International Journal of Food Microbiology 2009-01-01

Effects of pH and oil-in-water emulsions on growth and physicochemical cell surface properties ofListeria monocytogenes: Impact on tolerance to the bactericidal activity of disinfectants

Murielle Naïtali, Florence Dubois-Brissonnet, Gérard Cuvelier, Marie-Noëlle Bellon-Fontaine, Murielle Naïtali, Florence Dubois-Brissonnet, Gérard Cuvelier, Marie-Noëlle Bellon-Fontaine

Index: Int. J. Food Microbiol. 130(2) , 101-7, (2009)

Full Text: HTML

Abstract

This study characterizes the effects of an acidic pH and an emulsified oil-in-water phase in a culture medium on the behavior of Listeria monocytogenes. Two strains were tested, Scott A and CIP 78.39, and exhibited similar responses to growth media. First of all, the results showed that the emulsified oil phase had no effect on growth kinetics, whereas acidification of the initial pH (from 7.2 to 5.2) reduced both growth rates and growth yields. Secondly, physicochemical cell surface properties were evaluated. Growth in an emulsion resulted in a more marked increase in hydrophobicity in neutral than in acidic media, whereas the electrical charge remained unchanged. Furthermore, growth in acidic media – emulsified or not – induced a reduction in hydrophobicity as well as in the negative charge of cell surfaces. Thirdly, the results showed that tolerance to the bactericidal activity of didecyl dimethyl ammonium bromide (DDAB) and sodium dichloroisocyanuric acid (NaDCC) was strongly dependent on the pH of the growth phase. Acidic stress during growth increased tolerance to both disinfectants, but to a greater extent with DDAB than with NaDCC. Moreover, the presence of an emulsion during growth at an acidic pH had no effect on subsequent strain tolerance to disinfectants. By contrast, when the pH of the emulsion was neutral, the oil phase induced a more marked reduction in the tolerance of both strains to DDAB, but the reverse applied with NaDCC. Taken together, these results indicate a clear link between modifications to cell surface properties and tolerance to disinfectants, related to the hydrophobicity and electrical charges of both bacterial cells and disinfectants.


Related Compounds

Related Articles:

Assessment of the working range and effect of sodium dichloroisocyanurate on Pseudomonas aeruginosa biofilms and planktonic cells.

2012-01-01

[Biofouling 28(1) , 111-20, (2012)]

Analytical method for the quantitative determination of cyanuric acid as the degradation product of sodium dichloroisocyanurate in urine by liquid chromatography mass spectrometry.

2007-06-15

[J. Chromatogr. B. Analyt. Technol. Biomed. Life Sci. 853(1-2) , 360-3, (2007)]

Disinfection by-product formation and mitigation strategies in point-of-use chlorination with sodium dichloroisocyanurate in Tanzania.

2010-07-01

[Am. J. Trop. Med. Hyg. 83(1) , 135-43, (2010)]

Reactive airways dysfunction syndrome from acute inhalation of a dishwasher detergent powder.

2012-01-01

[Can. Respir. J. 19(3) , e25-8, (2012)]

Comparative sporicidal effects of disinfectants after release of a biological agent.

2007-06-01

[Mil. Med. 172(6) , 616-21, (2007)]

More Articles...