This video demonstrates a technique for detecting local and global calcium ion response upon Shigella infection of human epithelial cells. Shigella invades host cells and releases invasion effectors, impacting intracellular calcium levels. The amplitude and frequency of the local and global cytosolic calcium are studied using a fluorescent indicator.
Protocol
1. Preparations Bacteria preparation Plate the bacteria—Shigella wild-type strain expressing the AfaE adhesin (M90T-AfaE)—onto a trypticase soy (TCS) agar plate containing 0.01% Congo red (CR) and incubate them for 18 h at 37 °C. Note: To increase their reproducibility, the Shigella plates obtained in step 1.1.1 are stored at 4 °C and should be used within a week because all colonies on CR medium wil…
Divulgations
The authors have nothing to disclose.
Materials
Fluo-4 AM
Invitrogen
F14201
Metamorph version 7.7
Universal Imaging
CoolLED illumination system pE-2
Roper Scientific
Micro-dish 35 mm, high
IBIDI
81156
Trypticase Soy (TCS) broth
Thermofisher
B11768
TCS agar
Thermofisher
B11043
Congo red
Sigma-Aldrich
75768
M90T-AfaE
Sun et al. 2017
Shigella flexneri serotype V. expressing the AfaE adhesin
ipgD-AfaE
Sun et al. 2017
Isogenic ipgD mutant strain expressing the AfaE adhesin