Evaluating the Safety Properties of Probiotic Lactobacillus spp. from Fermented Food in Egypt

Assessing the safety profile of a Lactobacillus spp. is fundamental to deciding whether it can be utilized as a probiotic. Subsequently, the study was conducted to estimate the safety properties of 156 Lactobacillus spp. that were isolated from fermented food. Concerning the safety characteristics, it was observed that all 156 isolates could not secrete gelatinaze and hemolysin enzymes, but only two isolates performed complete blood lysis and were isolated from pickles. Data also showed that tetK only appeared in all three examined strains: L. plantarum 47, MK616469, L. pentosus 68, MK616468, and L. paracasei 77,  MT383743. Results revealed that all nine tested isolates (100%) were resistant to 3rd generation cephalosporin (sulbactam/cefoperazone  SUL/CEF105), aminoglycosides (kanamycin K30), Quinolones & Fluoroquinolone (ofloxacin OFX10 and norfloxacin NOR or NX10), glycopeptides (vancomycin VA30), and penicillins  (piperacillin PRL 75 and 100). On the other hand,  the strains (100%)  were sensitive to penicillin G (P10), cephalosporins (cefradin CE30), 3rd generation cephalosporin (ceftriaxone CRO30), polymyxin (colistin CL30). Meanwhile, the probiotic trial results exhibited the reduction of biofilm formation by some foodborne pathogens by cell-free supernatant (CFS) of the lactobacilli strains. The outcome displayed that the inhibition zone by CFS disappeared at pH 6.5, while at 100°C, it did not. Data also displayed that L. plantarum 47, MK616469, showed better tolerance till 6% NaCL, while at 65 °C for 30 min., the survival rate was relatively low. The presence of antibiotic resistance determinants among lactobacilli from fermented foods could be concluded.