Haemophilus Test Medium (HTM)

[所属分类:培养基配方] [发布时间:2021-3-23] [发布人: ] [阅读次数:] [返回]

Haemophilus Test Medium

(HTM)

培养基配方

Composition per liter:
Beef infusion.............................................................................300.0g
Acid hydrolysate of casein..........................................................17.5g
Agar............................................................................................17.0g
Yeast extract..................................................................................5.0g
Starch............................................................................................1.5g
HTM supplement.....................................................................10.0mL
pH 7.4 ± 0.2 at 25°C
Source:  This medium is available as a premixed powder from Oxoid
Unipath.
HTM Supplement:
Composition per 10.0mL:
Nicotinamide adenine dinucleotide ............................................0.03g
Hematin.......................................................................................0.03g
Preparation of HTM Supplement: Add components to distilled/deionized water and bring volume to 10.0mL. Mix thoroughly. Filter sterilize.
Preparation of Medium: Add components, except HTM supplement, to distilled/deionized water and bring volume to 990.0mL. Mix thoroughly. Gently heat and bring to boiling. Autoclave for 15 min at 15 psi pressure–121°C. Cool to 45°–50°C. Aseptically add 10.0mL of sterile HTM supplement. Mix thoroughly. Pour into sterile Petri dishes or distribute into sterile tubes.
Use:  For the susceptibility testing of Haemophilus influenzae. The medium forms part of the recommended methods of the United States National Committee for Clinical Laboratory Standards (NCCLS). Haemophilus influenzae require complex media for growth. These complex media have aggravated the routine susceptibility testing of Haemophilus influenzae because of antagonism between some essential nutrients and certain antimicrobial agents. This medium overcomes those limitations. The transparency of the medium allows zones of inhibition to be read easily through the bottom of the Petri dish. HTM contains low levels of antimicrobial antagonists, which allows testing of trimethoprim/sulphamethoxazole to be carried out.