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Antimicrobial activity of a 14‐residue peptide against Escherichia coli O157:H7
Author(s) -
Appendini P.,
Hotchkiss J. H.
Publication year - 1999
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1046/j.1365-2672.1999.00921.x
Subject(s) - escherichia coli , peptide , chemistry , lysis , residue (chemistry) , antimicrobial , enterobacteriaceae , minimum inhibitory concentration , biochemistry , intracellular , antimicrobial peptides , chromatography , in vitro , organic chemistry , gene
An amphiphilic, cationic peptide composed of eight leucines and six lysines was synthesized by solid phase peptide synthesis (SPPS). The synthetic peptide was bactericidal within 10 min at concentrations as low as 3 μg ml −1 against mid‐exponential Escherichia coli O157:H7 suspended in buffer. Concentrations of 25 μg ml −1 caused up to 7 log 10 cfu ml −1 reductions. When tested against E. coli O157:H7 grown in TSB, the peptide was bactericidal and bacteriostatic at concentrations of 50 and 25 μg ml −1 , respectively. An inhibitory effect was also observed against stationary phase cells. The synthetic peptide caused the release of u.v.‐absorbing materials from the E. coli O157:H7 as well as an increase in its O.D. 600 nm . Intracellular K + and ATP depletion were also observed. These results suggest that the peptide increased the cell membrane permeability but it did not lyse the cells.