title: Incidence of Bacteriocins Produced by Food-Related Lactic Acid Bacteria Active towards Oral Pathogens.
abstract: In the present study we investigated the incidence of bacteriocins produced by 236 lactic acid bacteria (LAB) food isolates against pathogenic or opportunistic pathogenic oral bacteria. This set of LAB contained several strains (≥17%) producing bacteriocins active against food-related bacteria. Interestingly only Streptococcus macedonicus ACA-DC 198 was able to inhibit the growth of Streptococcus oralis, Streptococcus sanguinis and Streptococcus gordonii, while Lactobacillus fermentum ACA-DC 179 and Lactobacillus plantarun ACA-DC 269 produced bacteriocins solely against Streptococcus oralis. Thus, the percentage of strains that were found to produce bacteriocins against oral bacteria was ~1.3%. The rarity of bacteriocins active against oral LAB pathogens produced by food-related LAB was unexpected given their close phylogenetic relationship. Nevertheless, when tested in inhibition assays, the potency of the bacteriocin(s) of S. macedonicus ACA-DC 198 against the three oral streptococci was high. Fourier-transform infrared spectroscopy combined with principal component analysis revealed that exposure of the target cells to the antimicrobial compounds caused major alterations of key cellular constituents.  Our findings indicate that bacteriocins produced by food-related LAB against oral LAB  may be rare, but deserve further investigation since, when discovered, they can be  effective antimicrobials.
authors: Laboratory of Dairy Research, Department of Food Science and Technology,  Agricultural University of Athens, Iera Odos 75, Athens 11855, Greece. kpapadimitriou@aua.gr.
authors: Georgia
authors: G
authors: Zoumpopoulou
authors: Eudoxie
authors: E
authors: Pepelassi
authors: William
authors: W
authors: Papaioannou
authors: Marina
authors: M
authors: Georgalaki
authors: Petros A
authors: PA
authors: Maragkoudakis
authors: Petros A
authors: PA
authors: Tarantilis
authors: Moschos
authors: M
authors: Polissiou
authors: Effie
authors: E
authors: Tsakalidou
authors: Konstantinos
authors: K
authors: Papadimitriou