Effects of Short-Term Alkaline Adaptation on Surface Properties of Listeria monocytogenes 10403S
نویسندگان
چکیده
The changes in cell surface properties associated with alkali stress can significantly disrupt cell metabolism and structures, preventing effective interactions between bacterial cells and their environment. Listeria monocytogenes is known to display an adaptive response to alkali stress that enhances its capacity to more effectively survive subsequent severe alkali challenge. In this study, we examined the effects of adaptation to alkali conditions (pH 9.5/ 1h) in reducing detrimental effects in hydrophobicity and cell morphology in Listeria monocytogenes 10403S during severe (subsequent) short-term alkali challenge (pH 12.0/ 1h). Severe alkali challenge induced larger reductions in hydrophobicity (i.e., lower MATH values) in non adapted control cells than in mild alkali adapted cells. SEM revealed greater morphological diversity in suspensions of non alkali adapted cells than in suspensions of mild alkali adapted cells, i.e., a larger proportion of alkali adapted cells retained the normal (bacillary) morphology. Non adapted cells displayed considerable morphological heterogeneity including elongation, rupture and cellular deformation. Short-term alkaline adaptation in L. monocytogenes involves direct changes in the cell surface properties and organisation which facilitate the well recognised phenotypic abilities of this pathogen to persist and/or grow in alkaline conditions. Alkali adaptation may be significant in the persistence of this pathogen in the presence of alkali detergents in food processing environments and alkali natural habitats, and has direct clinical implications in relation to virulence and response to mammalian defence mechanisms.
منابع مشابه
Strain-Specific Interactions of Listeria monocytogenes with the Autophagy System in Host Cells
Listeria monocytogenes is an intracellular bacterial pathogen that can replicate in the cytosol of host cells. These bacteria undergo actin-based motility in the cytosol via expression of ActA, which recruits host actin-regulatory proteins to the bacterial surface. L. monocytogenes is thought to evade killing by autophagy using ActA-dependent mechanisms. ActA-independent mechanisms of autophagy...
متن کاملThe effect of short-time microwave exposures on Listeria monocytogenes inoculated onto chicken meat portions
Listeria monocytogenes can be found throughout the environment and in many foods. It is associated primarily with meat and animal products. Listeria monocytogenes has become increasingly important as a food-borne pathogen. The aim of this study was to evaluate the effect of microwave (MW) treatment of chicken meat samples which were inoculated with L. monocytogenes. D...
متن کاملCritical role of anteiso-C15:0 fatty acid in the growth of Listeria monocytogenes at low temperatures.
Listeria monocytogenes is a food-borne pathogen capable of growth at refrigeration temperatures. Membrane lipid fatty acids are major determinants of a sufficiently fluid membrane state to allow growth at low temperatures. L. monocytogenes was characterized by a fatty acid profile dominated to an unusual extent (> 95%) by branched-chain fatty acids, with the major fatty acids being anteiso-C15:...
متن کاملThe Listeria monocytogenes strain 10403S BioCyc database
Listeria monocytogenes is a food-borne pathogen of humans and other animals. The striking ability to survive several stresses usually used for food preservation makes L. monocytogenes one of the biggest concerns to the food industry, while the high mortality of listeriosis in specific groups of humans makes it a great concern for public health. Previous studies have shown that a regulatory netw...
متن کامل