Efficacy of Sakacin on Selected Food Pathogenic Microorganisms Isolated from Fermented Milk Products

The efficacy of sakacin on selected food pathogenic microorganisms isolated from fermented milk products was investigated. The L. sake was isolated using the pour plate technique and was characterized based on it colony, cell morphology and some biochemical tests. This isolate was identified using standard scheme. The L. sake FCF 33 was propagated in De Man Rogosa Sharpe (MRS) broth for bacteriocin (sakacin) production. The sakacin had inhibitory effects on all test microorganisms (ranging from +5mm to +6mm) except Shigella dysenteriae N11, Salmonella typhimurium N8, Klebsiella ozaenae W24 and Proteus mirabilis N16a). Bacteriocins are antimicrobial substances of lactic acid bacteria (LAB) have gained tremendous attention as potential bio preservatives in the food and dairy industries. The LAB can serve as probiotics, which are products aimed at delivering living, potentially beneficial bacterial cells to the gut ecosystem of humans and other animals.

Selection of polyvalent bacteriophages infecting Salmonella enterica serovar Choleraesuis

Background: Ideally, bacteriophages of pathogenic bacterial hosts should be polyvalent to be able to replicate in an alternative nonpathogenic bacterium. Thus, accidental infection by the original host can be avoided when bacteriophage lysates are used in biocontrol protocols. Results: From 15 wastewater samples, collected at different sites in the V Region in Chile, we selected three bacteriophages (FC, FP, and FQ) capable of productively infecting Salmonella enterica serovar Choleraesuis. By transmission electron microscopy (TEM) observation, the bacteriophages were found to belong to the order Caudoviridae. Molecular analyses indicated that FC, FP, and FQ contained double-stranded DNA genomes, of sizes similar to bacteriophage P22, and distinct recognition sites for the restriction endonucleases HaeIII and HindIII. Assays of host range revealed that the bacteriophages were polyvalent and thus capable of infecting different strains of Escherichia coli and other serovars of Salmonella . Conclusion: We have isolated newbacteriophages of the serovar Choleraesuiswith various potential applications in relation to this pathogenic bacterium.