TY - JOUR
T1 - Toxin/antitoxin systems induce persistence and work in concert with restriction/modification systems to inhibit phage
AU - Fernández-García, Laura
AU - Song, Sooyeon
AU - Kirigo, Joy
AU - Battisti, Michael E.
AU - Petersen, Maiken E.
AU - Tomás, María
AU - Wood, Thomas K.
PY - 2024/1
Y1 - 2024/1
N2 - Myriad bacterial anti-phage systems have been described and often the mechanism of programmed cell death is invoked for phage inhibition. However, there is little evidence of “suicide” under physiological conditions for these systems. Instead of death to stop phage propagation, we show here that persister cells, i.e., transiently-tolerant, dormant, antibiotic-insensitive cells, are formed and survive using the Escherichia coli C496_10 tripartite toxin/antitoxin system MqsR/MqsA/MqsC to inhibit T2 phage. Specifically, MqsR/MqsA/MqsC inhibited T2 phage by 105-fold and reduced T2 titers by 3,000-fold. During T2 phage attack, in the presence of MqsR/MqsA/MqsC, evidence of persistence includes the single-cell physiological change of reduced metabolism (via flow cytometry), increased spherical morphology (via transmission electron microscopy), and heterogeneous resuscitation. Critically, we found restriction-modification systems (primarily EcoK McrBC) work in concert with the toxin/antitoxin system to inactivate phage, likely while the cells are in the persister state. Hence, a phage attack invokes a stress response similar to antibiotics, starvation, and oxidation, which leads to persistence, and this dormant state likely allows restriction/modification systems to clear phage DNA.
AB - Myriad bacterial anti-phage systems have been described and often the mechanism of programmed cell death is invoked for phage inhibition. However, there is little evidence of “suicide” under physiological conditions for these systems. Instead of death to stop phage propagation, we show here that persister cells, i.e., transiently-tolerant, dormant, antibiotic-insensitive cells, are formed and survive using the Escherichia coli C496_10 tripartite toxin/antitoxin system MqsR/MqsA/MqsC to inhibit T2 phage. Specifically, MqsR/MqsA/MqsC inhibited T2 phage by 105-fold and reduced T2 titers by 3,000-fold. During T2 phage attack, in the presence of MqsR/MqsA/MqsC, evidence of persistence includes the single-cell physiological change of reduced metabolism (via flow cytometry), increased spherical morphology (via transmission electron microscopy), and heterogeneous resuscitation. Critically, we found restriction-modification systems (primarily EcoK McrBC) work in concert with the toxin/antitoxin system to inactivate phage, likely while the cells are in the persister state. Hence, a phage attack invokes a stress response similar to antibiotics, starvation, and oxidation, which leads to persistence, and this dormant state likely allows restriction/modification systems to clear phage DNA.
KW - persistence
KW - phage inhibition
KW - toxin/antitoxin systems
KW - Bacteriophages
KW - Humans
KW - DNA Restriction-Modification Enzymes
KW - Antitoxins
U2 - 10.1128/spectrum.03388-23
DO - 10.1128/spectrum.03388-23
M3 - Journal article
C2 - 38054715
AN - SCOPUS:85182501725
SN - 2165-0497
VL - 12
SP - e0338823
JO - Microbiology Spectrum
JF - Microbiology Spectrum
IS - 1
ER -