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The phage K lytic enzyme LysK and lysostaphin act synergistically to kill MRSA

Stephen C Becker1, Juli Foster-Frey, David M Donovan

  • 1Animal Biosciences and Biotechnology Laboratory, Animal and Natural Resources Institute, Agricultural Research Service-U.S. Department of Agriculture, Beltsville Agricultural Research Center, 10300 Baltimore Avenue, Beltsville, MD 20705, USA.

FEMS Microbiology Letters
|August 30, 2008
PubMed

Insights

LysK and lysostaphin are potent antimicrobial agents effective against methicillin-resistant Staphylococcus aureus (MRSA). Optimal conditions for LysK were identified, and the study found these agents work synergistically to combat MRSA infections.

Area of Science:

  • Microbiology
  • Biochemistry
  • Antimicrobial Research

Background:

  • Staphylococcus aureus, particularly methicillin-resistant S. aureus (MRSA), poses a significant public health threat.
  • Bacteriophage endolysins like LysK and bacteriocins like lysostaphin are promising alternatives to conventional antibiotics.
  • Previous research indicated that both LysK and lysostaphin can lyse MRSA cells.

Purpose of the Study:

  • To determine the optimal reaction conditions for recombinant His-tagged LysK protein activity.
  • To establish the minimum inhibitory concentration (MIC) of C-His-LysK.
  • To investigate the potential synergistic antimicrobial activity between LysK and lysostaphin against MRSA.

Main Methods:

  • Recombinant His-tagged LysK protein was purified and its enzymatic activity was assessed under varying pH and NaCl concentrations.
  • The minimum inhibitory concentration (MIC) of C-His-LysK was determined using standard microbiological assays.
  • A checkerboard assay was employed to evaluate the synergistic antimicrobial effects of LysK and lysostaphin in combination.

Main Results:

  • Optimal activity for recombinant His-tagged LysK was observed within a pH range of 6-10 and a NaCl concentration of 0.3-0.5 M.
  • The MIC of C-His-LysK was determined to be 32.85 ± 4.87 µg/mL.
  • The checkerboard assay demonstrated a synergistic antimicrobial effect when LysK and lysostaphin were used in combination against MRSA.

Conclusions:

  • LysK exhibits optimal enzymatic activity under specific biochemical conditions (pH 6-10, 0.3-0.5 M NaCl).
  • LysK and lysostaphin exhibit significant antimicrobial synergy, offering a potential strategy for enhanced MRSA treatment.
  • The findings support the development of LysK and lysostaphin as a dual-action therapeutic approach against MRSA infections.

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