Beneficial and Safety Properties of a Bacteriocinogenic and Putative Probiotic subsp. 2a Strain.

This work aimed to evaluate some of the probiotic features and safety of the bacteriocin-producing subsp. 2a. The effect of selected commercial drugs from different generic groups and antibiotics on the growth of subsp. 2a was also determined. The presence of virulence factors was determined based on PCR with total DNA from subsp. 2a. Good growth of subsp. 2a was recorded in MRS broth supplemented with 0.2% or 0.4% oxbile or in MRS broth adjusted to a pH from 5.0-9.0. Auto-aggregation of subsp. 2a was 62.59%. Different levels of co-aggregation were recorded between subsp. 2a and ATCC19443, ATCC15521 and ScottA. Growth of subsp. 2a was not inhibited by commercial drugs from different generic groups. The inhibitory effect on the growth of subsp. 2a was recorded only in the presence of Arotin [selective serotonin reuptake inhibitor antidepressant] Minimal Inhibition Concentration (MIC) 1.0 mg/mL, Atlansil [Antiarrhythmic] MIC 0.625 mg/mL, Diclofenac potassium [non-steroidal anti-inflammatory drug (NSAID)] MIC 2.5 mg/mL and Spidufen [NSAID] MIC 15.0 mg/mL. Only two antibiotics tested in this study, Amoxil and Urotrobel, inhibited the growth of subsp. 2a with a MIC of <0.5 mg/mL and 5.0 mg/mL, respectively. However, subsp. 2a generated positive PCR results on the DNA level for A (vancomycin resistance), (hyaluronidase), (enterococcal surface protein), (adhesion of collagen) and A (cytolisin) and a high virulence profile when examined for the presence of virulence factors. It is important to underline that cytolysis has been described as a virulence and antibacterial factor.