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.

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.