Anti-microbial efficacy of L-glutaminase (EC 3.5.1.2) against multidrug-resistant Pseudomonas aeruginosa infection.

The aims of this study were isolation-purification and characterization of L-glutaminase from L. gasseri BRLHM clinical isolates and investigation of its efficiency as an antimicrobial agent against multidrug-resistant P. aeruginosa. The MICs of L-glutaminase and gentamicin reference were evaluated by the well-diffusion method. The biofilm on the IUD contraceptive was visualized using atomic force microscopy (AFM) image analyses. The purified L-glutaminase possessed significant antimicrobial activity against P. aeruginosa isolates (p < 0.05), and the antibiofilm formation activity of the purified L-glutaminase was stronger than the antibiofilm activity of the referral standard drug, gentamicin (P < 0.05), which were checked by the inhibition of the biofilm formation on the IUD contraceptive device. Investigations indicated that L-glutaminase may have a crucial role in future clinical applications.

L-asparaginase from human breast milk Lactobacillus reuteri induces apoptosis using therapeutic targets Caspase-8 and Caspase-9 in breast cancer cell line.

BACKGROUND: Breast cancer is the most fatal type of cancer in women worldwide. Many chemotherapeutics targeted breast cancer however, they have frightening side effects. One method of controlling cancer cell growth is targeting apoptosis. OBJECTIVE: This study aimed to induce apoptosis in breast cancer cells by purifying L-asparaginase from human breast milk Lactobacillus reuteri isolates via inhibition of Caspases 8 and 9. METHODS: The best L. reuteri isolates producing L-asparagine with the highest enzyme activity were identified from human breast milk and chosen for L-asparaginase purification. The MTT cell viability assay used for measure the toxicity of the enzyme. Breast cancer cell line was used to study the effect of the enzyme on the caspase 8 and caspase 9 gene expression. RESULTS: The MTT cell viability assay showed the inhibition rates ranged between 30% and 80%, of cell death, occurred when 3.125, 6.25, 12.5, 25, 50, and 100 µg/ml of the enzyme used and IC50 was 4.305 µg/ml. The breast cell lines were treated with the enzyme at a concentration of IC50 value. The Cas8 and Cas9 genes expression in L-asparagine treated breast cancer cell line at a concentration of IC50 value were upregulated (the fold of gene expression are 2.071 and 1.197 respectively). CONCLUSIONS: Breast milk L. reuteri L-asparaginase induces apoptosis via Cas8 and Cas9 upregulation in the breast cancer cell line. L. reuteri L-asparaginase treatment may be the hopeful approach for the management of breast cancer. Furthermore, the results may highlight the fact that the presence of L-asparaginase-producing L. reuteri isolates in human breast milk may aid in breast cancer improvement or even prevention.

Establishing novel roles of bifidocin LHA, antibacterial, antibiofilm and immunomodulator against Pseudomonas aeruginosa corneal infection model.

Bifidocin LHA, a novel bacteriocin, was extracted from bee honey B. adolescentis and purified. Bifidocin LHA was characterized as a protein in nature, without lipid or carbohydrate moieties, the molecular weight was 16,000 Da protein, heat-stable and active at a wide range of pH values, bactericidal effect, detergent, and solvents did not affect bifidocin activity and can be classified as type II bacteriocin. In vitro, the antibacterial activity of purified bifidocin LHA was significantly higher than crude bifidocin LHA (P < 0.05) against Pseudomonas aeruginosa (P. aeruginosa). The antibiofilm activity of bifidocin LHA was significantly higher than the antibiofilm activity of Amikacin (P < 0.05). In vivo, bifidocin LHA demonstrates a significant decreased in the number of P. aeruginosa in the eye, while complete clearance of P. aeruginosa comparing with the control (P < 0.05) when treating with Bifidobacterium adolescentis and bifidocin LHA together. Bifidobacterium adolescentis and bifidocin LHA treatment together induced substantial elevation of IL10 and IL-12 concentrations (P < 0.01) that helped to prevent damage caused by the inflammatory response. Succeeded to eradicate P. aeruginosa infection improved by histological patterns of the eye tissues. This study indicated Bifidobacterium adolescentis and bifidocin LHA consider as crucial strategies for the practical treatment of eye infection in the future.

Evidence of anti- K. pneumoniae biofilm activity of novel Entrococcus faecalis enterocin GLHM.

