Characterisation of ropy slime-producing Lactobacillus sakei using repetitive element sequence-based PCR

Eighteen previously characterised Lactobacillus sakei strains exhibiting va rying slime production capabilities in vacuum-packaged meat products were a nalysed using repetitive element sequence-based PCR (rep-PCR). The single p rimers BOXA1R and RW3A and the primer pair REP1R-Dt and REP2R-Dt were evalu ated for their applicability in L. sakei genotyping. The five different pat terns produced by RW3A were the least useful, with the discriminatory power equal to ribotyping. BOXA1R and REP-primer pair both produced six differen t banding patterns and the combination of these results yielded seven diffe rent rep-types. Rep-PCR was concluded to have approximately the same discri minatory power as randomly amplified polymorphic DNA (RAPD) analysis, but w as inferior to pulsed-field gel electrophoresis (PFGE). However, if the res ults of rep-PCR and RAPD were combined, the discrimination was comparable t o PFGE, with the exception that within Ribogroup I non-slime-producing stra ins were indistinguishable from weak slims producers. It was concluded that the combination of the two PCR-based typing techniques, rep-PCR and RAPD, would be a valuable tool in large scale contamination studies at meat proce ssing plants, since results can be obtained rapidly with fewer isolates nee ding further analysis by PFGE. (C) 1999 Elsevier Science B.V. All rights re served.