TY - JOUR
T1 - Manganese acquisition is essential for virulence of Enterococcus faecalis
AU - Colomer-Winter, Cristina
AU - Flores-Mireles, Ana L.
AU - Baker, Shannon P.
AU - Frank, Kristi L.
AU - Lynch, Aaron J.L.
AU - Hultgren, Scott J.
AU - Kitten, Todd
AU - Lemos, José A.
N1 - Funding Information:
CCW was supported by the American Heart Association GSA Predoctoral Fellowship 16PRE29860000. This research was also supported by grants from the National Institute of Allergy and Infectious Disease AI135158 (JAL), AI1114926 (TK) and AI10874901 (SJH), National Institute of Diabetes and Digestive Kidney Diseases DK051406 (SJH) and P50-DK0645400 (SJH), American Heart Association 17SDG33350092 (KLF) and Uniformed Services University of the Health Sciences R0733973 (KLF). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The modified shuttle-vector pTG001 for construction of complementation strains was a gift from Dr. Anthony O. Gaca at Harvard Medical School. Wild-type calprotectin and calprotectin ΔMn Tail mutant [His (103–105)-Asn] were generously provided by Dr. Eric Skaar and Dr. Walter Chazin at Vanderbilt University. We thank Dr. Jessica Kajfasz for critical reading of the manuscript and Dr. Cara Olsen at the USUHS Biostatistics Consulting Center for valuable input on the statistical analysis of in vivo qPCR data.
Publisher Copyright:
© 2018, Public Library of Science. All rights reserved. https://creativecommons.org/publicdomain/zero/1.0/.
PY - 2018/9
Y1 - 2018/9
N2 - Manganese (Mn) is an essential micronutrient that is not readily available to pathogens during infection due to an active host defense mechanism known as nutritional immunity. To overcome this nutrient restriction, bacteria utilize high-affinity transporters that allow them to compete with host metal-binding proteins. Despite the established role of Mn in bacterial pathogenesis, little is known about the relevance of Mn in the pathophysiology of E. faecalis. Here, we identified and characterized the major Mn acquisition systems of E. faecalis. We discovered that the ABC-type permease EfaCBA and two Nramp-type transporters, named MntH1 and MntH2, work collectively to promote cell growth under Mn-restricted conditions. The simultaneous inactivation of EfaCBA, MntH1 and MntH2 (ΔefaΔmntH1ΔmntH2 strain) led to drastic reductions (>95%) in cellular Mn content, severe growth defects in body fluids (serum and urine) ex vivo, significant loss of virulence in Galleria mellonella, and virtually complete loss of virulence in rabbit endocarditis and murine catheter-associated urinary tract infection (CAUTI) models. Despite the functional redundancy of EfaCBA, MntH1 and MntH2 under in vitro or ex vivo conditions and in the invertebrate model, dual inactivation of efaCBA and mntH2 (ΔefaΔmntH2 strain) was sufficient to prompt maximal sensitivity to calprotectin, a Mn- and Zn-chelating host antimicrobial protein, and for the loss of virulence in mammalian models. Interestingly, EfaCBA appears to play a prominent role during systemic infection, whereas MntH2 was more important during CAUTI. The different roles of EfaCBA and MntH2 in these sites could be attributed, at least in part, to the differential expression of efaA and mntH2 in cells isolated from hearts or from bladders. Collectively, this study demonstrates that Mn acquisition is essential for the pathogenesis of E. faecalis and validates Mn uptake systems as promising targets for the development of new antimicrobials.
AB - Manganese (Mn) is an essential micronutrient that is not readily available to pathogens during infection due to an active host defense mechanism known as nutritional immunity. To overcome this nutrient restriction, bacteria utilize high-affinity transporters that allow them to compete with host metal-binding proteins. Despite the established role of Mn in bacterial pathogenesis, little is known about the relevance of Mn in the pathophysiology of E. faecalis. Here, we identified and characterized the major Mn acquisition systems of E. faecalis. We discovered that the ABC-type permease EfaCBA and two Nramp-type transporters, named MntH1 and MntH2, work collectively to promote cell growth under Mn-restricted conditions. The simultaneous inactivation of EfaCBA, MntH1 and MntH2 (ΔefaΔmntH1ΔmntH2 strain) led to drastic reductions (>95%) in cellular Mn content, severe growth defects in body fluids (serum and urine) ex vivo, significant loss of virulence in Galleria mellonella, and virtually complete loss of virulence in rabbit endocarditis and murine catheter-associated urinary tract infection (CAUTI) models. Despite the functional redundancy of EfaCBA, MntH1 and MntH2 under in vitro or ex vivo conditions and in the invertebrate model, dual inactivation of efaCBA and mntH2 (ΔefaΔmntH2 strain) was sufficient to prompt maximal sensitivity to calprotectin, a Mn- and Zn-chelating host antimicrobial protein, and for the loss of virulence in mammalian models. Interestingly, EfaCBA appears to play a prominent role during systemic infection, whereas MntH2 was more important during CAUTI. The different roles of EfaCBA and MntH2 in these sites could be attributed, at least in part, to the differential expression of efaA and mntH2 in cells isolated from hearts or from bladders. Collectively, this study demonstrates that Mn acquisition is essential for the pathogenesis of E. faecalis and validates Mn uptake systems as promising targets for the development of new antimicrobials.
UR - http://www.scopus.com/inward/record.url?scp=85054598640&partnerID=8YFLogxK
U2 - 10.1371/journal.ppat.1007102
DO - 10.1371/journal.ppat.1007102
M3 - Article
C2 - 30235334
AN - SCOPUS:85054598640
VL - 14
JO - PLoS Pathogens
JF - PLoS Pathogens
SN - 1553-7366
IS - 9
M1 - e1007102
ER -