Many enterocins were produced from the lactic acid bacteria, Enterococcus faecalis, they belonged to different types of bacteriocins and have different characteristics. The present study aimed to search for another enterocin and test its ability to inhibit Klebsiella pneumoniae biofilm as compared with the most effective antibacterial agent. E. faecalis isolates were isolated from stools of breastfeeding babies. Klebsiella pneumoniae isolates were from urinary tract infections and urinary catheters. K. pneumoniae isolates showed biofilm formation potential and multidrug resistance phenotype but amikacin was the most effective one. Enterocin production by gene harboring E. faecalis was screened, then enterocin was purified, characterized, and antibacterial activity and MIC of enterocin were determined. Produced enterocin has characteristics differ from other discovered enterocins. Furthermore, the crude and purified enterocin of E. faecalis possess significant antibacterial activity against K. pneumoniae isolates as compare with control (p < 0.05), and antibiofilm activity of enterocin was stronger than the antibiofilm activity of amikacin (P < 0.05), as well as the enterocin, was potent than the amikacin in preventing the formation of biofilm on the catheter. In conclusion, a novel enterocin was produced from Enterococcus faecalis (enterocin GLHM) is proteinous bacteriocin, relatively heat-stable and have full activity at neutral pH and was belong to type II bacteriocin. Enterocin GLHM have anti-K. pneumoniae and anti-K. pneumoniae biofilm significantly better than amikacin.

Antibacterial immunomodulatory and antibiofilm triple effect of Salivaricin LHM against Pseudomonas aeruginosa urinary tract infection model.

The study sought to purify and characterize a novel bacteriocin from oral L. salivarius and studying the effect of L. salivarius and its bacteriocin against multidrug-resistant (MDR) P. aeruginosa in vivo and in vitro. Saliva Lactobacillus salivarius bacteriocin was prepared and purified. The molecular weight of purified L. salivarius bacteriocin was 13,500Da protein. The antibacterial activity of purified salivaricin LHM was higher than crude (P<0.05) and was active at a wide range of pH values, thermostable and has no lipid or carbohydrate moiety. The antibiofilm activity of salivaricin LHM was observed. In vivo, Lactobacillus salivarius and salivaricin LHM significantly decrease the effect of bacteria in the kidney and bladder, while there is an improvement of P. aeruginosa infection in ureter salivaricin LHM-treated groups (P<0.05). Analysis of serum IL-10 and IL-4 levels revealed salivaricin LHM has prophylaxis effect. In conclusion, salivaricin LHM is protein in nature, without lipid or carbohydrate moieties, heat-stable and active at a wide range of pH values and can be classified as type II bacteriocin. Lactobacillus salivarius and salivaricin LHM has anti-pseudomonas activity, immunomodulatory by increasing pro-inflammatory cytokines and antibiofilm against P. aeruginosa urinary tract infection model in vivo and in vitro.

Treatment strategy by lactoperoxidase and lactoferrin combination: Immunomodulatory and antibacterial activity against multidrug-resistant Acinetobacter baumannii.

Lactoperoxidase (Lpo) and Lactoferrin (Lf) were extracted from camel colostrum milk and purified. The antibacterial activity of the two purified proteins was estimated against 14 isolates of multidrug resistance Acinetobacter baumannii. A combination of Lpo and Lf exhibited bactericidal action against A. baumannii in vitro. A mouse model of acute A. baumannii pneumonia was improved. The injection of combined Lpo and Lf after infection leads to significant clearance of A. baumannii rates in lung as well as blood culture P < 0.05 in comparing with control. Furthermore, the results showed a significant P < 0.05 reduction in the Bronchoalveolar lavage albumin concentration, lung injury and lactate dehydrogenase activity in comparing with control. In addition, the combination of Lpo and Lf treatment induced substantial elevation of IL-4 and IL10 concentrations p < 0.0 5 that helped to prevent damage caused by the inflammatory response. We concluded that combination of Lpo and Lf had a major inhibition effect against A. baumannii in comparing with imipenem as well as their immunomodulatory activity against resistant A. baumannii was increased by a synergistic effect of them as a crude combination. This study indicated two combined proteins consider as crucial strategy for practical treatment of pneumonia in the future.

Two novel roles of buffalo milk lactoperoxidase, antibiofilm agent and immunomodulator against multidrug resistant Salmonella enterica serovar Typhi and Listeria monocytogenes.

The increasing occurrence of multidrug resistant bacteria causing bacteremia infection, constitutes a major health problem, difficult-to-treat bacteremia due to its ability to form biofilm. Buffalo milk lactoperoxidase (BMLpo) is effective and safe to use as bacteriostatic agent. The MIC of BMLpo and amikacin were used to evaluate the antibiofilm activity against resistant L. monocytogenes and S. typhi. Prophylactic effects of BMLpo against L. monocytogenes and S. typhi bacteremia in vivo have been tested and ELISA test used to evaluate serum cytokines. Significant antibiofilm activity of BMLpo observed against the highest biofilm producer isolates. Our results showed that the prophylactic effect of BMLpo in BALB/c mice bacteremic model. A significant clearance of L. monocytogenes and S. typhi, investigated in blood and different organs tissues in BMLpo-treated infected groups when compared to the non-treated groups. Further, analysis of serum cytokines levels revealed that BMLpo prophylaxis modulates their release in different way when it compared to the control. This study showed, BMLpo effects as an alternative antibiofilm agent to compact gram negative pathogens, and protects the host against bacteremia infection. Moreover, the BMLpo role as an immunomodulatory. These investigations indicated the BMLpo crucial role in the practical clinical applications.