Intracellular pH Campylobacter jejuni when treated with aqueous chlorine dioxide

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Nada Smigic, Andreja Rajkovic, Nils Arneborg, Henrik Siegumfeldt, Frank Devlieghere, Dennis Sandris Nielsen

The aim of this study was to investigate the response of Campylobacter jejuni at single-cell level when exposed to different concentrations of chlorine dioxide (ClO2). The parameter of choice, intracellular pH (pHi), was determined by using fluorescence ratio imaging microscopy with a pH-sensitive, ratiometric 5(6)-carboxyfluorescein diacetate succinimidyl ester probe. In addition, the culturability expressed in colony counts was determined. Our results revealed that several subpopulations with different physiological states, as judged by their pHi, were created by ClO2 treatment. The greater the concentration of ClO2, the smaller the subpopulation of healthy cells with pHi¿>¿6.8 and the smaller the colony count as determined on nonselective agar plates. ClO2 at concentrations (60¿ppm) induced injuries that resulted in complete loss of culturability and adversely affected the ability to resuscitate under subsequent more favorable conditions. The presence of injured cells in food could present a risk for public health. Additional hurdles have to be included in food preservation to suppress the survival and recovery of injured cells.

Original languageEnglish
JournalFoodborne Pathogens and Disease
Volume8
Issue number2
Pages (from-to)325-328
ISSN1535-3141
DOIs
Publication statusPublished - 2011

ID: 32670338