Antagonistic activity of Bacillus amyloliquefaciens subsp. amyloliquefaciens against multidrug resistant Serratia rubidaea
Serratia rubidaea is an opportunistic Gram-negative pathogen that has developed antimicrobial resistance to a variety of commercial antibiotics. The spread of this multidrug-resistant pattern predicts that it will get harder and harder to treat S. rubidaea infections in the future. For this perception, antimicrobial proteins might represent a safe, effective, and biodegradable alternative because their site of action is on cyclic peptides. In this study, one candidate Bacillus amyloliquefaciens subsp. amyloliquefaciens was isolated from the soil of Sundarban mangrove forest, and its identification was confirmed both using the PCR (Polymerase chain reaction) method and the BIOLOG™ microbial identification system. The antibacterial protein, which has a molecular mass of about 50 kDa, was isolated from B. amyloliquefaciens subsp. amyloliquefaciens. Sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was used to confirm the extracted protein's purity. This potential protein was discovered to develop and exhibit antagonistic activity throughout a broad temperature, pH, and salinity range. At doses ranging from 300 to 400 μg/ml, this protein has antagonistic activity against multidrug resistant S. rubidaea and a wide range of other resistant pathogenic bacteria such as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and so on. The research provides new insights to develop bio-control agents that can be applied for prevent, treat, and control infectious diseases caused by multidrug resistant S. rubidaea, as well as other pathogenic bacteria.