TY - JOUR
T1 - Bacterial endosymbiosis is widely present among zygomycetes but does not contribute to the pathogenesis of mucormycosis
AU - Ibrahim, Ashraf S.
AU - Gebremariam, Teclegiorgis
AU - Liu, Mingfu
AU - Chamilos, Georgios
AU - Kontoyiannis, Dimitrios P.
AU - Mink, Richard
AU - Kwon-Chung, Kyung J.
AU - Fu, Yue
AU - Skory, Christopher D.
AU - Edwards, John E.
AU - Spellberg, Brad
N1 - Funding Information:
Financial support: This work was supported by the Public Health Service (grants R01 AI063503 and R21 AI064716 to A.S.I). B.J.S. is supported by the Public Health Service (grant K08 AI060641), an American Heart Beginning Grant-in-Aid (0665154Y), and a Liu Young Investigator in Biomedical Research Award. K.J.K.-C. is supported by funds from the intramural program of the National Institute of Allergy and Infectious Diseases, National Institutes of Health. Research described in this article was conducted in part at the research facilities of the Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center.
PY - 2008/10/1
Y1 - 2008/10/1
N2 - Environmental isolates of the fungus Rhizopus have been shown to harbor a bacterial endosymbiont (Burkholderia) that produces rhixozin, a plant mycotoxin. We sought to define the role of rhizoxin production by endosymbionts in the pathogenesis of mucormycosis. Endosymbiotic bacteria were identified by polymerase chain reaction in 15 (54%) of 28 clinical isolates of Zygomycetes, with 33% of the bacterial strains showing ≥87% identity to Burkholderia 16S rDNA. The presence of rhizoxin in myclial extracts from fungi harboring bacteria was confirmed by high-performance liquid chromatography analysis. However, fungal strains with or without endosymbionts did not differ in their ability to cause endothelial cell injury in vitro, nor did antibiotic-mediated eradication of endosymbionts and rhizoxin production decrease the virulence of fungal strains in mice or flies. In summary, although bacterial endosymbiosis is widely detected in clinical isolates of Zygomycetes, including Rhizopus oryzae strains, we found no evidence that bacterial endosymbionts and rhizoxin contribute to the pathogenesis of mucormycosis in the models studied.
AB - Environmental isolates of the fungus Rhizopus have been shown to harbor a bacterial endosymbiont (Burkholderia) that produces rhixozin, a plant mycotoxin. We sought to define the role of rhizoxin production by endosymbionts in the pathogenesis of mucormycosis. Endosymbiotic bacteria were identified by polymerase chain reaction in 15 (54%) of 28 clinical isolates of Zygomycetes, with 33% of the bacterial strains showing ≥87% identity to Burkholderia 16S rDNA. The presence of rhizoxin in myclial extracts from fungi harboring bacteria was confirmed by high-performance liquid chromatography analysis. However, fungal strains with or without endosymbionts did not differ in their ability to cause endothelial cell injury in vitro, nor did antibiotic-mediated eradication of endosymbionts and rhizoxin production decrease the virulence of fungal strains in mice or flies. In summary, although bacterial endosymbiosis is widely detected in clinical isolates of Zygomycetes, including Rhizopus oryzae strains, we found no evidence that bacterial endosymbionts and rhizoxin contribute to the pathogenesis of mucormycosis in the models studied.
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U2 - 10.1086/591461
DO - 10.1086/591461
M3 - Article
C2 - 18694335
AN - SCOPUS:51849109554
SN - 0022-1899
VL - 198
SP - 1083
EP - 1090
JO - Journal of Infectious Diseases
JF - Journal of Infectious Diseases
IS - 7
ER -