Use of multiparameter analysis for Vibrio alginolyticus viable but nonculturable state determination

Abstract

Background:Vibrio alginolyticus is known to enter into a viable but nonculturable (VBNC) state in response to environmental conditions unfavorable to the growth. Cells in VBNC condition pose a public health threat because they are potentially pathogenic.Methods:We constructed a pathway for the identification of the most significant variables and the characterization of those variables able to discriminate the groups under investigation. Different parameters measured by the image processing software were chosen as the most representative of V. alginolyticus cell morphology (length index for dimension) and metabolic activity (density profile indexes). To detect relationships between the groups of treatment performed, we carried out a principal components analysis (PCA).Results:The PCA analysis indicated that increasing coccoid shape transformation was related to both metabolic and dimension variations, delineating a well defined graph profile. Indeed, we discovered that specific morphological variations occur when cells in the culturable state pass into VBNC condition, namely comma‐shaped culturable bacteria are converted into coccoid‐shaped VBNC cells. The results were also supported by scanning electron microscopy analysis.Conclusions:This technique allows the analysis of a large number of vibrio samples in a short period of time. The obtained multiparameter information may complement genetic/molecular analyses facilitating, in an automatic fashion, further studies to evaluate the potential risk of this pathogen in the environment. It may also be a useful tool for large‐scale cell biology studies and high content screening. © 2006 International Society for Analytical Cytology

Modulation of Caspase Activity Regulates Skeletal Muscle Regeneration and Function in Response to Vasopressin and Tumor Necrosis Factor

“…PCA is a procedure for analyzing multivariate data that establishes “metric” differences between groups under investigation on the basis of their characterizing multivariate data [72]. We studied 6 treatment groups, each of which contained numerous individual samples.…”

“…We studied 6 treatment groups, each of which contained numerous individual samples. Several parameters that are indicative of muscle functional properties (maximum force, weight of each muscle, specific force, fatigue index and fatigue time) were considered in the PCA, as previously described [72]–[74]. PCA transforms the original variables into new uncorrelated ones that can be displayed in a bidimensional space and that account for most of the variability observed, thus reducing the dimensionality of the data and allowing a large number of variables to be visualized in a two dimensional plot.…”

Current Perspectives on Viable but Non-culturable State in Foodborne Pathogens

“…The list includes many pathogens, such as E. coli O157:H7, Staphylococcus aureus and C. jejuni , which cause foodborne disease in healthy individuals, as observed in outbreaks of epidemic diarrhea or collective food poisoning (Chaisowwong et al, 2012; Dinu and Bach, 2013; Pasquaroli et al, 2014). It also includes some pathogens such as Vibrio alginolyticus, Vibrio parahaemolyticus , and Salmonella that mainly infect human beings by first infecting other organisms (like poultry, livestock, and seafood) (Bates and Oliver, 2004; Albertini et al, 2006; Braden, 2006). Table 1 also lists the main survival environment of foodborne pathogenic bacteria, including soil, freshwater, seawater, raw food, organisms, and even dust.…”

“…One common method is based on microscopic enumeration with staining procedure to directly detect the viable cells, including the direct counting method of viable bacterial cells (DVC) based on the substrate absorption ability (Kogure et al, 1979), the respiration detection method (such as CTC or INT) based on the ability of the electron transport system (Albertini et al, 2006) and the LIVE/DEAD ® BacLight TM fluorescence staining method based on the cell membrane structure integrity (Cunningham et al, 2009). …”

The potential of flow cytometry in the study of Bacillus cereus

“…The viable but nonculturable issue within the genus, Bacillus , is not as contentious as within, e.g. the genus Vibrio (Adams 2005; Albertini et al. 2006).…”