Rapid identification of Lactobacillus brevis using the polymerase chain reaction

Aims: Species-specific PCR was applied to identify Lactobacillus brevis and the sensitivity and the specificity of the protocol were determined. Methods and Results: Strains of Lact. brevis obtained from foods, particularly dairy products, and various strain collections, were identified by PCR using primers which amplified a 1340 by fragment within the 16S rRNA gene. The PCR product was obtained after amplification of all the Lact. brevis strains tested; the size of the amplicon was as expected. No PCR products were observed after amplification from DNA of several lactic acid bacteria (LAB) species. Conclusions: A PCR method was optimized to identify Lact. brevis. The protocol was highly efficient and sensitive. Significance and Impact of the Study: Conventional phenotypic methods often lead to ambiguous identification of LAB species belonging to Lact. brevis. The proposed protocol is sensitive, specific, and can be applied to total DNA extracted by use of chelating matrix with loss of neither sensitivity nor specificity.