Antimicrobial properties of the equine alpha-defensin DEFA1 against bacterial horse pathogens.
Defensins are small effector molecules of the innate immune system, synthesised by various organisms including plants and animals. The peptides act as endogenous antibiotics with an antimicrobial activity against a broad spectrum of microbes including bacteria, fungi and viruses. alpha-Defensins are a subgroup of the defensin family, their synthesis is limited to some tissues and furthermore to some mammalian species including the horse. Equine DEFA1 is an enteric alpha-defensin exclusively produced in Paneth cells. The peptide showed an activity against a broad spectrum of microbes, but typical pathogens of the horse were not included in the previous antimicrobial studies. Here, we report the antibacterial properties of DEFA1 against clinical isolates of typical horse pathogens including Rhodococcus equi, various streptococci strains, Salmonella choleraesuis, and Pasteurella multocida. The recombinantly expressed DEFA1 peptide exerted potent activity against these pathogenic bacteria. The highest susceptibility showed R. equi. Three genetically different strains of R. equi were killed at low micromolar concentrations, comparable with conventionally used antibiotics.
Bruhn
O
O
Institute of Animal Breeding and Husbandry, University of Kiel, Hermann-Rodewald-Strasse 6, D-24118 Kiel, Germany.
Cauchard
J
J
Schlusselhuber
M
M
Gelhaus
C
C
Podschun
R
R
Thaller
G
G
Laugier
C
C
Leippe
M
M
Grötzinger
J
J
D000193:Actinomycetales Infections / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D006734:Horse Diseases / Q000188:drug therapy / Q000382:microbiology*; D006736:Horses; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D008969:Molecular Sequence Data; D016979:Pasteurella multocida / Q000187:drug effects / Q000254:growth & development; D011994:Recombinant Proteins / Q000494:pharmacology; D016929:Rhodococcus equi / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D012475:Salmonella / Q000187:drug effects / Q000254:growth & development; D013291:Streptococcus / Q000187:drug effects / Q000254:growth & development; D023084:alpha-Defensins / Q000494:pharmacology*
D000890:Anti-Infective Agents; D011994:Recombinant Proteins; D023084:alpha-Defensins