Antimicrobial Effects of Lactobacillus Plantarum and Lactobacillus Paracasei Isolated from Honey against Staphylococcus Aureus

BACKGROUND AND OBJECTIVE: Lactobacilli are gram positive, catalase-negative, and found in a variety of fermented foods such as honey, as well as human normal flora. The aim of this study was to identify lactobacillus Plantarum and lactobacillus Paracasei in Iranian honey samples and to investigate the probiotic and antimicrobial properties of them against Staphylococcus aureus. METHODS: This cross-sectional study investigated 88 honey samples from different areas in Iran at 6 months, from May to September, 2016. Samples were cultured in MRS broth and after were cultured on MRS agar. Sequencing of 16S rDNA gene was used to detect lactobacillus isolates. Then probiotic capacity (acid and bile resistance) of isolates was measured. Antimicrobial activity of lactobacillus isolates was investigated by diffusion method from wells and antibiotic resistance by disc diffusion method. FINDINGS: From 88 honey samples, 39 Lactobacillus isolates were isolated, four L. plantarum and two L. paracasei were identified by molecular technique. Every six isolates tolerated acidity but were sensitive to bile salt. Five isolates inhibited the growth of S. aureus. The most antibiotic resistance of Lactobacillus strains was seen to vancomycin(100%), nalidixic acid(100%) and streptomycin(100%). CONCLUSION: Iranian honey samples can be a source for different Lactobacillus species as L. plantarum and L. Paracasei which some of these species could have wonderful inhibitory effects against pathogen bacteria like S. aureus

Antimikrobielle Eigenschaften von aus Joghurt und Milch isolierten Milchsäurebakterien gegen Shigella-Stämme

Background: Lactic acid bacteria (LAB) are normal flora of the mouth, intestines and the female genital tract. They are also frequently found in meat, vegetables, and dairy products. Most of probiotic bacteria belong to the LAB group. Some probiotic LAB are useful in prevention and treatment of diarrheal diseases. The aim of this study was to investigate the antimicrobial properties of LAB isolated from traditional yogurt and milk against Shigella strains.Materials and methods: Forty LAB strains were isolated from traditional yogurt and milk. The antimicrobial activity of LAB against Shigella strains (eight S. flexneri , four S. sonnei ) was examined using the agar-well diffusion assay. LAB strains with antimicrobial effect against all Shigella strains were identified by 16S rRNA gene sequencing.Results: Six LAB strains inhibited the growth of all 12 Shigella strains. Lb. paracasei Y1-3, Lb. paracasei Y8-1 and Lb. fermentum Y2-2 were isolated from yogurt. Lb. paracasei M18-1, Lb. parelimentarius M4-3 and Lb. plantarum M19-1 were isolated from milk.Conclusion: This study showed that Lactobacillus strains with good inhibitory activity against S. flexneri and S. sonnei could be isolated from traditional yogurt and milk.Hintergrund: Milchsäurebakterien (LAB) gehören zur normalen Flora der Mundhöhle, des Darmtrakts und des weiblichen Genitaltrakts. Sie sind häufig in Fleisch, Gemüse und Milchprodukten nachweisbar. Die meisten probiotischen Bakterien gehören zu den LAB. Einige probiotische LAB sind zur Prävention und Behandlung infektiöser Diarrhoen geeignet. Zielsetzung der Studie war die Untersuchung antimikrobieller Eigenschaften von aus traditionellem Joghurt und Milch isolierten LAB gegen Shigella-Stämme.Materialien und Methode: 40 LAB-Stämme wurden aus traditionellem Joghurt und Milch isoliert. Die antimikrobielle Wirkung der LAB gegen die Shigella-Stämme (acht S. flexneri , vier S. sonnei ) wurde im Agardiffusionstest ermittelt. Antimikrobiell wirksame LAB Stämme wurden mittels 16S rRNA Gensequenzing identifiziert.Ergebnisse: Sechs LAB Stämme hemmten die Vermehrung der geprüften 12 Shigella Stämme. Lactobacillus (Lb.) paracasei Y1-3, Lb. paracasei Y8-1 und Lb. fermentum Y2-2 wurden aus Joghurt, Lb. paracasei M18-1, Lb. parelimentarius M4-3 und Lb. plantarum M19-1 aus Milch isoliert.Schlussfolgerung: Aus Joghurt und Milch konnten Lactobacillus-Stämme mit guter Hemmwirkung gegen S. flexneri und S. sonnei isoliert werden