Study of the Synergistic effect between purified and produced bacteriocin from bacteria Lactococcus lactis ssp. lactis Against Species of Pathogenic bacteria

Abstract

This study confirmed the diagnosis of eight isolates of Lactococcus lactis ssp. lactis based on cultural ,microscopical, biochemical tests and as well as Confirm the diagnosis with VITEK 2 system,While six isolates were collected from the pathogenic bacteria, including both bacteria Saphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aerouginosa ,Escherichia coli , Enterobacter clocae and Serratia marcescens these isolates were identified by cultural ,microscopical, biochemical tests as well as VITEK 2 system. Antibiotic susceptibility of isolates was tested against (9) of antibiotics. Results showed that all isolated were resistant to ceftazidime and all of them were sensitive to ciprofloxacin, Imipenem, Meropenem and Amikacin, While variable in resistance against other antibiotics. Screening from isolates L. Lactis spp. lactis was done by the well diffusion method , The results showed that L. lactis ssp. lactis (Lc4) was the most efficient in producing bacteriocin as well observed inhibitory activity increased by increasing its concentration and that the concentration of the filtrate twice was better in obtaining higher inhibition diameters compared to the one- fold concentration The concentrated bacteriocin was purified using the gel filtration column and Sephacryl S-200. The results showed the high inhibitory activity of the bactericin purified compared to the one-fold concentration and two-fold before purification. Synergistic effect between purified bacteriocin and the product of isolation L. lactis ssp. lactis (Lc4) with some the antibiotics as anantibiotic Cefotaxime, Tetracycline, Aztreoname, Vancomycin and Ceftazidime was observed, as the effectiveness of these antibiotics increased with the presence of purified bacteriocin.