Enumeration, Occurrence, and Significance of Injured Indicator Bacteria in Drinking Water

Recovery of Hydrogen Peroxide-Sensitive Culturable Cells of Vibrio vulnificus Gives the Appearance of Resuscitation from a Viable but Nonculturable State

“…1). Furthermore, we feel that such a definition of the VBNC state does not distinguish it from established views of injured bacteria (1,2,11,19,20,27,28,30,31), failing to describe a specific program of differentiation into a long-term survival state (akin to spore formation) as opposed to degeneration into a short-term injured state followed by further degeneration to death. The continued decline of hydrogen peroxide-sensitive cells has also been noted with Escherichia coli (21), with complete loss of culturability of such cells obtained in studies with Vibrio parahaemolyticus (22) and V. vulnificus (L. Sides, M. F. Hite, and J. D. Oliver, Abstr.…”

“…The transient nature of the hydrogen peroxide-sensitive culturable cells suggests a model in which cells of V. vulnificus inoculated into cold ASW gradually degenerate, passing through a hydrogen peroxide-sensitive injured state as they die. Injury in bacteria has been defined by respected workers in the field, such as Speck and McFeters, as an increased sensitivity to components of growth media which are not normally inhibitory (11,19,20,27,28,30,31); the injured state is transient, resulting from cumulative damage, and death in bacteria has been defined by these workers as the point "where injury extends beyond the ability of a cell to multiply and form a colony" (28,31). Amendment of plate count media with catalase or sodium pyruvate has long been employed as a means to recover injured bacterial cells (3,7,14,16,17,18,29).…”

Viability PCR, a Culture-Independent Method for Rapid and Selective Quantification of Viable Legionella pneumophila Cells in Environmental Water Samples

“…Methods used to determine disinfection efficacy have traditionally been based on viability assays using conventional plate counting. A problem associated with this practice is that bacteria may become unable to form colonies on selective media because of reversible injury or because they enter into a VBNC state (17,20,31,33,35). Concerning Legionella, the monitoring of the disinfection efficacy using culture techniques requires prolonged incubation periods due to the low growth rate of these bacteria.…”

Rapid and Simple Quantification of Bacterial Cells by Using a Microfluidic Device

“…Culture methods are widely used for bacterial enumeration; however, for accurate enumeration of bacterial numbers, including injured or starved cells, it is important to use culture-independent techniques (16). Fluorescent staining is suitable for this purpose, and various fluorescent dyes have been used to detect bacterial cells by epifluorescence microscopy and flow cytometry (3,10,13,21).…”