Open AccessTwo distinct sensing pathways allow recognition of K lebsiella pneumoniae by D ictyostelium amoebae
Author(s) -
Lima Wanessa C.,
Balestrino Damien,
Forestier Christiane,
Cosson Pierre
Publication year - 2014
Publication title -
cellular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.542
H-Index - 138
eISSN - 1462-5822
pISSN - 1462-5814
DOI - 10.1111/cmi.12226
Subject(s) - dictyostelium , biology , dictyostelium discoideum , bacteria , bacillus subtilis , microbiology and biotechnology , klebsiella pneumoniae , chemotaxis , mutant , microorganism , slime mold , gene , receptor , escherichia coli , biochemistry , genetics
Summary Recognition of bacteria by metazoans is mediated by receptors that recognize different types of microorganisms and elicit specific cellular responses. The soil amoebae D ictyostelium discoideum feeds upon a variable mixture of environmental bacteria, and it is expected to recognize and adapt to various food sources. To date, however, no bacteria‐sensing mechanisms have been described. In this study, we isolated a D ictyostelium mutant ( fspA KO ) unable to grow in the presence of non‐capsulated K lebsiella pneumoniae bacteria, but growing as efficiently as wild‐type cells in the presence of other bacteria, such as B acillus subtilis . fspA KO cells were also unable to respond to K . pneumoniae and more specifically to bacterially secreted folate in a chemokinetic assay, while they responded readily to B . subtilis. Remarkably, both WT and fspA KO cells were able to grow in the presence of capsulated LM 21 K . pneumoniae , and responded to purified capsule, indicating that capsule recognition may represent an alternative, FspA ‐independent mechanism for K . pneumoniae sensing. When LM 21 capsule synthesis genes were deleted, growth and chemokinetic response were lost for fspA KO cells, but not for WT cells. Altogether, these results indicate that D ictyostelium amoebae use specific recognition mechanisms to respond to different K . pneumoniae elements.