diphtheriae, the present results imply regulation of adherence and slime production as part of a global response to iron-limited environmental conditions that includes derepression of genes for the synthesis of cytotoxin and siderophores and for transport of the Fe(III)-siderophore complexes. The expression of dissimilar microbial virulence determinants may be coordinately controlled by common regulatory systems. The significant changes in the degree of lectin binding specific for d-mannose, d-galactose and sialic acid residues may have an effect on binding of host cells. diphtheriae surface carbohydrate moieties. Thus, iron exerts a regulatory role on adhesive properties of diphtheria bacilli, and low iron availability modulates the expression of C. Lectin binding assays demonstrated a reduction in the number of sialic acid residues and an increase in d-mannose and d-galactose residues on the surfaces of both strains.
Conversely, iron limitation inhibited adherence to glass and expression of electron-dense material on the bacterial surface. Inhibition assays suggested the involvement of nonfimbrial protein combination 67-72p on hemagglutination of diphtheria bacilli grown under iron-limited conditions. Iron-limited conditions enhanced interaction of strain 241 with erythrocytes and HEp-2 cells. The effects of iron concentration on adhesive properties were different for strains 241 and CDC-E8392, of the sucrose-fermenting and non-sucrose-fermenting biotypes, respectively.
#Tsb medium free#
A comparison was made between bacteria grown in (i) Trypticase soy broth (TSB), (ii) TSB treated with dipyridyl to deplete free iron, and (iii) TSB enriched with FeCl 3. mitis and evaluated their adherence to human group B erythrocytes and HEp-2 cells.
The present study investigated the influence of low iron availability on the expression of proteins and surface sugar residues of two toxigenic strains of Corynebacterium diphtheriae subsp. Sodium Chloride maintains osmotic balance Dipotassium Phosphate is a buffering agent.įor Casein Soya Bean Digest Broth QC tested according to the USP/EP/JP methodology and requirements, please use NCM0004.Iron limitation may cause bacterial pathogens to grow more slowly however, it may also stimulate these microorganisms to produce greater tissue damage, given that many virulence factors are controlled by the iron supply in the environment. Dextrose is the carbon energy source that facilitates organism growth. TSB is recommended for testing bacterial contaminants in cosmetics and complies with established standards in the food industry.Įnzymatic Digest of Casein and Enzymatic Digest of Soybean Meal are nitrogen sources in TSB. Clostridia and non-sporulating anaerobes grow luxuriantly in this broth when incubated under anaerobic conditions. This medium was originally developed for use without blood in determining the effectiveness of sulfonamides against pneumococci and other organisms. Tryptic Soy Broth, a general purpose medium, is commonly referred to as Casein Soya Bean or Soybean- Casein Digest Broth, and abbreviated as TSB. Tryptone Soy Broth (TSB) is a general-purpose broth which will support the growth of a wide range of micro-organisms and is not intended for use in the diagnosis of disease or other conditions in humans.