Identification of lactobacilli by culture and PCR Aliquots of saliva were plated onto Rogosa agar (Merck, Darmstadt, Germany) to obtain Lactobacillus counts and on selective agar for tentative identification of the L. reuteri (DSM 17938 and PTA 5289) strains [33]. All plates were anaerobically incubated at 37°C for 48-72 h, except L. reuteri PTA 5289, which was anaerobically incubated at 40°C for 72 h.