Functional characterization of two defensin isoforms of the hard tick Ixodes ricinus

Parasites & Vectors

Table 1 Minimal inhibition concentrations (MICs) and minimal microbicidal concentrations (MMCs) of def1 and def2 isoforms.

Bacterial, yeast and viral species	MIC [μM]		MMC [μM]
	def1	def2	def1	def2
Bacillus subtilis (G+)	1.5	0.75	2	1
Micrococcus luteus (G+)	0.75	0.37	10	5
Staphylococcus luteus (G+)	50	25	50	25
Escherichia coli (G-)	no effect^a	no effect^a
Pseudomonas aeruginosa (G-)	no effect^b	no effect^b
Candida albicans (yeast)	no effect^b	no effect^b
TBEV (Flaviviridae)	no effect^b	no effect^b	no effect^b	no effect^b
WNV (Flaviviridae)	no effect^b	no effect^b	no effect^b	no effect^b

Determination of MICs and MMCs for each peptide and bacteria was performed at least 3-times in doublets. Def2 peptide was significantly more efficient in the inhibition of growing G-positive bacteria (G+) in cultures and in microbicidal experiments. Gram negative bacteria (G-), as well as yeast, WNV and two strains of TBEV (Hypr and Neudoerfl), were not influenced by these peptides (^a no effect up to 50 μM; ^b no effect up to 100 μM).

ISSN: 1756-3305