Proteolytic degradation of human antimicrobial peptide LL-37 by Bacillus anthracis may contribute to virulence.
In this paper we report on the susceptibilities of a range of Bacillus species to the human antimicrobial peptide LL-37. B. subtilis showed a low level of resistance to killing by LL-37 (50% growth-inhibitory concentration [GI50], 1 microg/ml). B. cereus and B. thuringiensis showed intermediate levels of resistance to killing (GI50s, 33 microg/ml and 37 microg/ml, respectively). B. anthracis showed the highest level of resistance (GI50s, 40 to 66 microg/ml). The degradation of LL-37 by B. anthracis culture supernatant was blocked by the metalloprotease inhibitors EDTA and 1,10-phenanthroline, and the gene encoding the protease responsible for LL-37 degradation was not plasmid borne. Our findings suggest that alongside the classical plasmid-based virulence determinants, extracellular metalloproteases of B. anthracis may play a role in survival in the host.
Thwaite
Joanne E
JE
Biomedical Sciences, Dstl Porton Down, Salisbury, Wiltshire SP4 0JQ, United Kingdom. jethwaite@dstl.gov.uk
Hibbs
Stephen
S
Titball
Richard W
RW
Atkins
Timothy P
TP
D023181:Antimicrobial Cationic Peptides / Q000378:metabolism* / Q000494:pharmacology; D001407:Bacillus / Q000145:classification / Q000187:drug effects / Q000254:growth & development / Q000502:physiology; D001408:Bacillus anthracis / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development / Q000472:pathogenicity*; D054804:Cathelicidins; D017077:Culture Media, Conditioned / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D006801:Humans; D045726:Metalloproteases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008826:Microbial Sensitivity Tests / Q000379:methods; D011480:Protease Inhibitors / Q000494:pharmacology; D013171:Spores, Bacterial / Q000187:drug effects; D014774:Virulence
D023181:Antimicrobial Cationic Peptides; D054804:Cathelicidins; D017077:Culture Media, Conditioned; D011480:Protease Inhibitors; D045726:Metalloproteases