TY - JOUR
T1 - A single mechanosensitive channel protects Francisella tularensis subsp. holarctica from hypoosmotic shock and promotes survival in the aquatic environment
AU - Williamson, David R.
AU - Dewan, Kalyan K.
AU - Patel, Tanmay
AU - Wastella, Catherine M.
AU - Ning, Gang
AU - Kirimanjeswara, Girish S.
N1 - Funding Information:
We thank Martin Pavelka, University of Rochester, for providing the pMP812 plasmid and Karl Klose, University of Texas at San Antonio, for providing the pKK214-GFP plasmid. We also thank The Huck Institutes of the Life Sciences for the facilities and technical support. This study was supported by a T32 training grant AI 074551 (NIAID/NIH) to D.R.W. and AI077917 (NIAID/NIH), AES4605 (USDA), and startup funds from Penn State University and The Huck Institutes of the Life Sciences to G.S.K. The funders had no role in the study design, data collection and interpretation, or the decision to submit the work for publication
Publisher Copyright:
© 2018 American Society for Microbiology.
PY - 2018/3/1
Y1 - 2018/3/1
N2 - Francisella tularensis subsp. holarctica is found in North America and much of Europe and causes the disease tularemia in humans and animals. An aquatic cycle has been described for this subspecies, which has caused waterborne outbreaks of tularemia in at least 10 countries. In this study, we sought to identify the mechanosensitive channel(s) required for the bacterium to survive the transition from mammalian hosts to freshwater, which is likely essential for the transmission of the bacterium between susceptible hosts. A single 165-amino-acid MscS-type mechanosensitive channel (FtMscS) was found to protect F. tularensis subsp. holarctica from hypoosmotic shock, despite lacking much of the cytoplasmic vestibule domain found in well-characterized MscS proteins from other organisms. The deletion of this channel did not affect virulence within the mammalian host; however, FtMscS was required to survive the transition from the host niche to freshwater. The deletion of FtMscS did not alter the sensitivity of F. tularensis subsp. holarctica to detergents, H2O2, or antibiotics, suggesting that the role of FtMscS is specific to protection from hypoosmotic shock. The deletion of FtMscS also led to a reduced average cell size without altering gross cell morphology. The mechanosensitive channel identified and characterized in this study likely contributes to the transmission of tularemia between hosts by allowing the bacterium to survive the transition from mammalian hosts to freshwater.
AB - Francisella tularensis subsp. holarctica is found in North America and much of Europe and causes the disease tularemia in humans and animals. An aquatic cycle has been described for this subspecies, which has caused waterborne outbreaks of tularemia in at least 10 countries. In this study, we sought to identify the mechanosensitive channel(s) required for the bacterium to survive the transition from mammalian hosts to freshwater, which is likely essential for the transmission of the bacterium between susceptible hosts. A single 165-amino-acid MscS-type mechanosensitive channel (FtMscS) was found to protect F. tularensis subsp. holarctica from hypoosmotic shock, despite lacking much of the cytoplasmic vestibule domain found in well-characterized MscS proteins from other organisms. The deletion of this channel did not affect virulence within the mammalian host; however, FtMscS was required to survive the transition from the host niche to freshwater. The deletion of FtMscS did not alter the sensitivity of F. tularensis subsp. holarctica to detergents, H2O2, or antibiotics, suggesting that the role of FtMscS is specific to protection from hypoosmotic shock. The deletion of FtMscS also led to a reduced average cell size without altering gross cell morphology. The mechanosensitive channel identified and characterized in this study likely contributes to the transmission of tularemia between hosts by allowing the bacterium to survive the transition from mammalian hosts to freshwater.
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U2 - 10.1128/AEM.02203-17
DO - 10.1128/AEM.02203-17
M3 - Article
C2 - 29269496
AN - SCOPUS:85042013629
VL - 84
JO - Applied and Environmental Microbiology
JF - Applied and Environmental Microbiology
SN - 0099-2240
IS - 5
M1 - e02203-17
ER -