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Inhibitory activity of Streptococcus thermophilus unconcentrated and concentrated filtrate was studied against some pathogenic bacteria included: Pseudomonas aeruginosa, Klebsiella spp., Staphylococcus aureu, Escherichia coli. Inhibitory activity of protein that extracted from S. thermophilus concentrated filtrate was studied after precipitate by ammonium sulphate and inhibitory activity of lipophilic fraction that extracted from concentrated filtrate with chloroform-methanol (1:1 vol/ vol) was studied against pathogenic bacteria. Also inhibitory activity of biosurfactant produced by S. thermophilus was studied against growth and biofilm formation for pathogenic bacteria. The results showed that unconcentrated and concentrated filtrate had inhibitory activity against all pathogenic bacteria. Also protein and lipophilic fraction had inhibitory effect against pathogenic bacteria, while the biosurfactant show inhibitory activity against growth of all pathogenic bacteria but show inhibitory effect on biofilm formation only for pathogenic bacteria S. aureus and E. coli.

This experimental in vivo purpose of this study was to look into the immunomodulatory effects of purified staphylokinase produced by local clinical Staphylococcus aureus isolates compared with streptokinase which is used as a thrombolytic agent. All mice (40) injected intramuscularly (i.m.) with different concentrations of the purified lyophilized staphylokinase and streptokinase for 12 days, and immunized with 10% SRBCs (i.p) on day 4 and 8 of the schedule, and Staphylococcus aureus suspension and normal saline for positive and negative control groups. Focus on the estimation of Arthus and delayed-type hypersensitivity with the absolute neutrophil count, measurement of antibody titter by Hemagglutination, and detecting serum concentration of cytokines (IL4 -IL10 -IL 17) and TLR-2 by using sandwich ELISA. The statistical analysis found a significant difference (P ≤ 0.01) between staphylokinase and streptokinase treated groups and control groups (positive and negative). The data showed an increase in cytokine levels in treated groups compared with control groups. Observed in A2 (4µg staphylokinase) and B2 (4µg streptokinase)groups, also significant elevation (P ≤ 0.01) of IL-10 level in all groups as compared to positive and negative control groups but the highest value was observed in A3 (8µg) and B3 (8µg) group. In conclusion, the staphylokinase is better than streptokinase because of the increasing level of IL-10 and less appearance of hypersensitivity, so decline in IL-4 and its small size, in addition, to act as an immunomodulator that indicates the possibility to use in the treatment of thrombosis.

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This study was conducted to isolate and identify killer yeast Hanseniaspora uvarum from dates vinegar and measurement the ability of this yeast to produce killer toxin. The antimicrobial activity of the concentrated supernatant containing partially purified concentrated killer toxin was also detected against several pathogenic bacteria and yeast species, which includes two types of yeast Rhodotorula mucilaginosa and Candida tropicalis and four human pathogenic bacteria Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeurginosa. In addition, the antagonistic activity of examined yeast have been studied toward four types of fungi, where two are pathogenic for human Trichophyton mentagrophytes and Trichophyton rubrum and two are plant pathogens Fusarium solani and Sclerotinia sclerotiorum. The results of killer toxin production experiments revealed the ability of yeast to produce killer toxin with molecular weight at 18 kDa by 12 % SDS electrophoresis. The optimal conditions for killer toxin production were studied, and their antimicrobial activity was determined. The results revealed that killer toxin production was increased at 4 % NaCl, the highest inhibtion zone was 20 mm for S. aureus, while the lowest inhibition zone was 7 mm for E. coli. Killer activity was increased at pH 4 and the best inhibtion zone obtained was about 16 mm for K. pneumoniae, while 8 mm for E. coli and C. tropicalis. The temperature was also affect the production of killer toxin, where 25 °C is the best temperature for toxin production of examined yeast, The best killer activity was 21 mm for C. tropicalis. The antagonistic activity of killer yeast H. uvarum toward pathogenic fungal growth was determined and showed killer activity about 61.11, 44.44, 33.33 and 24.44 % against T. mentagrophytes, T. rubrum, F. solani and S. sclerotiorum in comparison to the control.