Cultural methods for the production of heat-stable enterotoxin by porcine strains of Escherichia coli and its detection by the infant mouse test. 1982

E Olsson

Casamino acids-yeast extract medium (CAY) and a tryptone-yeast extract medium (TY-1) were evaluated in testing for production of heat-stable enterotoxin (ST) by porcine strains of Escherichia coli using the infant mouse assay. More strains were ST-positive when grown in CAY medium than in TY-1 medium. Questionably or indeterminately ST positive strains were investigated in detail to determine whether or not they were weak ST producers. Growth in four different media and in different batches of CAY medium, inactivation of culture supernatant fluids at a lower temperature, addition of mitomycin C to growing cultures and preparation of periplasm-cytoplasm fractions of bacteria by sonication, all failed to yield ST positive samples. ST value limits (i.e. ratios of intestinal weight to remaining body weight of challenged mice), which clearly differentiated positive or negative strains for ST production, were set for CAY medium. A minimal salts-amino acids medium (MSA) was devised. Both in shake flask and fermenter cultures MSA medium gave better ST yields than CAY and a previously described defined medium.

UI MeSH Term Description Entries
D007700 Kinetics The rate dynamics in chemical or physical systems.
D003470 Culture Media Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN. Media, Culture
D003967 Diarrhea An increased liquidity or decreased consistency of FECES, such as running stool. Fecal consistency is related to the ratio of water-holding capacity of insoluble solids to total water, rather than the amount of water present. Diarrhea is not hyperdefecation or increased fecal weight. Diarrheas
D004768 Enterotoxins Substances that are toxic to the intestinal tract causing vomiting, diarrhea, etc.; most common enterotoxins are produced by bacteria. Staphylococcal Enterotoxin,Enterotoxin,Staphylococcal Enterotoxins,Enterotoxin, Staphylococcal,Enterotoxins, Staphylococcal
D004926 Escherichia coli A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc. Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D005243 Feces Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia
D001681 Biological Assay A method of measuring the effects of a biologically active substance using an intermediate in vivo or in vitro tissue or cell model under controlled conditions. It includes virulence studies in animal fetuses in utero, mouse convulsion bioassay of insulin, quantitation of tumor-initiator systems in mouse skin, calculation of potentiating effects of a hormonal factor in an isolated strip of contracting stomach muscle, etc. Bioassay,Assay, Biological,Assays, Biological,Biologic Assay,Biologic Assays,Assay, Biologic,Assays, Biologic,Bioassays,Biological Assays
D013552 Swine Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA). Phacochoerus,Pigs,Suidae,Warthogs,Wart Hogs,Hog, Wart,Hogs, Wart,Wart Hog
D013553 Swine Diseases Diseases of domestic swine and of the wild boar of the genus Sus. Disease, Swine,Diseases, Swine,Swine Disease

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