Bacteria that comes back from the dead? Actually... no
"Living-dead" bacteria exist in limbo: biologically active but not proliferating. Buried in this zombie state, disease-causing bacteria could come back from the dead to re-infect patients. Researchers at EPFL have produced the first evidence of this strange phenomenon in tuberculosis, suggesting new avenues for treatment.
Sadly, not zombie bacteria. If something is metabolically active then it's definitely not "dead." Hibernating bacteria more like it! Lots of species go into hibernation or dormancy states in times of stress but they can't be considered dead.