A Defined, Glucose-Limited Mineral Medium for the Cultivation of Listeria spp

Abstract

Members of the genus Listeria are fastidious bacteria with respect to their nutritional requirements, and several minimal media described in the literature fail to support growth of all Listeria spp. Furthermore, strict limitation by a single nutrient, e.g., the carbon source, has not been demonstrated for any of the published minimal media. This is an important prerequisite for defined studies of growth and physiology, including "omics." Based on a theoretical analysis of previously published mineral media for Listeria, an improved, well-balanced growth medium was designed. It supports the growth, not only of all tested Listeria monocytogenes strains, but of all other Listeria species, with the exception of L. ivanovii. The growth performance of L. monocytogenes strain Scott A was tested in the newly designed medium; glucose served as the only carbon and energy source for growth, whereas neither the supplied amino acids nor the buffering and complexing components (MOPS [morpholinepropanesulfonic acid] and EDTA) supported growth. Omission of amino acids, trace elements, or vitamins, alone or in combination, resulted in considerably reduced biomass yields. Furthermore, we monitored the specific growth rates of various Listeria strains cultivated in the designed mineral medium and compared them to growth in complex medium (brain heart infusion broth [BHI]). The novel mineral medium was optimized for the commonly used strain L. monocytogenes Scott A to achieve optimum cell yields and maximum specific growth rates. This mineral medium is the first published synthetic medium for Listeria that has been shown to be strictly carbon (glucose) limited.

Pathway analysis using 13C‐glycerol and other carbon tracers reveals a bipartite metabolism of Legionella pneumophila

“…However, depending on the microorganism, the same substrate might be metabolized by different modules. Other than L. pneumophila , L. monocytogenes can grow on glycerol as sole carbon source in vitro (Schneebeli and Egli, ). Intracellularly, L. monocytogenes uses amino acids, glucose‐6‐phosphate and glycerol imported from the host cell (Grubmüller et al ., ).…”

Mycobacterium tuberculosis in the Face of Host-Imposed Nutrient Limitation

“…Nutritional immunity is likely responsible for this phenomenon. In other intracellular pathogens that are naturally amino acid dependent, such as L. pneumophila (16), F. tularensis (17), and L. monocytogenes (18), auxotrophy always comes with a sophisticated virulence mechanism allowing the pathogen to circumvent nutritional immunity by manipulating the host to provide large amounts of the needed growth factor. The human pathogens evolved to access host nutrients by stimulating host protein degradation, manipulation of autophagy, or degradation of complex metabolites such as glutathionine.…”

“…For example, the mammalian enzyme indoleamine 2,3-dioxygenase (IDO) actively degrades tryptophan and is activated during pathogen infection to starve the intruders of this essential amino acid (13–15). In response to host nutrient deprivation, many human pathogens, e.g., Legionella pneumophila (16), Francisella tularensis (17), and Listeria monocytogenes (18), have acquired elaborate mechanisms to circumvent nutritional immunity and access essential metabolites. Such nutritional virulence mechanisms (19) allowed these pathogens to evolve into natural auxotrophs for up to 10 amino acids (16, 17), a characteristic that results in partial dependency on the host.…”

Isotopologue profiling of the listerial N‐metabolism

“…To study metabolic properties or to perform an analysis of the proteome of L. monocytogenes , however, media have been developed for optimizing the supply of carbon, nitrogen, energy sources, amino acids, vitamins, and specific growth factors. The composition of these media provided the first insights into the metabolism of this pathogen (Phan‐Thanh and Gormon, ; Siddiqi and Khan, ; Schneebeli and Egli, ). For example, glutamine (Gln) is required as a primary nitrogen‐ (N‐) source for growing L. monocytogenes in modified Welshimer's broth (MWB) that is supplemented with a set of amino acids (Welshimer, ; Premaratne et al ., ).…”