Dec 5, 2024
1:45pm - 2:00pm
Sheraton, Third Floor, Fairfax B
Ashutosh Kumar1,Nicolas Perry1,Apurba Paul1,Mehmet Ozdogan1,Gregory Timp1
University of Notre Dame1
Ashutosh Kumar1,Nicolas Perry1,Apurba Paul1,Mehmet Ozdogan1,Gregory Timp1
University of Notre Dame1
This work represents a first step towards the illumination of the biological mechanisms underpinning live cell physiology with nanometer resolution. Using low-energy (30 keV), low-dose, probe-corrected,
integrated
differential
phase-
contrast
scanning
transmission
electron
microscopy (iDPC-STEM) in conjunction with a liquid flow cell, two genetically engineered
Mycoplasma species,
M. mobile and
M. pneumoniae, which are among the smallest, simplest, self-replicating bacteria, were scrutinized with nanometer-resolution without compromising cell viability. The viability was scored at a
lethal
dose to
50% of the population at LD
50 > 3600
e-/nm
2 at a beam energy of 30 keV by expression of an inducible fluorescent reporter following exposure to the electron beam in genetically engineered strains of the bacteria, which is in stark contrast with the LD
50 < 56
e-/nm
2 observed at 300 keV. The higher LD
50 at a beam energy of 30 keV opened a wide window for high-resolution imaging of cell physiology. Within this window, the mechanisms for gliding motility in
Mycoplasma, which are essential to infection and mediate attachment to a host, were elucidated with < 3 nm resolution.