR), polytrinucleotide (GTG)₅‐PCR and BOX‐PCR, were evaluated for the molecular differentiation of 12 probiotic Lactobacillus strains previously isolated from the gastrointestinal tract of chickens and used as a multistrain probiotic. This study represents the first analysis of the comparative efficacy of these four rep‐PCR methods and their combination (composite rep‐PCR) in the molecular typing of Lactobacillus strains based on a discriminatory index (D). RESULTS: Species‐specific and strain‐specific profiles were observed from rep‐PCR. From the numerical analysis of composite rep‐PCR, BOX‐PCR, (GTG)₅‐PCR, REP‐PCR and ERIC‐PCR, D values of 0.9118, 0.9044, 0.8897, 0.8750 and 0.8529 respectively were obtained. Composite rep‐PCR analysis was the most discriminative method, with eight Lactobacillus strains, namely L. brevis ATCC 14869^T, L. reuteri C 10, L. reuteri ATCC 23272^T, L. gallinarum ATCC 33199^T, L. salivarius ATCC 11741^T, L. salivarius I 24, L. panis JCM 11053^T and L. panis C 17, being differentiated at the strain level. CONCLUSION: Composite rep‐PCR analysis is potentially a useful fingerprinting method to discriminate probiotic Lactobacillus strains isolated from the gastrointestinal tract of chickens. Copyright © 2011 Society of Chemical Industry