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Effect of human defensins on lactobacilli and liposomes
Author(s) -
Hugo A.A.,
Tymczyszyn E.E.,
GómezZavaglia A.,
Pérez P.F.
Publication year - 2012
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 - 10.1111/j.1365-2672.2012.05433.x
Subject(s) - liposome , propidium iodide , lactobacillus , chemistry , microbiology and biotechnology , strain (injury) , biochemistry , beta defensin , biology , antimicrobial peptides , peptide , fermentation , apoptosis , anatomy , programmed cell death
Aims To study the effect of human β‐defensins ( HBD ‐1 and HBD ‐2) on lactobacilli membranes as well as on liposomes prepared from purified bacterial lipids. Methods and Results L actobacillus delbrueckii subsp. bulgaricus CIDCA 331 and L act. delbrueckii subsp. lactis CIDCA 133 were grown in M an, R ogosa, S harpe broth for 16 h at 37°C. After being washed, micro‐organisms were treated with 0·1–10 μg ml −1 of HBD ‐1 and HBD ‐2 (30 min, 37°C). Bacterial damage was determined by flow cytometry after propidium iodide staining. In parallel experiments, release of carboxyfluorescein from liposomes prepared from bacterial lipids was determined fluorometrically (excitation 485/20 nm, emission 528/20 nm) in the presence of HBD ‐1, HBD ‐2 or N isin. Exposure of lactobacilli to HBD ‐2 resulted in a significant membrane permeabilization being L act. delbrueckii subsp. bulgaricus CIDCA 331 the most susceptible strain. Liposomes prepared with lipids from strain CIDCA 133 were destabilized neither by HBD ‐1 nor by HBD ‐2, whereas liposomes derived from strain CIDCA 331 were susceptible to HBD ‐2 but not to HBD ‐1. Effect of defensins was strongly inhibited in the presence of NaCl , and the activity increased in water. Conclusions Results reported in the presented work indicate that lipid composition of bacterial membranes lead to a different interaction with cationic peptides such as defensins. Significance and Impact of the study The results represent an advance in the understanding of the differential effect of HBD s on micro‐organisms. Differences in susceptibility to anti‐microbial peptides could modify the fate of micro‐organisms after the interaction with host's cells.