INVESTIGADORES
TYMCZYSZYN Emma Elizabeth
artículos
Título:
Effect of human defensins on lactobacilli and liposomes
Autor/es:
HUGO AYELEN; E.E. TYMCZYSZYN; GÓMEZ ZAVAGLIA A.; PÉREZ, P. F.
Revista:
JOURNAL OF APPLIED MICROBIOLOGY
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2012 vol. 113 p. 1491 - 1497
ISSN:
1364-5072
Resumen:
Aims: To study the effect of human b-defensins (HBD-1 and HBD-2) on lactobacilli membranes
as well as on liposomes prepared from purified bacterial lipids.
Methods and Results: Lactobacillus
delbrueckii subsp. bulgaricus CIDCA 331 and Lact. delbrueckii subsp. lactis CIDCA 133 were grown in Man, Rogosa, Sharpe
broth for 16 h at 37°C. After being
washed, micro-organisms were treated with 0_110 lg 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 Nisin. Exposure of lactobacilli
to HBD-2 resulted in a significant membrane permeabilization being Lact. 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 HBDs on micro-organisms. Differences in
susceptibility to anti-microbial peptides could modify the fate of
micro-organisms after the interaction with hosts cells.