Resuscitation of Escherichia coli VBNC cells depends on a variety of environmental or chemical stimuli

Abstract

Aims: To analyse viable but nonculturable (VBNC) state induction in Escherichia coli and resuscitation of VBNC suspensions in several conditions. Methods and Results: VBNC were induced in four media, two temperatures and six strains, but only cells produced at 4°C were able to resuscitate. Resuscitation of 14 VBNC suspensions obtained in several conditions occurred in the presence of supernatants of growing cells, in minimal medium supplemented with amino acids or after temperature change, depending on strain. A limited time period beyond no more resuscitation that could be observed was also confirmed. Conclusions: The supernatants positive effect is suggested to be because of a nonproteinaceous molecule, and a combination of methionine, glutamine, threonine, serine and asparagine could be used as primary mix for resuscitation experiments. Significance and Impact of the Study: Escherichia coli resuscitation was already attempted in several conditions, but it is the first time that a positive result was observed in minimal medium supplemented with amino acids or after temperature change. The role of amino acids in resuscitation is of special interest since was never reported for any species.

Development of aminoglycoside and β-lactamase resistance among intestinal microbiota of swine treated with lincomycin, chlortetracycline, and amoxicillin

“…Therefore, the tetracycline resistance rate could remain at a high level before treatment and increase from 69.8 to 75.4 to 85.4% to 97.1% after treatment in this study. Viable but non-culturable (VBNC) bacteria were not considered in the bacterial enumeration assay under the culture condition described in the method, because they accounted for only a few of each zoonotic pathogen (Pinto et al, 2011; Trevors, 2011). …”

The importance of the viable but non-culturable state in human bacterial pathogens

“…Such a study is required to provide new information on the conditions that would lead to faster VBNC state inductions. Pinto et al (2011) suggested that in E. coli , the origin of the strains and the incubation temperature are key factors for the speed at which VBNC cells appear in a bacterial population.…”

“…For example, Chaveerach et al (2003) were able to resuscitate C. jejuni by incubating the VBNC cells in embryonated chicken eggs but not in rich medium, showing that the condition or stimulus required for resuscitation could be very specific. In fact, many factors can influence the successfulness of resuscitation, such as the strain used, the age of VBNC cells, the conditions that induced the VBNC state and, of course, the conditions provided for resuscitation (Pinto et al, 2011). A comprehensive study done by Pinto et al (2011) clearly demonstrated the effects of these four factors on the resuscitation of E. coli .…”

Can sludge dewatering reactivate microorganisms in mesophilically digested anaerobic sludge? Case of belt filter versus centrifuge

“…Rather, a resuscitation event is suggested which occurs in much shorter times compared to the times needed for doubling of bacteria (Gupte et al, 2003). It was also reported that unlike regrowth of culturable cells, resuscitation of E. coli was possible during a limited time interval and the number of resuscitation event declined gradually (Pinto et al, 2011). This present study suggests that when a temperature increase is combined with some other factors such as oxygenation after the anaerobic digestion process, favorable reactivation conditions might be provided for the indicator bacteria.…”