'Viable but non-culturable cells' are dead.

Area of Science:

• Microbiology
• Bacterial Physiology
• Stress Response

Background:

• Bacteria can enter dormant states to survive environmental stress, including antibiotics.
• Persister cells, a subpopulation of bacteria, inactivate ribosomes to become dormant.
• Stress can also lead to the formation of dead, hollow cell shells.

Purpose of the Study:

• To differentiate between viable persister cells and non-viable cell shells.
• To clarify the mechanisms of bacterial resuscitation after stress.
• To address the misclassification of dead cell shells as viable in microbiology.

Main Methods:

• Analysis of bacterial dormancy and resuscitation pathways.
• Distinguishing between persister cells and cell shells based on viability markers.
• Experimental data interpretation to assess resuscitation potential.

Main Results:

• Persister cells possess an elegantly regulated pathway for dormancy and resuscitation.
• Dead cell shells, despite intact membranes, lack the cellular content for revival.
• Resuscitation observed in stressed bacterial populations is attributed to viable persister cells.

Conclusions:

• Bacterial resuscitation after stress is mediated by viable persister cells, not dead cell shells.
• The concept of 'viable but non-culturable cells' (VBNCs) may have historically misidentified dead cell shells as viable.
• Accurate identification of dormant bacterial states is crucial for understanding infection persistence and treatment failure.