Application of colony BOXA2R-PCR for the differentiation and identification of lactic acid COCCI

Repetitive-PCR (rep-PCR) is a well-established genetic method for bacterial strain fingerprinting that is used mostly with REP, ERIC, (GTG)5, BOXA1R and occasionally BOXA2R repetitive primers. In this study, it was demonstrated that BOXA2R-PCR could effectively discriminate between Lactococcus lactis, Leuconostoc mesenteroides and Streptococcus thermophilus; differentiate Lactococcus lactis strains and subspeciate them into lactis and cremoris in a single reaction; generate unique strain fingerprints of various lactic acid bacteria (LAB species) commonly isolated from fermented dairy products, including occasional spoilage bacteria and yeasts. Furthermore, using direct colony PCR a reproducible and rapid method was developed for the differentiation and identification of lactic acid cocci. The simplicity and speed of this microbial identification method has potential practical value for dairy microbiologists, which was demonstrated through a microbiota investigation of select Australian retail dairy products. •Direct colony BOXA2R-PCR:-subspeciates Lactococcus lactis into lactis and cremoris genotypes and differentiates strains in a single reaction.-fingerprints strains isolated from LAB fermented food products, including occasional contaminant bacteria and yeasts.-discriminates Lc. lactis, Leuc. mesenteroides and Str. thermophilus from each other and from enterococci.