New antimicrobial peptide active against Gram-positive pathogens

• Background & objectives: Human and animal cystatins have been shown to inhibit the replication of certain viruses and bacteria, though it is not directly demonstrated that the effects are due to protease inhibitory capacity of the cystatins. We report antibacterial properties of a novel antimicrobial peptidyl derivative, (2S)-2-(N-alpha-benzyloxycarbonyl-arginyl-leucylamido)-1-(E)-cinnamoyla mido-3-methylbutane, structurally based upon the aminoterminal segment of the inhibitory centre of the human cysteine protease inhibitor, cystatin C. Methods: Clinical isolates of group A, B, C and G streptococci were collected. The antibacterial activity of Cystapep 1 derivative was tested by agar well diffusion method. Results: Cystapep 1, displayed antibacterial activity against several clinically important Gram-positive bacteria. It displayed minimal inhibitory and bactericidal concentrations of about 16 mug/ml for both Staphylococcus aureus and Streptococcus pyogenes. In radial agar diffusion assays, groups A, B, C and G streptococci as well as staphylococci were generally susceptible to the action of Cystapep 1, whereas pneumococci and enterococci were less susceptible. No activity against Gram-negative bacteria was observed. Interpretation & conclusion: Cystapep 1 also showed high activity against methicillin-resistant Staph. aureus (MRSA) and multi-antibiotic resistant coagulase negative staphylococci (CNS), suggesting its mechanism of action to be different from most currently used antibiotics.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Mikrobiologi inom det medicinska området (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Microbiology in the medical area (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Farmakologi och toxikologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Pharmacology and Toxicology (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Läkemedelskemi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Medicinal Chemistry (hsv//eng)

Keyword

Staphylococcus aureus

antimicrobial peptide

cystatin C

Streptococcus

pyogenes

Publication and Content Type

art (subject category)

ref (subject category)