The effect of supernatant of Lactobacillus plantarum against Salmonella Typhi biofilm formation

Lactic acid bacteria are a safe and healthy alternative to antibiotics that have been attracted in many recent studies Methods: Salmonella. Typhi was diagnosed with the VETIC system, biofilm formation was detected by Congo red method and the microtiterplate method. L. plantarum capsule from (Swanson) company ATCC 53103 was used to obtain L.plantarum life cells. Results: The diagnostic results showed that 11 bacterial isolates from feces with a percentage 1.27% and 37(61%) bacterial isolates from blood represented S. Typhi bacteria with a total of 48 isolates and various levels of biofilm productivity, which were categorized as having strong production by 87%, average production by 6.25%, and weak production of membrane bioavailability by 2.1%. The inhibiting effect of L. Plantarum potential as a probiotic was investigated using the bacterial Cell Free Supernatant (CFS) of the same bacteria, which gave the highest inhibition area for S. Typhi and for three bacterial isolates, it was (16,18,17) mm compared to the inhibition of suspension which gave the lowest inhibition areas (16,15,15)mm. The results also showed that the CFS produced by L. plantarum had the ability to inhibit biofilm formation by 20 isolates of S. T. bacteria, in comparison with the positive control reading. The highest inhibition rate was 84.5% towards isolate S.T.4 and the lowest 70.8% inhibition of the S.t.35 isolate trend. Therefore, L. plantarum suspension can be presented as a viable healthy and therapeutic probiotic agent.