CMCase produced by a novel Bacillus subtilis strain Fatma/1 degraded bacterial biofilms of some nosocomial pathogens in vitro

Nosocomial bacteria's ability to produce biofilms helps them survive in a variety of environments, such as hospitals, wounds, and medical devices. Cellulases can destroy cellulose, one of the major structural components of biofilms, representing an important part of the bacterial biofilm matrix. Bacterial strains were obtained from diabetic foot hospital patients and tested for their ability to produce biofilms in vitro. Isolates were identified as Staphylococcus aureus, Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Escherichia coli using a standard set of biochemical assays commonly used at hospital laboratory. Biofilm degradation by CMCase enzyme was evaluated through in vitro tube method, microscopic observation and crystal violet assay. CMCase had a high effectiveness in eliminating P. aeruginosa biofilms and a modest capacity to remove biofilms of other strains used in this study. Light microscopy demonstrated fully disseminated cells of P. aeruginosa biofilm exposed to CMCase. Besides, Using CMCase dramatically eliminated 87.5% of the carbohydrate content of its biofilm matrix.