Stepwise changes in viable but nonculturable Vibrio cholerae cells.

Area of Science:

• Microbiology
• Cell Biology
• Bacterial Pathogenesis

Background:

• Many bacterial species enter a viable but nonculturable (VBNC) state when environmental conditions become unfavorable for growth.
• The VBNC state is a survival strategy, but the mechanisms and requirements for bacterial resuscitation from this state are not fully understood.
• Vibrio cholerae, the causative agent of cholera, can adopt the VBNC state, posing challenges for its detection and control.

Purpose of the Study:

• To investigate the dynamic changes in resuscitation requirements for VBNC-state Vibrio cholerae.
• To determine if VBNC Vibrio cholerae cells can be resuscitated by specific treatments or co-cultivation methods.
• To characterize the temporal progression of the VBNC state in Vibrio cholerae.

Main Methods:

• Induction of the VBNC state in Vibrio cholerae strains.
• Sequential application of resuscitation treatments, including catalase, HT-29 cell extract, and co-cultivation with HT-29 cells.
• Fluorescence microscopy to assess cell viability during different stages of the VBNC state.
• Testing of both V. cholerae O1 and O139 serogroups.

Main Results:

• VBNC Vibrio cholerae cells initially resuscitated with catalase or HT-29 cell extract.
• A subsequent state emerged where these factors were ineffective, but co-cultivation with HT-29 cells enabled resuscitation.
• Eventually, cells entered a non-resuscitatable state, even with HT-29 co-cultivation.
• These temporal changes in resuscitation requirements were observed in both V. cholerae O1 and O139 serogroups.

Conclusions:

• The viable but nonculturable (VBNC) state in Vibrio cholerae is not static but a dynamic process with evolving resuscitation requirements.
• Co-cultivation with specific host cells (HT-29) plays a crucial role in resuscitating VBNC Vibrio cholerae at later stages.
• Understanding the temporal dynamics of the VBNC state is critical for developing effective strategies to detect and control Vibrio cholerae.