Expression of Bacillus cereus hemolysin II in Bacillus subtilis renders the bacteria pathogenic for the crustacean Daphnia magna.
Hemolysin II (HlyII) is a pore-forming toxin of the opportunistic pathogen Bacillus cereus. Despite our understanding of the mechanism of HlyII cytotoxicity in vitro, many of its characteristics, including potential target cells, conditions of its action and expression, are not known. Here we report that the expression of hlyII in Bacillus subtilis renders the bacteria hemolytic and is able to kill the crustacean Daphnia magna. The hemolytic activity of hlyII-encoded B. subtilis strains in culture media is positively correlated with virulence in D. magna. Fluorescence microscopy reveals postinfection changes in the mitochondrial potential of intestinal tissue, suggesting that the formation of ionic pores leads to cell death. In the presence of the transcriptional regulator HlyIIR, HlyII expression decreases 200-fold, and B. subtilis expressing both hlyII and hlyIIR remains hemolytic, but not pathogenic to the crustacean.
Sineva
Elena V
EV
Laboratory of Molecular Microbiology, Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow Region, Russia. esineva@gmail.com
Andreeva-Kovalevskaya
Zhanna I
ZI
Shadrin
Andrey M
AM
Gerasimov
Yury L
YL
Ternovsky
Vadim I
VI
Teplova
Vera V
VV
Yurkova
Tatyana V
TV
Solonin
Alexander S
AS
D000818:Animals; D001409:Bacillus cereus / Q000235:genetics*; D001412:Bacillus subtilis / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism / Q000633:toxicity; D003621:Daphnia / Q000187:drug effects / Q000382:microbiology*; D015870:Gene Expression; D015964:Gene Expression Regulation, Bacterial; D006460:Hemolysin Proteins / Q000235:genetics* / Q000378:metabolism / Q000633:toxicity; D014774:Virulence
C085361:ApxII toxin, bacteria; D001426:Bacterial Proteins; D006460:Hemolysin Proteins