细菌素Enterocin-162对临床常见多重耐药菌的抗菌活性研究OA

Objective To investigate the antimicrobial activity of the bacteriocin(Enterocin-162)secreted by Enterococcus faecalis SHAMU-EF162 strain against clinically common multidrug-resistant organisms(MDROs).Methods The growth kinetics curve of the SHAMU-EF162 strain was monitored through the microcultivation assay.The antagonistic activity of the SHAMU-EF162 strain against Staphylococcus aureus(S.aureus)was eva-luated using Oxford cup method.Enterocin-162 crude extract was prepared by macroporous resin adsorption,gradi-ent ethanol elution,rotary evaporation drying,and reconstitution.The protein content in the crude extract was detected by Coomassie brilliant blue staining.The thermal,pH,and protease stability of Enterocin-162,as well as its antimicrobial activity against methicillin-resistant S.aureus(MRSA),multidrug-resistant Pseudomonas aerugi-nosa(MDR-PA),extended-spectrum β-lactamases-producing Escherichia coli(ESBLs-EC),and carbapenem-resistant Klebsiella pneumoniae(CRKP)clinical isolates were assessed by Oxford cup method.Results Enterocin-162 can withstand exposure to 100℃heat,pH 2.0,pH 12.0,chymotrypsin,bromelain,trypsin,proteinase K,and the mixture of four proteases.The antimicrobial activity of 30 μL crude extract of Enterocin-162(containing approximately 14.8 μg of protein or polypeptide)against clinical isolates of MRSA,MDR-PA,ESBLs-EC,and CRKP was superior to those of antimicrobial disks of vancomycin,polymyxin,epicycline,amikacin,and levofloxa-cin.Conclusion Enterocin-162 is likely to be a stable,efficient,and broad-spectrum new class I bacteriocin,with the potential to be developed into a novel antimicrobial agent,and providing a new option for the treatment of common MDRO infection in clinical practice.