Anti-Salmonella Polyclonal antibody

Salmonella biofilms are responsible for contamination in food processing environments as well as serious foodborne diseases. In this study, bacteriocins purified from Pediococcus acidilactici K10 (bacteriocin K10) and HW01 (bacteriocin HW01) strains were investigated for their potential to inhibit Salmonella Typhimurium biofilm. Both bacteriocins significantly inhibited the biofilm formation of S. Typhimurium by crystal violet staining method (P < 0.05). Fluorescence and scanning electron microscopy analyses confirmed that the S. Typhimurium biofilm was reduced in the presence of bacteriocins. After the biofilm formation of S. Typhimurium for 1-24 h, both bacteriocins K10 and HW01 exhibited similar patterns of decreased viability of S. Typhimurium biofilm cells up to 24 h (P < 0.05). The growth of S. Typhimurium planktonic cells was also significantly inhibited by treatment with bacteriocin K10 at 24 h and by treatment with bacteriocin HW01 at 12 and 24 h (P < 0.05). Furthermore, S. Typhimurium biofilm on the surfaces of stainless steel and chicken meat was effectively reduced by the treatment with both bacteriocins K10 and HW01. These results suggest that the bacteriocins of P. acidilactici could be effective anti-biofilm agents to control S. Typhimurium contamination in food matrices and food processing facilities.

An endophytic strain of Streptomyces antimycoticus L-1 was isolated from healthy medicinal plant leaves of Mentha longifolia L. and used for the green synthesis of silver nanoparticles (Ag-NPs), through the use of secreted enzymes and proteins. UV-vis spectroscopy, Fourier-transform infrared (FT-IR), transmission electron microscopy (TEM), X-ray diffraction (XRD), and dynamic light scattering (DLS) analyses of the Ag-NPs were carried out. The XRD, TEM, and FT-IR analysis results demonstrated the successful biosynthesis of crystalline, spherical Ag-NPs with a particle size of 13-40 nm. Further, the stability of the Ag-NPs was assessed by detecting the surface Plasmon resonance (SPR) at 415 nm for one month or by measuring the NPs surface charge (-19.2 mV) by zeta potential analysis (zeta). The green-synthesized Ag-NPs exhibited broad-spectrum antibacterial activity at different concentrations (6.25-100 ppm) against the pathogens Staphylococcus aureus, Bacillus subtilis Pseudomonas aeruginosa, Escherichia coli, and Salmonella typhimurium with a clear inhibition zone ranging from (9.5 +/- 0.4) nm to (21.7 +/- 1.0) mm. Furthermore, the green-synthesized Ag-NPs displayed high efficacy against the Caco-2 cancerous cell line (the half maximal inhibitory concentration (IC50) = 5.7 +/- 0.2 ppm). With respect to antibacterial and in-vitro cytotoxicity analyses, the Ag-NPs concentration of 100 ppm was selected as a safe dose for loading onto cotton fabrics. The scanning electron microscopy connected with energy-dispersive X-ray spectroscopy (SEM-EDX) for the nano-finished fabrics showed the distribution of Ag-NPs as 2% of the total fabric elements. Moreover, the nano-finished fabrics exhibited more activity against pathogenic Gram-positive and Gram-negative bacteria, even after 10 washing cycles, indicating the stability of the treated fabrics.