Viable but nonculturable explained

Viable but nonculturable (VBNC) bacteria refers as to bacteria that are in a state of very low metabolic activity and do not divide, but are alive and have the ability to become culturable once resuscitated.^[1]

Bacteria in a VBNC state cannot grow on standard growth media, though flow cytometry can measure the viability of the bacteria.^[1] Bacteria can enter the VBNC state as a response to stress, due to adverse nutrient, temperature, osmotic, oxygen, and light conditions.^[1] The cells that are in the VBNC state are morphologically smaller, and demonstrate reduced nutrient transport, rate of respiration, and synthesis of macromolecules.^[1] Sometimes, VBNC bacteria can remain in that state for over a year.^[1] It has been shown that numerous pathogens and non-pathogens can enter the VBNC state, which therefore has significant implications in pathogenesis, bioremediation, and other branches of microbiology.^[1]

The existence of the VBNC state is controversial. The validity and interpretation of the assays to determine the VBNC state have been questioned.^[2]

VBNC pathogens

Species known to enter a VBNC state:^[3]

• Aeromonas hydrophila
• Aeromonas salmonicida
• Agrobacterium tumefaciens
• Burkholderia cepacia
• Burkholderia pseudomallei
• Brettanomyces bruxellensis^[4]
• Campylobacter coli
• Campylobacter jejuni
• Campylobacter lari
• Cytophaga allerginae
• Enterobacter aerogenes
• Enterobacter cloacae
• Enterococcus faecalis
• Enterococcus hirae
• Enterococcus faecium
• Erwinia amylovora
• Escherichia coli (including EHEC)
• Francisella tularensis
• Helicobacter pylori
• Klebsiella aerogenes
• Klebsiella pneumoniae
• Klebsiella planticola
• Legionella pneumophila
• Listeria monocytogenes
• Micrococcus luteus
• Mycobacterium tuberculosis
• Mycobacterium smegmatis
• Pasteurella piscicida
• Pseudomonas aeruginosa
• Pseudomonas syringae
• Pseudomonas putida KT2440^[5]
• Ralstonia solanacearum
• Rhizobium leguminosarum
• Rhizobium meliloti
• Salmonella enterica
• Salmonella Typhi
• Salmonella Typhimurium
• Serratia marcescens
• Shigella dysenteriae
• Shigella flexneri
• Shigella sonnei
• Streptococcus faecalis
• Vibrio alginolyticus
• Vibrio anguillarum
• Vibrio campbellii
• Vibrio cholerae
• Vibrio harveyi
• Vibrio mimicus
• Vibrio parahaemolyticus
• Vibrio shiloi
• Vibrio vulnificus (types 1 and 2)
• Xanthomonas campestris
• Xanthomonas axonopodis pv. citri
• Yersinia pestis^[6]

Notes and References

1. Oliver JD . The viable but nonculturable state in bacteria . The Journal of Microbiology . 43 . special issue (No. S) . 93–100 . February 2005 . 15765062 .
2. Book: Stokell . Joshua R. . Steck . Todd R. . eLS. Viable but Nonculturable Bacteria . 2012 . 10.1002/9780470015902.a0000407.pub2 . 978-0470016176.
3. Oliver . JD. . Recent findings on the viable but nonculturable state in pathogenic bacteria. . FEMS Microbiol Rev . 34 . 4 . 415–25 . Jul 2010 . 10.1111/j.1574-6976.2009.00200.x . 20059548 . free .
4. News: Capozzi V. etal . Viable But Not Culturable (VBNC) state of Brettanomyces bruxellensis in wine: New insights on molecular basis of VBNC behaviour using a transcriptomic approach..
5. Pazos-Rojas . LA. . Desiccation-induced viable but nonculturable state in Pseudomonas putida KT2440, a survival strategy. . PLOS ONE . 17 . 7 . e0219554 . Jul 2019 . 10.1371/journal.pone.0219554 . 31323038 . 6641147 . free .
6. 21436885. 3059211. 2011. Pawlowski. D. R.. Entry of Yersinia pestis into the viable but nonculturable state in a low-temperature tap water microcosm. PLOS ONE. 6. 3. e17585. Metzger. D. J.. Raslawsky. A. Howlett. A. Siebert. G. Karalus. R. J.. Garrett. S. Whitehouse. C. A.. 10.1371/journal.pone.0017585. free.