Table 3.
Media composition of manual blood culture bottles.
| Medium or Component/Additives | Short description/Comment/References |
|---|---|
| CULTURE MEDIUM | |
| Thioglycolate | Favors growth of anaerobes (76) |
| Tryptic Soy broth (TSB) | General purpose medium, favors Pseudomonas species (77, 78) |
| Thiol broth | Favors growth of Streptococcus species (78) |
| Brain-Heart Infusion (BHI) | General purpose medium, facilitates recovery of yeasts and Gram-positive organisms (79) |
| Columbia broth | General purpose medium, favors growth of anaerobes |
| Supplemented peptone broth | General purpose medium; superior to TSB for most common pathogens in blood culture (80) |
| Hypertonic medium (Brucella broth) | Supposedly improves cellular stability and increases recovery rates of some bacteria, including Staphylococcus aureus, Escherichia coli, Candida species (81); evidence regarding its efficacy is mixed (77) |
| ADDITIVES | |
| Sodium-polyanethole sulfate (SPS) | Anticoagulant; SPS also inhibits lysozyme, inactivates clinically achievable concentrations of some aminoglycoside and polymyxin antibiotics, inhibits parts of the complement cascade, and inhibits phagocytosis (69). Higher SPS concentrations, while promoting the recovery of Gram-positive cocci, decrease the recovery of Gram-negative bacteria. Certain species of bacteria are inhibited by SPS, such as Neisseria species, Peptostreptococcus anaerobius, Moraxella catarrhalis, and Gardnerella vaginalis (69, 77). |
| Gelatin | Counteracts the inhibition of growth of bacterial species by SPS in-vitro (80, 82). Evidence for its clinical efficacy however is not strong (82–86). |
| Yeast extract | Promotes bacterial growth (77) |
| Saponin | Lytic agent (used in lysis-centrifugation system); improves recovery of Streptococcus species |
| Hemin (X-factor) | Promotes growth of fastidious organisms such as Haemophilus influenzae and Neisseria species (87) |
| NAD (V-factor) | Promotes growth of fastidious organisms such as Haemophilus influenzae and Neisseria species (87) |
| Pyridoxine | Promotes growth of pyridoxine-dependent organisms such as certain Streptococcus species |
| Para-amino benzoic acid | Inhibits the effect of sulfonamide antibiotics |
| Cysteine | Reducing agent; improves recovery of anaerobic bacteria and Streptococcus pneumoniae (77) |