TY - JOUR
T1 - Symbiotic bacteria contribute to innate immune defenses of the threatened mountain yellow-legged frog, Rana muscosa
AU - Woodhams, Douglas C.
AU - Vredenburg, Vance T.
AU - Simon, Mary Alice
AU - Billheimer, Dean
AU - Shakhtour, Bashar
AU - Shyr, Yu
AU - Briggs, Cheryl J.
AU - Rollins-Smith, Louise A.
AU - Harris, Reid N.
N1 - Funding Information:
The authors thank J. Morgan, M. Stice, and T. Tunstall for field assistance and B.A. Lam for assistance in the laboratory. L.A. Rollins-Smith was funded by an Integrated Research Challenges in Environmental Biology (IRCEB) grant IBN-9977063 (J.P. Collins, P.I.) and grant IOB-0520847 from the U.S. National Science Foundation. R.N. Harris was funded by NSF grant 0413981, and C.J. Briggs was funded by the NIH/NSF Ecology of Infectious Disease Program grant R01 ES12067 from the National Institute of Environmental Health Sciences. D. Woodhams was partially supported by an NHBLI Immunology of Blood and Vascular Systems Training Grant 5T32 HL069765-05 (J. Hawiger, P.I.).
PY - 2007/9
Y1 - 2007/9
N2 - Symbiotic microorganisms influence health and disease and may contribute to the innate immune defenses of amphibians. The mountain yellow-legged frog, Rana muscosa, is currently undergoing unprecedented population declines. One cause of recent declines is the pathogenic chytrid fungus, Batrachochytrium dendrobatidis (Bd). Skin swabs for detection of Bd, skin peptide secretions, and symbiotic skin bacteria were collected from 70 adult R. muscosa from two populations designated "Sixty Lake" and "Conness" in 2004-2005. The Conness population has persisted with the presence of Bd for at least 6 years whereas the Sixty Lake population is newly infected and declining. Of the frogs sampled at Conness, 67.5% were infected; whereas 96.7% of the Sixty Lake frogs were infected. Sixty Lake frogs were also more intensely infected than frogs at Conness. We isolated symbiotic bacteria that may contribute to immune defense. A significantly greater proportion of individuals with at least one anti-Bd bacterial species present were found at Conness (85%) than at Sixty Lake (62%). We observed no apparent differences in total skin peptides recovered; however, peptide mixtures from frogs at Sixty Lake showed better growth inhibitory activity against Bd than peptides from frogs at Conness. By MALDI-TOF MS analysis, there were no differences between the two populations in the previously described antimicrobial peptides (ranatuerin-2Ma, ranatuerin-2Mb, and temporin-1M). Antimicrobial skin peptides are only one factor in the resistance of R. muscosa to Bd infection. We suggest that symbiotic bacteria with the ability to persist in the presence of mucosal peptides may inhibit infection and colonization of the skin by Bd and increase the effectiveness of innate defense mechanisms in the skin.
AB - Symbiotic microorganisms influence health and disease and may contribute to the innate immune defenses of amphibians. The mountain yellow-legged frog, Rana muscosa, is currently undergoing unprecedented population declines. One cause of recent declines is the pathogenic chytrid fungus, Batrachochytrium dendrobatidis (Bd). Skin swabs for detection of Bd, skin peptide secretions, and symbiotic skin bacteria were collected from 70 adult R. muscosa from two populations designated "Sixty Lake" and "Conness" in 2004-2005. The Conness population has persisted with the presence of Bd for at least 6 years whereas the Sixty Lake population is newly infected and declining. Of the frogs sampled at Conness, 67.5% were infected; whereas 96.7% of the Sixty Lake frogs were infected. Sixty Lake frogs were also more intensely infected than frogs at Conness. We isolated symbiotic bacteria that may contribute to immune defense. A significantly greater proportion of individuals with at least one anti-Bd bacterial species present were found at Conness (85%) than at Sixty Lake (62%). We observed no apparent differences in total skin peptides recovered; however, peptide mixtures from frogs at Sixty Lake showed better growth inhibitory activity against Bd than peptides from frogs at Conness. By MALDI-TOF MS analysis, there were no differences between the two populations in the previously described antimicrobial peptides (ranatuerin-2Ma, ranatuerin-2Mb, and temporin-1M). Antimicrobial skin peptides are only one factor in the resistance of R. muscosa to Bd infection. We suggest that symbiotic bacteria with the ability to persist in the presence of mucosal peptides may inhibit infection and colonization of the skin by Bd and increase the effectiveness of innate defense mechanisms in the skin.
KW - Antimicrobial peptide
KW - Batrachochytrium dendrobatidis
KW - Herd immunity
KW - Innate immune defense
KW - MALDI mass spectrometry
KW - Rana muscosa
KW - Symbiotic bacteria
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U2 - 10.1016/j.biocon.2007.05.004
DO - 10.1016/j.biocon.2007.05.004
M3 - Article
AN - SCOPUS:34547509968
SN - 0006-3207
VL - 138
SP - 390
EP - 398
JO - Biological Conservation
JF - Biological Conservation
IS - 3-4
ER -