• rep-PCR;
  • fingerprinting;
  • Lactobacillus spp.;
  • probiotic


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 14869T, L. reuteri C 10, L. reuteri ATCC 23272T, L. gallinarum ATCC 33199T, L. salivarius ATCC 11741T, L. salivarius I 24, L. panis JCM 11053T 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